Polymer nanorings with uranium specific clefts for selective recovery of uranium from acidic effluents via reductive adsorption - Kushwaha, Shilpi; Mane, Manoj; Ravindranathan, Sapna; Das, Amitava (ACS Sensors, 2020)
Nanostructured polymeric materials, functionalized with an appropriate receptor, have opened up newer possibilities for designing a reagent that shows analyte-specific recognition and efficient scavenging of an analyte that has either a detrimental influence on human physiology and environment or on its recovery for further value addition. Higher active surface area, morphological diversity, synthetic tunability for desired surface functionalization, and the ease of regeneration of a nanostructured material for further use have provided such materials with a distinct edge over conventional reagents. The use of a biodegradable polymeric backbone has an added significance owing to the recent concern over the impact of polymers on the environment. Functionalization of biodegradable sodium alginate with AENA (6.85% grafting) as the receptor functionality led to a unique open framework nanoring (NNRG) morphology with a favorable spatial orientation for specific recognition and efficient binding to uranyl ions (U) in an aqueous medium over a varied pH range. Nanoring morphology was confirmed by transmission electron microscopy and atomic force microscopy images. The nanoscale design maximizes the surface area for the molecular scavenger. A combination of all these features along with the reversible binding phenomenon has made NNRG a superior reagent for specific, efficient uptake of UO22+ species from an acidic (pH 3-4) solution and compares better than all existing UO22+-scavengers reported till date. This could be utilized for the recovery of uranyl species from a synthetic acidic effluent of the nuclear power. The results of the U uptake experiments reveal a maximum adsorption capacity of 268 mg of U per g of NNRG in a synthetic nuclear effluent. X-ray photoelectron spectroscopy studies revealed a reductive complexation process and stabilization of U(IV)-species in adsorbed uranium species (U@NNRG).
Keywords: biodegradable polymeric backbone; molecular recognition; nanostructured material; sodium alginate; uranium; uranyl-specific receptor

Proteomic analysis detects deregulated reverse cholesterol transport in human subjects with ST-segment elevation myocardial infarction (vol 222, 103796, 2020) - Das, Apabrita Ayan; Choudhury, Kamalika Roy; Jagadeeshaprasad, M. G.; Kulkarni, Mahesh J.; Mondal, Prakash Chandra; Bandyopadhyay, Arun (Journal of Proteomics, 2020)

Proteomic analysis detects deregulated reverse cholesterol transport in human subjects with ST-segment elevation myocardial infarction - Das, Apabrita Ayan; Choudhury, Kamalika Roy; Jagadeeshaprasad, M. G.; Kulkarni, Mahesh J.; Mondal, Prakash Chandra; Bandyopadhyay, Arun (Journal of Proteomics, 2020)
Reverse cholesterol transport (RCT) plays a critical role in removing cholesterol from the arterial wall. However, very few reports directly relate chronic inflammation and RCT with atherosclerosis. The present study was undertaken to investigate clinical implications of significantly altered circulating proteins in subjects with ST-segment elevation myocardial infarction (STEMI) in the manifestation of atherosclerotic events. Using a casecontrol design, more than 2500 proteins in both STEMI and healthy control subjects were identified by Orbitrap mass spectrometer. Quantitative proteomics study revealed downregulation of 26 proteins while expression of 38 proteins increased significantly in STEMI subjects compared to healthy controls. Pathway enrichment analyses indicated that most of the identified proteins were related to chronic inflammation, atherosclerosis, and RCT. Altered proteins such as AZGP1, ABCA5, Calicin, PGLYRP2, HAVCR2 and C17ORF57 were further validated by Western blotting analysis of human plasma. Pathophysiological significance was studied using macrophage derived foam cell for their critical role in RCT which indicated the imbalance of RCT via the interaction of AZGP1 with CD36. In summary, this study revealed a unique relationship of some novel proteins apparently responsible for impaired RCT and chronic inflammation leading to atherothrombosis and myocardial infarction. Significance: In the present study we identified >= 2500 unique circulating proteins in healthy control and clinically diagnosed STEMI subjects among which 423 proteins were found to be common in both the groups. We further show 64 proteins significantly different between healthy control and STEMI subjects. Proteomic analyses reveal a panel of proteins associated with atherosclerosis and STEMI. One of the proteins, AZGP1, an adipokine, is likely to act as the missing link between chronic inflammation and cholesterol transport. Deregulation of reverse cholesterol transport might be orchestrated by AZGP1, CD36, ABCA5, and PPARy in STEMI subjects. The present study employs shotgun and quantitative proteomics followed by in vitro validations demonstrating a biochemical basis for reverse cholesterol transport in the local milieu of the luminal wall of the artery which are critical for plaque build-up and atherosclerosis.
Keywords: Atherosclerosis; AZGP1; CD36; Plasma proteomics; Reverse cholesterol transport; STEMI

Reduction of trap and polydispersity in mutually passivated quantum dot solar cells - Sharma, Ashish; Mahajan, Chandan; Rath, Arup K. (ACS Applied Energy Materials, 2020)
Control over surface passivation is a key to manage the optoelectronic properties in low-dimensional nanomaterials because of their high surface-to-volume ratios. Tunable band gap quantum dots (QDs) are a potential building block for the development of optoelectronic devices like solar cells, photodetectors, and light-emitting diodes. Long and insulating surface ligands of colloidally synthesized QDs are exchanged by short ligands to attain compact arrangement in thin films to facilitate the charge transport process. However, the ligand exchange process often resulted in reduced surface passivation, inhomogeneous QD fusion, and deterioration of energy band gap, which adversely impact their performance in solar cells. Here, we introduce a surface passivation strategy where the QDs are mutually passivated by the organic ligand 3-methyl mercapto propionate and inorganic halometallate ligands to develop a conducting QD ink. The mutually passivated QDs (MPQDs) show significant improvement in optoelectronic properties in maintaining the trap-free energy band gap and size monodispersity. The photovoltaic performance of MPQDs shows a 33% average increase in power conversion efficiency (PCE) over the conventional halometallate passivation to attain 9.6% PCE in MPQD solar cells. The improvements in photovoltaic parameters are corroborated by the reduction in density of the intermediate trap states and an increase in depletion width and diffusion length in MPQD-based solar cells.
Keywords: polydispersity; quantum dot; solar cells; surface passivation; trap states

Reply to “comment on ‘arresting an unusual amide tautomer using divalent cations’” - Kashid, Somnath M.; Singh, Reman K.; Kwon, Hyejin; Seol, Jin Gyu; Kim, Yung Sam; Mukherjee, Arnab; Bagchi, Sayan (Journal of Physical Chemistry B, 2020)
In our publication, we assigned the blue-shifted shoulder of N-methylacetamide (NMA) in the infrared (IR) spectrum (∼1645 cm<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">–1) to an iminolate tautomer stabilized in the presence of divalent metal cations (e.g., 5 M Ca<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">2+).<a class="ref ref1" style="outline: none; background-color: transparent; text-decoration-line: underline; color: rgb(26, 13, 171); transition: color 0.3s ease 0s; overflow-wrap: break-word; word-break: break-word; display: inline-block; font-family: Roboto, arial, sans-serif; font-size: 17px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">(1) Cremer and co-workers comment that this shoulder arises from the dehydration of the amide oxygen upon interaction with the metal cations.<a class="ref ref1a ref2" style="outline: none; background-color: transparent; text-decoration-line: underline; color: rgb(26, 13, 171); transition: color 0.3s ease 0s; overflow-wrap: break-word; word-break: break-word; display: inline-block; font-family: Roboto, arial, sans-serif; font-size: 17px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">(2,3) Their assignment is based on three interesting experimental observations: (1) the IR spectrum of <span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">15N-isotope-labeled NMA does not show any considerable red-shift compared to that of NMA; (2) a new peak appears for NMA at 1680 cm<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">–1 in the presence of 1 M DCl, which shows a 17 cm<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">–1 red-shift for <span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">15N-labeled NMA; and (3) the IR spectrum of acetone C═O stretch also demonstrates a blue-shifted shoulder in the presence of a high concentration of CaCl<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; bottom: -0.25em; font-family: Roboto, arial, sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 300;">2.

Residue-based propensity of aggregation in the Tau amyloidogenic hexapeptides AcPHF6*and AcPHF6 - Dangi, Abha; Balmik, Abhishek Ankur; Ghorpade, Archana Kisan; Gorantla, Nalini Vijay; Sonawane, Shweta Kishor; Chinnathambi, Subashchandrabose; Marelli, Udaya Kiran (RSC Advances, 2020)
In Alzheimer's disease and related tauopathies, the aggregation of microtubule-associated protein, Tau, into fibrils occursviathe interaction of two hexapeptide motifs PHF*(275)VQIINK(280)and PHF(306)VQIVYK(311)as beta-sheets. To understand the role of the constituent amino acids of PHF and PHF* in the aggregation, a set of 12 alanine mutant peptides was synthesized by replacing each amino acid in PHF and PHF* with alanine and they were characterized by nuclear magnetic resonance (NMR) spectroscopy, circular dichroism (CD), transmission electron microscopy (TEM) and ThS/ANS fluorescence assay. Our studies show that while the aggregation was suppressed in most of the alanine mutant peptides, replacement of glutamine by alanine in both PHF and PHF* enhanced the fibrillization.

Role of cholesterol-mediated effects in GPCR heterodimers - Prasanna, Xavier; Mohole, Madhura; Chattopadhyay, Amitabha; Sengupta, Durba (Chemistry and Physics of Lipids, 2020)
G protein-coupled receptors (GPCRs) are transmembrane receptors that mediate a large number of cellular responses. The organization of GPCRs into dimers and higher-order oligomers is known to allow a larger repertoire of downstream signaling events. In this context, a crosstalk between the adenosine and dopamine receptors has been reported, indicating the presence of heterodimers that are functionally relevant. In this paper, we explored the effect of membrane cholesterol on the adenosine(2A) (A(2A)) and dopamine D-3 (D-3) receptors using coarse-grain molecular dynamics simulations. We analyzed cholesterol interaction sites on the A(2A) receptor and were able to reproduce the sites indicated by crystallography and previous atomistic simulations. We predict novel cholesterol interaction sites on the D-3 receptor that could be important in the reported cholesterol sensitivity in receptor function. Further, we analyzed the formation of heterodimers between the two receptors. Our results suggest that membrane cholesterol modulates the relative population of several co-existing heterodimer conformations. Both direct receptor-cholesterol interaction and indirect membrane effects contribute toward the modulation of heterodimer conformations. These results constitute one of the first examples of modulation of GPCR hetero-dimerization by membrane cholesterol, and could prove to be useful in designing better therapeutic strategies.
Keywords: Adenosine(2A) receptor; Cholesterol; Dopamine D-3 receptor; G protein-coupled receptors; Heterodimer; MARTINI coarse-grain simulation

Room temperature processed in-situ carbon-coated vanadium carbide (VC@C) as a high capacity robust Li/Na battery anode material - Mahajan, Mani; Roy, Kingshuk; Parmar, Swati; Singla, Gourav; Pandey, O. P.; Singh, K.; Vaidhyanathan, Ramanathan; Ogale, Satishchandra (Carbon, 2020)
3D carbide systems with their robust physical and mechanical properties have always attracted multiple application interests. In this report, we have synthesized a three-dimensional in-situ carbon coated cubic carbide, Vanadium Carbide (VC@C), by a very simple, scalable and cost-effective room temperature mechano-chemical ball-milling procedure and researched its promise as effective anode material for Li and Na ion batteries. We have demonstrated that VC@C shows an impressive initial discharge/lithiation capacity of 1165 mAh g(-1) with a high reversible capacity of 640 mAh g(-1) after 100 charge-discharge cycles at an applied current density of 0.1 A g(-1). We have also found that this material renders a very promising rate performance with significantly low capacity drop after exposing it to variable current densities ranging from 0.05 A g(-1) to 2 A g(-1) with an excellent stability up to 1000 cycles owing to its structural robustness, as verified by post-cycling characterizations. A Li-ion full cell study using LiCoO2 as cathode also showed excellent promise in terms of practical application demonstrating a reversible capacity of 95 mAh g(-1) after 100 cycles. Even for Na insertion/de-insertion VC@C shows a clear promise in terms of capacity, cyclic stability and rate performance. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords: 3D carbide; In-situ synthesis; Li-ion battery; Post cycling characterization; Room temperature ball milling; Williamson-Hall analysis

Selective monoalkylation of hydroquinone in the presence of SO3H-functionalized ionic liquids as catalysts - Bhongale, Priyanka V.; Joshi, Sunil S.; Mali, Nilesh A. (Chemical Papers, 2020)
A process aiming atO-alkylation of hydroquinone (HQ), where ionic liquids (ILs) act as catalyst is objectively described. Five SO3H-functionalized ILs having different cations were prepared and characterized by NMR and FTIR techniques. The acidity and thermal stability of ILs were determined by Hammett function and thermogravimetric analysis (TGA), respectively. The catalytic activity of these ILs were tested forO-alkylation of HQ with methanol in 4-methoxyphenol (4MP) in the presence of small amount of benzoquinone (BQ). The effect of reaction parameters such as temperature, time, catalyst loading and substrate concentration on the conversion of HQ and product distribution was examined and optimized to maximize the yield of 4MP using 1,3-disulfonic acid imidazolium hydrogen sulfate (IL2) catalyst. Maximum yield of desired product 4MP 93.79% was obtained at 338 K temperature, 5.45 x 10(-2) mol HQ, 8.33 x 10(-3) mol BQ, and 10.37 mol% catalyst loading in 120 min reaction time. Single-product formation was observed up to 338 K temperature but higher temperature (above 338 K) and longer reaction time resulted in the formation of 2,4-dimethoxyphenol (24DMP) as a by-product. Catalyst recyclability was also established up to the fifth run which showed no declination in its activity.
Keywords: 4-Methoxyphenol; Benzoquinone; Hydroquinone; ionic liquids; O-alkylation

Silver-catalyzed cascade cyclization/1,6-conjugate addition of homopropargyl sulfonamides to p-quinone methides: an approach to diverse 3-diarylmethine substituted dihydropyrroles - Shirsath, Sachin R.; Ghotekar, Ganesh S.; Bahadur, Vir; Gonnade, Rajesh G.; Muthukrishnan, M. (Journal of Organic Chemistry, 2020)
A silver-catalyzed cycloisomerization/1,6-conjugate addition of homopropargyl sulfonamides to p-quinone methides to access diverse diarylmethine substituted dihydropyrroles has been disclosed. The reaction pathway involves an intramolecular cascade cyclization of homopropargyl sulfonamides to generate a highly reactive dihydropyrrole intermediate in situ followed by conjugate addition with p-quinone methides. This method provides an efficient and scalable route for the synthesis of 3-diarylmethine substituted dihydropyrroles, in one pot.

Solution-phase hybrid passivation for efficient infrared-band gap quantum dot solar cells - Mahajan, Chandan; Sharma, Ashish; Rath, Arup K. (ACS Applied Materials & Interfaces, 2020)
The broad tunability of the energy band gap through size control makes colloidal quantum dots (QDs) promising for the development of photovoltaic devices. Large-size lead sulfide (PbS) QDs, exhibiting a narrow energy band gap, are particularly interesting as they can be used to augment perovskite and c-Si solar cells due to their complementary NIR absorption. However, their complex surface chemistry makes them difficult to process for the development of solar cells. The shape of the QDs transformed from octahedron to cuboctahedron as their size increases, a phenomenon guided by surface energy minimization. As a result, the surface properties change drastically for large-size QDs, which exhibit nonpolar (200) facets and polar (111) facets, as opposed to only (111) facets in small-size QDs. Recent advancements in solution-phase surface passivation strategies, used for the development of high-performance solar cells using the small size and wide band gap QDs, failed to translate a similar enhancement in the case of large-size and narrow band gap QDs. Here, we report a hybrid passivation strategy for large-size and narrow band gap QDs to passivate both (111) and (200) facets, respectively, using inorganic lead triiodide (PbI3-) and organic 3-chloro-1-propanethiol (CPT). By employing charge balance calculation, we identified the desired narrow band gap for QDs to complement the perovskite and c-Si absorption. The distinct choice of the organic ligand CPT enhances the colloidal stability of QDs in the solution phase and improves surface passivation to stop QD fusion in solid films. Photophysical properties show narrower excitonic and emission peaks and a reduction in the Stokes shift. Hybrid passivation leads to a 94% increase in the power conversion efficiency of solar cells and a 74% increase in the external quantum efficiency at the excitonic peak.
Keywords: infrared band gap; polydispersity; quantum dot; solar cells; surface passivation; trap states

Structural and electrical characterization studies for ternary composite of polypyrrole - Megha, R.; Ravikiran, Y. T.; Kumari, S. C. Vijaya; Prakash, H. G. Raj; Revanasiddappa, M.; Manjunatha, S.; Dastager, Syed G.; Thomas, S. (Journal of Materials Science-Materials in Electronics, 2020)
In this work, temperature dependence of alternate current (AC) and direct current (DC) conductivities of optimized polypyrrole/silver-tantalum oxide (PPy/Ag-Ta2O5), a ternary conducting polymer composite is comparatively studied with those of PPy and PPy/Ag. For the purpose, silver (Ag) nanoparticles were encapsulated with polypyrrole (PPy) by in situ oxidative polymerization to form core-shell structured PPy/Ag composite for which Ag nanoparticles were extracted from green tea. The PPy/Ag composite was then mechanically mixed with tantalum pentoxide (Ta2O5) to form PPy/Ag-Ta(2)O(5)ternary composite. Increase in depth of delocalization band of PPy in ternary composite as compared to those of PPy/Ag composite and PPy, indicating its increased AC conductivity confirmed from the comparative FTIR analyses. Interaction between PPy/Ag composite and Ta(2)O(5)in the ternary composite was confirmed from XRD studies. The formation of core-shell structured PPy/Ag composite and Ta(2)O(5)particles embedded in such PPy/Ag composite to form PPy/Ag-Ta(2)O(5)ternary composite confirmed from TEM and Raman studies. The frequency- and temperature-dependent electrical conductivity studies revealed increase in AC conductivity of the ternary composite as compared to those of PPy/Ag composite and pure PPy attributed mainly to interfacial effects. The charge transport in these samples predicted to be due to correlated barrier hopping of charges was confirmed by calculating their respective AC and DC activation energies.

Structural, Hirshfeld surface and in vitro cytotoxicity evaluation of five new N-aryl-N'-alkoxycarbonyl thiocarbamide derivatives - Pandey, Sunil K.; Pratap, Seema; Rai, Sunil K.; Marverti, Gaetano (Phosphorus Sulfur and Silicon and the Related Elements, 2020)
Five new compounds, N-(2, 4-dichlorophenyl)-N'-(methoxycarbonyl) thiocarbamide (1), N-(2, 4-dichlorophenyl)-N'-(ethoxycarbonyl) thiocarbamide (2), N-(2, 4-dichlorophenyl)-N'-(2, 2, 2-trichloroethoxycarbonyl) thiocarbamide (3), N-(2,4-dichlrophenyl)-N'-(pentoxycarbonyl) thiocarbamide (4) and N-(4-nitrophenyl)-N'-(pentoxycarbonyl) thiocarbamide (5), have been synthesized by the reaction of various alkoxy chloroformates with 2, 4-dichloroaniline/4-nitroaniline.The molecular structures of the compounds were elucidated by using spectroscopic methods (FT-IR, H-1 and C-13 NMR) and single-crystal X-ray structure analysis of compounds 2 and 5. Antiperiplanar orientation of C = O and C = S group across C-N bonds of thiocarbamide core may be due to the presence of intramolecular (N-H center dot center dot center dot O-C) hydrogen bond in the crystal structure of both the compounds. The presence of intermolecular interactions (C-H center dot center dot center dot S, C-H center dot center dot center dot O and N-H center dot center dot center dot S) in the molecular structure of the compounds has been studied in detail using Hirshfeld surfaces and their associated twodimensional fingerprint plots. In vitro cytotoxicity screening of the synthesized compounds evaluated on a panel of seven human cancer cell lines (cervical carcinoma (2008, C13*), colorectal (HT29 and HCT116) and ovarian carcinoma (A2780, A2780/CP and IGROV-1)) demonstrated significant inhibitory properties.
Keywords: Hirshfeld surface analysis; In vitro cytotoxicity; Thiocarbamide; X-ray crystal structure determination

Structural, molecular, functional and immunological characterization of Wuchereria bancrofti-galectin - Yasin, Nazeer; Laxmanappa, Hoti Sugerappa; Muddapur, Uday M.; Cheruvathur, Jennifer; Prakash, S. M. Udaya; Thulasiram, Hirekodathakallu Venkataramaiah (International Journal of Biological Macromolecules, 2020)
Galectins regulate growth and differentiation of immune cells and inflammation through their carbohydrate-binding function in humans, while also play a role in parasite survival. This study focused on the galectin of lymphatic filarial parasite Wuchereria bancrofti (Wb-Gal). The multiple sequence alignment with other galectins showed that the Wb-Gal belonged to galactoside binding lectin family, particularly tandem repeat type galectin-9. A homology model of Wb-Gal was developed in the I-TASser server using high similarity 3D structures with a quality score of 89.5. Molecular docking and dynamics studies revealed that the CCRD and NCRD of Wb-Gal bind with galactose and lactose. Further, Wb-Gal was cloned into the pET28 vector, expressed in E. coli Rosetta strain and purified by affinity chromatography. In the hemagglutination assays, the rWb-Gal bound to lactose, galactose, and glucose. Indirect Enzyme-Linked Immunosorbent Assay (ELISA) using different clinical filarial sera showed that the IgG and IgM response was against Wb-Gal x very high in all filarial clinical groups, whereas the IgA and IgG2 response was minimum to negligible. There was an enhanced response of IgG1 and IgG4 antibodies in Microfilaremics (MF) cases compared to Chronic Pathology (CP) and Endemic Normal (EN) individuals. Interestingly, the IgE response was comparatively higher in EN than MF and CP. These studies show that Wb-Gal is a member of the lectin family of proteins binding to different carbohydrates and may have an important role in the pathophysiology of filarial infection which needs to be investigated in greater detail. (C) 2020 Elsevier B.V. All rights reserved.
Keywords: Filariasis; Hemagglutination assay; Immunomodulation; Wuchereria bancrofti galectin

Structural studies on 10-hydroxygeraniol dehydrogenase: a novel linear substrate-specific dehydrogenase from Catharanthus roseus - Sandholu, Anand S.; Mujawar, Sharmila P.; Ramakrishnan, Krithika; Thulasiram, Hirekodathakallu V.; Kulkarni, Kiran (Proteins-Structure Function and Bioinformatics, 2020)
Conversion of 10-hydroxygeraniol to 10-oxogeranial is a crucial step in iridoid biosynthesis. This reaction is catalyzed by a zinc-dependent alcohol dehydrogenase, 10-hydroxygeraniol dehydrogenase, belonging to the family of medium-chain dehydrogenase/reductase (MDR). Here, we report the crystal structures of a novel 10-hydroxygeraniol dehydrogenase from Catharanthus roseus in its apo and nicotinamide adenine dinucleotide phosphate (NADP(+)) bound forms. Structural analysis and docking studies reveal how subtle conformational differences of loops L1, L2, L3, and helix alpha 9' at the orifice of the catalytic site confer differential activity of the enzyme toward various substrates, by modulating the binding pocket shape and volume. The present study, first of its kind, provides insights into the structural basis of substrate specificity of MDRs specific to linear substrates. Furthermore, comparison of apo and NADP(+) bound structures suggests that the enzyme adopts open and closed states to facilitate cofactor binding.
Keywords: 10-hydroxygeraniol dehydrogenase; iridoid biosynthesis; medium-chain dehydrogenase; monoterpene indole alkaloids; reductase; X-ray crystallography

Structure and regulation of SWEET transporters in plants: an update - Anjali, Anjali; Fatima, Urooj; Manu, M. S.; Ramasamy, Sureshkumar; Senthil-Kumar, Muthappa (Plant Physiology and Biochemistry, 2020)
Sugar will eventually be exported transporters (SWEETs), a novel family of sugar transporters found in both eukaryotes and prokaryotes, facilitate sugar flux across the cell membrane. Although these transporters were first discovered in plants, their homologs have been reported in different organisms. SWEETs have critical roles in various developmental processes, including phloem loading, nectar secretion, and pathogen nutrition. The structure of bacterial homologs, called SemiSWEETs, has been well studied thus far. Here, we provide an overview of SWEET protein structure and dynamic function by analyzing the solved crystal structures and predicted models that are available for a few SWEETs in a monocot plant (rice) and dicot plant (Arabidopsis thaliana). Despite the advancement in structure-related studies, the regulation of SWEETs remains unknown. In light of reported regulatory mechanisms of a few other sugar transporters, we propose the regulation of SWEETs at the post-translational level. We then enumerate the potential post-translational modification sites in SWEETs using computational tools. Overall, in this review, we critically analyze SWEET protein structure in plants to predict the post-translational regulation of SWEETs. Such findings have a direct bearing on plant nutrition and defense and targeting the regulation at these levels will be important in crop improvement.
Keywords: oligomerization; Phosphorylation; Post-translational modification; Sugar transporters; Sugar will eventually be exported transporters

Study of interfacial adhesion between nickel-titanium shape memory alloy and a polymer matrix by laser surface pattern - Samal, Sneha; Tyc, Ondrej; Heller, Ludek; Sittner, Petr; Malik, Monika; Poddar, Pankaj; Catauro, Michelina; Blanco, Ignazio (Applied Sciences-Basel, 2020)
The aim of this article is to investigate the interfacial adhesion of Ni-Ti shape memory alloy with a polymer matrix of Poly (methyl methacrylate) (PMMA). The surface pattern on Ni-Ti plates was channeled by a solid state laser machine. The laser machine allows for creating channels on the Ni-Ti surface for infiltration of the PMMA matrix, which could be attached as an intra-surface locking pattern to the Ni-Ti surface. The influence of the PMMA matrix on the surface of the NiTi plate was evaluated by thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA). The surface characterization was carried out by an optical microscope on the PMMA/NiTi composite after mechanical testing. During mechanical testing, the polymer displays the multiple cracks in the longitudinal direction that result in slipping and fracture. TMA and DMA analyses were performed on the Ni-Ti- and PMMA-coated Ni-Ti ribbon to observe elasticity and the storage modulus for both samples. Better adhesion than 80 % was observed in the Ni-Ti surface, in the laser surface pattern, in comparison to the free plain surface. However, the polymer acts as mechanical backing that caused a reduction in the shape-memory properties of the composite material.
Keywords: adhesion; mechanical properties; NiTi composites; NiTi plate; PMMA; Polymer; surface features

Synthesis and antimycobacterial screening of new 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-3-yl)quinoline derivatives - Thakare, Prashant P.; Walunj, Yogesh; Chavan, Abhijit; Bobade, Vivek D.; Sarkar, Dhiman; Mhaske, Pravin C. (Journal of Heterocyclic Chemistry, 2020)
A new series of 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-pyrazol-3-yl)quinoline (6a-t) have been synthesized by a click reaction of 4-(4-ethynyl-1-phenyl-1H-pyrazol-3-yl)quinoline (4a-d) with a substituted benzyl azide (5a-e). The starting alkyne derivatives4a-dare obtained from Bestmann-Ohira reaction of 1-phenyl-3-(quinolin-4-yl)-1H-pyrazole-4-carbaldehyde and dimethyl(1-diazo-2-oxopropyl)phosphonate. The newly synthesized compounds are screened againstM. tuberculosisH37Ra dormant and active,Escherichia coli,Pseudomonas fluorescence,Staphylococcus aureusandBacillus subtilisstrains at 30 mu g/mL concentration. Most of the screened compounds showed good to moderate antibacterial activity againstS. aureus,B. subtilis, andMycobacterium tuberculosisH37Ra strains. The synthesized derivatives of quinolinyl-pyrazole-4-carbaldehyde and quinolinyl-pyrazole-4-ethyne reportd good to moderate activity against both strains ofM. tuberculosisH37Ra. Ten derivatives of quinolinyl-pyrazole presented good activity againstB. subtilis. These results suggested that further optimization and development of quinolinyl-pyrazolyl-1,2,3-triazole moeity could serve as lead compounds for antimycobacterial activity.

Synthesis and characterization of nylon 6 polymer nanocomposite using organically modified Indian bentonite - Kumaresan, S.; Rokade, Dhammaraj S.; Marathe, Yogesh N.; Ingole, Pravin G.; Pawar, Radheshyam R.; Pol, Harshawardhan V.; Bajaj, Hari C. (SN Applied Sciences, 2020)
In this present research work two different organic compounds are applied for the modification of Indian origin bentonite. One is with n-hexadecyltrimethylammonium bromide (CTAB), intercalated with an interlayer of bentonite via cation exchange mechanism. Whereas, another with 3-Aminopropyl trimethoxysilane (APTES) interlayer functionalization with bentonite –OH group. APTES and CTAB–intercalated bentonites samples were further cross modified with CTAB and APTES to obtain novel co-surfactant locked organo bentonite modeling (CLOM) like matrices. Original and modified bentonite samples were comparatively evaluated by advanced characterization techniques such as, powder X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis (TGA). Moreover, the applicability of the developed CLOM like materials were investigated in nylon 6 nanocomposite preparation by melt compounding method using a micro twin co-rotated extruder. Additionally, CLOM-nylon-6 polymer nanocomposites were characterized by wide angle X-ray diffraction, TGA, differential scanning calorimetry, atomic force microscopy and tensile strength measurement. The observed thermograph results confirmed no significant difference in the thermal properties of the developed composites. Whereas, the significant variation observed in the tensile strength results particularly for developed composite 5% of N6-OAMSB and N6 AMOSB 5 showed 111.5 and 76.6% respective enhancement in tensile strength results when compared with a bare nylon-6 polymer.

Synthesis and characterization of supported heteropoly acid: efficient solid acid catalyst for glycerol esterification to produce biofuel additives - Magar, Subhash; Mohanraj, Govindraj T.; Jana, Sumit Kumar; Rode, V, Chandrashekhar (Inorganic and Nano-Metal Chemistry, 2020)
Esterification of glycerol with acetic acid has been studied with different solid acid catalysts, prepared by impregnating phospotungustic, silicotungstic, and phosphomolybdic acids on polymeric material polyvinylpyrrolidone. These results were compared with commercially available montmorillonite KSFO catalyst showed that PVP-DTP gave higher selectivity to di- and triacetins. This study was mainly focused on increasing the selectivity toward triacetin which is an excellent alternative to fossil fuel based fuel additives. The detail characterization was done for the PVP-DTP catalyst which gave complete conversion of glycerol and maximum selectivity of 34% toward triacetin. Complete conversion of glycerol was achieved at 110 degrees C within 6 h of reaction time. The characterization of the catalyst was performed by SEM/EDX, X-ray diffraction, thermogravimetic techniques, and FT-IR analysis.TPD-NH3 characterization showed that DTP supported on PVP increases the catalyst acidity of PVP. The highest acidity of PVP-DTP is also confirmed using NH3-TPD analysis.
Keywords: Glycerol; phospostugustic acid; povidone; solid acid catalyst; triacetin

Synthesis, characterisation, Hirshfeld surface and in vitro cytotoxicity evaluation of new N-aryl-N `-Alkoxycarbonyl thiocarbamide derivatives - Pandey, Sunil K.; Pratap, Seema; Rai, Sunil K.; Marverti, Gaetano; Kaur, Manpreet; Jasinski, Jerry P. (Journal of Molecular Structure, 2020)
Four new compounds N-(4-nitrophenyl)-N'-(isobutoxycarbonyl) thiocarbamide (1), N-(2, 4-nitrophenyl)-N'-(isobutoxycarbonyl) thiocarbamide (2), N-(4-nitrophenyl)-N'-(ethoxycarbonyl) thiocarbamide (3) and N-(2-Chloro- 4-nitrophenyl)-N'-(ethoxycarbonyl) thiocarbamide (4) were prepared and their structures confirmed by using various spectroscopic (FT-IR, UV-Visible, H-1 and C-13 NMR) and single crystal X-ray studies of 1 and 3. The presence of intramolecular (N-H center dot center dot center dot O=C) hydrogen bond in the crystal structure of both the compounds causes planarity of carbonyl thiocarbamide unit and trans orientation of C=O and C=S group. The intermolecular contacts (C-H center dot center dot center dot S, C-H center dot center dot center dot O and N-H center dot center dot center dot S) present in crystal structures have been examined by Hirshfeld surface analysis and their associated 2D fingerprint plots. All the compounds were assessed for their in vitro cytotoxic properties against a panel of seven human cancer cells such as cervical carcinoma (2008, C13*), colorectal (HT29 and HCT116) and ovarian carcinoma (A2780, A2780/CP and IGROV-1). Among them, compounds 2 and 4 exhibited better activity than 1 and 3 against all the cell lines tested. (C) 2019 Elsevier B.V. All rights reserved.
Keywords: Hirshfeld surface analysis; In vitro cytotoxicity; Thiocarbamide; X-ray crystal structure

Synthesis, crystal structure and Hirshfeld surface analysis of the hydrated form of N’, N-(1,4-phenylenebis(methanylylidene) di(iso-nicotinic hydrazide) - Ingle, Kapil S.; Mohurle, Smital A.; Bairagi, Keshab M.; Shaikh, Tabrez R.; Venugopala, Katharigatta N.; Chandrashekharappa, Sandeep; Gonnade, Rajesh G.; Nayak, Susanta K. (Chemical Data Collections, 2020)
<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">The title compound, C<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">20<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">H<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">16<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">N<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">6<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">O<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;"> was synthesized by reflux with isonicotinic hydrazide and terephthaldehyde in ethanol solvent with the acidic condition. The single-crystal X-ray structure determination of the title compound, <em style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">N, N<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">-(1,4-phenylene bis (methanylylidene) di(iso-nicotinic hydrazide), reveals that the molecule crystallizes in center of symmetry with water molecules (Dihydrated form, C<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">20<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">H<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">16<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">N<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">6<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">O<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">.2H<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">O) through N-H∙∙∙O and C-H∙∙∙O hydrogen bondings. Further, the crystal structure is stabilized by O-H∙∙∙O and weak C-H∙∙∙N hydrogen bondings with the formation of infinite chain and dimer. Further, surface analysis and fingerprint plot reveal that the significant hydrogen bonding such as H•••O (15.9%) and N•••H (11.4%) interactions play the most crucial role for its molecular packing.

Synthesis of 2-azabicyclo[m.n.0]-alkanes and their application towards the synthesis of strychnos and stemona classes of alkaloids - Majumder, Binoy; Pandey, Ganesh (European Journal of Organic Chemistry, 2020)
2-Azabicyclo[m.n.0]alkane ring systems, the conceptual precursors towards the synthesis of Strychnos and Stemona classes of alkaloids, were synthesized from tert-butyl 2-(phenylsulfonyl)-7-aza-bicyclo[2.2.1]hept-2-ene-7-carboxylate by alkyl Grignard reaction and intramolecular cyclisation of the in situ generated ring opening product 2. The synthesized cis-hexahydroindole 3 and cis-octahydro-benzo[b]azepine 5 scaffolds were utilized to construct the advanced intermediates 25 and 35, respectively, towards the synthesis of the corresponding Strychnos and Stemona classes of alkaloids.
Keywords: alkaloids; amines; Grignard reaction; Michael addition; Natural products

Synthesis of ethyl furfuryl ether (potential biofuel) by etherification of furfuryl alcohol with ethanol over heterogenized reusable H1Cs2PW12O40 catalyst - Mulik, Nagesh L.; Niphadkar, Prashant S.; Bokade, Vijay V. (Research on Chemical Intermediates, 2020)
{Ethyl furfuryl ether (EFE) considered as potential biofuel can replace petroleum diesel up to 100%. EFE also has efficient blending properties with biodiesel to improve its cold flow properties. Herein we demonstrate efficient synthesis of EFE by etherification of renewable furfuryl alcohol (FAlc) with ethanol over heterogenized heteropoly acids. Cs-exchanged heterogenized heteropoly acid (H3-xCsxPW12O40
Keywords: B; etherification; Ethyl furfuryl ether; Furfuryl alcohol; H3-xCsxPW12O40; Heterogenized heteropoly acid; L ration

Synthesis of novel of 2, 5-disubstituted 1, 3, 4-oxadiazole derivatives and their in vitro anti-inflammatory, anti-oxidant evaluation, and molecular docking study - Kashid, Bharat B.; Salunkhe, Pravin H.; Dongare, Balasaheb B.; More, Kishor R.; Khedkar, Vijay M.; Ghanwat, Anil A. (Bioorganic & Medicinal Chemistry Letters, 2020)
A series of novel 2, 5-disubstituted 1, 3, 4-Oxadiazole derivatives as a potential anti-inflammatory, and antioxidant agent were synthesized via cyclisation. Hydrazide molecule treated with substituted acids in the presence of phosphorus oxychloride (POCl3) as an efficient reagent as well as solvent by conventional method with shorter reaction time and excellent yield. The newly synthesized 1, 3, 4-oxadiazole derivatives exhibited excellent to good anti-inflammatory and anti-oxidant activities compaired to the standard drugs. Molecular docking study on the crucial anti-inflammatory target-cyclooxygenase-2 (COX-2) revealed the ability of the scaffold to correctly recognize the active site and achieve significant bonded and non-bonded interactions with key residues therein. This study could identify potential compounds which can be pertinent starting points for structure-based drug design to obtain newer anti-inflammatory agents.
Keywords: 1; 3; 4-Oxadiazole; Anti-inflammatory; Anti-Oxidant; Biological activity; computational chemistry

Synthesis of phospho-polypeptides via phosphate-containing N-carboxyanhydride: application in enzyme-induced self-assembly, and calcium carbonate mineralization - Mondal, Basudeb; Das, Soumen; Panda, Sidharth; Dutta, Tahiti; Sen Gupta, Sayam (ChemPlusChem, 2020)
An easy synthetic strategy was developed to synthesize the phosphate-functionalized amino acid N-carboxyanhydride (NCA), using simple primary amine initiators to obtain homo and block phospho-polypeptides with controlled molecular weight and molecular weight distribution. The methodology was extended to the synthesis of the end-functionalized homo polypeptides (15 to 50 repeat unit) and block co-polypeptides with PEG (0.7 K, 2 K, and 5 K) and glycopolypeptide (15-unit mannose glycopolypeptide) as one of the blocks. The deprotected fully water-soluble anionic phosphate-based polypeptides showed pH-dependent helical conformation with a helical content of 20 %, which further changed to beta-sheets upon addition of the enzyme alkaline phosphatase (ALP) due to dephosphorylation. The block co-polypeptide containing PEG as one of the blocks led to its self-assembly into colloidal structures, such as vesicles with a hydrodynamic diameter of similar to 250 nm, due to the formation of amphiphilic block co-polymer upon dephosphorylation. The nature of the colloidal structures formed can be temporally controlled by the extent of dephosphorylation. Finally, the phospho-polypeptides serve as a template for the mineralization of calcium carbonate with varying polymorphs and morphologies.
Keywords: Biomineralization; enzymes; phosphopolypeptides; Proteins; Self-assembly

Synthesis of silver nanoparticles colloids in imidazolium halide ionic liquids and their antibacterial activities for gram-positive and gram-negative bacteria - Patil, Virendra; Mahajan, Swapnil; Kulkarni, Mohan; Patil, Kashinath; Rode, Chandrashekhar; Coronas, Alberto; Yi, Gi-Ra (Chemosphere, 2020)
Four 1-butyl-3-methylimidazolium halide ionic liquids were synthesized via metathesis and anion exchange reactions. Silver nanoparticles (AgNPs) colloids were synthesized in four ionic liquids in the pressurized reactor by reduction of silver nitrate with hydrogen gas, without adding solvents or stabilizing agents. Antibacterial activities of base ionic liquids and AgNPs colloids in ionic liquids were reviewed by well-diffusion method for gram-positive Bacillus cereus (NCIM-2155) and gram-negative Escherichia coli (NCIM-2931) bacteria. Antibacterial activities of ionic liquids and AgNPs colloids in ionic liquids were observed to be controlled by ionic liquids anions and AgNPs particle size. The 1 -butyl-3-methylimidazolium iodide ionic liquid exhibited higher antibacterial activities among the studied ionic liquids. Further, the presence of AgNPs in 1-butyl-3-methylimidazolium iodide, ionic liquid enhanced its antibacterial activity for Bacillus cereus and Escherichia coli bacteria. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords: Anion effect; antibacterial activity; Imidazolium halides; ionic liquids; silver nanoparticles

TDR Targets 6: driving drug discovery for human pathogens through intensive chemogenomic data integration - Landaburu, Lionel Uran; Berenstein, Ariel J.; Videla, Santiago; Maru, Parag; Shanmugam, Dhanasekaran; Chernomoretz, Ariel; Aguero, Fernan (Nucleic Acids Research, 2020)
The volume of biological, chemical and functional data deposited in the public domain is growing rapidly, thanks to next generation sequencing and highly-automated screening technologies. These datasets represent invaluable resources for drug discovery, particularly for less studied neglected disease pathogens. To leverage these datasets, smart and intensive data integration is required to guide computational inferences across diverse organisms. The TDR Targets chemogenomics resource integrates genomic data from human pathogens and model organisms along with information on bioactive compounds and their annotated activities. This report highlights the latest updates on the available data and functionality in TDR Targets 6. Based on chemogenomic network models providing links between inhibitors and targets, the database now incorporates network-driven target prioritizations, and novel visualizations of network subgraphs displaying chemical- and target-similarity neighborhoods along with associated target-compound bioactivity links. Available data can be browsed and queried through a new user interface, that allow users to perform prioritizations of protein targets and chemical inhibitors. As such, TDR Targets now facilitates the investigation of drug repurposing against pathogen targets, which can potentially help in identifying candidate targets for bioactive compounds with previously unknown targets. TDR Targets is available at https://tdrtargets.org.

Template assisted synthesis of Ni,N co-doped porous carbon from Ni incorporated ZIF-8 frameworks for electrocatalytic oxygen reduction reaction - Priya K., Vaishna; Thomas, Minju; Illathvalappil, Rajith; K., Shijina; Kurungot, Sreekumar; Nair, Balagopal N.; Mohamed, A. Peer; Anilkumar, Gopinathan M.; Yamaguchi, Takeo; Hareesh, U. S. (New Journal of Chemistry, 2020)
A heteroatom doped porous carbon electrocatalyst with enhanced oxygen reduction reaction (ORR) performance in alkaline medium was obtained by high temperature treatment of Ni incorporated ZIF-8 frameworks and its composite with g-C(3)N(4)as a supporting matrix template. The morphology and porosity of this heteroatom containing carbon were tuned by varying the Ni : Zn molar ratio in Ni/Zn ZIF-8 and Ni/Zn ZIF-8@g-C(3)N(4)composites. The template aided synthetic strategy using g-C(3)N(4)helped in the controlled decomposition of composites leading to a heteroporous sheet like architecture with increased nitrogen content. The Ni/Zn ZIF-8 sample on heat treatment in the 800-1000 degrees C temperature range led to the formation of Ni,N co-doped porous carbon (Ni-NPC) with Ni-C active sites. The defective sites induced by nickel carbide along with the distributed N atoms on the carbon surface enabled active O(2)adsorption sites. The high surface area, high degree of graphitisation as well as the defects created by well dispersed N and Ni on porous carbon matrices favoured charge separation leading to higher electrochemical ORR activity. The Ni,N co-doped carbon catalyst in alkaline medium exhibited a limiting current density of 5.2 mA cm(-2)with a half-wave potential of 0.76 Vvs.RHE in 0.1 M KOH. The catalyst also showed improved methanol tolerance and better stability compared to the standard Pt/C catalyst.

Terminal uridylyl transferase mediated site-directed access to clickable chromatin employing CRISPR-dCas9 - George, Jerrin Thomas; Azhar, Mohd; Aich, Meghali; Sinha, Dipanjali; Ambi, Uddhav B.; Maiti, Souvik; Chakraborty, Debojyoti; Srivatsan, Seergazhi G. (Journal of the American Chemical Society, 2020)
Locus-specific interrogation of target genes employing functional probes such as proteins and small molecules is paramount in decoding the molecular basis of gene function and designing tools to modulate its downstream effects. In this context, CRISPR-based gene editing and targeting technologies have proved tremendously useful, as they can be programmed to target any gene of interest by simply changing the sequence of the single guide RNA (sgRNA). Although these technologies are widely utilized in recruiting genetically encoded functional proteins, display of small molecules using CRISPR system is not well developed due to the lack of adequate techniques. Here, we have devised an innovative technology called sgRNA-Click (sgR-CLK) that harnesses the power of bioorthogonal click chemistry for remodeling guide RNA to display synthetic molecules on target genes. sgR-CLK employs a novel posttranscriptional chemoenzymatic labeling platform wherein a terminal uridylyl transferase (TUTase) was repurposed to generate clickable sgRNA of choice by site-specific tailoring of multiple azide-modified nucleotide analogues at the 3' end. The presence of a minimally invasive azide handle assured that the sgRNAs are indeed functional. Notably, an azide-tailed sgRNA targeting the telomeric repeat served as a Trojan horse on the CRISPR-dCas9 system to guide synthetic tags (biotin) site-specifically on chromatin employing copper-catalyzed or strain-promoted click reactions. Taken together, sgR-CLK presents a significant advancement on the utility of bioorthogonal chemistry, TUTase, and the CRISPR toolbox, which could offer a simplified solution for site-directed display of small molecule probes and diagnostic tools on target genes.

Thermodynamic analysis and experimental validation of multi-composition ammonia liquor absorption engine cycle for power generation - Satpute, Satchidanand R.; Takalkar, Gorakshnath; Mali, Nilesh; Bhagwat, Sunil (International Journal of Energy Research, 2020)
Energy conservation, utilization, and effective integration are of utmost importance for future sustenance. Accordingly, this work focuses on the generation of power from the low-grade temperature below 150 degrees C. A proposed novel multi-composition ammonia liquor absorption engine (MALAE) power cycle can be used toward the above purpose by supplying renewable energy obtained from low concentration type solar collectors. Proposed MALAE power cycle minimizes heal loss due to heat recovery and uses high purity NH3 vapors to expand through the isentropic turbine. MALAE power system is modeled and simulated using NH3-H2O as a working fluid for a reboiler temperature of 115 degrees C. The purpose of this work is to simulate the proposed MALAE power cycle with the distillation column and two solution heat exchanger (SHE). MALAE modeling and simulation is accomplished in SCILAB software. The simulation outcome is validated with the pilot-scale 5 kW experimental setup and validation showed +/- 5% deviation. A comparison of MALAE cycle with published cycles signifies higher efficiency of MALAE cycle toward the utilization of low-grade energy from a temperature range of 100 degrees C to 150 degrees C. Finally, detailed parametric analysis of MALAE cycle efficiency is presented in terms of number of plates, distillation pressure and vapor flowrate, absorber temperature, pressure partial condenser temperature, and heat loads.
Keywords: absorption power cycle; ammonia water; low-temperature heat source; solar energy; Thermal Efficiency

TIAs pathway genes and associated miRNA identification in Vinca minor: supporting aspidosperma and eburnamine alkaloids linkage via transcriptomic analysis - Verma, Priyanka; Singh, Noopur; Khan, Shamshad Ahmad; Mathur, Ajay Kumar; Sharma, Ashok; Jamal, Farrukh (Physiology and Molecular Biology of Plants, 2020)
V. minorcontains monomeric eburnamine-type of indole alkaloids having utilization as a neuro-medicinal plant. The biosynthetic pathway studies using miRNAs has been the focal point for plant genomic research in recent years and this technique is utilized to get an insight into a possible pathway level study inV. minoras understanding of genes in this prized medicinal plant is meagrely understood. The de novo transcriptomic analysis using Illumina Next gen sequencing has been performed in glasshouse shifted plant and transformed roots to elucidate the possible non confirmed steps of terpenoid indole alkaloids (TIAs) pathway inV. minor. A putative TIA pathway is elucidated in the study including twelve possible TIAs biosynthetic genes. The specific miRNA associated with TIAs pathway were identified and their roles were discussed for the first time inV. minor. The comparative analysis of transcriptomic data of glasshouse shifted plant and transformed roots showed that the raw reads of transformed roots were higher (83,740,316) compared to glasshouse shifted plant (67,733,538). The EST-SSR prediction showed the maximum common repeats among glasshouse shifted plant and transformed roots, although small variation was found in trinucleotide repeats restricted to glasshouse shifted plant. The study reveals overall 37 miRNAs which were observed to be true and can have a role in pathway as they can regulate the growth and alkaloid production. The identification of putative pathway genes plays an important role in establishing linkage between Aspidosperma and Eburnamine alkaloids.
Keywords: de novo transcriptomic analysis; EST-SSR; miRNA; Terpenoid indole alkaloids; Vinca minor

Time: a web application for obtaining insights into microbial ecology using longitudinal microbiome data (vol 9, 36, 2018) - Baksi, Krishanu D.; Kuntal, Bhusan K.; Mande, Sharmila S. (Frontiers in Microbiology, 2020)
Keywords: clustering; community state; Granger causality algorithm; Microbiome; time series; visualization; Web server

Ti-superoxide catalyzed oxidative amidation of aldehydes with saccharin as nitrogen source: synthesis of primary amides - Kamble, Rohit B.; Mane, Kishor D.; Rupanawar, Bapurao D.; Korekar, Pranjal; Sudalai, A.; Suryavanshi, Gurunath (RSC Advances, 2020)
A new heterogeneous catalytic system (Ti-superoxide/saccharin/TBHP) has been developed that efficiently catalyzes oxidative amidation of aldehydes to produce various primary amides. The protocol employs saccharin as amine source and was found to tolerate a wide range of substrates with different functional groups. Moderate to excellent yields, catalyst reusability and operational simplicity are the main highlights. A possible mechanism and the role of the catalyst in oxidative amidation have also been discussed.

Total synthesis of (+)-petromyroxol, (-)-iso-petromyroxol, and possible diastereomers - Mullapudi, Venkannababu; Ahmad, Iram; Senapati, Sibadatta; Ramana, V, Chepuri (ACS Omega, 2020)
The total synthesis of (+)-petromyroxol (1) and its seven diastereomers including the ()-tso-petromyroxol (2) is described. The employed strategy involves the use of easily available CS-epimeric epoxides 5 and 5' and nonselective anomeric C1-allylation, proceeding with or without inversion at C2 thereby giving the possibility of synthesizing all possible diastereomers. Extensive two-dimensional (2D) NMR analyses of all eight diastereomers have been carried out to assign the chemical shifts of the central carbons land the corresponding attached hydrogens and to learn how the C/H-chemical shifts of the tetrahydrofuran ring were influenced by the adjacent centers.

Total synthesis of (+)-petromyroxol (vol 56, pg 3933, 2015) - Mullapudi, Venkannababu; Ramana, Chepuri V. (Tetrahedron Letters, 2020)

Transient alpha-helix in the N-terminal RNA recognition motif of polypyrimidine tract binding protein senses RNA secondary structure - Maris, Christophe; Jayne, Sandrine; Damberger, Fred F.; Beusch, Irene; Dorn, Georg; Ravindranathan, Sapna; Allain, Frederic H-T (Nucleic Acids Research, 2020)
The polypyrimidine tract binding protein (PTB) is a multi-domain protein involved in alternative splicing, mRNA localization, stabilization, polyadenylation and translation initiation from internal ribosome entry sites (IRES). In this latter process, PTB promotes viral translation by interacting extensively with complex structured regions in the 5'-untranslated regions of viral RNAs at pyrimidine-rich targets located in single strand and hairpin regions. To better understand how PTB recognizes structured elements in RNA targets, we solved the solution structure of the N-terminal RNA recognition motif (RRM) in complex with an RNA hairpin embedding the loop sequence UCUUU, which is frequently found in IRESs of the picornovirus family. Surprisingly, a new three-turn alpha 3 helix C-terminal to the RRM, folds upon binding the RNA hairpin. Although alpha 3 does not mediate any contacts to the RNA, it acts as a sensor of RNA secondary structure, suggesting a role for RRM1 in detecting pyrimidine tracts in the context of structured RNA. Moreover, the degree of helix formation depends on the RNA loop sequence. Finally, we show that the alpha 3 helix region, which is highly conserved in vertebrates, is crucial for PTB function in enhancing Encephalomyocarditis virus IRES activity.

Trending methods employed for polymerization induced self-assembly - Mane, Shivshankar R. (New Journal of Chemistry, 2020)
Mother Nature produces a perfectly defined architecture that inspires researchers to make polymeric macromolecules for an array of functions. Preparation of a pre-defined polymer architecture is a key challenge to a researcher. The present article describes the recent development in Polymerization Induced Self-Assembly (PISA) to synthesize polymeric nanoparticles with pre-defined morphology and precise control over size and shape. This methodology has become a potential strategy for the synthesis of various block copolymer nano-objects. The PISA strategy produces core-shell polymeric nanoparticles with a wide scope of morphologies including spheres, worms, rods, and vesicles. A few parameters including the degree of polymerization, core-forming monomers, macro-CTA and solid content of the final product are precisely employed for the PISA procedure to accomplish the ideal size and shape. PISA opens a new avenue for the production of polymeric nano-objects.

Triazine-based organic polymer-catalysed conversion of epoxide to cyclic carbonate under ambient CO2 pressure - Biswas, Tanmoy; Halder, Arjun; Paliwal, Khusboo S.; Mitra, Antarip; Tudu, Gouri; Banerjee, Rahul; Mahalingam, Venkataramanan (Chemistry-An Asian Journal, 2020)
In this work we have achieved epoxide to cyclic carbonate conversion using a metal-free polymeric catalyst under ambient CO2 pressure (1.02 atm) using a balloon setup. The triazine containing polymer (CYA-ANIS) was prepared from cyanuric chloride (CYA-Cl) and o-dianisidine (ANIS) in anhydrous DMF as solvent by refluxing under the N-2 gas environment. The presence of triazine and amine functional groups in the polymer results in the adsorption of CO2 up to 7 cc/g at 273 K. This inspired us to utilize the polymer for the conversion of a series of functionalised epoxides into their corresponding cyclic carbonates in the presence of tetrabutyl ammonium iodide (TBAI) as co-catalyst. The product has wide range of applications like solvent in lithium ion battery, precursor for polycarbonate, etc. The catalyst was efficient for the conversion of different mono and di-epoxides into their corresponding cyclic carbonates under atmospheric pressure in the presence of TBAI as co-catalyst. The study indicates that epoxide attached with electron withdrawing groups (like, CH2Cl, glycidyl ether, etc.) displayed better conversion compared to simple alkane chain attached epoxides. This is mainly due to the stabilization of electron rich intermediates produced during the reaction (e. g. epoxide ring opening or CO2 incorporation into the halo-alkoxide anion). This catalyst mixture was capable to maintain its reactivity up to five cycles without losing its activity. Post catalytic characterization clearly supports the heterogeneous and recyclable nature of the catalyst.
Keywords: CO2 fixation; cyclic carbonates; epoxides; Heterogeneouscatalyst; metal free catalyst; Triazinepolymer

Triethyl phosphite/benzoyl peroxide mediated reductive dealkylation of O-benzoylhydroxylamines: a cascade synthesis of secondary amides - Aegurla, Balakrishna; Mandle, Ram D.; Shinde, Prasad G.; Parit, Ratan S.; Kamble, Sanjay P.; Sudalai, Arumugam; Senthilkumar, Beeran (European Journal of Organic Chemistry, 2020)
A new triethyl phosphite/benzoyl peroxide (BPO) mediated system has been developed for the synthesis of secondary amides with good to excellent yields in a single step. This unprecedented cascade process involves sequential reduction of N-O bond and benzoylation followed by dealkylation of N-C bond ofO-benzoylhydroxylamines (O-BHA). The methodology is versatile as it tolerates a variety of aromatic and aliphaticO-BHA as substrates to access secondary amides.
Keywords: Amides; Cascade reactions; O-Benzoylhydroxylamines; Redox reactions; synthetic methods

Triton X-114 fractionated subcellular proteome ofleptospira interrogansshows selective enrichment of pathogenic and outer membrane proteins in the detergent fraction - Thoduvayil, Sikha; Dhandapani, Gunasekaran; Brahma, Rahul; Devasahayam Arokia Balaya, Rex; Mangalaparthi, Kiran K.; Patel, Krishna; Kumar, Manish; Tennyson, Jebasingh; Satheeshkumar, P. K.; Kulkarni, Mahesh J.; Pinto, Sneha M.; Prasad, T. S. Keshava; et al. (Proteomics, 2020)
The Triton X-114-based solubilization and temperature-dependent phase separation of proteins is used for subcellular fractionation where, aqueous, detergent, and pellet fractions represents cytoplasmic, outer membrane (OM), and inner membrane proteins, respectively. Mass spectrometry-based proteomic analysis of Triton X-114 fractions of proteomic analysis ofLeptospira interrogansidentified 2957 unique proteins distributed across the fractions. The results are compared with bioinformatics predictions on their subcellular localization and pathogenic nature. Analysis of the distribution of proteins across the Triton X-114 fractions with the predicted characteristics is performed based on ``number'' of unique type of proteins, and ``quantity'' which represents the amount of unique protein. The highest number of predicted outer membrane proteins (OMPs) and pathogenic proteins are found in aqueous and pellet fractions, whereas detergent fraction representing the OM has the highest quantity of OMPs and pathogenic proteins though lower in number than the aqueous and pellet fractions. This leaves the possibility of an upsurge in pathogenic proteins and OMPs on the OM under pathogenic conditions suggesting their potential use to combat leptospirosis. Further, the Triton X-114 subcellular fractions are more correlated to enrichment of pathogenic proteins predicted by MP3 software than predicted localization.
Keywords: intensity-based absolute quantification; Leptospira; outer membrane protein; subcellular localization; Triton X-114

Tweaking palladium electronic structure to attain oxygen reduction activity superior to platinum/C - Sarma, Saurav Ch.; Kaja, Sai Manoj; Mishra, Vidyanshu; Vinod, Chathakudath Prabhakaran; Peter, Sebastian C. (ACS Applied Energy Materials, 2020)
Enhancing oxygen reduction (ORR) activity through alloying is crucial to improve the performance of a fuel-cell catalysts. In this work, we have studied the alloying effects of 4f rare-earth (RE) metals with palladium. The modified catalyst exhibits better activity (E-onset = 1 V and E-1/2 = 0.88 V) and higher selectivity toward H2O (similar to 97%) compared to the state-of-the-art catalysts due to complete dissociation of O-2. Hirshfeld charge analysis and 2D-electron localization function reveal improved adsorbate-adsorbent interaction on the catalyst surface. This work paves a strategy to design highly selective non-Pt-based catalysts for the ORR by controlling electronic structures and surface oxide formation.
Keywords: d-band center; DFT calculation; durability; EuPd; oxygen reduction reaction; YbPd

Ultrahigh sensitive carbon-based conducting rubbers for flexible and wearable human-machine intelligence sensing - Ajeev, Arya; Javaregowda, Bharathkumar H.; Ali, Ashik; Modak, Mrudul; Patil, Shreya; Khatua, Saumyakanta; Ramadoss, Marimuthu; Kothavade, Premkumar Anil; Arulraj, Arul Kashmir (Advanced Materials Technologies, 2020)
The wearable strain sensors with multifunctional applications can fuel the rapid development of human-machine intelligence for various sectors like healthcare, soft robotics, and Internet of Things applications. However, achieving the low-cost and mass production of wearable sensors with ultra-high performance remains challenging. Herein, a simple, cost-effective, and scalable methodology to fabricate the flexible and highly sensitive strain sensors using carbon black and latex rubbers (LR) is presented. The LR-based strain sensor demonstrates excellent flexibility, fast response (approximate to 600 ms), ultra-high sensitivity (maximum gauge factor of 1.2 x 10(4) at 250% strain), and long-term stability over 1000 cycles. The LR-based strain sensors are sensitive to monitor subtle human motions such as heart pulse rate and voice recognition along with high-strain human joint operations. Additionally, the sensing mechanism of LR bands is investigated by surface topographies and electromechanical response under various strained/unstrained conditions. Further, a smart glove-based sensor module made of LR strain bands with an Arduino reader for the human-machine intelligence device for non-verbal communication in military applications is demonstrated.
Keywords: conducting rubbers; gauge factor; human– machine interfacing; voice recognition; wearable strain sensors

Understanding alloy structure and composition in sinter-resistant AgPd@SiO2 encapsulated catalysts and their effect on catalytic properties (vol 41, pg 14652, 2017) - Mondal, Sourik; Rajesh, Thattarathody; Dhar, Basab B.; Snellman, Markus; Li, Junjie; Deepak, Francis Leonard; Devi, R. Nandini (New Journal of Chemistry, 2020)

Understanding the ML black box with simple descriptors to predict cluster-adsorbate interaction energy - Agarwal, Sheena; Mehta, Shweta; Joshi, Kavita (New Journal of Chemistry, 2020)
Density functional theory (DFT) is currently one of the most accurate and yet practical theories used to gain insight into the properties of materials. Although successful, the computational cost required is still the main hurdle even today. In recent years, there has been a trend of combining DFT with Machine Learning (ML) to reduce the computational cost without compromising accuracy. Finding the right set of descriptors that are simple to understand in terms of giving insights about the problem at hand, lies at the heart of any ML problem. In this work, we demonstrate the use of nearest neighbor (NN) distances as descriptors to predict the interaction energy between the cluster and an adsorbate. The model is trained over a size range of 5 to 75 atom clusters. When the training and testing is carried out on mutually exclusive cluster sizes, the mean absolute error (MAE) in predicting the interaction energy is similar to 0.24 eV. MAE reduces to 0.1 eV when testing and training sets include information from the complete range. Furthermore, when the same set of descriptors are tested over individual sizes, the MAE further reduces to similar to 0.05 eV. We bring out the correlation between dispersion in the nearest neighbor distances and variation in MAE for individual sizes. Our detailed and extensive DFT calculations provide a rationale as to why nearest neighbor distances work so well. Finally, we also demonstrate the transferability of the ML model by applying the same recipe of descriptors to systems of different elements like (Na-10), bimetallic systems (Al6Ga6, Li4Sn6, and Au40Cu40) and also different adsorbates (N-2, O-2, and CO).

Understanding unfolding and refolding of the antibody fragment (Fab). I. In-vitro study - Gani, Kayanat; Bhambure, Rahul; Deulgaonkar, Prashant; Mehta, Deepa; Kamble, Manoj (Biochemical Engineering Journal, 2020)
In-vitro protein refolding is a major rate-limiting step in the large scale production of antibody fragments expressed using a microbial source like E. coli. This investigation is focused on understanding the in-vitro unfolding and refolding of the multi-domain protein involving inter-domain disulfide linkage, like antibody fragment (Fab). Solubilization behavior of the inclusion bodies and unfolding events of Fab fragment (Biosimilar rHu Ranibizumab) were studied using nano-differential scanning fluorimetry (nano-DSF). Fab unfolding behavior was studied by fitting experimental data with the two-state and three-state thermodynamic model. Based on the Fab unfolding understanding, a two-stage design of experiment (DoE) strategy was used for the optimization of the in-vitro refolding condition of a Fab fragment. Refolding yield of 56.03 +/- 1.15 % was achieved using the optimized oxidative refolding conditions maintained by appropriate dilution factor and redox reagent ratio. Refolding kinetics of the rHu Ranibizumab was analyzed using a three-parameter kinetic model showing rate constant k(1) :7.05e(-6) l/mg.min, k(2) :0.57 l/mg.min, and k(3) :310.19 l/mg.min. Based on observed refolding kinetics, it was concluded that the Fab refolding follows a three-state mechanism with the refolding intermediate/(s) formation from light and heavy chain of the Fab fragment as an overall rate-limiting step. The method described here is a useful tool to identify high-yield scalable refolding conditions for multi-domain proteins involving inter-domain disulfide bonds.
Keywords: Antibody fragment; In-vitro refolding; Refolding kinetics; rHu Ranibizumab; Two-state and Three-state models

Unraveling the hidden role of the counteranion in ``cation in a cage'' systems - Mukherjee, Anagh; Ghule, Siddharth; Tiwari, Mrityunjay K.; Vanka, Kumar (Journal of Physical Chemistry A, 2020)
The current work showcases general principles at play in systems consisting of cations present inside molecular cages. Such systems, relevant to chemistry and biology, have been carefully investigated by computational methods. The important Ge(II)-encapsulating cage systems have been studied first. The very fact that such compounds exist appears highly unlikely, given the highly reactive nature of the Ge(II) dication. Our studies reveal what really occurs in solution when such complexes are formed: the Ge(II) dications are actually present as [Ge-X](+) (where X is the ``non-coordinating'' counterion employed in such systems) during entry and subsequent existence at the center of the cage. Hence, what is actually present is a ``pseudomonocation''. Interestingly, such pseudomonocation-encapsulated cages are seen to be equally relevant in systems of biological importance, such as for dicationic s block-based ionophores. In explaining such cases, the concept of ``isoionicity'' is introduced, demonstrating that the counterion-coordinated dications are isoionic with a monocation, such as Li(I), isolated in the same ionophore.

Unravelling the distinct surface interactions of modified graphene nanostructures with methylene blue dye through experimental and computational approaches - Manappadan, Zinoy; Kumar, Shubham; Joshi, Krati; Govindaraja, Thillai; Krishnamurty, Sailaja; Selvaraj, Kaliaperumal (Journal of Hazardous Materials, 2020)
Nanoscopic modifications leading to multi-dimensional graphene structures are known to significantly influence their candidature for several applications including catalysis, energy storage, molecular sensing and most significantly adsorption and remediation of harmful materials such as dyes. The present work attempts to identify the key trajectories that connect the structural qualification with a chosen application, viz., the interactive forces in dye remediation. Various physico-chemically Modified Graphene Nanostructures (MGNs) such as 2 dimensional Graphite, Graphene Oxide (GO), reduced GO (rGO), holey rGO, and 3 dimensional GO hydrogel and Holey GO hydrogel are chosen and synthesised herein. These represent varieties of physicochemical features with respect to their dimensionality, surface features such as oxygen functionality, nanoscopic holes etc., that contribute to their characteristic overall surface interactions. Methylene Blue (MB), a popular industrial effluent posing major environmental concern is chosen to be a probe adsorbate in this case study. An exclusive real time in-situ UV visible spectral experiment provides the revealing reasons behind the outstanding performance of 2D GO sheets with an adsorption capacity of greater than 92 % even at high MB concentrations (>2000 ppm). A complex dependency of various factors such as surface oxygen, morphology, nanoporosity etc. on the unique overall interaction with an adsorbent such as MB by all these adsorbates is demonstrated using experimental and DFT based computational studies. Electrostatics and hydrogen bonding are understood to be the two dominant forces driving the MB adsorption on the best performing GO here.
Keywords: Density functional theory; In-situ UV-vis spectroscopy; Interactions; Methylene blue; Modified Graphene Nanostructures

Unsymmetrical squaraine dyes for dye-sensitized solar cells: position of the anchoring group controls the orientation and self-assembly of sensitizers on the TiO2 surface and modulates its flat band potential - Singh, Ambarish Kumar; Maibam, Ashakiran; Javaregowda, Bharathkumar H.; Bisht, Rajesh; Kudlu, Ashwath; Krishnamurty, Sailaja; Krishnamoorthy, Kothandam; Nithyanandhan, Jayaraj (Journal of Physical Chemistry C, 2020)
The position of the anchoring group is systematically changed with a series of alkyl group wrapped donor-acceptor-donor (D-A-D) based squaraine dyes, 4-SQ to 7-SQ, for the use in dye-sensitized solar cells (DSSCs). By this approach, the orientation as well as the self-assembly of the sensitizers can be controlled on the semiconducting TiO2 surface. All of the dyes functionalized with hydrophobic alkyl groups at sp(3)-C and N atoms of the indoline units that is far away from the TiO2 surface to control the self-assembly of dyes and passivate the surface. Controlling both the orientation as well as the self-assembly of the sensitizers synergistically enhances the V-oc of the DSSC device by imparting the dipole moment on the TiO2 surface and minimizing the interfacial charge recombination process of electrons from TiO2 to the oxidized electrolyte, respectively. Further, the presence of a meta-carboxyl group with respect to the N atom of the indoline donor unit for the dyes 4-SQ and 6-SQ makes them nonconductive for the charge injection process, which sheds light on the importance of through-space electron transfer for the device performance. Emission from the relaxed twisted state was found to be a deactivation pathway for 4-SQ on TiO2 and ZrO2, which revealed the importance of structural factors that promote spatial interaction between the sensitizer and metal oxide surface. Computational studies showed the systematic changes in the dipole moment for the sensitizers 4-SQ, 5-SQ, and 6-SQ upon anchoring to the TiO2 surface. The DSSC device performance varied with the position of anchoring groups in the sensitizers. The DSSC device performance of 5-SQ indicates a J(sc) value of 11.35 mA cm(-2), V-oc of 0.698 V, and ff of 77% corresponding to a power conversion efficiency of 6.08% in the presence of 3 equiv of coadsorbent CDCA, which is nearly 1.5 times higher than 6-SQ (V-oc 0.7 V, J(sc) 7.76 mA cm(-2), ff 76%, and eta 4.14%) and 2.6 times higher than 4-SQ (V-oc 0.658 V, J(sc) 4.42 mA cm(-2), ff 78%, and eta 2.28%). IPCE studies revealed the importance of orientation for the charge injection and self-assembly of dyes, as devices with 5-SQ and 6-SQ as a sensitizer showed 94 and 77% response at 578 nm, respectively, which correspond to the aggregated structure of the dye. Mott-Schottky and IPCE experiments showed that the orientation of sensitizers could modulate the V-oc due to the shift in the flat band potential of TiO2.

Valorization of cow urine and dung: A model biorefinery (2018) - Mandavgane, S. A.; Kulkarni, B. D. (Waste and Biomass Valorization, 2020)
Cow is one of the most common livestock of Indian farmers. Small farm households are strongly dependent on livestock for income as it contributes nearly 16% of their total earnings. As much as two-thirds of rural community depends on livestock for their livelihood. Farmers in India maintain a hybrid farming system, that is, a combination of crop cultivation and livestock, which are complementary to each other. Traditionally, the output of one enterprise is the input of another enterprise. Recent research suggests that in addition to milk, urine and dung obtained from cow are valuable resources of bioactive compounds, which can be converted into value-added products. In this review, we provide an outline for the physicochemical composition and valorization of cow urine and dung. They are utilized in agriculture as a pesticide, manure, and acts as a soil rejuvenator. Cow dung is used for bio energy production by fermentation and gasification. Medicinal and cosmetic products are prepared following ayurvedic formulations described in ‘Panchagavya’. Cow dung ash is used as adsorbent, construction material, mosquito repellent and electrolyte. A case study of manufacturing unit producing arrays of products from cow urine and dung is also presented.
Keywords: Bio gas; Cow dung; Cow urine; Waste utilization

Variations in activity of Ru/TiO(2 )and Ru/Al2O3 catalysts for CO2 hydrogenation: an investigation by in-situ infrared spectroscopy studies - Dongapure, Pavan; Bagchi, Sayan; Mayadevi, S.; Devi, R. Nandini (Molecular Catalysis, 2020)
CO2 hydrogenation to methane, an important reaction strategically and also for value adding to CO2, is investigated on two different catalysts, Ru supported on alumina as well as titania to understand better low temperature activity of Ru/TiO2 catalyst. In-situ infrared studies are carried out in three different steps, viz., (i) CO2 adsorption on fully reduced catalyst (ii) reaction of these adsorbed species with gaseous H-2 and (iii) under co-feed of CO2 and H-2, at different temperatures. On Ru/Al2O3 catalyst, CO2 reacts with hydroxyls on the support surface to form carbonate and adsorbs reductively on metal as CO. Further reduction to formate and methyl species occurs on reaction with H. Small concentration of the reactive intermediate formyl forms only at high temperatures. Whereas, bare TiO2 itself seems capable of reductive adsorption of CO2 as formate indicating enhanced reducibility of titania based catalyst. Formyl groups are observed at low temperatures in Ru/TiO2 in step (ii), which further forms methyl and gaseous methane at much lower temperatures when compared to alumina catalyst. Highly reactive CO species loosely bound to metal-support interface observed at high temperatures, which is not present on Ru/Al2O3 catalyst also makes this catalyst superior. In comparison, linearly bound CO seen in alumina catalyst is not as reactive.
Keywords: CO2 hydrogenation; In-situ infra red spectroscopy; Ru/Al2O3; Ru/TiO2

Visual exploration of microbiome data (vol 44, 119, 2019) - Kuntal, Bhusan K.; Mande, Sharmila S. (Journal of Biosciences, 2020)
In the October 2019 Special Issue of theJournal of Bioscienceson Current Trends in Microbiome Research, in the Review article titled `'Visual exploration of microbiome data'' by Bhusan K. Kuntal and Sharmila S. Mande (DOI: 10.1007/s12038-019-9933-z; Vol. 44, Article No. 119), affiliation 3 for Bhusan K. Kuntal was incorrectly mentioned as `'Academy of Scientific and Innovative Research, CSIR-National Chemical Laboratory Campus, Pune 411008, India''. The correct affiliation should read as `'Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201 002, India''.

Wavelength dependent luminescence decay kinetics in `quantum-confined' g-C(3)N(4)nanosheets exhibiting high photocatalytic efficiency upon plasmonic coupling - Mondal, Sanjit; Sahoo, Lipipuspa; Vaishnav, Yuvraj; Mishra, Samita; Roy, Raj Sekhar; Vinod, C. P.; De, Arijit K.; Gautam, Ujjal K. (Journal of Materials Chemistry A, 2020)
Serendipitous observations offer newer insights into materials properties. Here we describe g-C(3)N(4)nanosheets exhibiting remarkably blue-shifted photoluminescence within the 390-580 nm range centred at 425 nm which matches more closely with its `quantum-dots', and yet is excitation-wavelength independent. Moreover, surprisingly, the luminescence decay becomes increasingly slow at higher emission wavelengths, by up to 10 times. The nanosheets absorb only a fraction of visible-light. To improve this, when we designed a nanocomposite of g-C(3)N(4)and Au nanoparticles (NPs), it retained the PL characteristics and also exhibited excellent light-harvesting and photocatalytic efficiency for benzylamine (BA) oxidation. The surface plasmon resonance of the Au NPs is responsible for the high visible-light response and assisting the reaction by the `hot-electron' injection mechanism, while an uncharacteristic, pronounced co-catalytic effect by them further improves the efficiency. The conversion is 98% with >99% selectivity over 1.5 h of natural sunlight and open-air, probably the highest efficiency for BA photo-oxidation reactions. Even though such a dual role by plasmonic NPs has remained unscrutinized, we argue that the charge-transfer processes for the `hot-carrier' injection and co-catalytic events are well-separated in time due to a much slower photon incident frequency on a catalyst particle, enabling both to occur simultaneously in the same particle.

[1,3]-Claisen rearrangement via removable functional group mediated radical stabilization - Alam, Md Nirshad; Dash, Soumya Ranjan; Mukherjee, Anirban; Pandole, Satish; Marelli, Udaya Kiran; Vanka, Kumar; Maity, Pradip (Organic Letters, 2021)
A thermal O-to-C [1,3]-rearrangement of alpha-hydroxy acid derived enol ethers was achieved under mild conditions. The 2-aminothiophenol protection of carboxylic acids facilitates formation of the [1,3] precursor and its thermal rearrangement via stabilization of a radical intermediate. Experimental and theoretical evidence for dissociative radical pair formation, its captodative stability via aminothiophenol, and a unique solvent effect are presented. The aminothiophenol was deprotected from rearrangement products as well as after derivatization to useful synthons.

2D MoO2/N-Doped-carbon nanosheets as SERS tweezers: a non-noble metal reusable substrate for selective organic dye detection - Gaikwad, Supriya Hanmant; Mukherjee, Shatabdi Porel (ACS Applied Nano Materials, 2021)
The design and synthesis of a highly sensitive and exceptionally selective surface-enhanced Raman scattering (SERS) substrate with an excellent reusable property are of significant interest because of its vast prospective application in actual and complicated detection environments. Here, a simple synthesis strategy was presented to fabricate crystalline two-dimensional (2D) MoO2/N-doped-carbon nanosheets with the plasmonic property. The morphology, crystal phase, and surface property of MoO2 nanomaterials (NMs) were specifically controlled under suitable reaction conditions. In addition, the plasmonic MoO2/N-doped-carbon NM exhibited a SERS maximum enhancement factor up to 1.38 × 104 with a detection limit as low as 1.0 × 10–6 M. More importantly, the as-synthesized nanocomposite shows high selectivity as a “SERS Tweezer” toward methylene blue (MB) in binary and ternary mixed interfering analyte solutions, preserving detection sensitivity toward MB for three cycles via an “elect-and-eliminate” approach. This strategy will be helpful to design other plasmonic semiconductor NMs for successful tangible applications of selective SERS sensing for trace impurity detections in real and complex environments.

Accurate identification of bioactive meliaceae limonoids by UHPLC-MS/ms based structure-fragment relationships (SFRs) - Mulani, Fayaj A.; Nandikol, Sharvani S.; Haldar, Saikat; Thulasiram, V, Hirekodathakallu (ACS Omega, 2021)
Y Limonoids are bioactive plant specialized metabolites found in the Meliaceae family. The basic limonoids, i.e., azadiradione, epoxyazadiradione, and gedunin have been exploited for various bioactivities and therefore are the potential drug leads for tomorrow. However, their low abundance, structural similarity, and lack of adequate mass fragmentation data have hampered their accurate identification and quantification from various sources. In the present study, basic limonoids such as azadirone, azadiradione, epoxyazadiradione, and gedunin isolated from Neem were utilized for the synthesis of their derivatives and isotopologs. A total of 30 one compounds were used in this study among which five were isolated, two were biotransformed, and 24 were synthesized. Among the synthesized compounds nine are novel compounds including six deuterated analogs/isotopologs which are (1,3-H-2)-1,2dihydro-3 beta-hydroxyazadiradione (9), (1,3,16-H-2)-1,2-dihydro-3 beta-16 beta-dihydroxyazadiradione (10), 3 beta-hydroxyazadiradione (11), 3 beta-16 beta-dihydroxyazadiradione (12), (3-H-2)-3 beta-hydroxyazadiradione (13), (3,16-H-2)-3 beta-16 beta-dihydroxyazadiradione (14), (1,3,7-H-2)-1,2-dihydro-3 beta-hydroxy-7-deacetylazadiradione (15), 1,2,20,21,22,23-hexahydroazadiradione (17), and (1,3-H-2)-1,2-dihydro-3 beta-hydroxygedunin (29). These limonoids along with their semisynthesized derivatives were subjected to ultra high performance liquid chromatography mass spectrometry (UHPLC-MS/MS) and the fragmentation pathway was established based on structure-fragment relationships (SFRs), utilizing high resolution MS/MS data. We have developed a most reliable and easily reproducible protocol describing in depth analysis of SFRs based on the structural modifications and synthesis of isotopologs. Also, the MS/MS fragment library of these basic limonoids generated in this study acts as a fingerprint for accurate identification and quantification of limonoids by MS/MS analysis in various plant tissue extracts, phytopharmaceutical formulations and biological samples.

Annulation of enals with carbamoylpropiolates via NHC-catalyzed enolate pathway: access to functionalized maleimides/iso-maleimides and synthesis of aspergillus FH-X-213 - Viveki, Amol B.; Pol, Mahesh D.; Halder, Priyanka; Sonavane, Sameer R.; Mhaske, Santosh B. (Journal of Organic Chemistry, 2021)
Herein we report the N-heterocyclic carbene (NHC)-catalyzed [3 + 2] annulation of alpha,beta-unsaturated aldehydes with carbamoylpropiolates via an unusual enolate pathway leading to the construction of highly functionalized maleimides or isomaleimides. The electronic effect imposed by the alkyl/aryl group present on the amide nitrogen of carbamoylpropiolates plays a crucial role in the selective formation of these important five-membered heterocyclic building blocks. The developed protocol is mild and tolerates a wide range of substituents on both substrates. The application of this protocol in the synthesis of the antibacterial natural product Aspergillus FH-X-213 has also been demonstrated.

Antitumor effects of Ir(III)-2H-indazole complexes for triple negative breast cancer - Panchangam, Rajeeva Lochana; Rao, Ramdas Nishanth; Balamurali, Musuvathi Motilal; Hingamire, Tejashri B.; Shanmugam, Dhanasekaran; Manickam, Venkatraman; Chanda, Kaushik (Inorganic Chemistry, 2021)
In this work, we have synthesized a series of novel C,N-cyclometalated 2H-indazole-ruthenium(II) and -iridium(III) complexes with varying substituents (H, CH3, isopropyl, and CF3) in the R4 position of the phenyl ring of the 2H-indazole chelating ligand. All of the complexes were characterized by 1H, 13C, high-resolution mass spectrometry, and elemental analysis. The methyl-substituted 2H-indazole-Ir(III) complex was further characterized by single-crystal X-ray analysis. The cytotoxic activity of new ruthenium(II) and iridium(III) compounds has been evaluated in a panel of triple negative breast cancer (TNBC) cell lines (MDA-MB-231 and MDA-MB-468) and colon cancer cell line HCT-116 to investigate their structure–activity relationships. Most of these new complexes have shown appreciable activity, comparable to or significantly better than that of cisplatin in TNBC cell lines. R4 substitution of the phenyl ring of the 2H-indazole ligand with methyl and isopropyl substituents showed increased potency in ruthenium(II) and iridium(III) complexes compared to that of their parent compounds in all cell lines. These novel transition metal-based complexes exhibited high specificity toward cancer cells by inducing alterations in the metabolism and proliferation of cancer cells. In general, iridium complexes are more active than the corresponding ruthenium complexes. The new Ir(III)-2H-indazole complex with an isopropyl substituent induced mitochondrial damage by generating large amounts of reactive oxygen species (ROS), which triggered mitochondrion-mediated apoptosis in TNBC cell line MDA-MB-468. Moreover, this complex also induced G2/M phase cell cycle arrest and inhibited cellular migration of TNBC cells. Our findings reveal the key roles of the novel C–N-cyclometalated 2H-indazole-Ir(III) complex to specifically induce toxicity in cancer cell lines through contributing effects of ROS-induced mitochondrial disruption along with chromosomal and mitochondrial DNA target inhibition.

Aqueous methanol to formaldehyde and hydrogen on Pd/TiO2 by photocatalysis in direct sunlight: structure dependent activity of nano-Pd and atomic Pt-coated counterparts - Nalajala, Naresh; Salgaonkar, Kranti N.; Chauhan, Inderjeet; Mekala, Siva Prasad; Gopinath, Chinnakonda S. (ACS Applied Energy Materials, 2021)
In the present investigation, facet-controlled Pd nanoparticles with nanocube (Pd-NC) and truncated octahedron (Pd-TO) morphologies, and their counterparts with half-a-monolayer of atomic Pt coated (0.5 theta(Pt)-Pd-NC and 0.5 theta(Pt)-Pd-TO) surfaces were prepared. All of them were characterized and evaluated as cocatalyst after supporting them on commercial titania (P25) (Pd-NC/P25, Pd-TO/P25, 0.5 theta(Pt)-Pd-NC/P25, and 0.5 theta(Pt)-Pd-TO/P25) under direct sunlight and/or one sun conditions for the oxidation of methanol to formaldehyde along with solar hydrogen production. Pd-NC/P25 shows higher activity for hydrogen generation compared to Pd-TO/P25; however, activity reversal occurs with the above cocatalysts, but, after Pt-coating with further enhanced activity. The highest conversion of methanol (0.2 mu mol/h.mg) to 100% selective formaldehyde was observed with 0.5 theta(Pt)-Pd-TO/P25, while other catalysts show significantly lower methanol conversion in the following order: 0.5 theta(Pt)-Pd-TO/P25 > 0.5 theta(Pt)-Pd-NC/P25 > Pd-NC/P25 > Pd-TO/P25. Pt-coated on (111) facets of Pd-TO simulates the activity associated as that of Pt(111) facets and demonstrating the highest and facet dependent activity. The present study is truly in resonance with exploiting the surface properties for heterogeneous catalysis, and highlights that less than a monolayer of Pt is sufficient to simulate the activity as that of bulk Pt. It is worth exploring this concept to other metals and substrates too.
Keywords: heterogeneous catalysis; Nanomaterials; Oxidation; Photocatalysis; surface modification

Autophagy and unique aerial oxygen harvesting properties exhibited by highly photocatalytic carbon quantum dots - Mondal, Sanjit; Vinod, C. P.; Gautam, Ujjal K. (Carbon, 2021)
<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">Plastic pollution is a serious threat to the environment as they are not bio-degradable. Herein using waste-polyethylene, we report two inter-related important findings. First that they can be converted economically and completely into highly photocatalytic carbon quantum-dots (CQDs) using H<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">O<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;"> as a residue-free oxidant in an acid medium, and they have the ability to enrich a reaction medium with an extraordinary amount of molecular oxygen harvested from the air so that no separate oxygen source is needed while carrying out facile photocatalytic <a class="topic-link" href="https://www.sciencedirect.com/topics/engineering/oxidation-reaction" style="background-color: transparent; text-decoration-line: underline; text-decoration-thickness: 1px; text-decoration-color: rgb(46, 46, 46); color: rgb(46, 46, 46); word-break: break-word; text-underline-offset: 1px;" title="Learn more about oxidation reactions from ScienceDirect's AI-generated Topic Pages">oxidation reactions. Second, when they are not performing any photocatalytic reaction, they exhibit self-sensitized photo-oxidation to convert themselves completely to CO<span style="font-size: 13.5px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(46, 46, 46); font-family: NexusSerif, Georgia, "Times New Roman", Times, STIXGeneral, "Cambria Math", "Lucida Sans Unicode", "Microsoft Sans Serif", "Segoe UI Symbol", "Arial Unicode MS", serif; font-size: 18px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;"> in the presence of sunlight, a phenomenon that we term as ‘CQD-autophagy’ by drawing parallels to the death of useless-cells in the body. Such extinction from the reaction media is unique as no other material is known to do so and advantageous because the removal of carbon-dots from a solution is rather inefficient from an industry-viewpoint due to their high solubility. Instead, the inexpensive CQDs can be discarded casually with the notion that they will gradually get eliminated from the environment.
Keywords: Carbon dots; Oxygen-enrichment; Photocatalytic oxidation; Self-sensitized photo-oxidation

Bimetallic Ni-Pd synergism-mixed metal catalysis of the mizoroki-heck reaction and the suzuki-miyaura coupling of aryl bromides - Kashid, Abhijit A.; Patil, Dharmaraj J.; Mali, Ramling D.; Patil, Vijay P.; Neethu, T. V.; Meroliya, Heena K.; Waghmode, Shobha A.; Iyer, Suresh (Catalysis Letters, 2021)
A combination of Pd and Ni complexes activated aryl bromides for the thermal Mizoroki-Heck reaction and Suzuki coupling giving high yields in short reaction times. A thermal redox mechanism probably occurs whereby Ni complex transfers electron and reduces the Pd (II) to Pd (0) which then takes the reactants through the standard protocol of oxidative-addition, migratory insertion and reductive elimination, typical for the Mizoroki-Heck reaction and the Suzuki coupling. [GRAPHICS] .
Keywords: Bimetallic catalysis; Mizoroki-Heck; Nickel complexes; Pd(OAc)2; Suzuki coupling

Bimetallic Ni–Pd synergism—mixed metal catalysis of the mizoroki-heck reaction and the suzuki–miyaura coupling of aryl bromides - Kashid, Abhijit A.; Patil, Dharmaraj J.; Mali, Ramling D.; Patil, Vijay P.; Neethu, T. V.; Meroliya, Heena K.; Waghmode, Shobha A.; Iyer, Suresh (Catalysis Letters, 2021)
A combination of Pd and Ni complexes activated aryl bromides for the thermal Mizoroki-Heck reaction and Suzuki coupling giving high yields in short reaction times. A thermal redox mechanism probably occurs whereby Ni complex transfers electron and reduces the Pd (II) to Pd (0) which then takes the reactants through the standard protocol of oxidative-addition, migratory insertion and reductive elimination, typical for the Mizoroki-Heck reaction and the Suzuki coupling.

Biological process of lysine-tRNA charging is therapeutically targetable in liver cancer - Zhang, Ruyi; Noordam, Lisanne; Ou, Xumin; Ma, Buyun; Li, Yunlong; Das, Pronay; Shi, Shaojun; Liu, Jiaye; Wang, Ling; Li, Pengfei; Verstegen, Monique M. A.; Reddy, D. Srinivasa; et al. (Liver International, 2021)
Background & Aims Mature transfer RNAs (tRNA) charged with amino acids decode mRNA to synthesize proteins. Dysregulation of translational machineries has a fundamental impact on cancer biology. This study aims to map the tRNAome landscape in liver cancer patients and to explore potential therapeutic targets at the interface of charging amino acid with tRNA. Methods Resected tumour and paired tumour-free (TFL) tissues from hepatocellular carcinoma (HCC) patients (n = 69), and healthy liver tissues from organ transplant donors (n = 21), HCC cell lines, and cholangiocarcinoma (CC) patient-derived tumour organoids were used. Results The expression levels of different mature tRNAs were highly correlated and closely clustered within individual tissues, suggesting that different members of the tRNAome function cooperatively in protein translation. Interestingly, high expression of tRNA-Lys-CUU in HCC tumours was associated with more tumour recurrence (HR 1.1;P = .022) and worse patient survival (HR 1.1;P = .0037). The expression of Lysyl-tRNA Synthetase (KARS), the enzyme catalysing the charge of lysine to tRNA-Lys-CUU, was significantly upregulated in HCC tumour tissues compared to tumour-free liver tissues. In HCC cell lines, lysine deprivation, KARS knockdown or treatment with the KARS inhibitor cladosporin effectively inhibited overall cell growth, single cell-based colony formation and cell migration. This was mechanistically mediated by cell cycling arrest and induction of apoptosis. Finally, these inhibitory effects were confirmed in 3D cultured patient-derived CC organoids. Conclusions The biological process of charging tRNA-Lys-CUU with lysine sustains liver cancer cell growth and migration, and is clinically relevant in HCC patients. This process can be therapeutically targeted and represents an unexplored territory for developing novel treatment strategies against liver cancer.
Keywords: Cladosporin; liver cancer; lysine; Lysyl-tRNA Synthetase; tRNA-Lys-CUU; tRNAome

Biomass-derived activated carbon material from native European deciduous trees as an inexpensive and sustainable energy material for supercapacitor application - Jain, Amrita; Ghosh, Meena; Krajewski, Marcin; Kurungot, Sreekumar; Michalska, Monika (Journal of Energy Storage, 2021)
Activated carbons are one of the possible electrode materials for supercapacitors (SCs), which are widely used in commercial applications. Herein, we reported the synthesis of a novel activated carbon derived through a cavitation process from the mixture of native European deciduous trees, Birch, Fagaceae, and Carpinus betulus (commonly known as European hornbeam), which was employed as the electrode material in SC. From the morphological and structural characterization, we observed that the prepared sample is a desirable carbon with good porosity and high specific surface area of about 614 m(2) g(-1). The electrochemical properties of the synthesized material were evaluated with a three-electrode configuration in 1.0 M H2SO4 electrolyte. It was found that in device mode, the carbon material delivers a specific capacitance of 24 F g(-1) at 0.25 A g(-1) with excellent cycling stability of over 10000 consecutive charge/discharge cycles. Thus, our studies demonstrate the facile synthesis of biomass-derived carbon and its application as a versatile electrode material for SC applications.
Keywords: Biomass; Carbon material; Deciduous trees; Electrode material; supercapacitor

Chemistry, anti-diabetic activity and structural analysis of substituted dihydropyrimidine analogues - Bairagi, Keshab M.; Younis, Nancy Safwat; Emeka, Promise Madu; Venugopala, Katharigatta N.; Alwassil, I, Osama; Khalil, Hany Ezzat; Sangtani, Ekta; Gonnade, Rajesh G.; Mohanlall, Viresh; Nayak, Susanta K. (Journal of Molecular Structure, 2021)
In an effort to identify an anti-diabetic agent, a series of methyl/ethyl 4-(hydroxyphenyl)-6-methyl-2-oxo/thioxo-1,2,3,4 tetrahydropyrimidine-5-carboxylate analogues (4a-h) have been synthesized, purified, and characterized by using Fourier-Transform Infrared Spectroscopy (FT-IR) and NMR (H-1 and C-13). The synthesized compounds were screened for anti-hyperglycemic activity using Streptozotocin (STZ) induced diabetic rat model. The anti-hyperglycemic activity of dihydropyrimidine (DHPM) compound is mainly analyzed with the variation of substituents present on the phenyl ring and urea/thiourea group on pharmacophoric features. Further, the crystal structure and supramolecular characteristics of two compounds 4c and 4f were analyzed through a single-crystal X-ray method and the Hirshfeld Surface Analysis, which shows hydrogen bonding through N-H center dot center dot center dot O and N-H center dot center dot center dot S interactions with the formation of ring motif in the crystal structure. It is interesting to note that among the title compounds, the 4a, 4e, 4f, and 4g significantly displayed a better hypoglycemic effect in vivo rat model study. (C) 2020 Elsevier B.V. All rights reserved.
Keywords: Dihydropyrimidine (DHPM); Hypoglycemia; Streptozotocin (STZ); Type-2 diabetes mellitus (T2DM)

Cloning and expression of antibody fragment (Fab) I: effect of expression construct and induction strategies on light and heavy chain gene expression - Mehta, Deepa; Chirmade, Tejas; Tungekar, Aatir A.; Gani, Kayanat; Bhambure, Rahul (Biochemical Engineering Journal, 2021)
Dual promoter expression constructs offer time and cost-effective alternatives to produce multi-domain proteins like antibody fragments. This investigation is focused on understanding the effect of expression construct (dual promoter vs. co-transformation strategy), codon optimization, and induction strategies on yield and expression stoichiometry of LC and HC genes of antibody fragment at shake-flask and bioreactor scale. rHu biosimilar Ranibizumab was selected as a model protein for the study. Expression stoichiometry of HC and LC gene at mRNA level was studied using RTqPCR, whereas protein expression level was studied quantitatively using RP-HPLC and SDS-PAGE analysis. In the case of dual promoter expression construct, it was observed that LC gene cloned in the MCS1 of the duet vectors has > 2-fold expression than the HC gene, cloned in the MCS2. Transcript abundance profile of the HC and LC genes determined at different time intervals post-induction shows a difference in the gene expression at the transcriptional level. Comparative analysis of dual promoter and co-transformation strategy shows better stoichiometry in co-transformation (1:1.3), whereas higher protein yield in a dual expression system (>2.4 fold). The use of lactose and galactose as inducers show higher Fab yield of 2.30 +/- 0.03 g/L and 2.81 +/- 0.06 g/L with expression stoichiometry of 1:1.9 and 1:2 (HC: LC) respectively than IPTG-based induction with a protein yield of 1.40 +/- 0.02 g/L.
Keywords: Dual promoter vector; Expression stoichiometry; High cell density fermentation; rHu biosimilar Ranibizumab; Transcript abundance

Cold active lipases: biocatalytic tools for greener technology - Mhetras, Nutan; Mapare, Vidhyashri; Gokhale, Digambar (Applied Biochemistry and Biotechnology, 2021)
Lipases are enzymes that catalyze the ester bond hydrolysis in triglycerides with the release of fatty acids, mono- and diglycerides, and glycerol. The microbial lipases account for \$400 million market size in 2017 and it is expected to reach \$590 million by 2023. Many biotechnological processes are expedited at high temperatures and hence much research is dealt with thermostable enzymes. Cold active lipases are now gaining importance in the detergent, synthesis of chiral intermediates and frail/fragile compounds, and food and pharmaceutical industries. In addition, they consume less energy since they are active at low temperatures. These cold active lipases have not been commercially exploited so far compared to mesophilic and thermophilc lipases. Cold active lipases are distributed in microbes found at low temperatures. Only a few microbes were studied for the production of these enzymes. These cold-adapted enzymes show increased flexibility of their structures in response to freezing effect of the cold habitats. This review presents an update on cold-active lipases from microbial sources along with some structural features justifying high enzyme activity at low temperature. In addition, recent achievements on their use in various industries will also be discussed.
Keywords: Cold active lipases; Frail compounds; Psychrophilic microbes; Synthesis of chiral molecules

Colloidal assembly by directional ice templating - Biswas, Bipul; Misra, Mayank; Bisht, Anil Singh; Kumar, Sanat K.; Kumaraswamy, Guruswamy (Soft Matter, 2021)
We investigate directional ice templating of dilute aqueous colloidal particle dispersions and examine the nature of the assemblies that result. We coat micron-size polystyrene colloids with cross-linkable polymer (polyethyleneimine, PEI), add cross-linker, and subject this dispersion to unidirectional freezing. We work at sufficiently low colloid concentrations, such that the particles do not percolate on freezing. When the aqueous dispersion freezes, ice crystals force polymer-coated particles and cross-linker into close proximity. This results in the formation of cross-linked clusters of particles at ice crystal boundaries. We vary the particle volume fraction from phi similar to 2.5 x 10(-3) to phi similar to 5.0 x 10(-2) and observe that there is a transition from isolated single particles to increasingly large sized clusters. Most of the clusters formed under these conditions are either linear, two-particle wide chains, or sheet-like aggregates. The probability (P-n) of clusters containing n particles (n > 2) obeys a power law P-n similar to n(-eta), where eta strongly depends on the particle concentration in the dispersion, varying from 2.10 (for phi similar to 5.0 x 10(-2)) to 3.03 (for phi similar to 2.5 x 10(-3)). This change in eta is qualitatively different from the case of isotropic freezing, where eta is particle concentration-independent and depends only on the ice nucleation density. To understand the differences between isotropic and directional ice templating, we performed lattice simulations of a highly simplified model, where ice crystals grow at a constant rate to force clustering. We ignore hydrodynamic interactions and ice growth instabilities. Despite ignoring these experimental details, the simulations capture the experimental results, nearly quantitatively. As the ice crystals grow and the space available to the colloids ``closes up'' so that the particles cluster to form aggregates, crystallization protocol-induced differences in the geometry of these ``closed up'' spaces determine the scaling behaviour of P-n.

Combating multi-drug resistant malaria parasite by inhibiting falcipain-2 and heme-polymerization: Artemisinin-peptidyl vinyl phosphonate hybrid molecules as new antimalarials - Aratikatla, Eswar K.; Kalamuddin, Md; Rana, Kalpeshkumar C.; Datta, Gaurav; Asad, Mohd; Sundararaman, Srividhya; Malhotra, Pawan; Mohmmed, Asif; Bhattacharya, Asish K. (European Journal of Medicinal Chemistry, 2021)
<span style="color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">Artemisinin-based combination therapies (ACTs) have been able to reduce the clinical and pathological malaria cases in endemic areas around the globe. However, recent reports have shown a progressive decline in malaria parasite clearance in South-east Asia after ACT treatment, thus envisaging a need for new artemisinin (ART) derivatives and combinations. To address the emergence of drug resistance to current antimalarials, here we report the synthesis of artemisinin-peptidyl vinyl phosphonate hybrid molecules that show superior efficacy than artemisinin alone against chloroquine-resistant as well as multidrug-resistant Plasmodium falciparum strains with EC<span style="box-sizing: inherit; font-size: 12px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">50<span style="color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;"> in pico-molar ranges. Further, the compounds effectively inhibited the survival of ring-stage parasite for laboratory-adapted artemisinin-resistant parasite lines as compared to artemisinin. These hybrid molecules showed complete parasite clearance in vivo using P. berghei mouse malaria model in comparison to artemisinin alone. Studies on the mode of action of hybrid molecules suggested that these artemisinin-peptidyl vinyl phosphonate hybrid molecules possessed dual activities: inhibited falcipain-2 (FP-2) activity, a P. falciparum cysteine protease involved in hemoglobin degradation, and also blocked the hemozoin formation in the food-vacuole, a step earlier shown to be blocked by artemisinin. Since these hybrid molecules blocked multiple steps of a pathway and showed synergistic efficacies, we believe that these lead compounds can be developed as effective antimalarials to prevent the spread of resistance to current antimalarials.

Comprehensive tutorial on the pulsed laser deposition technique and developments in the fabrication of low dimensional systems and nanostructures - Masood, Khalid Bin; Kumar, Pushpendra; Malik, Mushtaq Ahmad; Singh, Jai (Emergent Materials, 2021)
Pulsed laser deposition (PLD) is a simple and extremely versatile technique to grow thin films and nanomaterials of a wide variety of materials. PLD allows the deposition of profoundly different materials, including high-temperature superconductors, oxides, nitrides, carbides, semiconductors, metals, and even polymers or fullerenes with high deposition rates. Growing thin films using PLD is now being used around the world for prototyping thin films of many inorganic materials and even in device fabrication protocols. This article covers the detailed development, versatility, and reliability of the ultraviolet (UV) excimer laser. It is envisioned that this review article is of interest for both the materials and chemical scientists engaged in more fundamental aspects of pulsed laser ablation and deposition. The present article highlights the historical developments of PLD technique, complete mechanism of thin film fabrication, optimization of the quality of thin films and the fabrication of thin films of the materials like ZnO, Graphene, MoS2, and WS2 which are being explored for various potential applications.

Computational insights into the role of external and local electric fields in macrocyclic chemical and biological systems - Mukherjee, Anagh; Ghule, Siddharth; Vanka, Kumar (ChemPhysChem, 2021)
The investigation of the role of the electric field in systems of widespread interest employing computational techniques is an emerging area of research. The outcome of applying an oriented external electric field (OEEF) on the geometric and electronic properties of the chemically unique pi-conjugated cyclic carbon ring compounds has been explored with density functional theory (DFT). Distinct changes in the structural and electronic features of such ring compounds are observed upon the application of OEEFs. Importantly, the calculations indicate that a mixed aliphatic-aromatic conjugated ring converts from a singlet to a triplet after the application of an OEEF, suggesting potential applications in optoelectronics for such molecules, without the need for photochemically induced change in the spin state. Furthermore, the influence of built-in local electric fields (LEFs) present in naturally occurring macrocyclic systems such as valinomycin has also been explored. Static and ab initio molecular dynamics (AIMD) calculations indicate that LEFs are the primary driving factor in determining the energetically favoured position of counter anions such as chloride (Cl-) in the potassium (K+) and sodium (Na+) coordinated valinomycin macrocycle structures: they exist inside the cage in the case of K+ sequestration by valinomycin and outside for Na+. This divergence has been proposed to be the determining factor for the selectivity of the valinomycin macrocycle for binding a K+ cation over Na+.
Keywords: counter anions; Density functional calculations; electric field; ion selectivity; macrocyclic systems

Construction of beta-cyclodextrin linked glycidyl methacrylate polymers for stereoselective separation of chiral drug - Wale, Apparav; Mulani, Khudbudin; Deshpande, Supriya; Rajan, C. R.; Ponrathnam, Surendra (Journal of Polymer Research, 2021)
In this present study, a series of cross-linked porous polymers based on Glycidyl Methacrylate (GMA) were synthesized by suspension polymerization using cyclohexanol and hexanol as pore generating solvents. beta-cyclodextrin (beta-CD) was covalently bonded to the polymers by using Hexamethylene Diisocyanate (HMDI) and Sebacoyl Chloride (SC) as spacer arms. The effects of matrix properties such as pore volume, type of crosslinker, and spacer on the loading of beta-cyclodextrin were investigated. The stereoselective binding of enantiomers of the anti-depressant drug citalopram was studied using beta-cyclodextrin loaded polymers under batch adsorption mode. The capacity factor and selectivity of isomers were investigated also. This study reveals that these beta-cyclodextrin bonded Glycidyl Methacrylate (GMA) polymers are potentially suitable for chromatographic separation of citalopram.
Keywords: beta-cyclodextrin; Citalopram; Glycidyl Methacrylate (GMA) beads; HPLC etc; Stereoslelctivity

Continuous citrate-capped gold nanoparticle synthesis in a two-phase flow reactor - Damilos, Spyridon; Alissandratos, Ioannis; Panariello, Luca; Radhakrishnan, Anand N. P.; Cao, Enhong; Wu, Gaowei; Besenhard, Maximilian O.; Kulkarni, Amol A.; Makatsoris, Charalampos; Gavriilidis, Asterios (Journal of Flow Chemistry, 2021)
A continuous manufacturing platform was developed for the synthesis of aqueous colloidal 10-20 nm gold nanoparticles (Au NPs) in a flow reactor using chloroauric acid, sodium citrate and citric acid at 95 degrees C and 2.3 bar(a) pressure. The use of a twophase flow system - using heptane as the continuous phase - prevented fouling on the reactor walls, while improving the residence time distribution. Continuous syntheses for up to 2 h demonstrated its potential application for continuous manufacturing, while live quality control was established using online UV-Vis photospectrometry that monitored the particle size and process yield. The synthesis was stable and reproducible over time for gold precursor concentration above 0.23 mM (after mixing), resulting in average particle size between 12 and 15 nm. A hydrophobic membrane separator provided successful separation of the aqueous and organic phases and collection of colloidal Au NPs in flow. Process yield increased at higher inlet flow rates (from 70% to almost 100 %), due to lower residence time of the colloidal solution in the separator resulting in less fouling in the PTFE membrane. This study addresses the challenges for the translation of the synthesis from batch to flow and provides tools for the development of a continuous manufacturing platform for gold nanoparticles.
Keywords: Continuous manufacturing; Nanomaterials; Online analysis; phase separation; segmented flow

Controlled di-lithiation enabled synthesis of phosphine-sulfonamide ligands and implications in ethylene oligomerization - Mote, Nilesh R.; Gaikwad, Shahaji R.; Khopade, V, Kishor; Gonnade, Rajesh G.; Chikkali, Samir H. (Dalton Transactions, 2021)
Catalyst design for ethylene oligomerization has attracted significant interest. Herein, we report the synthesis of phosphine-sulfonamide-derived palladium complexes and examine their performance in ethylene oligomerization. Arresting a dilithiation intermediate of N-(2-bromophenyl)-4-methylbenzenesulfonamide (1) at -84 degrees C selectively produced N-(2-(bis(2-methoxyphenyl)phosphanyl)phenyl)-4-methylbenzenesulfonamide (L1A). However, the same reaction at -41 degrees C delivered a different ligand; 2-(bis(2-methoxyphenyl)phosphanyl)-4-methyl-N-phenylbenzenesulfonamide (L2A). The generality of our strategy has been demonstrated by preparing N-(2-(diphenylphosphanyl)phenyl)-4-methylbenzenesulfonamide (L1B) and 2-(diphenylphosphanyl)-4-methyl-N-phenylbenzenesulfonamide (L2B). Subsequently, L1A and L1B were treated with a palladium precursor to yield 5-membered complexes C1 and C2, respectively. In contrast, L2A upon treatment with palladium produced a 6-membered metal complex C3. Thus, a small library of 7 palladium complexes (C1-C7) were synthesized by varying the donor moiety (pyridine, DMSO, and acetonitrile). The identity of palladium complexes was unambiguously ascertained using a combination of spectroscopic and analytical methods, including single-crystal X-ray diffraction. The performance of the complexes C1-C7 was investigated in ethylene oligomerization and almost all of them were found to be active. The resultant ethylene oligomers were characterized using H-1 and C-13 NMR, MALDI-ToF-MS, and GPC. Detailed screening of reaction parameters revealed 100 degrees C and 40 bars ethylene to be optimal conditions. Complex C5 outperformed other complexes and produced ethylene oligomers with a molecular weight of 1000-1900 g mol(-1).

Convenient and mild protocol for preparation of α –trimethylsilyloxyphosphonates using sulfamic acid and their oxidation to α – ketophosphonates in the presence of N-bromosuccinimide - Mitragotri, Satish; Kulkarni, Makarand; Desai, Uday; Wadagaonkar, Prakash (Arkivoc, 2021)
A convenient and mild protocol was developed for the trimethylsilylation of α-hydroxyphosphonates using hexamethyldisilazane as the silylating agent in the presence of sulfamic acid (SA) as a heterogeneous solid acid catalyst in dichloromethane as the reaction medium. The utility of SA as the catalyst for deprotection of α-trimethylsilyloxyphosphonates to parent α-hydroxyphosphonates by making a switch to a protic solvent such as methanol was also demonstrated. Furthermore, the oxidation of α–trimethylsilyloxyphosphonates to corresponding α–ketophosphonates was achieved in excellent yields employing N-bromosuccinimide in the presence of catalytic quantity of AIBN.

Copolymers of bipyridinium and metal (Zn & Ni) porphyrin derivatives; theoretical insights and electrochemical activity towards CO2 - Kochrekar, Sachin; Kalekar, Ajit; Mehta, Shweta; Damlin, Pia; Salomaki, Mikko; Granroth, Sari; Meltola, Niko; Joshi, Kavita; Kvarnstrom, Carita (RSC Advances, 2021)
This study reports the electropolymerization of novel keto functionalized octaethyl metal porphyrins (Zn2+ and Ni2+) in the presence of 4,4 `-bipyridine (4,4 `-bpy) as a bridging nucleophile. The polymer films were characterized by electrochemical, spectroscopic (UV-Vis, XPS, FT-IR and Raman spectroscopy) and imaging (AFM and SEM) techniques. The absorption and electronic spectra confirm the presence of both porphyrin and 4,4 `-bipyridine units in the film. The surface morphology reveals homogeneous film deposition with average roughness values of approx. 8 nm. The theoretical studies performed offered insights into the interplay of different metal centres (Zn2+ and Ni2+) and the keto functionality of the porphyrin unit in the formation of copolymer films. The electrochemical interaction of polymer films with CO2 suggests a reversible trap and release of CO2 with low energy barriers for both the polymers.

Crystal structure analysis of highly efficient chiral resolution of (RS)-arginine-fumaric acid cocrystal under preferential enrichment conditions - Manoj, Kochunnoonny; Takahashi, Hiroki; Iwama, Sekai; Gonnade, G. Rajesh; Tsue, Hirohito; Tamura, Rui (Journal of Molecular Structure, 2021)
Two new hydrate cocrystals, (RS)-arginine-fumaric acid-H2O ( 2 ) and (S)-arginine-2 fumaric acid-H2O ( 3 ), were obtained by the slow evaporation of the saturated aqueous ethanol solution of a 1:1 mixture of S-enriched arginine (33% ee) and fumaric acid or (S)-arginine and fumaric acid, respectively. Cocrystals 2 and 3 possess an isostructural molecular organization containing homochiral 1D chains of arginine sim-ilar to that of the anhydrous cocrystal of (RS)-arginine-fumaric acid ( 1 ). The latter showed an efficient ``preferential enrichment (PE)'', a unique spontaneous enantiomeric resolution phenomenon by simple recrystallization from the highly supersaturated solution. The formation of unstable cocrystals 2 and 3 seems to have played a crucial role in the enrichment of arginine in the mother liquor under PE crystal-lization conditions. (c) 2021 Elsevier B.V. All rights reserved.
Keywords: Arginine; cocrystals; crystal structure; Enantiomeric resolution; preferential enrichment

CsPbBr3/Cs4PbBr6 perovskite@COF nanocomposites for visible-light-driven photocatalytic applications in water - Kour, Prachi; Mukherjee, Shatabdi Porel (Journal of Materials Chemistry A, 2021)
For the first time, we have synthesized all-inorganic CsPbBr3/Cs4PbBr6 perovskite@COF nanocomposites under atmospheric conditions and tuned the crystal structures of the perovskite as well. The nanocomposite is reasonably stable and maintains its crystalline properties even when dipped into water for 60 minutes. The perovskite@COF nanocomposite shows efficient visible-light-driven photocatalytic performance to degrade Methyl orange (10 mL; 20-100 ppm). The rate of photodegradation was about 0.245 min(-1) with high catalytic activity and recyclability for three to six cycles.

Curious case of aqueous warfarin: structural isomers or distinct excited states? - Sakpal, Sushil S.; Ghosh, Deborin; Manae, Meghna A.; Hazra, Anirban; Bagchi, Sayan (Journal of Physical Chemistry B, 2021)
Warfarin is a potent anti-coagulant drug and is on the World Health Organization's List of Essential Medicines. Additionally, it displays fluorescence enhancement upon binding to human serum albumin, making warfarin a prototype fluorescent probe in biology. Despite its biological significance, the current structural assignment of warfarin in aqueous solution is based on indirect evidence in organic solvents. Warfarin is known to exist in different isomeric forms-open-chain, hemiketal, and anionic forms-based on the solvent and pH. Moreover, warfarin displays a dual absorption feature in several solvents, which has been employed to study the ring-chain isomerism between its open-chain and hemiketal isomers. In this study, our pH-dependent experiments on warfarin and structurally constrained warfarin derivatives in aqueous solution demonstrate that the structural assignment of warfarin solely on the basis of its absorption spectrum is erroneous. Using a combination of steady-state and time-resolved spectroscopic experiments, along with quantum chemical calculations, we assign the observed dual absorption to two distinct pi ->pi* transitions in the 4-hydroxycoumarin moiety of warfarin. Furthermore, we unambiguously identify the isomeric form of warfarin that binds to human serum albumin in aqueous buffer.

DART: deep learning enabled topological interaction model for energy prediction of metal clusters and its application in identifying unique low energy isomers - Modee, Rohit; Agarwal, Sheena; Verma, Ashwini; Joshi, Kavita; Priyakumar, U. Deva (Physical Chemistry Chemical Physics, 2021)
Recently, machine learning (ML) has proven to yield fast and accurate predictions of chemical properties to accelerate the discovery of novel molecules and materials. The majority of the work is on organic molecules, and much more work needs to be done for inorganic molecules, especially clusters. In the present work, we introduce a simple topological atomic descriptor called TAD, which encodes chemical environment information of each atom in the cluster. TAD is a simple and interpretable descriptor where each value represents the atom count in three shells. We also introduce the DART deep learning enabled topological interaction model, which uses TAD as a feature vector to predict energies of metal clusters, in our case gallium clusters with sizes ranging from 31 to 70 atoms. The DART model is designed based on the principle that the energy is a function of atomic interactions and allows us to model these complex atomic interactions to predict the energy. We further introduce a new dataset called GNC_31-70, which comprises structures and DFT optimized energies of gallium clusters with sizes ranging from 31 to 70 atoms. We show how DART can be used to accelerate the process of identification of low energy structures without geometry optimization. Albeit using a topological descriptor, DART achieves a mean absolute error (MAE) of 3.59 kcal mol(-1) (0.15 eV) on the test set. We also show that our model can distinguish core and surface atoms in the Ga-70 cluster, which the model has never encountered earlier. Finally, we demonstrate the transferability of the DART model by predicting energies for about 6k unseen configurations picked up from molecular dynamics (MD) data for three cluster sizes (46, 57, and 60) within seconds. The DART model was able to reduce the load on DFT optimizations while identifying unique low energy structures from MD data.

Density functional theory-based study of the magnetic and optical properties of PbMO3 (M = Cr, Fe) using the modified BeckeJohnson mBJ functional (vol 128, pg 275, 2019) - Mahmood, Q.; Hassan, M.; Bhamu, K. C.; Yaseen, M.; Ramay, S. M.; Mahmood, A. (Journal of Physics and Chemistry of Solids, 2021)

Design, synthesis, and structural analysis of cladosporin-based inhibitors of malaria parasites - Babbar, Palak; Das, Pronay; Manickam, Yogavel; Mankad, Yash; Yadav, Swati; Parvez, Suhel; Sharma, Amit; Reddy, Srinivasa (ACS Infectious Diseases, 2021)
Here we have described a systematic structure activity relationship (SAR) of a set of compounds inspired from cladosporin, a tool compound that targets parasite (Plasmodium falciparum) lysyl tRNA synthetase (KRS). Four sets of analogues, synthesized based on point changes in the chemical scaffold of cladosporin and other logical modifications and hybridizations, were assessed using high throughput enzymatic and parasitic assays along with in vitro pharmacokinetics. Co-crystallization of the most potent compound in our series (CL-2) with PfKRS revealed its structural basis of enzymatic binding and potency. Further, we report that CL-2 has performed better than cladosporin in terms of metabolic stability. It thus represents a new lead for further optimization toward the development of antimalarial drugs. Collectively, along with a lead compound, the series offers insights on how even the slightest chemical modification might play an important role in enhancing or decreasing the potency of a chemical scaffold.

Development of aerial and belowground tubers in potato is governed by photoperiod and epigenetic mechanism - Kondhare, Kirtikumar R.; Kumar, Amit; Patil, Nikita S.; Malankar, Nilam N.; Saha, Kishan; Banerjee, Anjan K. (Plant Physiology, 2021)
Plants exhibit diverse developmental plasticity and modulate growth responses under various environmental conditions. Potato (Solanum tuberosum), a modified stem and an important food crop, serves as a substantial portion of the world's subsistence food supply. In the past two decades, crucial molecular signals have been identified that govern the tuberization (potato development) mechanism. Interestingly, microRNA156 overexpression in potato provided the first evidence for induction of profuse aerial stolons and tubers from axillary meristems under short-day (SD) photoperiod. A similar phenotype was noticed for overexpression of epigenetic modifiers-MUTICOPY SUPRESSOR OF IRA1 (StMSI1) or ENAHNCER OF ZESTE 2 (StE[z]2), and knockdown of B-CELL-SPECIFIC MOLONEY MURINE LEUKEMIA VIRUS INTEGRATION SITE 1 (StBMI1). This striking phenotype represents a classic example of modulation of plant architecture and developmental plasticity. Differentiation of a stolon to a tuber or a shoot under in vitro or in vivo conditions symbolizes another example of organ-level plasticity and dual fate acquisition in potato. Stolon-to-tuber transition is governed by SD photoperiod, mobile RNAs/proteins, phytohormones, a plethora of small RNAs and their targets. Recent studies show that polycomb group proteins control microRNA156, phytohormone metabolism/transport/signaling and key tuberization genes through histone modifications to govern tuber development. Our comparative analysis of differentially expressed genes between the overexpression lines of StMSI1, StBEL5 (BEL1-LIKE transcription factor [TF]), and POTATO HOMEOBOX 15 TF revealed more than 1,000 common genes, indicative of a mutual gene regulatory network potentially involved in the formation of aerial and belowground tubers. In this review, in addition to key tuberization factors, we highlight the role of photoperiod and epigenetic mechanism that regulates the development of aerial and belowground tubers in potato.

Diverse reactivity of NOBF4 towards silylene, disilene, germylene and stannylene - Parvin, Nasrina; Sen, Nilanjana; Muhasina, Puthan Veetil; Tothadi, Srinu; Parameswaran, Pattiyil; Khan, Shabana (Chemical Communications, 2021)
{The reactivity of NOBF4 towards silylene, disilene, germylene, stannylenes has been described. Smooth syntheses of compounds of composition [PhC(NtBu)(2)E(= O -> BF3)N(SiMe3)(2)

Durable metalloporphyrin 2D-polymer for photocatalytic hydrogen and oxygen evolution from river and sea waters - Ranjeesh, Kayaramkodath Chandran; George, Leena; Maibam, Ashakiran; Krishnamurty, Sailaja; Babu, Sukumaran Santhosh (ChemCatChem, 2021)
It is highly imaginary that the outcome of a combination of two complementary resources leads to answer an alarming global issue. One such possible example is the solar seawater splitting for `clean fuel' H-2 generation. Since the catalytic activity and stability of the photocatalysts are substantially challenged in seawater, the design of an efficient and stable photocatalyst is highly desirable. Herein, we demonstrate the solar seawater splitting by a two-dimensional polymer catalyst derived from metalloporphyrin bearing multi-hydroxyl groups. A bimetallic (Co and Ni) porphyrin 2D-polymer exhibits excellent long-term durability of 15 cycles of H-2 and O-2 generation in 200 days from pure water without a considerable decrease in efficiency. Detailed studies using river and seawaters also show the reliable performance of the catalyst over repeated cycles. Here the deactivation modes of catalytic activity have been nullified by the layered metalloporphyrin polymer structure through stable pi-pi stacking, signifying the molecular design of 2D-polymer photocatalyst.
Keywords: 2D-polymer; Photocatalyst; porphyrin; Self-assembly; water splitting

Effect of CaCl2 and ZnCl2 salts on isobaric vapor-liquid equilibrium in separation of the azeotropic mixture of ethanol plus water - Ghuge, Pravin D.; Mali, Nilesh A.; Joshi, Sunil S. (Fluid Phase Equilibria, 2021)
Present work analyzes potential of calcium chloride (CaCl2) and zinc chloride (ZaCl(2)) salts as entrainer for breaking the minimum boiling azeotrope of ethanol and water. Isobaric vapor-liquid equilibrium (VLE) data for the binary systems of water + ethanol and ternary system of water + ethanol + calcium chloride, and water + ethanol + zinc chloride were measured at a constant pressure of 94.5 kPa. The effect of salts on the relative volatility of ethanol to water as well as on the vapor phase mole fractions of ethanol were also studied experimentally. From the experimental results, it is observed that with addition of salts, the azeotropic point of the ethanol and water system can be eliminated. Salting out effects in case of calcium chloride was more than that zinc chloride salt. The results obtained in this work showed that calcium chloride could be a better choice for separation of the water + ethanol azeotrope. Electrolyte nonrandom two-liquid (eNRTL) model was used to correlate the experimental VLE data. The model prediction with the regressed parameters was found in well agreement with the experimental data. The experimental data obtained in this work was found thermodynamically consistent using van Ness test. (C) 2021 Elsevier B.V. All rights reserved.
Keywords: Azeotrope; eNRTL; Ethanol; salts; Vapor-liquid equilibrium; Water

Effect of object shape on the flow past microstructures in small channel - Mule, Gunwant M.; Kulkarni, Amol A. (Fluid Dynamics Research, 2021)
Flow past objects in microfluidics and microscale devices are used to perturb the flow and thereby achieve effective mixing and heat transfer. This paper presents the observations on the flow past bluff (elliptical, rectangular and triangular) cylindrical micropillars (objects) having different cross-sectional area in a micro-channel through 2D simulations. The pertinent range of Re based on object dimension (0.1 Re 150) was chosen to understand the wake dynamics that would remain relevant for comparison with literature data. Drag coefficient, recirculation region, critical Reynolds number for flow oscillations and vortex strength in a channel were studied. The drag coefficient was found to increase with aspect ratio of the object. The critical Re for flow oscillations was found to increase with the cross-sectional area of the object. The vortex strength in a channel was seen highest for triangular cylinder compared to elliptical and rectangular cylinder.
Keywords: 2D simulations; flow past objects; micro and mini-channels; micropillars; wake dynamics

Eichhornia crassipes mediated bioinspired synthesis of crystalline nano silver as an integrated medicinal material: a waste to value approach - Moudgil, Aliesha; Deval, Animesh S.; Dharne, Mahesh S.; Sarkar, Dhiman M.; Choudhari, Amit S.; Chaudhari, Bhushan P. (Journal of Cluster Science, 2021)
The present study deals with the synthesis of silver nanoparticles from Eichhornia crassipes. Dynamic light scattering (DLS), Transmission electron microscopy (TEM), UV-Vis spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy and X-ray diffraction (XRD) were performed for nanoparticle characterization. The aqueous plant extract of Eichhornia crassipes was phytochemically analyzed for phenol, flavonoid, reducing sugar content, alkaloids, saponins and carotenoids. The synthesized particles after optimization of important parameters have an average diameter of 12.48 +/- 3.43 nm with a spherical morphology and zeta potential of - 31.53 mV. At 100 mu g/ml of nanoparticle concentration, the antioxidant activity of 93.6% was observed. MIC (Minimum inhibitory concentration) values exhibiting the antimicrobial attributes reported an estimated value of 7.8 mu g/ml for gram-negative and higher values of 31.25 and 250 mu g/ml for gram-positive bacteria. The antibiofilm assay showed 86.89% and 74.7% of the reduction in violacein synthesis and biofilm inhibition respectively at 15 mu g/ml nanoparticle concentration. The anticancer assay reported the IC50 (Inhibitory concentration) values of 13.32, 14.71 and 19.91 mu g/ml for HeLa, HCT 116 and L6 cell lines respectively. Thus the study establishes a significant integrative treatment to combat secondary infections in cancer patients. Graphic
Keywords: antibacterial activity; Antibiofilm activity; Anticancer activity; Antioxidant activity; Eichhornia crassipes; silver nanoparticles

Electrocatalytic nitrogen reduction directed through the p-band center of boron on BSAC@Mo2C - Maibam, Ashakiran; Krishnamurty, Sailaja; Dar, Manzoor Ahmad (Materials Advances, 2021)
Greener modes of ammonia synthesis via the electrocatalytic route have been investigated on pristine and defective Mo2C based monolayers anchored with metal-free boron atom catalysts. Boron single atom catalysts (SACs) on the defective Mo2C monolayer has been found to activate N2 strongly with an adsorption energy of −1.92 eV and reduce it to NH3 efficiently with a significantly low overpotential of 0.41 eV. The exothermic adsorption of N2 and low overpotential for the nitrogen reduction reduction (NRR) appertain to the p-band center of the boron atom catalyst and charge transfer between the adsorbed N2 and the catalyst, respectively. This work brings forth the correlation between electron occupancy on the boron center and NRR catalytic efficiency on a metal-free SACs@Mo2C monolayer couple, thereby serving as a lead in designing metal free electrocatalysts for the NRR.

Electronic and optical properties of vacancy ordered double perovskites A(2)BX(6) (A=Rb, Cs; B=Sn, Pd, Pt; and X=Cl, Br, I): a first principles study - Faizan, Muhammad; Bhamu, K. C.; Murtaza, Ghulam; He, Xin; Kulhari, Neeraj; AL-Anazy, Murefah Mana; Khan, Shah Haidar (Scientific Reports, 2021)
The highly successful PBE functional and the modified Becke-Johnson exchange potential were used to calculate the structural, electronic, and optical properties of the vacancy-ordered double perovskites A(2)BX(6) (A=Rb, Cs; B=Sn, Pd, Pt; X=Cl, Br, and I) using the density functional theory, a first principles approach. The convex hull approach was used to check the thermodynamic stability of the compounds. The calculated parameters (lattice constants, band gap, and bond lengths) are in tune with the available experimental and theoretical results. The compounds, Rb2PdBr6 and Cs2PtI6, exhibit band gaps within the optimal range of 0.9-1.6 eV, required for the single-junction photovoltaic applications. The photovoltaic efficiency of the studied materials was assessed using the spectroscopic-limited-maximum-efficiency (SLME) metric as well as the optical properties. The ideal band gap, high dielectric constants, and optimum light absorption of these perovskites make them suitable for high performance single and multi-junction perovskite solar cells.

Electronically integrated mesoporous Ag-TiO2 nanocomposite thin films for efficient solar hydrogen production in direct sunlight - Mani, Sunesh S.; Rajendran, Sivaraj; Nalajala, Naresh; Mathew, Thomas; Gopinath, Chinnakonda S. (Energy Technology, 2021)
The synthesis of mesoporous TiO2 by a solution-based assembly process and Ag/TiO2 nanocomposites is provided. The efficacy of Ag/TiO2 nanocomposite as photocatalyst in thin-film form is demonstrated for solar hydrogen generation in sunlight. Integration of Ag with TiO2 dramatically enhanced the H-2 production: with 1 wt% Ag on TiO2 (TiAg-1), the H-2 yield was observed to be 4.59 mmol h(-1) g(-1), which is 2.3 (30) times larger than 0.5 wt% Ag on TiO2. TiAg-1 shows 4.3 times higher activity in film form compared with its powder counterpart. High photocatalytic efficiency is attributed to the surface plasmon resonance effect of Ag, electronic integration of Ag with TiO2, and subsequent valence band broadening, large distribution of Ag nanoparticles and abundant Ag-TiO2 Schottky junctions, and the later minimizes electron-hole recombination. Interparticle mesoporous network increases necking and the high surface area offers easy accessibility of the reactants to a large number of active sites.
Keywords: heterogeneous catalysis; heterojunctions; plasmon effect; Silver; solar energy conversion; Solar hydrogen

Energy and life cycle impact assessment for xylitol production from corncob - Dasgupta, Diptarka; Sidana, Arushdeep; Ghosh, Prasenjit; Sharma, Tripti; Singh, Jasvinder; Prabhune, Asmita; More, Snehal; Bhaskar, Thallada; Ghosh, Debashish (Journal of Cleaner Production, 2021)
The conversion of biobased feedstocks into energy and value-added chemicals is one main approach to address the current global challenge for waste mitigation through the biorefinery mode. Corncob biomass which is one of the most abundant agricultural residue in India with a high hemicellulose content, can serve as a potential low-cost raw material for food-grade xylitol production. The present study demonstrates a process for xylitol production from corncob biomass with detailed energy and life cycle analysis for viability assessment. The major highlight of the process is the use of microbial fermentation, where biomass-derived D-xylose is converted to xylitol with high selectivity. Overall, 0.502 kg of xylitol crystals could be produced from 3.5 kg of corncob biomass. Simulation analysis revealed that the evaporators are the primary consumers of energy, and the process of heat integration can significantly reduce the energy requirements of the overall process. Environmental impacts of the system evaluated showed emission results of 8.68 kg CO2 equivalent and revealed that marine aquatic and freshwater eco-toxicity are the only possible contributors to the environment. The results suggest that the process would have favourable energy balances, which can be used in pilot plant and heat exchanger network design and operation for xylitol production scale up to 500 L. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords: biomass valorization; Life cycle impact assessment; simulation; xylitol

Enhanced electrocatalytic activity of PtRu/nitrogen and sulphur co-doped crumbled graphene in acid and alkaline media - Pang, Liuqing; Miao, Yuanyuan; Bhange, Siddheshwar N.; Barras, Alexandre; Addad, Ahmed; Roussel, Pascal; Amin, Mohammed A.; Kurungot, Sreekumar; Szunerits, Sabine; Boukherroub, Rabah (Journal of Colloid and Interface Science, 2021)
The low mass activity and high price of pure platinum (Pt)-based catalysts predominantly limit their large-scale utilization in electrocatalysis. Therefore, the reduction of Pt amount while preserving the electrocatalytic efficiency represents a viable alternative. In this work, we prepared new PtRu2 nanoparticles supported on sulphur and nitrogen co-doped crumbled graphene with trace amounts of iron (PtRu2/PF) electrocatalysts. The PtRu2/PF catalysts exhibited enhanced electrocatalytic performance and stability for the hydrogen evolution reaction (HER) at pH = 0. Moreover, the prepared PtRu2/PF electrocatalyst displayed higher HER activity than commercial 20% Pt/C. The PtRu2/PF catalyst achieved a current density of 10 mA cm(-2) at an overpotential value of only 22 mV for HER, performing better activity than many other Pt-based electrocatalysts. Besides, the PtRu2/PF revealed a good performance for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in alkaline media. The PtRu2/PF catalyst recorded a current density of 10 mA cm(-2) at an overpotential of only 270 mV for OER in KOH (1.0 M) solution and an onset potential of 0.96 V vs. RHE (at 1 mA cm(-2)) for ORR in KOH (0.1 M) solution. (C) 2021 Elsevier Inc. All rights reserved.
Keywords: HER; OER; ORR; PtRu2; Sulphur and nitrogen co-doped crumbled graphene

Enhanced one-pot selective conversion of cellulose to ethylene glycol over NaZSM-5 supported metal catalysts - Sreekantan, Sreejith; Kirali, Arun Arunima; Marimuthu, Banu (New Journal of Chemistry, 2021)
The mesopores interconnected with microporous NaZSM-5 was synthesised by sol-gel method. Reactions involving cellulose using different bimetallic and trimetallic combinations of nickel, aluminium, and tungsten metals supported on NaZSM-5 have been carried out. Different weight percentages (wt%) of Al, Ni, and W were loaded onto the NaZSM-5 support via a wet impregnation method. The prepared catalysts were characterized using PXRD, FE-SEM, HR-TEM, BET, and XPS studies to investigate the presence of mesopores, the textural properties, the metal loading, and the active oxidation states. The catalytic activities of the xAl-yNi-zW/NaZSM-5 (where x, y, and z are the wt% values of Al, Ni, and W, respectively) supported catalysts were studied during the one-pot conversion of cellulose into ethylene glycol at 220 degrees C and with a pressure of 70 bar H-2 (at the reaction temperature) in water (as a solvent). The 5%Al-8%Ni-25%W/NaZSM-5 catalyst exhibited the highest cellulose conversion of 100%, with an ethylene glycol yield as high as 89% (C mol%) under moderate reaction conditions being reported for the first time. Al3+ in the catalyst hydrolyzed cellulose, and W5+ species acted as acid centres that facilitated the retro-aldol condensation reaction and eventually led to an increased EG yield in the presence of Ni. The catalyst was moderately stable after four consecutive runs for 6 h at 220 degrees C and at a H-2 reaction pressure of 70 bar, though a 12 h reaction resulted in the highest EG yield. The high yields under moderate reaction conditions promise an energy-efficient and economically feasible process.

Enhanced photocatalytic properties of a chemically modified blue phosphorene - Maibam, Ashakiran; Das, Sawan Kumar; Samal, Pragnya Paramita; Krishnamurty, Sailaja (RSC Advances, 2021)
It is high time to placate the peak demand for an efficient, economic and green fuel in the form of H-2 through photocatalytic water splitting. Several low dimensional materials have been explored for their photocatalytic properties on account of their surface to volume ratio. The present study illustrates the excellent photocatalytic potential of a two-dimensional material, viz. a chemically tempered blue-phosphorene sheet, with single atom thickness and high carrier mobility. Metal-free element, sulphur, is explored as a dopant in a 32-atom blue-phosphorene sheet. The dopant is inserted at three locations viz. central, edge and central edge positions with varying concentrations from 3.125% to 18.75% (corresponding to n = 1 to 6 sulphur atoms within a 32-atom blue-phosphorene sheet, P32-nSn). The cohesive energy studies predict the higher stability of even number S doped sheets as compared to their odd counterparts. Photocatalytic activity is studied in terms of band gap and band alignment for different concentrations of the former. Studies reveal that edge doping demonstrates better water molecule activation independent of S atom concentration. The edge doped systems not only provide the chemical activity to activate water, but also show feasible HER overpotentials of 1.24-1.29 eV at neutral medium. Finally, this work opens up a driving lead of non-corrosive catalysts for water molecule splitting.

Enhanced solubility, permeability, and tabletability of nicorandil by salt and cocrystal formation - Mannava, M. K. Chaitanya; Gunnam, Anilkumar; Lodagekar, Anurag; Shastri, Nalini R.; Nangia, Ashwini K.; Solomon, K. Anand (Crystengcomm, 2021)
Cocrystallization is a rational selection crystal engineering approach for the development of novel solid forms with enhanced physicochemical and mechanical properties. Nicorandil (NCR) is a niacinamide vitamin derivative used to treat angina pectoris. A binary solid form screen of NCR with homologous dicarboxylic acids afforded NCR-oxalic acid (NCR-OA, 1:1), NCR-fumaric acid (NCR-FA, 1:1), NCR-succinic acid (NCR-SA, 1:1), and NCR-suberic acid (NCR-SBA, 1:0.5). The binary solids were characterized by powder X-ray diffraction, IR and NMR spectroscopy, and DSC. NCR-FA and NCR-SBA were crystallized by slow evaporation from chloroform and toluene solvents, respectively. Single crystal X-ray diffraction confirmed that NCR-FA is a molecular salt, while NCR-SBA is a neutral cocrystal. NCR and the FA anion are connected via the robust carbovlate-pyridinium synthon, whereas in the NCR-SBA cocrystal, the components associate via the carboxylic acid- -pyridine synthon. The phase stability, solubility, dissolution rate, diffusion rate and tabletability studies have demonstrated that the binary solids exhibit improved physical and mechanical properties compared to the NCR drug. Specifically, the NCR-FA salt and NCR-SBA cocrystal have higher solubility, dissolution rate, and hardness at lower pressures, making the formulation suitable for tablet compression.

Entacapone polymorphs: crystal structures, dissolution, permeability, and stability - Bommaka, Manish Kumar; Mannava, M. K. Chaitanya; Rai, Sunil K.; Suresh, Kuthuru; Nangia, Ashwini K. (Crystal Growth & Design, 2021)
Entacapone (ETP) is a catechol-O-methyltransferase (COMT) drug used to treat Parkinson's disease. ETP is available in the marketplace under the brand name Comtan since 2010, and ETP form-I was first reported in a patent published in 2001. However, analysis of its Xray crystal structures and stability relationship of ETP polymorphs and their dissolution and permeability profile have not yet been reported. We crystallized two new conformational polymorphs of ETP from a water and acetone mixture and studied the structural origin of polymorphism and their phase transformations, stability, equilibrium solubility, dissolution, and permeability properties. The ETP molecule adopts different conformations in the polymorphic structures with slight changes in carbonyl and nitrile group orientations. Thermal analysis suggests that form-III and form-IV are enantiotropically related to form-I, which is the thermodynamically stable form at ambient conditions. In contrast, form-II is monotropically related to form-I. Equilibrium solubility, dissolution, and permeability studies show that form-II persists in the slurry medium and dissolves faster with a high flux rate compared to the stable form-I in phosphate buffer solution at 37 +/- 0.5 degrees C.

Exploring edge functionalised blue phosphorene nanoribbons as novel photocatalysts for water splitting - Maibam, Ashakiran; Chakraborty, Debalina; Joshi, Krati; Krishnamurty, Sailaja (New Journal of Chemistry, 2021)
Hydrogen gas, a highly combustible and eco-friendly fuel is stealing the limelight and its production is one of the major areas of research. An efficient and green method for producing clean hydrogen gas with no harmful by-product is water splitting. With the introduction of low dimensional materials, water splitting has become an easier and cost-effective process. The present work demonstrates the application of one such low dimensional material viz., edge functionalised Blue Phosphorene Nano-Ribbons (BPNRs) as potential photocatalysts. With a carrier mobility of 10(3) cm(2) V-1 s(-1) and a band gap of 1.5-3.0 eV, BPNRs are an attractive candidate for photocatalysis. BPNRs with different edge oreintations, viz. zigzag and armchair are functionalised with CH3O, COOCH3, CHO, COOH, OH, NH2, CONH2, SH, C6H5, and NO2 groups. Their performance towards activating water molecules at different sites on the nanoribbon is studied. The functionalised edges of the BPNRs are the active sites showing similar to 1.2% to 3.2% efficiency in activating the O-H bond of the water molecule. Among the different groups explored, CONH2 functionalised zigzag BPNR clearly exhibits a higher potential towards the adsorption of water molecules (-0.98 eV) and activation of O-H bonds with an elongation of 3.2% and a red shift of 500.6 cm(-1). This is attributed to the lone pair of electrons on the nitrogen atom contributing to the electron donating nature of the CONH2 functional group.

Expression, purification and crystallization of Asrij, A novel scaffold transmembrane protein - Motiwala, Zenia; Darne, Priti; Prabhune, Asmita; Inamdar, Maneesha S.; Kulkarni, Kiran (Journal of Membrane Biology, 2021)
Asrij/OCIAD1 is a scaffold transmembrane protein belonging to the Ovarian Carcinoma Immunoreactive Antigen Domain containing protein family. In Drosophila and mouse models, Asrij localizes at the endosomal and mitochondrial membrane and is shown to regulate the stemness of hematopoietic stem cells. Interaction of Asrij with ADP Ribosylation Factor 1 (Arf1) is shown to be crucial for hematopoietic niche function and prohemocyte maintenance. Here, we report the heterologous expression, standardization of detergents and purification methodologies for crystallization of Asrij/OCIAD1. To probe the activity of bacterially expressed Asrij, we developed a protein complementation assay and conclusively show that Asrij and Arf1 physically interact. Further, we find that sophorolipids improve the solubility and monodispersibility of Asrij. Hence, we propose that sophorolipids could be novel additives for stabilization of membrane proteins. To our knowledge, this is the first study detailing methodology for the production and crystallization of a heterologously expressed scaffold membrane protein and will be widely applicable to understand membrane protein structure and function. Graphic
Keywords: Asrij/OCIAD1; Membrane protein crystallography; sophorolipids

Facile access to functional polyacrylates with dual stimuli response and tunable surface hydrophobicity - Mohammad, Sk Arif; Dolui, Subrata; Kumar, Devendra; Mane, Shivshankar R.; Banerjee, Sanjib (Polymer Chemistry, 2021)
Magnetically separable and reusable Ni-Co alloy nanoparticles were employed to achieve ambient temperature reversible deactivation radical polymerization (RDRP) of methyl acrylate (MA), for the first time, yielding well-defined PMA (at least up to 124 500 g mol(-1)) with a low dispersity (D <= 1.20). The controlled polymerization character of RDRP of MA was confirmed from the linear semilogarithmic plot exhibiting pseudo first order kinetics, a linear increase of the molecular weight of the polymer with monomer conversion maintaining low D and the synthesis of PMAs of varying molecular weights from 2200 to 124 500 g mol(-1) with low D. In addition, linear PMA-Br was used as a macroinitiator for the synthesis of several well-defined PMA-b-poly(M) block copolymers (where ``M'' stands for (2-dimethylamino)ethyl methacrylate (DMAEMA), tert-butyl methylacrylate (TBMA) and 2,2,3,3,4,4,5,5-octafluoropentyl acrylate (OFPA)), with acceptable Ds (<= 1.24), demonstrating the high chain-end fidelity of the macroinitiator. The synthesized PMA-b-PDMAEMA demonstrated dual pH- and thermo-responsive properties. Upon hydrolysis, the synthesized PMA-b-PTBMA leads to the formation of unprecedented carboxylic acid-functionalized PMA derivatives. PMA-b-POFPA copolymers with varying OFPA mol% in the copolymer led to polymers with tunable surface hydrophobicity, as revealed by the water contact angle measurements.

Facile synthesis of CNT interconnected PVP-ZIF-8 derived hierarchically porous Zn/N co-doped carbon frameworks for oxygen reduction dagger - Singla, Gourav; Bhange, Siddheshwar N.; Mahajan, Mani; Kurungot, Sreekumar (Nanoscale, 2021)
In this work, a strategy has been adopted to construct an architecture through the coordination of polyvinylpyrrolidone (PVP) and a monodisperse zeolitic imidazolate framework (ZIF-8), which was entwined by carbon nanotubes (CNTs) firstly, followed by a pyrolysis process to obtain the hybrid catalyst. The meticulous design of the hybrid material using CNTs to interconnect the PVP assisted ZIF-8 derived porous carbon frameworks together produces a hierarchical pore structure and dual-heteroatom (Zn/N) doping (Zn-N/PC@CNT). Without further acid treatment, the hybrid material prepared after pyrolysis at 900 degrees C (PVP-ZIF-8@CNT-900) has been demonstrated as an efficient non-precious metal catalyst for the oxygen reduction reaction (ORR) with its superior stability compared to the commercial 20 wt% Pt/C catalyst in alkaline media. The catalyst shows better performance towards the ORR, with its more positive onset and half-wave potentials (E-onset = 0.960 V vs. RHE and E-1/2 = 0.795 V vs. RHE) than the counterpart system which is free of both CNT and PVP. The high performance of the hybrid catalyst can be ascribed to the co-existence of dual-active sites with hierarchical pore structures originating from the synergistic effects between Zn/N co-doped porous carbon and CNTs. We further demonstrated the single-cell performance by using the homemade system as the cathode catalyst for the Alkaline Exchange Membrane Fuel Cell (AEMFC) system, which showed a maximum power density of 45 mW cm(-2) compared to 60 mW cm(-2) obtained from the 40 wt% Pt/C catalyst.

Facile transfer of excited electrons in Au/SnS2 nanosheets for efficient solar-driven selective organic transformations - Mondal, Sanjit; Sahoo, Lipipuspa; Vinod, C. P.; Gautam, Ujjal K. (Applied Catalysis B-Environmental, 2021)
Solar driven aerial oxidation processes have gained importance in organic transformations leading to the development of many nanocrystalline photocatalysts. Although such nanomaterials have many potential advantages, they often underperform due to poor visible light absorption and rapid recombination of excitons. Incorporation of plasmonic nanoparticles (NPs) on the catalyst surfaces can extend their response to visible light and improve photocatalytic efficiency by the `hot-electron' injection mechanism. Nanostructures of SnS2 too absorb a part of the visible light to induce many photocatalytic reactions, though their ability to perform the selective and controlled organic transformations has not yet been observed. Herein, we demonstrate the first example of such transformation with the oxidative coupling of various benzylamine (BA) derivatives to imines under ambient conditions using SnS2 nanosheets (NSs). The reaction rate improves manifold and shows similar to 98 % conversion (>99 % selectivity) in 2 h under direct sunlight and open-air when the NSs were decorated with 1.5 wt% Au NPs on (Au/SnS2), making it one of the best catalysts for this reaction. We found that the large enhancement in activity upon Au loading is accompanied by a noticeable change in photo-induced charge accumulation behaviour in Au/SnS2 from the usual ``spike and overshoot'' one and contributed by facile transfer of excited electrons across the Au-SnS2 heterojunction in which Au NPs act as both sources and sinks for the photo-excited electrons. Finally, a detailed mechanism of the oxidation reaction has been proposed.
Keywords: Benzylamine oxidation; Hot-electron injection; Plasmonic nanoparticle; SnS2 nanosheet; Solar energy harvesting

Finite temperature behavior of carbon atom-doped silicon clusters: depressed thermal stabilities, coexisting isomers, reversible dynamical pathways and fragmentation channels - Joshi, Krati; Maibam, Ashakiran; Krishnamurty, Sailaja (New Journal of Chemistry, 2021)
Silicon carbide clusters are significant due to their predominant occurrence in meteoric star dust, particularly in carbon-rich asymptotic giant branch stars. Of late, they have also been recognized as nanoclusters with potential applications in technology. Them both being elements of the same group, there is excellent potential for precise control over the physico-chemical properties of such molecular length-scale materials through atomic engineering and this has been explored recently by various experimentalists. This report simulates one of the significant physical properties, viz. conformational stability, of various carbon-doped silicon clusters as a function of temperature using Born-Oppenheimer molecular dynamics methodology. Single carbon atom-doped silicon clusters with 4-9 atoms (i.e., Si3C-Si8C) are chosen for this study as the gas phase geometries of these clusters have been characterized using a combination of experimental and theoretical methods in the recent past. The simulations ratify that various conformations do not interconvert among themselves at 300 K. The interconversion occurs at 500 K or above, thereby ratifying the possibility of the coexistence of multiple conformations of a given cluster, which are generally synthesized under subroom temperature conditions. Furthermore, the above single carbon atom-doped silicon clusters: (a) have depressed thermal stabilities as compared to their pristine counterparts with the exception of a Si5C conformation; (b) undergo multifarious evolution of the cluster, through the reversible dynamical and fragmentation pathways as a function of temperature and (c) single carbon atom-doped silicon clusters with 7 atoms (starting from Si6C) and above undergo a fragmentation at nearly 2000 K. The underlying electronic and structural properties of various clusters are discussed to explain the above observations with a note on critical fragmentation energy barriers required for the segmentation of clusters with seven or more atoms.

FnCas9-based CRISPR diagnostic for rapid and accurate detection of major SARS-CoV-2 variants on a paper strip - Kumar, Manoj; Gulati, Sneha; Ansari, Asgar H.; Phutela, Rhythm; Acharya, Sundaram; Azhar, Mohd; Murthy, Jayaram; Kathpalia, Poorti; Kanakan, Akshay; Maurya, Ranjeet; Vasudevan, Janani Srinivasa; Aparna, S.; et al. (eLife, 2021)
The COVID-19 pandemic originating in the Wuhan province of China in late 2019 has impacted global health, causing increased mortality among elderly patients and individuals with comorbid conditions. During the passage of the virus through affected populations, it has undergone mutations, some of which have recently been linked with increased viral load and prognostic complexities. Several of these variants are point mutations that are difficult to diagnose using the gold standard quantitative real-time PCR (qRT-PCR) method and necessitates widespread sequencing which is expensive, has long turn-around times, and requires high viral load for calling mutations accurately. Here, we repurpose the high specificity of Francisella novicida Cas9 (FnCas9) to identify mismatches in the target for developing a lateral flow assay that can be successfully adapted for the simultaneous detection of SARS-CoV-2 infection as well as for detecting point mutations in the sequence of the virus obtained from patient samples. We report the detection of the S gene mutation N501Y (present across multiple variant lineages of SARS-CoV-2) within an hour using lateral flow paper strip chemistry. The results were corroborated using deep sequencing on multiple wild-type (n = 37) and mutant (n = 22) virus infected patient samples with a sensitivity of 87% and specificity of 97%. The design principle can be rapidly adapted for other mutations (as shown also for E484K and T716I) highlighting the advantages of quick optimization and roll-out of CRISPR diagnostics (CRISPRDx) for disease surveillance even beyond COVID-19. This study was funded by Council for Scientific and Industrial Research, India.

Gibberellic acid induces unique molecular responses in ‘thompson seedless’ grapes as revealed by non-targeted metabolomics - Jadhav, Uma; Mundhe, Swapnil; Kumar, Yashwant; Jogaiah, Satisha; Upadhyay, Anuradha; Gupta, Vidya S.; Kadoo, Narendra Y. (Journal of Plant Growth Regulation, 2021)
Compact clusters and small berry size are the major problems associated with the commercialization of table grapes. The application of gibberellic acid 3 (GA3) has been a long-followed practice to overcome these issues. To analyze the molecular response of ‘Thompson Seedless’ grapes to GA3 treatment, we investigated the metabolomes of its rachises, clusters, and berries, 6 h and 24 h after the treatment. Metabolite profiling using non-targeted metabolomics approach revealed several metabolites, including arginine, proline, tyrosine, kaempferol, resveratrol, catechin, and so on as possible biomarkers of GA3 treatment in grapes. GA3 treatment greatly impacted the alanine, aspartate, and glutamate metabolism pathways, and the GA3-mediated alterations in the levels of certain plant growth regulators and primary metabolites were in accordance with important growth and developmental processes in grapes. This study highlights the effect of GA3 on the profiles of certain polyphenols impacting the flavone and flavonol biosynthesis pathways and hence the nutritional aspect of grapes. The results of this study would be useful to develop self-elongating varieties simplifying the grape cultivation.

Gibberellic acid induces unique molecular responses in `thompson seedless' grapes as revealed by non-targeted metabolomics - Jadhav, Uma; Mundhe, Swapnil; Kumar, Yashwant; Jogaiah, Satisha; Upadhyay, Anuradha; Gupta, Vidya S.; Kadoo, Narendra Y. (Journal of Plant Growth Regulation, 2021)
Compact clusters and small berry size are the major problems associated with the commercialization of table grapes. The application of gibberellic acid 3 (GA(3)) has been a long-followed practice to overcome these issues. To analyze the molecular response of `Thompson Seedless' grapes to GA(3) treatment, we investigated the metabolomes of its rachises, clusters, and berries, 6 h and 24 h after the treatment. Metabolite profiling using non-targeted metabolomics approach revealed several metabolites, including arginine, proline, tyrosine, kaempferol, resveratrol, catechin, and so on as possible biomarkers of GA(3) treatment in grapes. GA(3) treatment greatly impacted the alanine, aspartate, and glutamate metabolism pathways, and the GA(3)-mediated alterations in the levels of certain plant growth regulators and primary metabolites were in accordance with important growth and developmental processes in grapes. This study highlights the effect of GA(3) on the profiles of certain polyphenols impacting the flavone and flavonol biosynthesis pathways and hence the nutritional aspect of grapes. The results of this study would be useful to develop self-elongating varieties simplifying the grape cultivation.
Keywords: Biosynthetic pathways; GA(3) response; GA(3) signaling; Sultana grapes; Untargeted metabolomics

Herbicidal bio-assay of isocladosporin enantiomers and determination of its plausible absolute configuration - Mankad, Yash; Das, Pronay; Pathan, Ejaj; Deshpande, V. M.; Reddy, D. Srinivasa (Journal of Antibiotics, 2021)
A fungal metabolite, isocladosporin was isolated from natural fungus, Cladosporium cladosporioides in the mid of 90s. Due to the lack of optical rotation of isolated natural product sample, the absolute configuration of the natural product remained undetermined for more than two decades. Herein, we demonstrated an SAR study of enantiomers of isocladosporin in herbicidal bio-assay against wheat coleoptile. Using this study as a comparative tool we further proposed the plausible absolute configuration of natural isocladosporin for the first time. The assigned configuration was also supported through biogenetic precursors.

Heterogeneous C-H functionalization in water via porous covalent organic framework nanofilms: a case of catalytic sphere transmutation - Sasmal, Himadri Sekhar; Bag, Saikat; Chandra, Bittu; Majumder, Poulami; Kuiry, Himangshu; Karak, Suvendu; Sen Gupta, Sayam; Banerjee, Rahul (Journal of the American Chemical Society, 2021)
Heterogeneous catalysis in water has not been explored beyond certain advantages such as recyclability and recovery of the catalysts from the reaction medium. Moreover, poor yield, extremely low selectivity, and active catalytic site deactivation further underrate the heterogeneous catalysis in water. Considering these facts, we have designed and synthesized solution-dispersible porous covalent organic framework (COF) nanospheres. We have used their distinctive morphology and dispersibility to functionalize unactivated C-H bonds of alkanes heterogeneously with high catalytic yield (42-99%) and enhanced regioand stereoselectivity (3 degrees:2 degrees = 105:1 for adamantane). Further, the fabrication of catalyst-immobilized COF nanofilms via covalent self-assembly of catalytic COF nanospheres for the first time has become the key toward converting the catalytically inactive homogeneous catalysts into active and effective heterogeneous catalysts operating in water. This unique covalent self-assembly occurs through the protrusion of the fibers at the interface of two nanospheres, transmuting the catalytic spheres into films without any leaching of catalyst molecules. The catalyst-immobilized porous COF nanofilms' chemical functionality and hydrophobic environment stabilize the high-valent transient active oxoiron(V) intermediate in water and restricts the active catalytic site's deactivation. These COF nanofilms functionalize the unactivated C-H bonds in water with a high catalytic yield (45-99%) and with a high degree of selectivity (cis:trans = 155:1; 3 degrees:2 degrees = 257:1, for cis-1,2-dimethylcyclohexane). To establish this approach's ``practical implementation'', we conducted the catalysis inflow (TON = 424 +/- 5) using catalyst-immobilized COF nanofilms fabricated on a macroporous polymeric support.

Highly efficient and extremely simple protocol for the oxidation α-hydroxyphosphonates to α-ketophosphonates using Dess-Martin periodinane - Kupwade, Ravindra; Mitragotri, Satish D.; Kulkarni, Makarand A.; Desai, Uday V.; Wadagaonkar, Prakash P. (ARKIVOC, 2021)

Hydrogenolysis of benzofuran using aqueous ethanol solution over graphite-supported platinum catalyst - Hiraishi, Yushi; Minakawa, Naohiro; Taniguchi, Kenkichi; Nagasawa, Yoshiyuki; Nanao, Hidetaka; Rode, V, Chandrashekhar; Sato, Osamu; Yamaguchi, Aritomo; Shirai, Masayuki (Journal of the Indian Chemical Society, 2021)
Graphite-supported platinum catalysts (Pt/G) were highly active for the hydrogenolysis of benzofuran to o-ethylphenol in aqueous ethanol solution at 523 K without using any external hydrogen gas. The hydrogenolysis activities and selectivity to o-ethylphenol in ethanol solution over Pt/G were higher than those with a conventional method using externally supplied hydrogen gas. Both water and ethanol were indispensable for the hydrogenolysis in aqueous ethanol solution at 523 K.
Keywords: Biomass conversion; Graphite support; Hydrogenolysis; platinum catalysts

Hydrophilic 3D interconnected network of bacterial nanocellulose/black titania photothermal foams as an efficient interfacial solar evaporator - Nabeela, Kallayi; Thorat, Meghana; Sumina, N. B.; Ramachandran, Animesh M.; Thomas, Reny Thankam; Preethikumar, Gopika; Mohamed, A. Peer; Asok, Adersh; Dastager, Syed Gulam; Pillai, Saju (ACS Applied Bio Materials, 2021)
The design and development of scalable, efficient photothermal evaporator systems that reduce microplastic pollution are highly desirable. Herein, a sustainable bacterial nanocellulose (BNC)-based self-floating bilayer photothermal foam (PTF<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; bottom: -0.25em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">b) is designed that eases the effective confinement of solar light for efficient freshwater production via interfacial heating. The sandwich nanoarchitectured porous bilayer solar evaporator consists of a top solar-harvesting blackbody layer composed of broad-spectrum active black titania (BT) nanoparticles embedded in the BNC matrix and a thick bottom layer of pristine BNC for agile thermal management, the efficient wicking of bulk water, and staying afloat. A decisive advantage of the BNC network is that it enables the fabrication of a lightweight photothermal foam with reduced thermal conductivity and high wet strength. Additionally, the hydrophilic three-dimensional (3D) interconnected porous network of BNC contributes to the fast evaporation of water under ambient solar conditions with reduced vaporization enthalpy by virtue of intermediated water generated via a BNC–water interaction. The fabricated PTF<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; bottom: -0.25em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">b is found to yield a water evaporation efficiency of 84.3% (under 1054 W m<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">–2) with 4 wt % BT loading. Furthermore, scalable PTF<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; bottom: -0.25em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">b realized a water production rate of 1.26 L m<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">–2 h<span style="outline: none; font-size: 12.75px; line-height: 0; position: relative; top: -0.5em; font-family: Georgia, serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400; background-color: rgb(244, 244, 244);">–1 under real-time conditions. The developed eco-friendly BNC-supported BT foams could be used in applications such as solar desalination, contaminated water purification, extraction of water from moisture, etc., and thus could address one of the major present-day global concerns of drinking water scarcity.

Hypervalent iodine(iii) induced oxidative olefination of benzylamines using Wittig reagents - Ramavath, Vijayalakshmi; Rupanawar, Bapurao D.; More, Satish G.; Bansode, Ajay H.; Suryavanshi, Gurunath (New Journal of Chemistry, 2021)
We have developed hypervalent iodine(iii) induced oxidative olefination of primary and secondary benzylamines using 2C-Wittig reagents, which provides easy access to alpha,beta-unsaturated esters. Mild reaction conditions, good to excellent yields with high (E) selectivity, and a broad substrate scope are the key features of this reaction. We have successfully carried out the gram-scale synthesis of alpha,beta-unsaturated esters.

Impingement dynamics of jets in a confined impinging jet reactor - Pal, Sayan; Madane, Ketan; Mane, Mayur; Kulkarni, Amol A. (Industrial & Engineering Chemistry Research, 2021)
The interaction of two impinging liquid jets in a confined impinging jet reactor (CUR) is explored. Multiphase flow simulations were performed using the volume of fluids (VOF) approach to investigate the impingement dynamics of liquid impinging jets, and single-phase CFD simulations have been performed to understand the turbulence and the mixing performance in the system. At identical inlet velocities, the liquid sheet formed on the impingement axis was found to move toward the liquid jet inlet of the lesser density fluid until reaching equilibrium. The formation and transient movement of liquid sheets are characterized for different jet velocities. An improved reactor geometry is proposed that reduces the wall effect on sheet formation and wall deposition on discharge points of jets. Upon breaking away from the impinging film, the two liquid phases are found to be intertwined in the form of ligaments and droplets after fragmentation of the sheet, providing a higher interfacial confirmed by performing high-throughput continuous antisolvent precipitation.

Implication of adsorption preferences of ions and surfactants on the shape control of gold nanoparticles: a microscopic, atomistic perspective - Meena, Santosh Kumar; Meena, Chandrakala (Nanoscale, 2021)
Shape modulation of nanoparticles is crucial for their tailored applications; however, it depends on surfactants, ions, reactants, and other additives present in the growth solution. Here we dissect the role of surfactants, their counterions (halide ions), silver ions, and gold reactant in gold nanoparticle anisotropic growth using polarizable surfaces and nanoseed molecular dynamics simulation models. Our planar surface models predict a 14%-16% increment in cetyltrimethylammonium bromide (CTAB) coverage on Au(111) and Au(100) due to the surface polarization effect. The CTAB micelle adsorbs compactly similar to that observed on non-polarizable surfaces. The cetyltrimethylammonium chloride (CTAC) micelle remains in solution leaving the polarizable gold surfaces unprotected, similar to that observed with the non-polarizable surfaces, which favors isotropic growth. The cetyltrimethylammonium iodide (CTAI) micelle adsorbs with higher surface densities than CTAB on all the surfaces. The surface polarizable penta-twinned nanoseed model predicts the total surface coverage of the cetyltrimethylammonium cation (CTA(+)), Br- and Ag+ to be around two times higher on the side as compared to the tip of the nanoseed, leading to a 2.6 times higher initial rate of adsorption of AuCl2- on the tip than on the side. Predicted CTA(+) surface densities on the tip and the side of the nanoseed are consistent with experimental results. Our simulations explain the growth mechanism of anisotropic nanoparticles and the microscopic origin of their controlled shapes.

Insights from a pan India Sero-epidemiological survey (Phenome-India Cohort) for SARS-CoV2 - Naushin, Salwa; Sardana, Viren; Ujjainiya, Rajat; Bhatheja, Nitin; Kutum, Rintu; Bhaskar, Akash Kumar; Pradhan, Shalini; Prakash, Satyartha; Khan, Raju; Rawat, Birendra Singh; Tallapaka, Karthik Bharadwaj; Anumalla, Mahesh; et al. (eLife, 2021)
To understand the spread of SARS-CoV2, in August and September 2020, the Council of Scientific and Industrial Research (India) conducted a serosurvey across its constituent laboratories and centers across India. Of 10,427 volunteers, 1058 (10.14%) tested positive for SARS-CoV2 anti-nucleocapsid (anti-NC) antibodies, 95% of which had surrogate neutralization activity. Three-fourth of these recalled no symptoms. Repeat serology tests at 3 (n = 607) and 6 (n = 175) months showed stable anti-NC antibodies but declining neutralization activity. Local seropositivity was higher in densely populated cities and was inversely correlated with a 30-day change in regional test positivity rates (TPRs). Regional seropositivity above 10% was associated with declining TPR. Personal factors associated with higher odds of seropositivity were high-exposure work (odds ratio, 95% confidence interval, p value: 2.23, 1.92-2.59, <0.0001), use of public transport (1.79, 1.43-2.24, <0.0001), not smoking (1.52, 1.16-1.99, 0.0257), non-vegetarian diet (1.67, 1.41-1.99, <0.0001), and B blood group (1.36, 1.15-1.61, 0.001).

Interconnected polyaniline nanostructures: enhanced interface for better supercapacitance retention - Mooss, Vandana A.; Vijayakumar, Vidyanand; Kurungot, Sreekumar; Athawale, Anjali A. (Polymer, 2021)
Polyaniline and its nanocomposites have emerged as desirable electrode materials for supercapacitors. However, achieving specific capacitance with long-term cyclic stability is still a challenge. The present study reports on novel hierarchically porous and cross-linked polyaniline synthesized by a method employing aniline (monomer) and phytic acid (dopant acid) in the presence of octyltrimethyl ammonium bromide (OTAB) surfactant. The electrochemical performance of the phytic acid doped sample has been compared with HCl doped samples, the former being superior, i.e., a specific capacitance of 523 and 325 F g(-1) at current densities of 0.25 and 10 A g(-1), respectively. Additionally, the same possess excellent cycling stability with retention of similar to 88% of its initial capacitance over 10,000 charge-discharge cycles. Further, the phytic acid doped sample exhibited a lower equivalent series resistance (0.98 Omega cm(2)) than the HCl doped sample (1.26 Omega cm(2)). These results reveal the capability of the phytic acid doped hierarchical polyaniline sample as a promising active material for electrochemical applications.
Keywords: Cyclic stability; Hierarchical polyaniline; Supercapacitance retention

Intramolecularly double-donor-stabilized stannylene and its coordination towards Ag(I) and Au(I) centers - Chibde, Purva; Raut, Ravindra K.; Kumar, Vikas; Deb, Rahul; Gonnade, Rajesh; Majumdar, Moumita (Chemistry-An Asian Journal, 2021)
The intramolecularly double-donor-stabilized stannylene 1 has been synthesized from the salt-metathesis reaction between two equivalents of lithium pyridine ene-amide L1 and SnCl2. Compound 1 exhibits dipolar behavior when reacted with B(C6F5)(3) leading to the zwitterionic compound 2. The reaction of 1 with one equivalent and 0.5 equivalent of AgOTf (OTf=trifluoromethane sulfonate) result in the formation of a stannylene-AgOTf complex 3 and a homoleptic distannylene-silver ionic complex 4, respectively. Analogous to complex 4, the gold(I) complex 5 has been synthesized from the reaction between two equivalents of 1 and 0.5 equivalent of AuCl.SMe2/Me3SiOTf. Complex 5 is the first example of homoleptic stannylene-Au(I) ionic complex among the very scarce reports on stannylene-gold(I) coordination complexes. All compounds have been structurally characterized using single crystal X-ray crystallography. Solution-state characterization have been performed using multinuclear NMR techniques. Detailed DFT calculations on the optimized geometries 1 o, 3 o-5 o reveal the change in sp- hybridization on the pyramidal Sn(II) center upon metal coordination and their bonding overlaps.
Keywords: coordination; gold cation; hybridization; intramolecular donor; stannylene

Iron catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols with p-quinone methides: new access to gamma,gamma-diaryl ketones - Shirsath, Sachin R.; Chandgude, Sagar M.; Muthukrishnan, M. (Chemical Communications, 2021)
An iron(iii) catalyzed tandem ring opening/1,6-conjugate addition of cyclopropanols to p-quinone methides leading to gamma,gamma-diaryl ketones has been described. This catalytic protocol provides a novel and efficient method to access gamma,gamma-diaryl ketone derivatives in good to excellent yields with high functional group tolerance. Importantly, gamma,gamma-diaryl ketone can be further functionalized to give a versatile set of useful products.

Laser cladding of PAC 718, tribaloy T-700 and METCO 41 C hard facing powders on AISI SS 304L substrate - More, S. R.; Bhatt, D. V.; Menghani, J.; Paul, C. P.; Desale, G. R. (Materials Science, 2021)
The present investigation aims to deposit the three different hard facing powder (Triboloy T-700 and PAC 718, and TETCO 41 C) on SS 304L using laser cladding technique. The single and overlapped clad track was deposited using 2 kW laser power system. The optimized laser process parameters and 50% overlap clad track was used to deposit a large surface area. The optimum laser process parameters were finalised using single clad structure study. The cross-sections of the clad layers were used to obtain the microstructure and micro-hardness from different regions namely, clad layer, diffusion layer, and substrate. Throughout the study, the laser power was kept constant i.e. 1.2 kW. For single clad deposition, the scanning speed and powder feed rate varied from 0.3 to 0.5 m/min and 4 to 9 g/min, respectively. T-700 and PAC 718 shows uniform developing micro-structure while METCO 41 C shows the development of mixed dendritic and cellular type microstructure. The Triboloy shows the maximum surface hardness of 534 Hv, 321 Hv for PAC 718, and 294 Hv for METCO 41 C.

Lead-free zero dimensional tellurium(iv) chloride-organic hybrid with strong room temperature emission as a luminescent material - Biswas, Anupam; Bakthavatsalam, Rangarajan; Bahadur, Vir; Biswas, Chinmoy; Mali, Bhupendra P.; Raavi, Sai Santosh Kumar; Gonnade, Rajesh G.; Kundu, Janardan (Journal of Materials Chemistry C, 2021)
Despite the current progress in `Pb-free' low dimensional main group metal halide based luminescent materials, it is challenging to synthesize Te(iv) halide hybrids with strong ambient emission with excitation features in the visible range as efficient and stable phosphors for potential lighting applications. Reported here is a (benzyltriethylammonium)(2)TeCl6 zero dimensional hybrid material with excitation features in the visible range and strong room temperature, broadband, intrinsic luminescence (PLQY similar to 15%) arising due to self-trapped excitons (STEs). Furthermore, a proof-of-concept LED architecture demonstrates successful optical down-conversion with a visible light excitation source. Here, exclusive adoption of a `regular' octahedral Te(iv)-halide unit structure with minimal static distortion provides a unique opportunity to unmask the role played by 5s(2) lone pair electrons in shaping the emissive properties. This effort may open up new avenues towards unravelling the role of lone pair stereoactivity in controlling the PLQY in low dimensional hybrids that has proven to be challenging for the reported (Sb, Sn) based low dimensional 5s(2) metal halide hybrid materials.

L-Histidine-derived smart antifouling biohybrid with multistimuli responsivity - Mohammad, Sk Arif; Dolui, Subrata; Kumar, Devendra; Mane, Shivshankar R.; Banerjee, Sanjib (Biomacromolecules, 2021)
A novel dual pH/thermoresponsive amphiphilic poly(histidine methacrylamide)-block-hydroxyl-terminated polybutadiene-block-poly(histidine methacrylamide) (PHisMAM-b-PB-b-PHisMAM) triblock copolymer biohybrid, composed of hydrophobic PB and ampholytic PHisMAM segments, is developed via direct switching from living anionic polymerization to recyclable nanoparticle catalyst-mediated reversible-deactivation radical polymerization (RDRP). The transformation involved in situ postpolymerization modification of living polybutadiene-based carbanionic species, end-capped with ethylene oxide, into dihydroxyl-terminated polybutadiene and a subsequent reaction with 2-bromo-2-methylpropionyl bromide resulting in a telechelic ATRP macroinitiator (Br-PB-Br). Br-PB-Br was used to mediate RDRP of an L-histidine-derived monomer, HisMAM, yielding a series of PHisMAM-b-PB-b-PHisMAM triblock copolymers. The copolymer's stimuli response was assessed against pH and temperature changes. The copolymer is capable of switching among its zwitterionic, anionic, and cationic forms and exhibited unique antifouling properties in its zwitterionic form. These novel triblock copolymers are expected to be show promising potential in biomedical applications.

Limonoid biosynthesis 3: functional characterization of crucial genes involved in neem limonoid biosynthesis - Pandreka, Avinash; Chaya, Patil S.; Kumar, Ashish; Aarthy, Thiagarayaselvam; Mulani, Fayaj A.; Bhagyashree, Date D.; Shilpashree, H. B.; Jennifer, Cheruvathur; Ponnusamy, Sudha; Nagegowda, Dinesh; Thulasiram, V. Hirekodathakallu (Phytochemistry, 2021)
Neem (Azadirachta indica L.) is well known for its medicinal, agricultural, and pesticidal applications since ages. The secondary metabolites, limonoids, confer these biological properties, wherein over 150 different limonoids have been reported from neem. To understand limonoid biosynthesis, we analyzed tissue-specific (kernel, pericarp, leaves, and flower) transcriptome that resulted in the identification of one farnesyl diphosphate synthase (AiFDS), one squalene synthase (AiSQS), three squalene epoxidases (AiSQE1, AiSQE2, and AiSQE3), two triterpene synthases (AiTTS1 and AiTTS2), cycloartenol synthase (AiCAS), two cytochrome P450 reductases, and ten cytochrome P450 systems. Comparative tissue-expression analysis indicated that AiFDS, AiSQS, AiSQE3, and AiTTS1 are expressed higher in the kernel than in the other tissues. Heterologously expressed recombinant AiTTS1 produced tirucalla-7,24-dien-3 beta-ol as the sole product. Expression profile data, phylogeny with triterpene synthases from Meliaceae and Rutaceae families, real-time PCR of different tissues, and transient transformation revealed the involvement of tirucalla-7,24-dien-3 beta-ol synthase (AiTTS1) in limonoid biosynthesis. Further, mutagenesis studies of AiTTS1 indicated that Y125 and F260 are probably involved in stabilization of dammarenyl cation. A 2.6-fold increase in production of tirucalla-7,24-dien-3 beta-ol was observed when AiSQE1 was coexpressed with mutant AiTTS1 in a yeast system. Furthermore, we functionally characterized the highly expressed cytochrome P450 reductases and cycloartenol synthase. This study helps in further analysis and identification of genes involved in limonoid biosynthesis in Meliaceae/Rutaceae and their production in a metabolically tractable heterologous system.
Keywords: 24-dien-3 beta-ol; Azadirachta indica A. Juss.; Cytochrome P450 system; Limonoids; Meliaceae; Tirucalla-7; Transcriptome

Limonoid biosynthesis 3: functional characterization of crucial genes involved in neem limonoid biosynthesis (vol 184, 112669, 2021) - Pandreka, Avinash; Chaya, Patil S.; Kumar, Ashish; Aarthy, Thiagarayaselvam; Mulani, Fayaj A.; Bhagyashree, Date D.; Shilpashree, H. B.; Jennifer, Cheruvathur; Ponnusamy, Sudha; Nagegowda, Dinesh; Thulasiram, Hirekodathakallu V. (Phytochemistry, 2021)

Lithium silicate nanosheets with excellent capture capacity and kinetics with unprecedented stability for high-temperature CO2 capture - Belgamwar, Rajesh; Maity, Ayan; Das, Tisita; Chakraborty, Sudip; Vinod, Chathakudath P.; Polshettiwar, Vivek (Chemical Science, 2021)
An excessive amount of CO2 is the leading cause of climate change, and hence, its reduction in the Earth's atmosphere is critical to stop further degradation of the environment. Although a large body of work has been carried out for post-combustion low-temperature CO2 capture, there are very few high temperature pre-combustion CO2 capture processes. Lithium silicate (Li4SiO4), one of the best known high-temperature CO2 capture sorbents, has two main challenges, moderate capture kinetics and poor sorbent stability. In this work, we have designed and synthesized lithium silicate nanosheets (LSNs), which showed high CO2 capture capacity (35.3 wt% CO2 capture using 60% CO2 feed gas, close to the theoretical value) with ultra-fast kinetics and enhanced stability at 650 degrees C. Due to the nanosheet morphology of the LSNs, they provided a good external surface for CO2 adsorption at every Li-site, yielding excellent CO2 capture capacity. The nanosheet morphology of the LSNs allowed efficient CO2 diffusion to ensure reaction with the entire sheet as well as providing extremely fast CO2 capture kinetics (0.22 g g(-1) min(-1)). Conventional lithium silicates are known to rapidly lose their capture capacity and kinetics within the first few cycles due to thick carbonate shell formation and also due to the sintering of sorbent particles; however, the LSNs were stable for at least 200 cycles without any loss in their capture capacity or kinetics. The LSNs neither formed a carbonate shell nor underwent sintering, allowing efficient adsorption-desorption cycling. We also proposed a new mechanism, a mixed-phase model, to explain the unique CO2 capture behavior of the LSNs, using detailed (i) kinetics experiments for both adsorption and desorption steps, (ii) in situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy measurements, (iii) depth-profiling X-ray photoelectron spectroscopy (XPS) of the sorbent after CO2 capture and (iv) theoretical investigation through systematic electronic structure calculations within the framework of density functional theory (DFT) formalism.

Machine learning classifiers aid virtual screening for efficient design of mini-protein therapeutics - Gaur, Neeraj K.; Goyal, Venuka Durani; Kulkarni, Kiran; Makde, Ravindra D. (Bioorganic & Medicinal Chemistry Letters, 2021)
De novo design of mini-proteins (4-12 kDa) has recently been shown to produce new candidates for protein therapeutics. They are temperature stable molecules that bind to the drug target with high affinity for inhibiting its interactions. The development of mini-protein binders requires laboratory screening of tens of thousands of molecules for effective target binding. In this study we trained machine learning classifiers which can distinguish, with 90% accuracy and 80% precision, mini-protein binders from non-binding molecules designed for a particular target; this significantly reduces the number of mini protein candidates for experimental screening. Further, on the basis of our results we propose a multi-stage protocol where a small dataset (few hundred experimentally verified target-specific mini-proteins) can be used to train classifiers for improving the efficiency of mini-protein design for any specific target.
Keywords: Drug design; machine learning; Mini-proteins; Protein therapeutics; virtual screening

Mechanical and microstructural studies in a polysaccharide-acrylate double network hydrogel - Torris, Arun; Nair, Sanoop; Mol, K. P. Raji; Sengupta, Poulomi; Badiger, Manohar (Journal of the Mechanical Behavior of Biomedical Materials, 2021)
Polymeric hydrogels continue to find a wide range of applications. However, a major drawback of hydrogels is the lack of mechanical strength. In this regard, ``Double Network Hydrogels'' (DN) have shown great promise recently. The toughness in DN hydrogels originates from the synergistic effect of two polymeric networks. In this work, we have synthesized a DN hydrogel consisting of a tightly cross linked carboxymethylcellulose (CMC) as the first network and loosely cross linked poly(hydroxyethylacrylate) (PHEA) as a second network (CMC-PHEADN). The required flexibility in the second network (PHEA) was induced by the presence of a small amount of stearyl methacrylate (SM) as a co-monomer in hydroxyl ethyl acrylate (HEA). The compressive strength of the CMC-PEHA-DN hydrogel was found to be 280 times more than that of CMC-SN hydrogel, and the presence of SM in DN hydrogels showed better recovery after deformation. Cell viability studies showed the biocompatibility of DN hydrogels. The micro-structural analysis of DN xerogels by 3D X-ray Microtomography indicated the presence of oriented pores in size range of 30-40 mu m. To the best of our knowledge, Microtomography was used for the first time to study the DN gels. These hydrogels can be used to develop implants that can withstand prolonged stress and expand the life span of implants.
Keywords: Carboxymethyl cellulose; Double network hydrogels; Poly(hydroxyethyl acrylate); Poly(hydroxyethyl-co-stearyl methacrylate)

Mechanical properties of anodic titanium dioxide nanostructures - Kulkarni, Mukta; Sepitka, Josef; Junkar, Ita; Bencina, Metka; Rawat, Niharika; Mazare, Anca; Rode, Chandrashekhar; Gokhale, Suresh; Schmuki, Patrik; Daniel, Matej; Iglic, Ales (Materiali in Tehnologije, 2021)
Highly ordered and uniform titanium dioxide (TiO2) nanotubes (NTs) with different morphologies (15 nm, 50 nm and 100 nm in diameter) were prepared by the electrochemical anodization of Ti substrates. The TiO2 NTs' surface properties were characterized by X-ray diffraction (XRD) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM). The elastic modulus (E) and the Vickers hardness (HV) of the Ti foil and of the different-morphology TiO2 NTs were evaluated with the nano-indentation technique. E and HV increase with the decreasing length/diameter of the NTs, meaning that NTs with smaller diameters are more resistant to mechanical wear. The elastic modulus of the TiO2 NTs with 15-nm and 50-nm diameters is similar to that of the human bone.
Keywords: Elastic modulus; mechanical properties; titanium dioxide (TiO2) nanotubes; Vickers hardness

Metagenomic analysis reveals genetic insights on biogeochemical cycling, xenobiotic degradation, and stress resistance in mudflat microbiome - Mohapatra, Madhusmita; Yadav, Rakeshkumar; Rajput, Vinay; Dharne, Mahesh S.; Rastogi, Gurdeep (Journal of Environmental Management, 2021)
<span style="color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">Mudflats are highly productive coastal ecosystems that are dominated by halophytic vegetation. In this study, the mudflat sediment microbiome was investigated from Nalabana Island, located in a brackish water coastal wetland of India; Chilika, based on the MinION shotgun metagenomic analysis. Bacterial, archaeal, and fungal communities were mostly composed of Proteobacteria (38.3%), Actinobacteria (20.7%), Euryarchaeota (76.1%), Candidatus Bathyarchaeota (6.8%), Ascomycota (47.2%), and Basidiomycota (22.0%). Bacterial and archaeal community composition differed significantly between vegetated mudflat and un-vegetated bulk sediments. Carbon, nitrogen, sulfur metabolisms, oxidative phosphorylation, and xenobiotic biodegradation were the most common microbial functionalities in the mudflat metagenomes. Furthermore, genes involved in oxidative stresses, osmotolerance, secondary metabolite synthesis, and extracellular polymeric substance synthesis revealed adaptive mechanisms of the microbiome in mudflat habitat. Mudflat metagenome also revealed genes involved in the plant growth and development, suggesting that microbial communities could aid halophytic vegetation by providing tolerance to the abiotic stresses in a harsh mudflat environment. Canonical correspondence analysis and co-occurrence network revealed that both biotic (vegetation and microbial interactions) and abiotic factors played important role in shaping the mudflat microbiome composition. Among abiotic factors, pH accounted for the highest variance (20.10%) followed by available phosphorus (19.73%), total organic carbon (9.94%), salinity (8.28%), sediment texture (sand) (6.37%) and available nitrogen (5.53%) in the mudflat microbial communities. Overall, this first metagenomic study provided a comprehensive insight on the community structure, potential ecological interactions, and genetic potential of the mudflat microbiome in context to the cycling of organic matter, xenobiotic biodegradation, stress resistance, and in providing the ecological fitness to halophytes. These ecosystem services of the mudflat microbiome must be considered in the conservation and management plan of coastal wetlands. This study also advanced our understanding of fungal diversity which is understudied from the coastal lagoon ecosystems.

Metal halide structure and the extent of distortion control the photo-physical properties of luminescent zero dimensional organic-antimony(iii) halide hybrids - Biswas, Anupam; Bakthavatsalam, Rangarajan; Mali, Bhupendra P.; Bahadur, Vir; Biswas, Chinmoy; Raavi, Sai Santosh Kumar; Gonnade, Rajesh G.; Kundu, Janardan (Journal of Materials Chemistry C, 2021)
Antimony(iii) halide based zero dimensional hybrids have gained attention as broadband emitters. Until now, quadrangular pyramidal SbX5 based and octahedral SbX6 based 0D hybrids have been reported utilizing different organic ligands demonstrating some structural tunability affecting their emissive properties. Utilizing a common organic ligand, here we demonstrate the structural tunability (quadrangular pyramidal, octahedral, or a combination thereof) of the metal halide unit in Sb(iii)Cl 0D hybrids with contrasting photo-physical properties (broadband, Stokes shift, strong/weak colored emission). The structure-property-mechanism correlation of the synthesized compounds [1 (C12H52Cl18N8O4Sb3; tris Sb green); 2 (C12H50Cl14N8O3Sb2; tris Sb red); 3 (C24H88Cl25N16O4Sb3; tris Sb yellow)] identifies crucial factors that control their emissive properties. The X-ray analysis reveals the structure (1-octahedral; 2-quadrangular pyramidal; 3-combination thereof) and the order of the extent of structural distortion as 1-3 MUCH LESS-THAN 2. The metal halide coordination environment asymmetry and its structure are observed to dictate PL emission energy (1-green; 2-red; 3-yellow) as supported by a qualitative Molecular Orbital scheme. The extent of structural distortion guides the observed Stokes shifts (1-165 nm; 2-290 nm; 3-200 nm; 1-3 < 2). Interestingly, the extent of distortion is found to be well correlated with the observed PLQY (1-45%; 2-6%; 3-43%; 1-3 >> 2). This report clearly demonstrates the structural tunability and the effect of the metal halide unit structure/distortion in shaping the emissive properties of 0D organic Sb(iii) halide hybrids.

Metal-free, acid-catalyzed 1,6-conjugate addition of NH-sulfoximines to para-quinone methides: accessing to diarylmethine imino sulfanone - More, Satish G.; Rupanawar, Bapurao D.; Suryavanshi, Gurunath (Journal of Organic Chemistry, 2021)
We have reported an efficient and metal-free method for the construction of alpha-diarylmethine imino sulfanone using acid-catalyzed 1,6-conjugate addition of sulfoximines on para-quinine methides (p-QMs). This method showed broad functional group tolerance and a wide range of substrate scope with good to excellent yield. The excellent protocol exhibits mild reaction conditions with high atom economy. The practicability of the present method was supported by a Gram-scale reaction.

Molecular insights of fungal endophyte co-inoculation with Trichoderma viride for the augmentation of forskolin biosynthesis in Coleus forskohlii - Mastan, Anthati; Rane, Digeshwar; Dastager, Syed G.; Babu, C. S. Vivek (Phytochemistry, 2021)
To understand the compatibility of three native endophytic fungi Phialemoniopsis cornearis (SF1), Macrophomina pseudophaseolina (SF2) and Fusarium redolens (RF1) with Trichoderma viride (TV1) on Coleus forskohlii in enhancing plant growth and forskolin content, field experiments were conducted. Co-inoculation of RF1+TV1 showed significant improvement in plant growth (52%), root biomass (67%), and in planter forskolin content (94%), followed by treatment with SF2+TV1 and SF1+TV1. qRT-PCR was carried out to quantify expression of five key forskolin biosynthetic pathway genes (CfTPS2, CfTPS3, CfTPS4, CfCYP76AH15, and CfACT1-8) in RF1+TV1 treated C. forskohlii plants. Elevated expression of CfTPS2, CfTPS4, CfCYP76AH15 and CfACT1-8 genes was observed with RF1+TV1 combination as compared to uninoculated C. forskohlii plants. Besides, RF1+TV1 treatment considerably reduced the severity of nematode infection of C. forskohlii plants under field conditions. Thus, congruent properties of F. redolens (RF1) were witnessed with co-inoculation of T. viride (TV1) under field conditions which resulted in enhanced forskolin content, root biomass, and reduced nematode infections in C. forskohlii. Overall, this approach could be an economical and sustainable step towards cultivation of commercially important medicinal plants.
Keywords: Co-inoculation; Coleus forskohlii; endophytes; Forskolin; Lamiaceae; Trichoderma viride

Molecular investigation of glycated insulin-induced insulin resistance via insulin signaling and AGE-RAGE axis - Walke, Prachi B.; Bansode, Sneha B.; More, Nikita P.; Chaurasiya, Arvindkumar H.; Joshi, Rakesh S.; Kulkarni, Mahesh J. (Biochimica ET Biophysica Acta-Molecular Basis of Disease, 2021)
Hyperglycemic condition in diabetes promotes glycation of various plasma proteins including insulin. Glycation of insulin has been reported to reduce its biological activity. Reduced biological activity of glycated insulin could be either due to reduced affinity for the insulin receptor and impaired insulin signaling, or it can act as a ligand for the receptor for advanced glycation end products (RAGE) and activates oxidative stress and pro-inflammatory pathways leading to insulin resistance. This study investigates the effect of glycated insulin on both insulin and RAGE signaling. Glycated insulin treatment to Chinese hamster ovary (CHO-IR-GLUT4) cells stably expressing insulin receptor (IR) and glucose transporter fused with a green fluorescent protein (GLUT4-GFP) resulted in the impairment of insulin signaling, as the phosphorylation of IR and AKT significantly reduced, which affected GLUT4 translocation and glucose uptake. Moreover, it also activated RAGE signaling as observed by increased expression of NADPH oxidase accompanied by an increase in reactive oxygen species (ROS). Immunofluorescence study indicated the translocation of NF-kappa B to the nucleus upon treatment of glycated insulin. This was associated with increased RAGE expression, Caspase 3, and cell death. Downregulation of RAGE with the losartan treatment restored the impaired insulin signaling and glucose uptake. Additionally, in silico study demonstrated that glycated insulin has reduced binding affinity to insulin receptor and increased binding affinity to RAGE. Overall, this study demonstrates the role of glycated insulin in exacerbating insulin resistance by impairing insulin signaling as well as stimulating AGE-RAGE signaling.
Keywords: AGE; Diabetes; Glycation; Hyperglycemia; insulin; RAGE

Neem derivatives inhibits tau aggregation - Nalini, Gorantla Vijay; Das, Rashmi; Mulani, Fayaj Alam; Thulasiram, Hirekodathakallu V.; Chinnathambi, Subashchandrabose (Journal of Alzheimer s Disease Reports, 2021)
Tau is a phosphoprotein with natively unfolded conformation that functions to stabilize microtubules in axons. Alzheimer's disease pathology triggers several modifications in tau, which causes it to lose its affinity towards microtubule, thus, leading to microtubule disassembly and loss of axonal integrity. This elicit accumulation of tau as paired helical filaments is followed by stable neurofibrillary tangles formation. A large number of small molecules have been isolated from Azadirachta indica with varied medicinal applications. The intermediate and final limonoids, nimbin and salannin respectively, isolated from Azadirachta indica, were screened against tau aggregation. ThS and ANS fluorescence assay showed the role of intermediate and final limonoids in preventing heparin induced cross-β sheet formation and also decreased hydrophobicity, which are characteristic nature of tau aggregation. Transmission electron microscopy studies revealed that limonoids restricted the aggregation of tau to fibrils; in turn, limonoids led to the formation of short and fragile aggregates. Both the limonoids were non-toxic to HEK293T cells thus, substantiating limonoids as a potential lead in overcoming Alzheimer's disease.

NHC-catalyzed desymmetrization of N-aryl maleimides leading to the atroposelective synthesis of N-Aryl succinimides - Barik, Soumen; Shee, Sayan; Das, Soumik; Gonnade, Rajesh G.; Jindal, Garima; Mukherjee, Subrata; Biju, Akkattu T. (Angewandte Chemie-International Edition, 2021)
Although the construction of axially chiral C-C bonds leading to the atroposelective synthesis of biaryls and allied compounds are well-known, the related synthesis of compounds bearing axially chiral C-N bonds are relatively rare. Described herein is the N-heterocyclic carbene-catalyzed atroposelective synthesis of N-aryl succinimides having an axially chiral C-N bond via the desymmetrization of N-aryl maleimides. The NHC involved intermolecular Stetter-aldol cascade of dialdehydes with prochiral N-aryl maleimides followed by oxidation afforded N-aryl succinimides in good yields and ee values. Preliminary studies on rotation barrier for the C-N bond, the temperature dependence, and detailed DFT studies on mechanism are also provided.
Keywords: asymmetric catalysis; axial chirality; desymmetrization; N-heterocyclic carbenes; organocatalysis

Ni-catalyzed highly enantioselective synthesis of sulfur protected P-stereogenic supramolecular phosphine - Koshti(S), Vijay S.; Chandanshive, Amol C.; Mote, Nilesh R.; Chikkali, Samir H. (Journal of Chemical Sciences, 2021)
As phosphines readily invert, the synthesis of P-chiral phosphines is a challenging task and has been rarely investigated. We report the synthesis of a nickel complex [Ni-((S,S)Me-FerroLANE)(phenyl)(I)] (Ni-Cat.1) and its performance in a P-C coupling reaction to generate P-chiral phosphine. The Ni-Cat.1 was synthesized by mixing ligand (S,S) Me-FerroLANE with the metal precursor [(diphenylphosphanyl)nickel(phenyl)(I)] in good yield. Ni-Cat.1 was characterized using different spectroscopic and analytical techniques. Treatment of racemic methyl(phenyl)phosphine (1) with 1-(3-iodophenyl)urea (2) produced the corresponding P-chiral supramolecular phosphine (3). Optimization of reaction parameters produced sulfur protected phosphine N-(3-(methyl(phenyl)phosphorothioyl)phenyl)formamide (3') with excellent enantiomeric excess (99% ee) and moderate conversion (51%).
Keywords: Asymmetric synthesis; Nickel catalyst; P-C coupling; P-Stereogenic phosphine; supramolecular ligands

Nitrogen activation to reduction on a recyclable V-SAC/BN-graphene heterocatalyst sifted through dual and multiphilic descriptors - Maibam, Ashakiran; Krishnamurty, Sailaja (Journal of Colloid and Interface Science, 2021)
<span style="color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">Efficient reduction of nitrogen to ammonia at a minimal cost would require a recherche catalyst tailored by assimilating the inherent electronic and reactive nature of Single Atom Catalysts (SACs) on heteroatom doped-graphene. A full-scale DFT study accounting for disparate descriptions of atomic orbitals and representation of support, has been carried out to identify the most active and recyclable SAC/B-graphene composite as catalyst for Nitrogen Reduction Reaction (NRR). Dual and Multiphilic descriptors derived reactivity pattern of six different metal SACs V, Fe, Ni, Ru, W and Re on periodic and non-periodic paradigms of pristine and BN-pair doped graphene supports, align with the calculated chemisorption efficacy and activation of N<span style="box-sizing: inherit; font-size: 12px; line-height: 0; position: relative; bottom: -0.25em; color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">2<span style="color: rgb(33, 33, 33); font-family: BlinkMacSystemFont, -apple-system, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Fira Sans", "Droid Sans", "Helvetica Neue", sans-serif; font-size: 16px; font-style: normal; font-variant-ligatures: normal; font-variant-caps: normal; font-weight: 400;">. The enzymatic route of nitrogen reduction on three most ideal metal SACs (V, W and Re) culminates Vanadium SAC, a relatively cheaper metal, anchored on BNring-graphene with an energy barrier of ⩽1.24 eV as a highly active and recyclable catalyst for NRR.

Organic-inorganic perovskitoid with zwitterion cysteamine linker and its crystal-crystal transformation to ruddlesden-popper phase - Kour, Prachi; Reddy, Mallu Chenna; Pal, Shiv; Sidhik, Siraj; Das, Tisita; Pandey, Padmini; Mukherjee, Shatabdi Porel; Chakraborty, Sudip; Mohite, Aditya D.; Ogale, Satishchandra (Angewandte Chemie-International Edition, 2021)
We demonstrate synthesis of a new low-D hybrid perovskitoid (a perovskite-like hybrid halide structure, yellow crystals, P21/n space group) using zwitterion cysteamine (2-aminoethanethiol) linker, and its remarkable molecular diffusion-controlled crystal-to-crystal transformation to Ruddlesden-Popper phase (Red crystals, Pnma space group). Our stable intermediate perovskitoid distinctly differs from all previous reports by way of a unique staggered arrangement of holes in the puckered 2D configuration with a face-sharing connection between the corrugated-1D double chains. The PL intensity for the yellow phase is 5 orders higher as compared to the red phase and the corresponding average lifetime is also fairly long (143 ns). First principles DFT calculations conform very well with the experimental band gap data. We demonstrate applicability of the new perovskitoid yellow phase as an excellent active layer in a self-powered photodetector and for selective detection of Ni2+ via On-Off-On photoluminescence (PL) based on its composite with few-layer black phosphorous.
Keywords: Crystal growth; organic-inorganic hybrid composites; perovskite phases; photodetectors; zwitterions

On the origin of controlled anisotropic growth of monodisperse gold nanobipyramids - Meena, Santosh Kumar; Lerouge, Frederic; Baldeck, Patrice; Andraud, Chantal; Garavelli, Marco; Parola, Stephane; Sulpizi, Marialore; Rivalta, Ivan (Nanoscale, 2021)
We elucidate the crucial role of the cetyl trimethylammonium bromide (CTAB) surfactant in the anisotropic growth mechanism of gold nano-bipyramids, nano-objects with remarkable optical properties and high tunability. Atomistic molecular dynamics simulations predict different surface coverages of the CTAB (positively charged) heads and their (bromide) counterions as function of the gold exposed surfaces. High concentration of CTAB surfactant promotes formation of gold nanograins in solution that work as precursors for the smooth anisotropic growth of more elongated nano-bipyramidal objects. Nanobipyramids feature higher index facets with respect to nanorods, allowing higher CTAB coverages that stabilize their formation and leading to narrower inter-micelles channels that smooth down their anisotropic growth. Absorption spectroscopy and scanning electron microscopy confirmed the formation of nanograins and demonstrated the importance of surfactant concentration on driving the growth towards nano-bipyramids rather than nanorods. The outcome explains the formation of the monodisperse bipyramidal nano-objects, the origin of their controlled shapes and sizes along with their remarkable stability.

Oxidative radical-mediated addition of ethers to quinone imine ketals: an access to hemiaminals - More, Satish G.; Kamble, Rohit B.; Suryavanshi, Gurunath (Journal of Organic Chemistry, 2021)
The highly regioselective synthesis of substituted hemiaminal via addition of ethers to quinone imine ketals (QIKs) has been developed under metal-free conditions. In the presence of tetrabutylammonium chloride and potassium persulfate (K2S2O8), QIKs couple efficiently with cyclic and acyclic ethers to give hemiaminals. This strategy offers an easy access to substituted hemiaminal ethers with high functional group tolerance in good to excellent yields.

Oxime ligands for Pd catalysis of the mizoroki-heck reaction, suzuki-miyaura coupling & annulation reactions - Bangar, Pronnoy G.; Nahide, Pradip D.; Meroliya, Heena K.; Waghmode, Shobha A.; Iyer, Suresh (Synthetic Communications, 2021)
Monodentate and bidentate chelating oximes are readily available ligands for the Pd catalysis of the Mizoroki-Heck reaction and the Suzuki coupling. High yields were obtained in the Suzuki coupling in aqueous dioxane with TBABr as additive. The oximes can be easily synthesized from the corresponding ketones or aldehydes and thus provide a very large number of nitrogen-based ligands. They have the advantage of not undergoing oxidative degradation, common for phosphine ligands. Chelating oximes with Pd(OAc)(2), activate aryl iodides to give high yields of the substitution products in the Mizoroki-Heck reactions as well as the Suzuki coupling. Acetophenone oxime ligand with Pd(OAc)(2), catalyzed the reaction of aryl iodides with 1,2-disubstituted alkenes in moderate to high yields. As a test example, the LaRock indole annulation and synthesis of isocoumarin were achieved with acetophenone oxime ligand and Pd(OAc)(2)in high yields.
Keywords: Isocoumarin; LaRock annulation; Mizoroki-Heck reaction; oximes; Suzuki coupling

Oxime ligands for Pd catalysis of the mizoroki–heck reaction, Suzuki–Miyaura coupling & annulation reactions - Bangar, Pronnoy G.; Nahide, Pradip D.; Meroliya, Heena K.; Waghmode, Shobha A.; Iyer, Suresh (Synthetic Communications, 2021)
AbstractMonodentate and bidentate chelating oximes are readily available ligands for the Pd catalysis of the Mizoroki–Heck reaction and the Suzuki coupling. High yields were obtained in the Suzuki coupling in aqueous dioxane with TBABr as additive. The oximes can be easily synthesized from the corresponding ketones or aldehydes and thus provide a very large number of nitrogen-based ligands. They have the advantage of not undergoing oxidative degradation, common for phosphine ligands. Chelating oximes with Pd(OAc)2, activate aryl iodides to give high yields of the substitution products in the Mizoroki–Heck reactions as well as the Suzuki coupling. Acetophenone oxime ligand with Pd(OAc)2, catalyzed the reaction of aryl iodides with 1,2-disubstituted alkenes in moderate to high yields. As a test example, the LaRock indole annulation and synthesis of isocoumarin were achieved with acetophenone oxime ligand and Pd(OAc)2 in high yields.

Ozone assisted autohydrolysis of wheat bran enhances xylooligosaccharide production with low generation of inhibitor compounds: a comparative study - Sonkar, Rutuja Murlidhar; Gade, Pravin Savata; Bokade, Vijay; Mudliar, Sandeep N.; Bhatt, Praveena (Bioresource Technology, 2021)
In the present study, ozone assisted autohydrolysis (OAAH) was evaluated for enhanced generation of xylooligosaccharide (XOS) from wheat bran. The total XOS yield with optimum ozone dose of 3% (OAAH-3) was found to be 8.9% (w/w biomass) at 110 degrees C in comparison to 7.96% at 170 degrees C by autohydrolysis (AH) alone. Although, there was no significant difference in oligomeric composition (DP 2-6), significant decrease in degradation products namely furfural (2.78-fold), HMF (3.15-fold), acrylamide (nil) and acetic acid (1.06-fold), was observed with OAAH-3 as a pretreatment option. There was 1-fold higher xylan to XOS conversion and OAAH-hydrolysate had higher DPPH radical scavenging activity than AH. PCA plots indicated clear enhancement in XOS production and lower generation of inhibitors with decrease in treatment temperature. Results of the study therefore suggest OAAH can be an effective pretreatment option that can further be integrated with downstream processing for concentration and purification of XOS.
Keywords: Advanced oxidation; Agro-industry waste; hydrothermal treatment; Ozonolysis; Xylooligosaccharide

Palladium supported on magnesium hydroxyl fluoride: an effective acid catalyst for the hydrogenation of imines and N-heterocycles - Kokane, Reshma; Corre, Yann; Kemnitz, Erhard; Dongare, Mohan K.; Agbossou-Niedercorn, Francine; Michon, Christophe; Umbarkar, Shubhangi B. (New Journal of Chemistry, 2021)
Palladium catalysts supported on acidic fluorinated magnesium hydroxide Pd/MgF2-x(OH)(x) were prepared through precipitation or impregnation methods. Applications to the hydrogenation of various aldimines and ketimines resulted in good catalytic activities at mild temperatures using one atmosphere of hydrogen. Quinolines, pyridines and other N-heterocycles were successfully hydrogenated at higher temperature and hydrogen pressure using low palladium loadings and without the use of any acid additive. Such reactivity trend confirmed the positive effect of the Bronsted and Lewis acid sites from the fluorinated magnesium hydroxide support resulting in the effective pre-activation of N-heterocycle substrates and therefore in the good catalytic activity of the palladium nanoparticles during the hydrogenations. As demonstrated in the hydrogenation of imines, the catalyst was recycled up to 10 times without either loss of activity or palladium leaching.

Performance of Aspergillus niger (NCIM 563) phytase based feed supplement for broiler growth and phosphorus excretion - Puppala, Kumar Raja; Buddhiwant, Priyanka G.; Agawane, Sachin B.; Kadam, Avinash S.; Mote, Chandrashekhar S.; Lonkar, Vijaysinh D.; Khire, Jayant M.; Dharne, Mahesh S. (Biocatalysis and Agricultural Biotechnology, 2021)
Despite availability of commercial enzymes, the phytase produced from relatively inexpensive systems with high yields are gaining global attention in the feed industries in post-antibiotic era. We studied A. niger NCIM 563 Phytase produced in solid state fermentation (SSF) derived Koji powder and evaluated its utility in the poultry feed for broiler growth performance and phosphorous (P) excretion. The ability of phytase in the dried powder was estimated to dephytinize the poultry feed under simulated gastric conditions. Poultry feed was formulated using A. niger NCIM 563 phytase followed by a 42 days feed trial on broilers. After supplementation of phytase to the diet, there was a reduction of dietary P, maintained growth performance, skeletal development of broilers and reduced levels of phytic acid and available P in the litter. Extracellular phytase was able to replace up to 0.1% P in poultry feed. Minimal downstream processing a low-cost feed supplement with significant phytase activity could provide added advantage for anti-nutrition free poultry feed.
Keywords: Phosphorus; Phytase; Poultry feed; Solid state fermentation

Pharmacore maping based on docking, ADME/toxicity, virtual screening on 3,5-dimethyl-1,3,4-hexanetriol and dodecanoic acid derivates for anticancer inhibitors - Prakash, Palanisamy; Vijayasarathi, Durairaj; Selvam, Kuppusamy; Karthi, Sengodan; Manivasagaperumal, Rengarajan (Journal of Biomolecular Structure & Dynamics, 2021)
Plants produced natural generating products play a significant role in drug discovery of new bioactive compounds and these are used for advancement of innovative curative drugs for specific target health diseases. In this study Docking and ADME/T virtual screening method are apply for in drug discovery and can be divided into ligand- and target structure-based. The aim of this study was to analyze theDecalepis hamiltoniiisolated compounds by using the evaluation of molecular docking and virtual screening of anticancer drugs. MOE docking ADME/Toxicity and virtual screening approaches. A docking energy -12.97 kcal/mol; -9.93- kcal/mol on cancer responsible protein was targeted. Further, the compounds were filtered through the rule of five, ADME/Toxicity risk and synthetic accessibility. The active compound were then docked to recognize the possible target binding pocket to obtain a set of a ligand poses and to prioritize the predicted active compounds. The scrutinize compounds, as well as their metabolites were evaluated for different pharmacokinetics parameter such as ADME/Toxicity. Therefore, the result shows that a large number of compounds were found to be ADME/toxicity positive to be a positive drug molecule against cancer, selected compounds under study satisfies parameters for ADME and Toxicity properties. The present study demonstrate to identifying the novel structures which are having similar structural feature with like activity with respect to the compounds 3,5-Dimethyl-1,3,4-Hexanetriol and Dodecanoic acid that are shown best binding energy with the receptors 4igk and 4b3z respectively. This study may provide significant clues for discovery novel drug inhibitors for cancer properties.
Keywords: ADME; Decalepis hamiltonii; docking; drug discovery; Toxicity; virtual screening

pH-dependent protein stability switch coupled to the perturbed pKa of a single ionizable residue - Mishra, Prajna; Patni, Divya; Jha, Santosh Kumar (Biophysical Chemistry, 2021)
The contribution of electrostatic interactions in protein stability has not been fully understood. Burial of an ionizable amino acid inside the hydrophobic protein core can affect its ionization equilibrium and shift its pKa differentially in the native (N) and unfolded (U) states of a protein and this coupling between the folding/ unfolding cycle and the ionization equilibria of the ionizable residue can substantially influence the protein stability. Here, we studied the coupling of the folding/unfolding cycle with the ionization of a buried ionizable residue in a multi-domain protein, Human Serum Albumin (HSA) using fluorescence spectroscopy. A pHdependent change in the stability of HSA was observed in the near native pH range (pH 6.0-9.0). The protonation-deprotonation equilibrium of a single thiol residue that is buried in the protein structure was identified to give rise to the pH-dependent protein stability. We quantified the pKa of the thiol residue in the N and the U states. The mean pKa of the thiol in the N state was upshifted by 0.5 units to 8.7 due to the burial of the thiol in the protein structure. Surprisingly, the mean pKa of the thiol in the U state was observed to be downshifted by 1.3 units to 6.9. These results indicate that some charged residues are spatially proximal to the thiol group in the U state. Our results suggest that, in addition to the N state, electrostatic interactions in the U state are important determinants of protein stability.
Keywords: electrostatic interactions; Fluorescence spectroscopy; Thermodynamic stability; Unfolded proteins

Phosphine-free manganese(II)-catalyst enables acceptorless dehydrogenative coupling of alcohols with indoles - Yadav, Vinita; Balaraman, Ekambaram; Mhaske, Santosh B. (Advanced Synthesis & Catalysis, 2021)
Herein, an air-stable, molecularly defined NNN-Mn(II) pincer complex catalyzed acceptorless dehydrogenative coupling of alcohols with indoles is reported. A wide variety of symmetrical and unsymmetrical bis(indolyl)methane derivatives as well as some structurally important products such as Vibrindole A, Turbomycin B alkaloid, Antileukemic, and Anticancer agents were synthesized. Mechanistic studies illustrate the importance of the NH moiety in the complex and the crucial role of metal-ligand cooperation during catalysis.
Keywords: acceptorless dehydrogenation; Alcohol; Indole; manganese; phosphine-free

Phosphite mediated asymmetric N to C migration for the synthesis of chiral heterocycles from primary amines - Rani, Soniya; Dash, Soumya Ranjan; Bera, Asish; Alam, Md Nirshad; Vanka, Kumar; Maity, Pradip (Chemical Science, 2021)
A phosphite mediated stereoretentive C-H alkylation of N-alkylpyridinium salts derived from chiral primary amines was achieved. The reaction proceeds through the activation of the N-alkylpyridinium salt substrate with a nucleophilic phosphite catalyst, followed by a base mediated [1,2] aza-Wittig rearrangement and subsequent catalyst dissociation for an overall N to C-2 alkyl migration. The scope and degree of stereoretention were studied, and both experimental and theoretical investigations were performed to support an unprecedented aza-Wittig rearrangement-rearomatization sequence. A catalytic enantioselective version starting with racemic starting material and chiral phosphite catalyst was also established following our understanding of the stereoretentive process. This method provides efficient access to tertiary and quaternary stereogenic centers in pyridine systems, which are prevalent in drugs, bioactive natural products, chiral ligands, and catalysts.

Photoactivatable prodrug for simultaneous release of mertansine and CO along with a BODIPY derivative as a luminescent marker in mitochondria: a proof of concept for NIR image-guided cancer therapy - Tiwari, Rajeshwari; Shinde, Prashant S.; Sreedharan, Sreejesh; Dey, Anik Kumar; Vallis, Katherine A.; Mhaske, Santosh B.; Pramanik, Sumit kumar; Das, Amitava (Chemical Science, 2021)
Controlled and efficient activation is the crucial aspect of designing an effective prodrug. Herein we demonstrate a proof of concept for a light activatable prodrug with desired organelle specificity. Mertansine, a benzoansamacrolide, is an efficient microtubule-targeting compound that binds at or near the vinblastine-binding site in the mitochondrial region to induce mitotic arrest and cell death through apoptosis. Despite its efficacy even in the nanomolar level, this has failed in stage 2 of human clinical trials owing to the lack of drug specificity and the deleterious systemic toxicity. To get around this problem, a recent trend is to develop an antibody-conjugatable maytansinoid with improved tumor/organelle-specificity and lesser systematic toxicity. Endogenous CO is recognized as a regulator of cellular function and for its obligatory role in cell apoptosis. CO blocks the proliferation of cancer cells and effector T cells, and the primary target is reported to be the mitochondria. We report herein a new mitochondria-specific prodrug conjugate (Pro-DC) that undergoes a photocleavage reaction on irradiation with a 400 nm source (1.0 mW cm(-2)) to induce a simultaneous release of the therapeutic components mertansine and CO along with a BODIPY derivative (BODIPY(PPH3)(2)) as a luminescent marker in the mitochondrial matrix. The efficacy of the process is demonstrated using MCF-7 cells and could effectively be visualized by probing the intracellular luminescence of BODIPY(PPH3)(2). This provides a proof-of-concept for designing a prodrug for image-guided combination therapy for mainstream treatment of cancer.

Photoactive anthraquinone-based host-guest assembly for long-lived charge separation - Jha, Ajay; Mote, Kaustubh R.; Chandra, Suman; Madhu, Perunthiruthy K.; Dasgupta, Jyotishman (Journal of Physical Chemistry C, 2021)
Porous 2D covalent organic frameworks (COF) that are assembled axially through weak p-stacking interactions can provide reticular charge transport channels while playing host to kinetically stabilized reactive molecular redox states. Here we demonstrate a host-guest supramolecular charge transfer (CT) assembly using photoactive anthraquinone-based COF as an acceptor while incarcerating the electron donor N,N-dimethylaniline (DMA) inside it. Employing femtosecond broadband transient absorption spectroscopy in combination with electron paramagnetic resonance (EPR) studies, we show that the CT occurs rapidly within <110 fs after photoexcitation, subsequently leading to long-lived charge separation with 13% quantum efficiency at room temperature. The photoinduced EPR signature of the long-lived confined DMA cation radical confirms the disparate regions of charge localization while H-1-C-13 correlation experiments using solid-state NMR spectroscopy enumerate the packing of the amines inside the host-guest COF assembly. Our work demonstrates the potency of charge transport pathways in supramolecular assemblies for efficient charge separation which if optimally tuned should pave the way for COF-based photocatalytic reaction centers.

PNA-mediated efflux inhibition as a therapeutic strategy towards overcoming drug resistance in Mycobacterium smegmatis - Ghosh, Saptarshi; Cotta, Karishma Berta; Hande, Aniket A.; Fernandes, Moneesha; Mehra, Sarika (Microbial Pathogenesis, 2021)
The emergence of antibiotic-resistant strains of Mycobacterium tuberculosis and the decelerating development of new and effective antibiotics has impaired the treatment of tuberculosis (TB). Efflux pump inhibitors (EPIs) have the potential to improve the efficacy of existing anti-TB drugs although with toxicity limitations. Peptide nucleic acids (PNAs), oligonucleotide mimics, by virtue of their high nucleic acid binding specificity have the capability to overcome this drawback. We, therefore, investigated the efflux pump inhibitory properties of a PNA designed against an efflux pump of Mycobacterium smegmatis. LfrA, an efflux pump found in M. smegmatis, is majorly involved in conferring innate drug resistance to this strain and, therefore, was selected as a target for gene silencing via PNA. qRT-PCR and EtBr assays confirmed the EPI activity of the anti-lfrA PNA. On testing the effect of the anti-lfrA PNA on the bactericidal activity of a fluoroquinolone, norfloxacin, we observed that 5 mu M of anti-lfrA PNA in combination with norfloxacin led to an enhanced killing of up to 2.5 log-fold against wild-type and a lab-generated multidrug resistant strain, exemplifying its potential in countering resistance. Improved efficacy was also observed against intra-macrophage mycobacteria, where the drug-PNA combination enhanced bacterial clearance by 1.3 log-fold. Further, no toxicity was observed with PNA concentrations up to 4 times higher than the efficacious anti-lfrA PNA concentration. Thus, PNA, as an adjuvant, presents a novel and viable approach to rejuvenate anti-TB therapeutics.
Keywords: Adjuvant; Antibiotic resistance; Antisense; Efflux pump; Gene silencing; Mycobacteria; Peptide nucleic acid (PNA)

Polycomb group methyltransferase StE(z)2 and deposition of H3K27me3 and H3K4me3 regulate the expression of tuberization genes in potato - Kumar, Amit; Kondhare, Kirtikumar R.; Malankar, Nilam N.; Banerjee, Anjan K. (Journal of Experimental Botany, 2021)
Polycomb repressive complex (PRC) group proteins regulate various developmental processes in plants by repressing target genes via H3K27 trimethylation, and they function antagonistically with H3K4 trimethylation mediated by Trithorax group proteins. Tuberization in potato has been widely studied, but the role of histone modifications in this process is unknown. Recently, we showed that overexpression of StMSI1, a PRC2 member, alters the expression of tuberization genes in potato. As MSI1 lacks histone-modification activity, we hypothesized that this altered expression could be caused by another PRC2 member, StE(z)2, a potential H3K27 methyltransferase in potato. Here, we demonstrate that a short-day photoperiod influences StE(z)2 expression in the leaves and stolons. StE(z)2 overexpression alters plant architecture and reduces tuber yield, whereas its knockdown enhances yield. ChIP-sequencing using stolons induced by short-days indicated that several genes related to tuberization and phytohormones, such as StBEL5/11/29, StSWEET11B, StGA2OX1, and StPIN1 carry H3K4me3 or H3K27me3 marks and/or are StE(z)2 targets. Interestingly, we observed that another important tuberization gene, StSP6A, is targeted by StE(z)2 in leaves and that it has increased deposition of H3K27me3 under long-day (non-induced) conditions compared to short days. Overall, our results show that StE(z)2 and deposition of H3K27me3 and/or H3K4me3 marks might regulate the expression of key tuberization genes in potato.
Keywords: ChIP-sequencing; Epigenetics; PcG; photoperiod; polycomb repressive complex; potato tuberization; short-day; Solanum tuberosum; StE(z)2

Polymer graphene-based nanofibers and their application for batteries - Mishra, Sasmita; Singh, Sandip; Singh, Ajeet (Electrospinning of Graphene, 2021)
Polymer graphene-based nanofibers are increasingly used in energy storage devices, especially in lithium-ion batteries and thus attracting more and more industrial and academic research in material chemistry. Metal-doped graphene-based polymer nanofibers are now gaining much attention and recently are successfully used in related energy storage devices, including supercapacitors and more. This chapter primarily focuses on a brief of nanofibers, electrospinning and graphene followed by the review of polymer graphene-based nanofibers in the present scenario.

Possible electron doping of geometrically perfect spin-1/2 kagome-lattice barlowite by reduced graphene oxide - Gupta, Kriti; Ninawe, Pranay; Jain, Anil; Dadwal, Arun; Anas, M.; Malik, V. K.; Yusuf, S. M.; Joy, Pattayil A.; Ballav, Nirmalya (Physical Review B, 2021)
Doping of quantum spin liquid (QSL) insulators by electron or hole leads to intriguing phase transitions to metallic and superconducting states. The barlowite family with geometrically perfect S = 1/2 kagome planes and tunable interkagome coupling is an emerging platform to realize spin-ordered, valence bond crystal, QSL states. Theoretical investigations on electron doping revealed localized states in the band gap of barlowite unlike metallicity in cuprate (Nd2CuO4). We present successful anchoring of phase-pure barlowite crystallites onto reduced graphene oxide (rGO). The resulting barlowite-rGO system was found to be an electrical semiconductor with Arrhenius activation energy of 0.07 eV. Semiconducting properties of the barlowite-rGO system were further modulated with retention of structural integrity. We have attributed such a transformation of electrical transport response to plausible electron doping thereby making charge-doping experiments on barlowite and its analogs propitious.

Protriptyline improves spatial memory and reduces oxidative damage by regulating NF kappa B-BDNF/CREB signaling axis in streptozotocin-induced rat model of Alzheimer's disease - Tiwari, Virendra; Mishra, Akanksha; Singh, Sonu; Mishra, Sandeep Kumar; Sahu, Kiran Kumari; Parul; Kulkarni, Mahesh J.; Shukla, Rakesh; Shukla, Shubha (Brain Research, 2021)
Antidepressants are well known to exert their role via upregulation of brain derived neurotrophic factor (BDNF). BDNF has been reported to exerts its neuroprotective effect in rodent and primate models as well as in patients of Alzheimer's disease (AD). The aim of our study was to evaluate the effect of protriptyline (PRT), a tricyclic antidepressant, in streptozotocin (STZ)- induced rat model of AD. Total 10 mu l of STZ was injected into each ventricle (1 mg/kg). PRT (10 mg/kg, i.p.) treatment was started 3-day post STZ administration and continued till 21 days. We found that STZ treatment significantly increased pTau, A beta 42 and BACE-1 expression, oxidative stress and neurodegeneration in hippocampus and cortex of adult rats. STZ induced impairment in spatial learning and retention memory was associated with increased WO and reduced CREB and BDNF expression in cortex and hippocampus. Interestingly, PRT treatment significantly reduced pTau, A beta 42 and BACE-1 levels, neurodegeneration, oxidative stress and glial activation, contributing to the improved spatial learning and retention memory in STZ treated rats. Moreover, PRT treatment significantly improved p-ERK/ERK ratio and enhanced BDNF and CREB levels by reducing NFXB and GFAP expression in STZ treated rats. Our data suggest that impaired NFXB and CREB signaling potentially contribute in AD pathogenesis by elevating oxidative stress and neuroinflammation mediated neurodegeneration. Our study has established protriptyline as a multi target molecule in pre-clinical model of AD and further investigations on PRT like molecules could pave way for further development of effective new treatments in neurodegenerative disorders.
Keywords: Alzheimer's disease; antidepressant; BDNF; Memory; Oxidative stress; Protriptyline

Raman spectroscopy-based sensitive, fast and reversible vapour phase detection of explosives adsorbed on metal-organic frameworks UiO-67 - Sen Bishwas, Mousumi; Malik, Monika; Poddar, Pankaj (New Journal of Chemistry, 2021)
In this work, we report highly sensitive, selective, rapid, and reversible detection of explosive molecules in the vapour phase, adsorbed on metal-organic frameworks (MOFs) under ambient laboratory conditions. The sensing is based on the quenching of the Raman intensity of a zirconium-based MOF, Zr6O4(OH)(4)(dcppy)(6) (MOF 1, UiO-67-dcppy; dcppy is 2-phenylpyridine-5,4'-dicarboxylate), where 50% of the signal quenches swiftly within similar to 5 s of its exposure to trinitrophenol (TNP) vapours, while 90% of the Raman signal was quenched in 30 s. The high surface area of porous MOFs provides increased adsorption of various nitro analytes. The quenching of Raman peaks resulted from the pi-pi interactions of the analytes with the benzene ring of the MOF. The sensors have also been proven to be reversible and stable by mild heat treatment (80 degrees C for 5 min). These notable results using Raman spectroscopy point to a new and important approach towards explosive sensing using metal-organic frameworks considering their vast versatility. This work emphasizes the importance of a non-invasive and non-destructive technique that can be used to develop handheld vapour phase explosive detectors.

Rapid and accurate nucleobase detection using FnCas9 and its application in COVID-19 diagnosis - Azhar, Mohd; Phutela, Rhythm; Kumar, Manoj; Ansari, Asgar Hussain; Rauthan, Riya; Gulati, Sneha; Sharma, Namrata; Sinha, Dipanjali; Sharma, Saumya; Singh, Sunaina; Acharya, Sundaram; Sarkar, Sajal; et al. (Biosensors & Bioelectronics, 2021)
Rapid detection of DNA/RNA pathogenic sequences or variants through point-of-care diagnostics is valuable for accelerated clinical prognosis, as witnessed during the recent COVID-19 outbreak. Traditional methods relying on qPCR or sequencing are tough to implement with limited resources, necessitating the development of accurate and robust alternative strategies. Here, we report FnCas9 Editor Linked Uniform Detection Assay (FELUDA) that utilizes a direct Cas9 based enzymatic readout for detecting nucleobase and nucleotide sequences without transcleavage of reporter molecules. We also demonstrate that FELUDA is 100% accurate in detecting single nucleotide variants (SNVs), including heterozygous carriers, and present a simple web-tool JATAYU to aid end-users. FELUDA is semi-quantitative, can adapt to multiple signal detection platforms, and deploy for versatile applications such as molecular diagnosis during infectious disease outbreaks like COVID-19. Employing a lateral flow readout, FELUDA shows 100% sensitivity and 97% specificity across all ranges of viral loads in clinical samples within 1hr. In combination with RT-RPA and a smartphone application True Outcome Predicted via Strip Evaluation (TOPSE), we present a prototype for FELUDA for CoV-2 detection closer to home.
Keywords: CRISPRDx; FELUDA; FnCas9; LFA; SARS-CoV2; SNV detection

Rapid identification and tracking of SARS-CoV-2 variants of concern - Chakraborty, Debojyoti; Agrawal, Anurag; Maiti, Souvik (Lancet, 2021)

Reduction of hydroxyl traps and improved coupling for efficient and stable quantum dot solar cells - Mandal, Debranjan; Dambhare, V. Neha; Rath, Arup K. (ACS Applied Materials & Interfaces, 2021)
Progress in quantum dot (QD)-based solar cells has been underpinned by the improvements in surface passivation and advancements in device engineering. Acute control over the surface properties is crucial to restrict the formation of in-gap trap states and improve the QD coupling in achieving conducting QD films. In this report, we demonstrate a solution-phase hybrid passivation strategy, which is beneficial in removing detrimental hydroxyl traps and improving the coupling between QDs by reducing the interdot distance. Advancement in surface passivation is translated to the long carrier lifetime, higher carrier mobility, and superior protection toward degradations in QD solids. The performance of solar cell devices is increased by 26% to reach an efficiency of 10.6%, compared to the state-of-the-art lead halide passivated solar cells. The improvement in solar cell performance is supported by the reduction of trap states and an 80 nm increase in thickness of the light-absorbing QD layer.
Keywords: ligand; mobility; quantum dot; solar cell; surface passivation

Repurposing the McoTI-II rigid molecular scaffold in to inhibitor of `papain superfamily' cysteine proteases - Mishra, Manasi; Singh, Vigyasa; Tellis, Meenakshi B.; Joshi, Rakesh S.; Singh, Shailja (Pharmaceuticals, 2021)
Clan C1A or `papain superfamily' cysteine proteases are key players in many important physiological processes and diseases in most living systems. Novel approaches towards the development of their inhibitors can open new avenues in translational medicine. Here, we report a novel design of a re-engineered chimera inhibitor Mco-cysteine protease inhibitor (CPI) to inhibit the activity of C1A cysteine proteases. This was accomplished by grafting the cystatin first hairpin loop conserved motif (QVVAG) onto loop 1 of the ultrastable cyclic peptide scaffold McoTI-II. The recombinantly expressed Mco-CPI protein was able to bind with micromolar affinity to papain and showed remarkable thermostability owing to the formation of multi-disulphide bonds. Using an in silico approach based on homology modelling, protein-protein docking, the calculation of the free-energy of binding, the mechanism of inhibition of Mco-CPI against representative C1A cysteine proteases (papain and cathepsin L) was validated. Furthermore, molecular dynamics simulation of the Mco-CPI-papain complex validated the interaction as stable. To conclude, in this McoTI-II analogue, the specificity had been successfully redirected towards C1A cysteine proteases while retaining the moderate affinity. The outcomes of this study pave the way for further modifications of the Mco-CPI design for realizing its full potential in therapeutics. This study also demonstrates the relevance of ultrastable peptide-based scaffolds for the development of novel inhibitors via grafting.
Keywords: Cathepsin; Clan CA cysteine proteases; cyclotide; cystatin; McoTI-II; papain; protein engineering

Resveratrol loaded cubic phase nanoparticles with enhanced oral bioavailability - Rawat, Neeraj Kumar; Torris, Arun; Bhat, Suresh; Mahadik, Kakasaheb; Patil, Sharvil (BioNanoScience, 2021)
Resveratrol (RES), a naturally occurring hydrophobic polyphenolic compound, has shown potential anticancer activity. However, due to low aqueous solubility and extensive first pass metabolism (primarily by cytochrome enzymes), it shows poor oral bioavailability. In the present work, novel RES loaded cubosomes of glycerol monooleate (GMO) and Gelucire 44/14 (GL44) (RES-Cubs) were prepared. RES-Cubs were prepared by emulsion evaporation technique and optimized using 32 factorial design. The optimized RES-Cubs were assessed for particle size, zeta potential, entrapment efficiency, FTIR, TEM, SAXS, in vitro resveratrol release and oral bioavailability. RES-Cubs showed an average particle size of 121.7 ± 2.54 nm with adequate entrapment efficiency of about 82.0 ± 2.35% w/w. The analysis of SAXS profile of RES-Cubs revealed Pn3m crystallographic space group containing diamond cubic phase. In vitro RES release profile of RES-Cubs exhibited markedly sustained release of resveratrol. Furthermore, RES-Cubs demonstrated considerable enhancement in oral bioavailability (ninefold) of resveratrol as compared to RES alone. The developed RES loaded cubosomes bearing cytochrome enzyme inhibitor property can act as promising nanocarrier in the delivery of lipophilic drugs with a drawback of in vivo degradation by cytochrome enzymes.

Reusable magnetic nanocatalyst for bio-fuel additives: the ultrasound-assisted synthesis of solketal dagger - Rajkumari, Kalyani; Changmai, Bishwajit; Meher, Ananta Kumar; Vanlalveni, Chhangte; Sudarsanam, Putla; Wheatley, Andrew E. H.; Rokhum, Samuel Lalthazuala (Sustainable Energy & Fuels, 2021)
Acetalization of glycerol into solketal, a potential fuel additive, is a promising approach to utilizing the large waste-stream of glycerol from the biodiesel industry. Herein, we report an efficient ultrasound-assisted room temperature synthesis of solketal by acetalization of glycerol with acetone using an easily recoverable sulfonic acid-functionalized, silica-coated Fe3O4 magnetic nanoparticle (Fe3O4@SiO2@SO3H MNP, FSS MNP) catalyst. The morphology, chemical composition and magnetic properties of the catalyst were elucidated. The acetalization of glycerol was carried out under ultrasonication at room temperature, resulting in 97% glycerol conversion after 15 minutes and 95% isolated yield of solketal with 100% selectivity for this acetal. The facile magnetic retrievability of the catalyst imparted operational simplicity to the solketal synthetic protocol, avoiding complicated catalyst separation and product purification processes. The FSS catalyst was magnetically recycled for up to five catalytic experiments, maintaining a glycerol conversion of 95% and without deterioration in its selectivity, composition, morphology or magnetic properties, thereby ameliorating the green aspects of the protocol.

Rigidity dictates spontaneous helix formation of thermoresponsive colloidal chains in poor solvent - Biswas, Bipul; Mitra, Debarshi; KP, Fayis; Bhat, Suresh; Chatterji, Apratim; Kumaraswamy, Guruswamy (ACS Nano, 2021)
The formation of helical motifs typically requires specific directional interactions. Here, we demonstrate that isotropic interparticle attraction can drive self-assembly of colloidal chains into thermo-reversible helices, for chains with a critical level of backbone rigidity. We prepare thermoresponsive colloidal chains by cross-linking PNIPAM microgel-coated polystyrene colloids (“monomers”), aligned in an AC electric field. We control the chain rigidity by varying cross-linking time. Above the LCST of PNIPAM, there is an effective attraction between monomers so that the colloidal chains are in a bad solvent. On heating, the chains decrease in size. For the most rigid chains, the decrease is modest and is not accompanied by a change in shape. Much less rigid chains form relatively compact structures, resulting in a large increase in the local monomer density. Unusually, chains with intermediate rigidity spontaneously assemble into helical structures. The chain helicity increases with temperature and plateaus above the collapse transition temperature of the microgel particles. We simulate a minimal model that captures the spontaneous emergence of the helical conformations of the polymeric chain and provides insight into this shape transition. Our work suggests that a purely mechanical instability for semiflexible filaments can drive helix formation, without the need to invoke directional interactions.

Role of Nd3+ concentration on the microstructure and scintillation behaviour of langbeinite sulphate - Poornima, Velswamy; Mohan, Subramaniam; Uma, Tiruchirappalli Sivagnanam (Materials Letters, 2021)
Langebeinite (K2Ca2(SO4)(3)) ceramics doped with increasing concentrations of Nd3+ ions (0.01-0.04 mol%) was prepared by wet chemical precipitation and calcination at 800 degrees C. Thermal studies revealed high temperature stability of the phosphors. UV-VIS-NIR spectroscopic analysis of phosphors reveal strong absorption peaks representing f -> f transitions. Direct bandgap derived from Kubelka-Munk plot was found to be similar to 5.66 eV. FTIR studies reveal tetrahedral symmetry of the SO42 ions. SEM micrographs reveal the formation of phosphors with wide particle size distribution and elemental composition was analysed using EDX studies. Scintillation studies representing a single high intensity peak around 784 nm is ascribed to I-4(9/2) -> F-4(5/2) + H-2(9/2) transition. Langbeinite phosphor with 0.02 mol% of Nd3+ exhibited maximum emission intensity indicating optimal concentration for scintillation studies favouring the development of NIR emitting phosphors. (c) 2020 Elsevier B.V. All rights reserved.
Keywords: Ceramics; Langebeinites; Luminescence; Microstructure; Neodymium; Scintillation

Role of Nd3+ concentration on the microstructure and scintillation behaviour of langbeinite sulphate (vol 284, 128997, 2021) - Poornima, Velswamy; Mohan, Subramaniam; Uma, Tiruchirappalli Sivagnanam (Materials Letters, 2021)

Ru-catalyzed asymmetric transfer hydrogenation of alpha-acyl butyrolactone via dynamic kinetic resolution: asymmetric synthesis of bis-THF alcohol intermediate of darunavir - More, V. Ganesh; Malekar, V. Pushpa; Kalshetti, Rupali G.; Shinde, Mahesh H.; Ramana, V. Chepuri (Tetrahedron Letters, 2021)
The Ru-catalyzed enantio- and diastereoselective dynamic kinetic resolution of alpha-(benzyloxy/benzoyloxy)acyl-gamma-butyrolactones has been examined via transfer hydrogenation. Employing the in situ prepared (R,R)-Ru-FsDPEN catalyst, the transfer hydrogenation of using formic acid/triethylamine at rt gave the corresponding (S)-3-((S)-2-(benzyloxy/benzoyloxy)-1-hydroxyethyl)dihydrofuran-2(3H)-on e with good to excellent diastereo- and enantioselectivity. One of the resulting hydrogenation product prepared on gram scales was utilized for the synthesis of (3R,3aS,6aR)-hexahydrofuro[2,3-b]furan-3-ol (1), a key synthetic intermediate of various HIV protease inhibitors such as darunavir with excellent enantio-(95% ee) and diastereoselectivities (dr 95:5). (C) 2021 Elsevier Ltd. All rights reserved.
Keywords: Bis-THF-OH intermediate; Darunavir; Dynamic kinetic resolution; Ru-catalysis; transfer hydrogenation

Safe water and technology initiative for water disinfection: application of natural plant derived materials - Mane, Maya B.; Bhandari, Vinay M.; Ranade, Vivek V. (Journal of Water Process Engineering, 2021)
Safe drinking water is the necessity of life. The present study reveals use of natural resources such as plant extracts and natural oils for water disinfection. Differences between oil and water soluble additives were highlighted for plant extracts and insoluble natural oils. A hybrid hydrodynamic cavitation process was quite effective in both the cases and high rates of disinfection were achieved. Studies were reported using oils (ginger, turmeric, lavender, tulsi) and rhizome derived plant extracts such as ginger, turmeric and mango ginger, as additives in process intensification (0.1% v/V). A vortex based cavitation device (vortex diode, nominal capacity 1 m3/h) was used with pressure drop of 1 bar. A high disinfection of 96% and 88% was obtained in 15 min for ginger oil and mango ginger extract respectively as compared to 44% using cavitation alone. Acoustic cavitation gave 94% and 30% disinfection with and without additive-mango ginger extract. The FTIR analyses before and after cavitation, with ginger additive, showed no by-products formation and indicated gingerol as active component in disinfection. The per-pass disinfection values were also higher, up to 5 times than cavitation alone. Hybrid hydrodynamic cavitation using natural plant derived materials can offer a promising technology alternative in water disinfection.
Keywords: Cavitation; Disinfection; Natural oil; Plant extract; Water treatment

Short enantioselective total synthesis of (+)-tofacitinib - Mane, Kishor D.; Kamble, Rohit B.; Suryavanshi, Gurunath (Tetrahedron Letters, 2021)
An enantioselective total synthesis of Tofacitinib (CP-690,550), a Janus tyrosine kinase (JAK3) specific inhibitor has been achieved from the readily available 4-piperidone. Proline catalysed hydroxylation is the key step for the synthesis of enantiopure 1-benzyl-4-methylpiperidin-3-ol. (C) 2021 Elsevier Ltd. All rights reserved.
Keywords: aminohydroxylation; Hydrogenation; L-proline; piperidone

Stabilization of the elusive antimony(I) cation and its coordination complexes with transition metals - Kumar, Vikas; Gonnade, Rajesh G.; Yildiz, Cem B.; Majumdar, Moumita (Angewandte Chemie-International Edition, 2021)
Upon stabilization by 5,6-bis(diisopropylphosphino)acenaphthene to form compound 1, the fugitive antimony (I) cation exhibited nucleophilic behavior towards coinage metals. Compound 1 was strategically synthesized at room temperature from SbCl3, the bis(phosphine), and trimethylsilyl trifluoromethanesulfonate taken in a 1:2:3 ratio, whereby the bis(phosphine) plays the dual role of a reductant and a supporting ligand. The generation of 1 involves two-electron oxidation of the ligand to form a P-P bonded diphosphonium dication. Compound 1 was separated from this dication to give both products in pure form in moderate yields. Despite the overall positive charge, the Sb-I site in 1 was found to bind to metal centers, forming complexes with Au-I, Ag-I and Cu-I. Compound 1 reduced Cu-II to Cu-I and formed a coordination complex with the resulting Cu-I species. The effects of the electron-rich bis(phosphine) and the constrained peri geometry in stabilizing and enhancing the nucleophilicity of 1 have been rationalized through computational studies.
Keywords: antimony(I) cation; coordination modes; nucleophilicity; phosphine ligands; reduction

Structural and computational investigation of an imine-based propeller-shaped macrocyclic cage - Madhu, Suresh; Raghavan, Sriram (SN Applied Sciences, 2021)
In this study, we present the synthesis, spectroscopic and structural characterization of self-assembling gem-dimethyl imine based molecular cage (IMC). Self-assembling macrocycles and cages have well-defined cavities and have extensive functionalities ranging from energy storage, liquid crystals, and catalysts to water splitting photo absorber. IMC has large voids i.e., 25% of the total crystal volume thus could accommodate wide substrates. The synthesized imine-based molecular cages are stabilized by coaxial π bonded networks and long-range periodic van der Waal and non-bonded contacts as observed from the crystal structure. IMC also has typical properties of soft condensed matter materials, hence theoretical prediction of stress and strain tensor along with thermophysical properties were computed on crystal system and were found to be stable. Molecular dynamics revealed IMC is stabilized by, strong interactions between the interstitial phenyl rings. Density functional theory (DFT) based physicochemical properties were evaluated and has band gap of around 2.38ev (520 nm) similar to various photocatalytic band gap materials.

Study of combinatorial drug synergy of novel acridone derivatives with temozolomide using in-silico and in-vitro methods in the treatment of drug-resistant glioma - Chakravarty, Malobika; Ganguli, Piyali; Murahari, Manikanta; Sarkar, Ram Rup; Peters, Godefridus Johannes; Mayur, Y. C. (Frontiers in Oncology, 2021)
Drug resistance is one of the critical challenges faced in the treatment of Glioma. There are only limited drugs available in the treatment of Glioma and among them Temozolomide (TMZ) has shown some effectiveness in treating Glioma patients, however, the rate of recovery remains poor due to the inability of this drug to act on the drug resistant tumor sub-populations. Hence, in this study three novel Acridone derivative drugs AC2, AC7, and AC26 have been proposed. These molecules when combined with TMZ show major tumor cytotoxicity that is effective in suppressing growth of cancer cells in both drug sensitive and resistant sub-populations of a tumor. In this study a novel mathematical model has been developed to explore the various drug combinations that may be useful for the treatment of resistant Glioma and show that the combinations of TMZ and Acridone derivatives have a synergistic effect. Also, acute toxicity studies of all three acridone derivatives were carried out for 14 days and were found safe for oral administration of 400 mg/kg body weight on albino Wistar rats. Molecular Docking studies of acridone derivatives with P-glycoprotein (P-gp), multiple resistant protein (MRP), and O6-methylguanine-DNA methyltransferase (MGMT) revealed different binding affinities to the transporters contributing to drug resistance. It is observed that while the Acridone derivatives bind with these drug resistance causing proteins, the TMZ can produce its cytotoxicity at a much lower concentration leading to the synergistic effect. The in silico analysis corroborate well with our experimental findings using TMZ resistant (T-98) and drug sensitive (U-87) Glioma cell lines and we propose three novel drug combinations (TMZ with AC2, AC7, and AC26) and dosages that show high synergy, high selectivity and low collateral toxicity for the use in the treatment of drug resistant Glioma, which could be future drugs in the treatment of Glioblastoma.
Keywords: acridone derivatives; drug combinations; drug resistance; Glioma; mathematical model; synergy index

Study on the failure of guide ropes used in mines - Singh, M. K.; Mallick, M.; Verma, M. K. (Insight, 2021)
The skips/cages in mine hoisting have to be guided to achieve high hoisting rates. Steel guide ropes are used in hoisting because they can safely guide the skips/cages and have been observed to be economical. Guide ropes are static in nature and are thus more prone to corrosion. An investigation into the causes of failure of a guide rope is discussed in this paper. The study consists of physical examination, examination of wear and corrosion, macro- and micro- examination, examination of the breaking load and individual tensile strength measurement of the rod. The main cause of failure is found to be corrosion. Heavy abrasion and corrosion together causes a substantial reduction in diameter of more than 60%. Corrosion raises the stress level and thereby weakens the grains, which is indicated by the cracks that have developed all along the grains as revealed through micro-examination. This affects the breaking strength and reveals a 37% loss of strength, as a result of which failure occurs.
Keywords: corrosion on steel guide rope; guide rope failure; steel guide rope; wear

Sulfonated polyvinyl alcohol ionomer membrane favoring smooth electrodeposition of zinc for aqueous rechargeable zinc metal batteries - Vijayakumar, Vidyanand; Torris, Arun; Kurian, Maria; Mathew, Megha Mary; Ghosh, Meena; Khairnar, Ajay B.; Badiger, Manohar V.; Kurungot, Sreekumar (Sustainable Energy & Fuels, 2021)
One of the failure mechanisms of aqueous rechargeable zinc metal batteries (AZMBs) involves high surface area zinc (HSAZ)/dendrite-like deposits over the Zn-metal anode during long-term cycling. Negatively charged (anionic) polymeric ionomer electrolyte membranes and separators are known for suppressing the dendrite-/HSAZ-induced failure of AZMBs. However, the preparation of cost-effective and non-fluorinated ionomers from cheap and environmentally friendly polymers is essential to leverage the feasibility of AZMBs. The current work demonstrates the potential of an ionomer electrolyte membrane (P-AS-C-Zn) made by the crystallization-induced physical cross-linking of sulfonated poly (vinyl alcohol) (PVS) and poly (vinyl alcohol) (PVA) as a dendrite-/HSAZ-inhibiting separator for AZMBs. The P-AS-C-Zn membranes exhibited excellent Zn plating/stripping behavior with a stable voltage vs. time profile beyond 1100 h, compared to their neutral PVA-C-Zn counterpart without any ionomer character (cell failure at close to 280 h). Applying the optimized P-AS-C-Zn membrane in a MnO2||Zn full cell helps retain about 50% of the initial capacity close to 600 cycles in the absence of extra manganese salt in the electrolyte, which is indeed promising.

Supported MoOx and WOx solid acids for biomass valorization: interplay of coordination chemistry, acidity, and catalysis - Sudarsanam, Putla; Gupta, Navneet Kumar; Mallesham, Baithy; Singh, Nittan; Kalbande, Pavan Narayan; Reddy, Benjaram M.; Sels, Bert F. (ACS Catalysis, 2021)
Supported molybdenum oxide (MoOx) and tungsten oxide (WOx) materials are a vital class of solid acid catalysts for the chemical industry because of their nontoxic nature, strong acidity, remarkable stability in water, hydrogen, and oxygen atmospheres, and excellent reusability performance. These fascinating solid acids play a pivotal role in developing sustainable catalytic routes for renewable biomass processing to produce value-added fuels, chemicals, and platform molecules. The coordination chemistry of MoOx and WOx on the support materials (oxides, carbons, or zeolites) controls their acidic strength, active site accessibility, and catalytic activity. Hence, significant efforts have been made toward optimizing the conditions used for catalyst synthesis and biomass processing to tune the coordination chemistry of MoOx and WOx with the substrate molecules and, thus, their acid-activity/selectivity performance. This Review provides a comprehensive overview of supported MoOx and WOx solid acids for biomass valorization. The importance of the biomass and the role of solid acids for biomass valorization were emphasized, followed by a brief discussion of supported MoOx and WO(x )solid acids. Afterward, the interplay of coordination chemistry, acidic strength, and catalytic activity of supported MoOx and WOx solid acids was discussed. Finally, their catalytic applications for the valorization of several biomass substrates and their derivatives were summarized. This Review will provide valuable insights for developing advanced supported WOx and MoOx solid acids for catalytic biomass valorization and other challenging acid-catalyzed processes.
Keywords: Acidity; biomass valorization; catalysis; Coordination chemistry; molybdenum oxide; tungsten oxide

Synergistic electronic coupling/cross-talk between the isolated metal halide units of zero dimensional heterometallic (Sb, Mn) halide hybrid with enhanced emission - Biswas, Anupam; Bakthavatsalam, Rangarajan; Das, Deep K.; Sam, Jisvin; Mali, Bhupendra P.; Biswas, Chinmoy; Maana, Narugopal; Thomson, Stuart; Raavi, Sai Santosh Kumar; Kurungot, Sreekumar; Gonnade, Rajesh G.; Dutta, Sudipta; et al. (Journal of Materials Chemistry C, 2021)
Heterometallic 0D metal halide hybrids, consisting of more than one kind of metal halide units, are anticipated to manifest synergistic effects on the photo-physical properties of the constituent metal halide units. Such architectures hold great promise for design and development of function-targeted materials. However, heterometallic 0D hybrids, featuring isolated metal halide units, typically do not show any synergistic effects due to large inter-unit spatial separations that inhibit interactions/coupling between the constituent metal halide units. It remains challenging to design synthetic strategies that would support structural modifications to allow synergistic electronic coupling between the metal halide units in heterometallic 0D hybrids. Here, we report synthesis and characterization of heterometallic (Sb, Mn) 0D hybrid, namely Tris SbMnCl, with isolated MnCl5 units, (Sb/Mn)Cl-6 units, dispersed in the organic ligand matrix and layer of dynamic and networked water molecules. Steady state and time resolved emission spectra (TRES) analysis suggests strong synergistic interaction between the isolated metal halide units. Efficient energy transfer from the strongly absorbing Sb centres to emissive Mn centres results in the observed enhanced emission. Proton conductivity measurements together with first-principles calculations suggest the unique role of the networked water molecules in mediating the electronic coupling/energy transfer between the separated metal halide units in Tris SbMnCl hybrid. This report highlights the role of structure/composition of the synthesized heterometallic 0D hybrid in attaining electronic dimensionality higher than 0D through synergistic electronic interaction between the isolated metal halide units.

Synthesis and application of silylene-stabilized low-coordinate Ag(I)-arene cationic complexes - Parvin, Nasrina; Sen, Nilanjana; Tothadi, Srinu; Muhammed, Shahila; Parameswaran, Pattiyil; Khan, Shabana (Organometallics, 2021)
We report the first examples of N-heterocyclic silylene-stabilized monocoordinate Ag(I) cationic complexes weakly bound to the free arene rings (C6H6, C6Me6, and C7H8). Further, the application of these electrophilic Ag(I) complexes as catalysts has been investigated toward A(3)-coupling reactions, which afforded a series of propargylamines in good to excellent yields with low catalyst loading under a solvent-free condition (19 examples).

Synthesis, crystal structures, dielectric and magnetic properties of manganese sulfonyldibenzoates - Balendra; Singh, Bharti; Banday, Azeem; Tewari, Shailabh; Kumar, Vineet; Murugavel, Sevi; Joy, P. A.; Ramanan, Arunachalam (Crystengcomm, 2021)
{A systematic investigation of the system manganese(II) salt-H(2)SBA-auxiliary ligand-solvent successfully led to the isolation of six new multidimensional coordination polymers: [Mn-5(2-pic)(2)(DMA)(4)(SBA)(4)]center dot 4DMA (1), [Mn-3(pyzc)(2)(DMF)(H2O)(SBA)(2)]center dot DMF center dot H2O (2), [Mn-5(pyzc)(2)(DMA)(4)(SBA)(4)]center dot 4DMA (3), [Mn-5(mpyzc)(2)(DMA)(4)(SBA)(4)]center dot 4DMA (4), [Mn-2(phen)(2)(H2O)(SBA)(2)]center dot 2DMA (5) and [Mn-3(phen)(2)(SBA)(3)]center dot 5DMF (6), where SBA = 4,4'-sulfonyldibenzoate 2-pic = 2-picolinate

Synthesis of anisotropic rod-like gold nanostructures in organic media (vol 133, 106, 2021) - Prasad, V. Bhagavatula L.; Sivasankaran, Prathap Chandran; Patel, Pitambar; Malekar, V. Pushpa; Maya, V. K.; Ramana, V. Chepuri (Journal of Chemical Sciences, 2021)

Synthesis of new 2-(thiazol-4-yl)thiazolidin-4-one derivatives as potential anti-mycobacterial agents - Abhale, Yogita K.; Shinde, Abhijit; Shelke, Monika; Nawale, Laxman; Sarkar, Dhiman; Mhaske, Pravin C. (Bioorganic Chemistry, 2021)
To search for potent antimycobacterial lead compounds, a new series of 3-substituted phenyl-2-(2-(substituted phenyl)thiazol-4-yl) thiazolidin-4-one (5a-t) derivatives have been synthesized by the condensation of 2 substituted phenyl thiazole-4-carbaldehyde with aromatic amine followed by cyclocondensation with thioglycolic acid. The structure of the newly synthesized 2-(thiazol-4-yl)thiazolidin-4-one derivatives were characterized by the spectroscopic analysis. The synthesized compounds were screened for antimycobacterial activity against Mycobacterium tuberculosis H37Ra (MTB) (ATCC 25177) and Mycobacterium bovis BCG (BCG, ATCC 35743). Most of the 2-(thiazol-4-yl)thiazolidin-4-one derivatives showed good to excellent antimycobacterial activity against both the Mtb strains. Nine derivatives 5c, 5g, 5j, 5m, 5n, 5o, 5p, 5s, and 5t showed excellent activity against M. bovis BCG with MIC 4.43 to 24.04 mu M were further evaluated for the cytotoxicity activity against HeLa A549, and HCT-116 cell lines and showed no significant cytotoxic activity at the maximum concentration evaluated. The potential antimycobacterial activities enforced that the thiazolyl-thiazolidin-4-one derivatives could lead to compounds that could treat tuberculosis.
Keywords: Cytotoxicity; Mycobacterium tuberculosis; Thiazole; Thiazolidin-4-one

Tandem acceptorless dehydrogenative coupling-decyanation under nickel catalysis - Midya, Siba P.; Subaramanian, Murugan; Babu, Reshma; Yadav, Vinita; Balaraman, Ekambaram (Journal of Organic Chemistry, 2021)
The development of new catalytic processes based on abundantly available starting materials by cheap metals is always a fascinating task and marks an important transition in the chemical industry. Herein, a nickel-catalyzed acceptorless dehydrogenative coupling of alcohols with nitriles followed by decyanation of nitriles to access diversely substituted olefins is reported. This unprecedented C=C bond-forming methodology takes place in a tandem manner with the formation of formamide as a sole byproduct. The significant advantages of this strategy are the low-cost nickel catalyst, good functional group compatibility (ether, thioether, halo, cyano, ester, amino, N/O/S heterocycles; 43 examples), synthetic convenience, and high reaction selectivity and efficiency.

Three in one: triple G-C-T base-coded brahma nucleobase amino acid: synthesis, peptide formation, and structural features - Wagh, Mahendra A.; Maity, Rahul; Bhosale, Rohit J.; Semwal, Divyam; Tothadi, Srinu; Vaidhyanathan, Ramanathan; Sanjayan, Gangadhar J. (Journal of Organic Chemistry, 2021)
This note reports the synthesis and peptide formation of a novel triple G-C-T nucleobase amino acid (NBA) building block featuring three recognition faces: DDA (G mimic), DAA (C mimic), and ADA (T mimic). Readily obtainable in multigram scale in a remarkably easy one-step reaction, this unique NBA building block offers scope for wide ranging applications for nucleic acid recognition and nucleic acid peptide/protein interaction studies.

Triazine-based janus G-C nucleobase as a building block for self-assembly, peptide nucleic acids, and smart polymers - Meena, Chhuttan L.; Singh, Dharmendra; Kizhakeetil, Bhavya; Prasad, Manasa; George, Malini; Tothadi, Srinu; Sanjayan, Gangadhar J. (Journal of Organic Chemistry, 2021)
This communication reports on the utility of a triazine-based self-assembling system, reminiscent of a Janus G-C nucleobase, as a building block for developing (1) supramolecular polymers, (2) peptide nucleic acids (PNAs), and (3) smart polymers. The strategically positioned self-complementary triple H-bonding arrays DDA and AAD facilitate efficient self-assembly, leading to a linear supramolecular polymer.

Unbiased phenotype-based screen identifies therapeutic agents selective for metastatic prostate cancer - Chung, Ivy; Zhou, Kun; Barrows, Courtney; Banyard, Jacqueline; Wilson, Arianne; Rummel, Nathan; Mizokami, Atsushi; Basu, Sudipta; Sengupta, Poulomi; Shaikh, Badaruddin; Sengupta, Shiladitya; Bielenberg, Diane R.; et al. (Frontiers in Oncology, 2021)
In American men, prostate cancer is the second leading cause of cancer-related death. Dissemination of prostate cancer cells to distant organs significantly worsens patients' prognosis, and currently there are no effective treatment options that can cure advanced-stage prostate cancer. In an effort to identify compounds selective for metastatic prostate cancer cells over benign prostate cancer cells or normal prostate epithelial cells, we applied a phenotype-based in vitro drug screening method utilizing multiple prostate cancer cell lines to test 1,120 different compounds from a commercial drug library. Top drug candidates were then examined in multiple mouse xenograft models including subcutaneous tumor growth, experimental lung metastasis, and experimental bone metastasis assays. A subset of compounds including fenbendazole, fluspirilene, clofazimine, niclosamide, and suloctidil showed preferential cytotoxicity and apoptosis towards metastatic prostate cancer cells in vitro and in vivo. The bioavailability of the most discerning agents, especially fenbendazole and albendazole, was improved by formulating as micelles or nanoparticles. The enhanced forms of fenbendazole and albendazole significantly prolonged survival in mice bearing metastases, and albendazole-treated mice displayed significantly longer median survival times than paclitaxel-treated mice. Importantly, these drugs effectively targeted taxane-resistant tumors and bone metastases - two common clinical conditions in patients with aggressive prostate cancer. In summary, we find that metastatic prostate tumor cells differ from benign prostate tumor cells in their sensitivity to certain drug classes. Taken together, our results strongly suggest that albendazole, an anthelmintic medication, may represent a potential adjuvant or neoadjuvant to standard therapy in the treatment of disseminated prostate cancer.
Keywords: bone; carcinoma; drug-screen; Metastasis; Prostate

Web-gLV: a web based platform for lotka-volterra based modeling and simulation of microbial populations (vol 10, 288, 2019) - Kuntal, Bhusan K.; Gadgil, Chetan; Mande, Sharmila S. (Frontiers in Microbiology, 2021)
Keywords: lotka-volterra; microbial population; Microbiome; Modeling; numerical-simulation; time-series; visualization; web-server

ZCTs knockdown using antisense LNA GapmeR in specialized photomixotrophic cell suspensions of Catharanthus roseus: Rerouting the flux towards mono and dimeric indole alkaloids - Verma, Priyanka; Khan, Shamshad Ahmad; Parasharami, Varsha; Mathur, Ajay Kumar (Physiology and Molecular Biology of Plants, 2021)
The present study was carried out to silence the transcription factor genes ZCT1, ZCT2 and ZCT3 via lipofectamine based antisense LNA GapmeRs transfection into the protoplasts of established photomixotrophic cell suspensions. The photomixotrophic cell suspensions with a threshold of 0.5% sucrose were raised and established using two-tiered CO2 providing flasks kept under high light intensity. The photomixotrophic cell suspensions showed morphologically different thick-walled cells under scanning electron microscopic analysis in comparison to the simple thin-walled parenchymatous control cell suspensions. The LC-MS analysis registered the vindoline production (0.0004 +/- 0.0001 mg/g dry wt.) in photomixotrophic cell suspensions which was found to be absent in control cell suspensions. The protoplasts were isolated from the photomixotrophic cell suspensions and subjected to antisense LNA GapmeRs silencing. Three lines, viz. Z1A, Z2C and Z3G were obtained where complete silencing of ZCT1, ZCT2 and ZCT3 genes, respectively, was observed. The Z3G line was found to show maximum production of vindoline (0.038 +/- 0.001 mg/g dry wt.), catharanthine (0.165 +/- 0.008 mg/g dry wt.) and vinblastine (0.0036 +/- 0.0003 mg/g dry wt.). This was supported by the multifold increment in the gene expression of TDC, SLS, STR, SGD, d4h, dat, CrT16H and Crprx. The present work indicates the master regulation of ZCT3 knockdown among all three ZCTs transcription factors in C. roseus to enhance the terpenoid indole alkaloids production. The successful silencing of transcription repressor genes has been achieved in C. roseus plant system by using photomixotrophic cell cultures through GapmeR based silencing. The present study is a step towards metabolic engineering of the TIAs pathway using protoplast transformation in C. roseus.
Keywords: Catharanthine; LC-MS; Protoplast; TIAs; Vinblastine; Vindoline

Zinc-air batteries catalyzed using Co3O4 nanorod-supported N-doped entangled graphene for oxygen reduction reaction - Manna, Narugopal; Singh, Santosh K.; Kharabe, Geeta Pandurang; Torris, Arun; Kurungot, Sreekumar (ACS Applied Energy Materials, 2021)
The work reported here deals with the development of an efficient non-platinum electrocatalyst for electrochemical oxygen reduction reaction (ORR) through a sequential pathway involving hydrothermal treatment followed by freeze-drying to build the desired structural architecture of the catalyst. The designed catalyst (Co3O4/nitrogen-doped entangled porous 3D graphene (NEGF)), which contains Co3O4 nanorods anchored on the surface of three-dimensional (3D)-structured N-doped graphene, was found to display higher ORR activity during single-electrode testing and demonstrate a Zn-air battery (ZAB) system. Under the hydrothermal treatment at 180 degrees C, in the presence of ammonia, nitrogen was doped into the carbon framework of graphene, which subsequently formed a self-assembled entangled 3D structure of graphene after freeze-drying. The hydrothermal treatment and freeze-drying processes were found to play vital roles in tuning the morphological and structural features of the catalyst. The doped nitrogen, apart from its favorable contribution toward ORR, helped facilitate efficient dispersion of oxide nanorods on graphene. Co3O4/NEGF displayed remarkable ORR activity in 0.1 M KOH solution, as evident from the 60 mV onset potential shift compared to the state-of-the-art Pt/C catalyst and the Tafel slope value of 74 mV dec(-1) vs 68 mV dec(-1) for Pt/C. The ZAB fabricated by employing Co3O4/NEGF as the cathode catalyst was found to be an efficient competitor for the system based on the Pt/C cathode. This high performance has been credited to the controlled interplay of the governing factors such as the interfacial interactions leading to the efficient dispersion of metal oxide nanorods, increased catalyst surface area, the cooperative effect arising from the defects present in the N-doped porous 3D graphene, and the synergetic interactions operating in the system.
Keywords: cobalt-oxide nanorod; freeze-drying; hydrothermal; N-doped entangled graphene; oxygen reduction reaction; zinc-air battery

2,4-Di-tert-butylphenol (2,4-DTBP) purified from streptomyces sp. KCA1 from phyllanthus niruri: isolation, characterization, antibacterial and anticancer properties - Seenivasan, Ayswarya; Manikkam, Radhakrishnan; Kaari, Manigundan; Sahu, Amit Kumar; Said, Madhukar; Dastager, Syed G. (Journal of King Saud University Science, 2022)
Objectives: The present study reports the bioactivity of 2,4-Di-tert-butylphenol (2,4-DTBP) purified from an endophytic Streptomyces species KCA1 isolated from the leaves of Phyllanthus niruri and its antibacterial and anticancer properties. Methods: The extracellular metabolites were produced from the strain KCA1 by submerged fermentation using ethyl acetate. The crude extract was further evaluated for antibacterial activity against set of pathogens. Active metabolite from the extract was purified using chromatography techniques and detected its antibacterial activity by disc diffusion assay. The molecular structure of the active molecule was identified through various spectral study. Moreover, the bioactive metabolite 2,4-DTBP was analyzed antibacterial and anti-proliferative activity. Results: Strain KCA1 was identified as Streptomyces sp. In the preliminary screening, the crude extract exhibited broad spectrum activity against various bacterial pathogens. Based on the spectral properties, the active metabolite was identified as 2,4-Di-tert-butylphenol. The MIC of active compound 2,4-DTBP inhibited E. coli ATCC 25922 and S. aureus ATCC 29213 at 50 lg/ml and 0.78 lg/ml, respectively. The IC50 value of 2,4-DTBP was found to be 11.0 lg/ml and 116.8 lg/ml, against breast cancer cell line (MCF7) and normal VERO cell line, respectively. Conclusions: This study concluded that 2,4-DTBP, produced from the endophytic Streptomyces sp. KCA1, is the potential candidate to develop as promising antibacterial and anticancer agent. (C) 2022 The Authors. Published by Elsevier B.V. on behalf of King Saud University.
Keywords: 2; 4-Di-tert-butylphenol; Antibacterial; antiproliferative activity; Endophytic Streptomyces

2-oxoglutarate-dependent dioxygenases drive expansion of steroidal alkaloid structural diversity in the genus Solanum - Sonawane, Prashant D.; Jozawiak, Adam; Barbole, Ranjit; Panda, Sayantan; Abebie, Bekele; Kazachkova, Yana; Gharat, Sachin A.; Ramot, Ofir; Unger, Tamar; Wizler, Guy; Meir, Sagit; Rogachev, Ilana; et al. (New Phytologist, 2022)
Solanum steroidal glycoalkaloids (SGAs) are renowned defence metabolites exhibiting spectacular structural diversity. Genes and enzymes generating the SGA precursor pathway, SGA scaffold and glycosylated forms have been largely identified. Yet, the majority of downstream metabolic steps creating the vast repertoire of SGAs remain untapped. Here, we discovered that members of the 2-OXOGLUTARATE-DEPENDENT DIOXYGENASE (2-ODD) family play a prominent role in SGA metabolism, carrying out three distinct backbone-modifying oxidative steps in addition to the three formerly reported pathway reactions. The GLYCOALKALOID METABOLISM34 (GAME34) enzyme catalyses the conversion of core SGAs to habrochaitosides in wild tomato S. habrochaites. Cultivated tomato plants overexpressing GAME34 ectopically accumulate habrochaitosides. These habrochaitoside enriched plants extracts potently inhibit Puccinia spp. spore germination, a significant Solanaceae crops fungal pathogen. Another 2-ODD enzyme, GAME33, acts as a desaturase (via hydroxylation and E/F ring rearrangement) forming unique, yet unreported SGAs. Conversion of bitter alpha-tomatine to ripe fruit, nonbitter SGAs (e.g. esculeoside A) requires two hydroxylations; while the known GAME31 2-ODD enzyme catalyses hydroxytomatine formation, we find that GAME40 catalyses the penultimate step in the pathway and generates acetoxy-hydroxytomatine towards esculeosides accumulation. Our results highlight the significant contribution of 2-ODD enzymes to the remarkable structural diversity found in plant steroidal specialized metabolism.
Keywords: Solanum; specialized metabolism; steroidal glycoalkaloids (SGAs); structural diversity; Tomato

Acetic acid-catalyzed regioselective C(sp(2))-H bond functionalization of indolizines: concomitant involvement of synthetic and theoretical studies - Mane, Kishor D.; Mukherjee, Anirban; Das, Gourab Kanti; Suryavanshi, Gurunath (Journal of Organic Chemistry, 2022)
An atom economical and environmentally benign protocol has been developed for the regioselective C(sp2)-H bondfunctionalization of indolizines. The acetic acid-catalyzed cross-coupling reaction proceeds under metal-free conditions, producing awide range of synthetically useful indolizine derivatives. The present protocol showed good functional group tolerance and broadsubstrate scope in good to excellent yields. Quantum mechanical investigation using density functional theory (DFT) has played acrucial role in understanding that acetic acid is the key player in determining the actual pathway as the catalyst and its ultrafastnature. Different pathways involving inter- and intramolecular proton transfer, with or without acetic acid, were investigated.Calculated results revealed that a proton shuttle mechanism is involved for the least energetic, most favorable acetic acid-catalyzedpathway. Furthermore, regioselectivity has also been explained theoretically.

Air-cathode interface-engineered electrocatalyst for solid-state rechargeable zinc-air batteries - Manna, Narugopal; Singh, Santosh K.; Kurian, Maria; Torris, Arun; Kurungot, Sreekumar (ACS Applied Energy Materials, 2022)
Solid-state rechargeable zinc-air batteries (ZABs) are gaining interest as a class of portable clean energy technology due to their advantages such as high theoretical energy density, intrinsic safety, and low cost. It is expected that an appropriately triple-phase boundary (TPB) engineered, bifunctional oxygen reaction (OER and ORR) electrocatalyst at the air- electrode of ZABs can redefine the performance characteristics of these systems. To explore this possibility, an electrode material consisting of manganese- cobalt-based bimetallic spinel oxide (MnCo2O4)-supported nitrogen-doped entangled graphene (MnCo2O4/NEGF) with multiple active sites responsible for facilitating both OER and ORR has been prepared. The porous 3D graphitic support significantly affects the bifunctional oxygen reaction kinetics and helps the system display a remarkable catalytic performance. The air electrode consisting of the MnCo2O4/NEGF catalyst coated over the gas diffusion layer (GDL) ensures the effective TPB, and this feature works in favor of the rechargeable ZAB system under the charging and discharging modes. As an important structural and functional attribute of the electrocatalyst, the porosity and nitrogen doping in the 3D conducting support play a decisive aspect in controlling the surface wettability (hydrophilicity/hydrophobicity) of the air electrode. The fabricated solid-state rechargeable ZAB device with the developed electrode displayed a maximum peak power density of 202 mW cm(-2), which is significantly improved as compared to the one based on the Pt/C + RuO2 standard catalyst pair (124 mW cm(-2)). The solid-state device which displayed an initial charge-discharge voltage gap of only 0.7 V at 10 mA cm(-2) showed only a small increment of 86 mV after 50 h.
Keywords: air-cathode interface; bifunctional oxygen catalyst; N-doped entangled graphene; solid-state zinc-air battery; spinel oxides

Algal biomass-loaded hydrogel scaffolds as a biomimetic platform with antibacterial and wound healing activities - Agarwal, Aakanksha; Kumar, Arun; Garg, Piyush; Chakraborty, Arnab; Verma, Ranjan; Sarwat, Maryam; Gupta, Ajay; Sasmal, Pijus K.; Verma, Yogesh Kumar; Chowdhury, Chiranjit; Mukherjee, Monalisa (ACS Applied Polymer Materials, 2022)
The confluence of hydrogel scaffolds and dried algal biomass (AB), consisting of all the bioactive compounds, offers the possibility to facilitate wound healing while simultaneously instilling antibacterial benefits. For this purpose, a single-step synthesis of algal (Chlorella sorokiniana) biomass-loaded hydrogel scaffolds (AHS) was achieved. C. sorokiniana has been used in different areas for several years and has proved attractive to the pharmaceutical and cosmetic industries. Of note, the presence of phytochemicals and various bioactive compounds provides an added health benefit. Hitherto, we report AHS with accelerated wound healing along with potent anti-inflammatory and antibacterial properties. AHS consisting of different concentrations of AB was applied for 14 days on excisional wounds in mice. Microscopic analyses, assessment of proinflammatory and anti-inflammatory cytokines, and histological studies were performed to investigate wound healing. These scaffolds were extensively characterized and studied using Fourier transform infrared, X-ray diffraction, Raman, atomic force microscopy, transmission electron microscopy, scanning electron microscopy, swelling, rheological, thermal, and mechanical analyses. AHS have excellent biocompatibility in addition to significant antibacterial activity against Escherichia coli (99%) and Staphylococcus aureus (98%). We believe that the as-synthesized AHS have the potential to broaden the arsenal of more effective wound healing processes along with antibacterial activities.
Keywords: antibacterial activity; Biomass; hydrogel scaffold; microalgae; wound Healing

Alternative splicing modulation mediated by G-quadruplex structures in MALAT1 lncRNA - Ghosh, Arpita; Pandey, Satya Prakash; Ansari, Asgar Hussain; Sundar, Jennifer Seematti; Singh, Praveen; Khan, Yasmeen; Ekka, Mary Krishna; Chakraborty, Debojyoti; Maiti, Souvik (Nucleic Acids Research, 2022)
MALAT1, an abundant lncRNA specifically localized to nuclear speckles, regulates alternative-splicing (AS). The molecular basis of its role in AS remains poorly understood. Here, we report three conserved, thermodynamically stable, parallel RNAG-quadruplexes (rG4s) present in the 3' region of MALAT1 which regulates this function. Using rG4 domain-specific RNA-pull-down followed by mass-spectrometry, RNA-immuno-precipitation, and imaging, we demonstrate the rG4 dependent localization of Nucleolin (NCL) and Nucleophosmin (NPM) to nuclear speckles. Specific G-to-A mutations that abolish rG4 structures, result in the localization loss of both the proteins from speckles. Functionally, disruption of rG4 in MALAT1 phenocopies NCL knockdown resulting in altered pre-mRNA splicing of endogenous genes. These results reveal a central role of rG4s within the 3' region of MALAT1 orchestrating AS.

Amino acid-derived ABCBA-type antifouling biohybrid with multi-stimuli responsivity and contaminant removal capability - Kumar, Devendra; Mohammad, Sk Arif; Kumar, Anand; Mane, Shivshankar R.; Banerjee, Sanjib (Polymer Chemistry, 2022)
Multi-stimuli (pH/thermo/redox)-responsive amphiphilic poly(cysteine methacrylamide)-block-poly(2-(dimethylamino)ethyl methacrylate)-block-polybutadiene-block-poly(2-(dimethylamino)ethyl methacrylate)-block-poly(cysteine methacrylamide) (PCysMAM-b-PDMAEMA-b-PB-b-PDMAEMA-b-PCysMAM) pentablock copolymer biohybrids, based on hydrophobic PB, ampholytic redox responsive PCysMAM and dual (pH and temperature) stimuli responsive PDMAEMA segments, are synthesized via a four-step synthesis protocol. The synthesis protocol involves: (1) in situ post polymerization modification of living polybutadiene-based carbanionic species to prepare hydroxyl terminated polybutadiene (HTPB); (2) introduction of an initiating functionality (capable of acting as an ATRP initiator) to HTPB, yielding a telechelic ATRP macroinitiator (Br-PB-Br); (3) recyclable alloy-mediated successive RDRP of DMAEMA and CysMAM, yielding a series of PCysMAM-b-PDMAEMA-b-PB-b-PDMAEMA-b-PCysMAM (A-B-C-B-A) pentablock copolymers with various chain lengths; and (4) conversion of the PDMAEMA block to poly(quaternary ammonium) (PQA) via quaternization. The stimuli responsiveness of the copolymer is investigated against changes in pH, temperature and redox. The pentablock copolymer self-assembles into spherical nanospheres, can switch between its monocationic, zwitterionic and monoanionic charged states, exhibits antifouling behaviour and is capable of removing ionic contaminants from water. These pentablock copolymers may emerge as a promising material for emerging applications.

Antibiotic natural product hunanamycin A: Lead identification towards anti-Salmonella agents - Shingare, Rahul D.; MacMillan, John B.; Reddy, D. Srinivasa (European Journal of Medicinal Chemistry, 2022)
Design and synthesis of library of compounds around the antibiotic natural product hunanamycin A scaffold and their biological evaluation are disclosed here. These efforts resulted in identification of a lead compound 36, which is a structurally simplified analogue of original hunanamycin A with impressive activity against Salmonella enterica and possesses other druggable properties. In addition, no acute oral toxicity was observed for compound 36 in Swiss albino mice dosed up to 2 g/kg. It has the potential to be developed for the treatment of food infections caused by Salmonella. (c) 2022 Published by Elsevier Masson SAS.
Keywords: Antibiotic natural product; Hunanamycin A; Riboflavin synthase; Salmonella; Structure activity relationship

Antimicrobial two-dimensional covalent organic nanosheets (2D-CONs) for the fast and highly efficient capture and recovery of phosphate ions from water - Dey, Subhasis; Das, Sribash; Patel, Anjali; Raj, K. Vipin; Vanka, Kumar; Manna, Debasis (Journal of Materials Chemistry A, 2022)
The retrieval of depleting resources from wastewater could help resolve the mounting demands for resources in our society. Phosphate is an essential nutrient for all living things. However, the diminution of global reserves of phosphate rock could significantly affect our food security in the near future. At the same time, the removal of phosphates and pathogens is of great importance for water security and de-eutrophication. The specific pH-dependent adsorption and desorption of phosphate ions by water-insoluble adsorbents is an exciting strategy for removing and recovering phosphates from contaminated water. Herein, we report the development of new two-dimensional guanidine-containing covalent organic nanosheets (2D-gCONs). This water-insoluble amorphous polymer (exfoliated) selectively sequestered phosphate ions in the presence of other competing anions and could be reused for multiple cycles. The polymer showed a fast removal of phosphate ions with a maximum adsorption capacity of 398 mg g(-1) (pH 7.0). The sequestered phosphate ions could be easily reclaimed, and the polymer could be recycled just by altering the pH (similar to 10.0) of the aqueous solution. The guanidinium moieties played a pivotal role in exfoliation in aqueous medium and in the antibacterial activities against Gram-negative and Gram-positive bacteria. We hypothesize that the current study may advance the design of water-insoluble CONs to remove and recover phosphate ions from wastewater and could help alleviate the negative impact of water eutrophication. This strategy can also be tweaked to address other severe environmental challenges.

Assessment of a multipoint dosing approach for exothermic nitration in CSTRs in series - Mule, G. M.; Kulkarni, S.; Kulkarni, A. A. (Reaction Chemistry & Engineering, 2022)
The exothermic aromatic nitration of a biaryl compound is studied using various configurations of CSTRs in series. The relative rates of heat generation and heat removal in different configurations are compared to identify safer options while taking scale-up-related decisions. The effects of different parameters on the steady-state temperatures of the CSTRs are demonstrated through simulations. The use of multipoint dosing in three different CSTRs of increasing volume in series was compared with the use of standard CSTRs of equal volume in series. The distribution of the nitrating agent in three different CSTRs in series helped to distribute the heat duty and thereby helped maximise the throughput almost 2.4-fold when compared with a conventional approach based on the co-addition of all the reactants in the first CSTR. Various feed combinations were studied, and suitable designs that fall within the safe operating range of CSTRs for highly exothermic reactions are given.

Behavioral and proteomic studies reveal methylglyoxal activate pathways associated with alzheimer’s disease - Patil, Gouri; Kulsange, Shabda; Kazi, Rubina; Chirmade, Tejas; Kale, Vaikhari; Mote, Chandrashekhar; Aswar, Manoj; Koratkar, Santosh; Agawane, Sachin; Kulkarni, Mahesh (ACS Pharmacology & Translational Science, 2022)
Diabetes is one of the major risk factors for Alzheimer’s disease (AD) development. The role of elevated levels of glucose, methylglyoxal (MGO), and advanced glycation end products (AGEs) in the pathogenesis of AD is not well understood. In this pursuit, we studied the role of methylglyoxal in the pathogenesis of AD in rat models. The elevated plus-maze (EPM) behavioral study indicated that MGO induces anxiety. Treatment of telmisartan (RAGE expression inhibitor) and aminoguanidine (MGO quencher) attenuated MGO induced anxiety. Further, hippocampal proteomics demonstrated that MGO treated rats differentially regulate proteins involved in calcium homeostasis, mitochondrial functioning, and apoptosis, which may affect neurotransmission and neuronal plasticity. The hippocampal tau phosphorylation level was increased in MGO treated rats, which was reduced in the presence of aminoguanidine and telmisartan. The plasma fructosamine level was increased upon MGO treatment. Hippocampal histochemistry showed vascular degeneration and neuronal loss upon MGO treatment. This study provides mechanistic insight into the role of MGO in the diabetes-associated development of AD.

Blue fluorescence of cyano-tryptophan predicts local electrostatics and hydrogen bonding in biomolecules - Haldar, Tapas; Chatterjee, Srijan; Alam, Md Nirshad; Maity, Pradip; Bagchi, Sayan (Journal of Physical Chemistry B, 2022)
Cyano-tryptophan is an unnatural fluorescent amino acid that emits in the visible region. Along with the structural similarity with tryptophan, the unique photophysical properties of this fluorophore make it an ideal probe for biophysical research. Herein, combining fluorescence spectroscopy, infrared spectroscopy, and molecular dynamics simulations, we show that the cyano-tryptophan's emission energy quantifies the underlying bond-specific noncovalent interactions in terms of the electric field. We further report the use of fluorophore's emission energy to predict its hydrogen bond characteristics. We demonstrate that combining experiments with molecular dynamics simulations can provide the hydrogen bonding status of the nitrile moiety. In addition, we report a method to differentiate between aqueous and nonaqueous hydrogen-bonding partners. Using a phenomenological approach, we demonstrate that the presence of the cyano-indole moiety is responsible for the distinct correlations between the fluorophore's emission and the electrostatic forces on the nitrile bond. As indole is a privileged scaffold for both native amino acids and nucleobases, cyano-indoles will have many multifaceted applications.

BQ-AurIPr: a redox-active anticancer Au(i) complex that induces immunogenic cell death - Mule, Ravindra D.; Kumar, Akhilesh; Sancheti, Shashank P.; Senthilkumar, B.; Kumar, Himanshu; Patil, Nitin T. (Chemical Science, 2022)
Immunogenic Cell Death (ICD) is a unique cell death mechanism that kills cancer cells while rejuvenating the anticancer immunosurveillance, thereby benefiting the clinical outcomes of various immuno-chemotherapeutic regimens. Herein, we report development of a library of benzo[a]quinolizinium-based Au(i) complexes through an intramolecular amino-auration reaction of pyridino-alkynes. We tested 40 candidates and successfully identified BQ-AurIPr as a novel redox-active Au(i) complex with potent anticancer properties. BQ-AurIPr efficiently triggered generation of DAMPs - the hallmarks of ICD - and was superior in terms of efficiency compared to FDA-approved drugs known to induce ICD. BQ-AurIPr significantly increased immunogenicity of cancer cells enhancing their phagocytosis when co-cultured with immune cells. Our investigation reveals that BQ-AurIPr induces oxidative stress inside mitochondria leading to mitophagy, as the mechanism for immunogenic cell death in A549 cells.

Cardol: Cashew nut shell liquid (CNSL) - derived starting material for the preparation of partially bio-based epoxy resins - Ketan Makwana; Amol B. Ichake; Vinayak Valodkar; G. Padmanaban; Manohar V. Badiger; Prakash P. Wadgaonkar (European Polymer Journal, 2022)
Cardol is one of the interesting constituents of cashew nut shell liquid (CNSL) - a by-product of cashew processing industry- and it amounts to 15–20% by weight in natural CNSL. Chemically, cardol is a 15-carbon chain-substituted resorcinol wherein the side chain predominately contains mixture of one, two and three double bonds. Cardol on reaction with epichlorohydrin in the presence of sodium hydroxide afforded diglycidyl ether of cardol (DGEC). DGEC is a viscous free-flowing liquid (bulk viscosity 70 cP at 25 °C) and thus offers advantages in terms of ease of processing. DGEC and various compositions of DGEC with commercially available diglycidyl ether of bisphenol A (DGEBA) were cured with two amine hardeners, namely, isophorone diamine (IPDA) and diethylene triamine (DETA). The effects of different ratios of amine/epoxy (nah/ne) on cure characteristics were studied. The epoxy thermosets were characterized by DSC, TGA, DMA and tensile testing. DSC analysis showed glass transition temperature (Tg) values in the range 63–155 °C for IPDA-cured thermosets, while DETA-cured thermosets exhibited Tg values in the range 45–145 °C. Td5% values, determined by TG analysis of epoxy thermosets, were in the range 347–359 °C indicating their reasonably good thermal stability. Dynamic mechanical analysis showed storage modulus (E’) in the range 0.75–2.54 GPa and 0.51–2.24 GPa for IPDA-cured and DETA-cured thermosets, respectively. The E’ value of epoxy thermosets was found to decrease with increase in molar proportion of DGEC in the formulations with DGEBA while elongation at break was found to increase from 3.1% to 9.7% and 2.8% to 5.1% for IPDA- and DETA-cured systems, respectively. SEM images of cryogenically fractured surfaces of cured thermosets based on studied compositions of DGEBA and DGEC did not indicate any phase separation implying homogeneous mixing of both the epoxy resins.
Keywords: bio-based; Cardol; cashew nut shell liquid (CNSL); Epoxy resins; Storage modulus