Studies on use of sodium poly acrylate (SPA) for low salt animal skinpreservation - Sandhya, K. V.; Brindha, Velappan; Abinandan, Sudharsanam; Vedaraman, N.; John, Sundar V.; Suresha, P. R.; Badiger, Manohar; Chinnaraj, Velappan kandukalpatti; Muralidharan, C. (IULTCS CONGRESS 2017, 2017)
In this study, commercial sodium poly acrylate (SPA) is used along with sodium chloride for low salt skin preservation. SPA is a super-absorbent polymer which can absorb water many times of its own weight.

Study of nanofiber scaffolds of PAA, PAA/CS, and PAA/ALG for its potential use in biotechnological applications - Rodolfo, Velasco; Ricardo, Vera-Graziano; López-Maldonado, E.A.; Mercedes, Oropeza; Dastager, Syed; Adriana, Álvarez-Andrade; Ana, leticia Iglesias; Luis, Jesús Villarreal-Gómez (International Journal of Polymeric Materials, 2017)
In recent times, electrospun nanofibers have been widely studied from several biotechnological approaches; in this work, poly (acrylic acid) solutions mixed with chitosan and alginate were electrospun and characterized in order to determine the behavior of these fibers when used in combination with bacteria, different samples were incubated with the bacterial strains: Streptomyces spp., Micromonospora spp. and Escherichia coli and a OD600 test was performed. The formation of nanofibers via electrospinning and the physicochemical properties of the obtained fibers were evaluated. Results showed that the presence of Chitosan enhanced the thermal stability of poly (acrylic acid), since poly (acrylic acid)/alginate fibers lost 5% of their mass at 41°C while poly (acrylic acid)/chitosan lost this amount at around 125°C. The fibers demonstrated suitable characteristics to be used as a bacteria bioreactor.

Study of the effect of operating parameters on the extractive distillation of isopropyl alcohol–water mixture using dimethyl sulphoxide as an entrainer - Ghuge, Pravin D.; Mali, Nilesh A.; Sirsam, R. S. (Indian Chemical Engineer, 2017)
Abstract: In this paper, the simulation analysis of separation of isopropyl alcohol (IPA)–water via extractive distillation by using dimethyl sulphoxide as an entrainer is presented. The steady-state simulation for this process was done using Aspen Plus simulator. The aim of this work is to study the effect of various operating parameters such as number of stages, molar reflux ratio, binary feed stage number, entrainer feed stage number, temperature of entrainer feed and entrainer to feed molar ratio on the purity and energy consumption. The sensitivity of these parameters serves as a basis to choose the optimum operating conditions to maximize the IPA purity and minimize the energy requirement. In this analysis, among various operating parameters, those which directly affect the IPA purity and the parameters which affect the reboiler duty, for the given separation task, are identified. Simulation results with optimum operating conditions and their economic analysis are also presented.
Keywords: Aspen Plus Simulators; Azeotrope; Computer software; Distillation; Energy requirements; Energy utilization; Extractive distillation; Isopropyl alcohol/water; Isopropyl alcohols; Operating parameters; Optimum operating conditions; Sensitivity analysis; simulation; SimulationSteady-state simulations; Solvents

Study of thermally coupled distillation systems for energy-efficient distillation - Saxena, Neha; Mali, Nilesh; Satpute, Satchidanand (Sadhana-Academy Proceedings in Engineering Sciences, 2017)
Distillation is one of the most widely used separation unit operations in process industries, although it is quite energy intensive. In many cases, the enormous energy requirements for distillation make it economically infeasible to carry out the separation. Thermally coupled distillation system (TCDS) is an advanced distillation method that provides significant energy savings of about 30% as compared with conventional distillation column sequences. The most well-known TCDS sequence, the Petlyuk configuration, has some operational challenges due to bidirectional vapour flow, which makes its implementation difficult in two-column mode. To overcome these limitations, a number of unidirectional vapour flow configurations have been proposed in the literature. The work on simulation analysis for such configurations is limited. In this paper, simulation models for two such configurations are developed, analyzed and compared with the Petlyuk and conventional distillation column sequences for separation of equimolar mixture of benzene-toluene-ethylbenzene.
Keywords: Distillation; energy efficient; Petlyuk; simulation; thermally coupled

Study on doped heterojunctions in TiO2 nanotubes: an efficient photocatalyst for solar water splitting - Preethi, L. K.; Antony, Rajini P.; Mathews, Tom; Walczak, Lukasz; Gopinath, Chinnakonda S. (Scientific Reports, 2017)
The two important factors that affect sunlight assisted water splitting ability of TiO2 are its charge recombination and large band gap. We report the first demonstration of nitrogen doped triphase (anatase-rutile-brookite) TiO2 nanotubes as sun light active photocatalyst for water splitting with high quantum efficiency. Nitrogen doped triphase TiO2 nanotubes, corresponding to different nitrogen concentrations, are synthesized electrochemically. Increase in nitrogen concentration in triphase TiO2 nanotubes is found to induce brookite to anatase phase transformation. The variation in density of intra-band states (Ti3+ and N 2p states) with increase in nitrogen doping are found to be critical in tuning the photocatalytic activity of TiO2 nanotubes. The presence of bulk heterojunctions in single nanotube of different nitrogen doped TiO2 samples is confirmed from HRTEM analysis. The most active nitrogen doped triphase TiO2 nanotubes are found to be 12 times efficient compared to pristine triphase TiO2, for solar hydrogen generation. The band alignment and charge transfer pathways in nitrogen doped TiO2 with triphase heterojunctions are delineated. Bulk heterojunctions among the three phases present in the nanotubes with intra-band defect states is shown to enhance the photocatalytic activity tremendously. Our study also confirms the theory that three phase system is efficient in photocatalysis compared to two phase system.

Sulfamic acid-catalyzed, environmentally benign synthesis of bis-tetronic acids at ambient temperature - Pandit, Kapil S.; Desai, Uday V.; Wadgaonkar, Prakash P.; Kodam, Kisan M. (Research on Chemical Intermediates, 2017)
An enviro-economic protocol has been described for the synthesis of bis-tetronic acids by pseudo-three-component condensation between aldehydes/isatins and tetronic acid using sulfamic acid as a solid acid catalyst. Easy commercial availability of the catalyst at extremely low cost, excellent yields and avoidance of conventional purification procedures are the main merits of this energy efficient protocol.

Superoxide generation and its involvement in the growth of mycobacterium smegmatis - Yeware, Amar M.; Shurpali, Ketaki D.; Athalye, Meghana C.; Sarkar, Dhiman (Frontiers in Microbiology, 2017)
Superoxide generation is inevitable in aerobic organisms, most of which have developed mechanisms to detoxify superoxides. However, its significance has not been clearly understood in mycobacteria. This study demonstrates that NADH oxidase is the major source of superoxide in Mycobacterium smegmatis and elucidates the involvement of superoxide in M. smegmatis growth. The maximum inhibition of superoxide generation was observed in the presence of diphenyleneiodonium chloride (DPI), an NADH oxidase inhibitor, compared to other standard inhibitors. After incubation for 24 h, the number of colony forming units (CFUs) was reduced by 6.8 log10 compared to the untreated culture. The inhibitory effect of DPI on M. smegmatis was reversed when the same culture was supplemented with menadione and pyrogallol, which are superoxide generators. Thus, this study reports the source of superoxide generation and its involvement in the growth of M. smegmatis.

Super-resolution probe to monitor HNO levels in the endoplasmic reticulum of cells - Ali, Firoj; Sreedharan, Sreejesh; Ashoka, Anila Hoskere; Saeed, Hiwa K.; Smythe, Carl G. W.; Thomas, Jim A.; Das, Amitava (Analytical Chemistry, 2017)
Selective detection of nitroxyl (HNO), which has recently been identified as a reactive nitrogen species, is a challenging task. We report a BODIPY-based luminescence ON reagent for detection of HNO in aqueous solution and in live RAW 264.7 cells, based on the soft nucleophilicity of the phosphine oxide functionality toward HNO. The probe shows high selectivity to HNO over other reactive oxygen/nitrogen and sulfur species. Luminescence properties of the BODIPY-based chemodosimetric reagent make it an ideal candidate for use as a reagent for super-resolution structured illumination microscopy. The viability of the reagent for biological in vivo imaging application was also confirmed using Artemia as a model.

Supramolecular synthons in bumetanide cocrystals and ternary products - Allu, Suryanarayana; Bolla, Geetha; Tothadi, Srinu; Nangia, Ashwini (Crystal Growth & Design, 2017)
A novel design strategy for cocrystals of the diuretic sulfonamide drug bumetanide (BUM) with carboxamides is reported based on reliable supramolecular synthons. Binary cocrystals of BUM with pyridine carboxamides, pyridones, and cytosine were obtained by solvent assisted grinding followed by solution crystallization. All cocrystal structures exhibit hydrogen bonding of the coformer with the carboxylic acid group of BUM via heterosynthons which replace the acid homodimer in the drug crystal structure. Pyridones are inserted as N-H center dot center dot center dot O dimers which are in turn bonded to the acid group of BUM, while the pyridine amide coformers interact via the acid amide heterosynthon. Cocrystal polymorphs were obtained for bumetanide isonicotinamide cocrystal structure with the sulfonamide pyridine and sulfonamide acid synthons. Careful crystal packing analysis of BUM structure and nine new binary adducts gave an idea for the design ternary cocrystals, and subsequently four new ternary crystalline products were crystallized. Whereas the binary cocrystal structures were confirmed by single crystal diffraction, the ternary combinations were chatacterized by their unique powder X-ray diffraction patterns as well as by thermal and spectroscopic techniques.

Surface disordered rutile TiO2-graphene quantum dot hybrids: a new multifunctional material with superior photocatalytic and biofilm eradication properties - Biswas, A.; Salunke, G.; Khandelwal, P.; Das, R.; Poddar, P. (New Journal of Chemistry, 2017)
The controlled introduction of defects in semiconductors has contributed to the development of electronic devices and technologies. Recently, chemical control over defects, formation of new hybrid materials and multifunctional nanostructures have been sought in energy, health, and environment related technologies. Surface-disordered anatase-TiO2 has received wide attention due to its exceptional photocatalytic performance. Herein, we demonstrate, for the first time, a one-step aqueous-phase synthesis of a surface-disordered rutile TiO2-graphene quantum dot (TG) hybrid material. The TG-hybrid is a rutile-TiO2 matrix in which homogeneous in situ insertion of GQDs occurs during the growth of the TiO2 particles. The TG-hybrid material showed superior photocatalytic performance with similar to 98% solar light driven photo-degradation of methylene blue (MB) dye within 6 min and similar to 86% of rhodamine-B (RhB) within 4 min which is much better than the photocatalytic performance shown by the rutile-TiO2 (similar to 30% and similar to 20%, respectively) and GQDs (similar to 15% and similar to 8%, respectively), themselves. Moreover, the TG-hybrid also showed enhanced toxicity to Gram-positive (S. aureus) as well as Gram-negative (E. coli, P. aeruginosa) bacterial cells. The growth-curves of E. coli cells, after incubating them with increasing concentrations of the TG-hybrid, showed that the TG-hybrid could effectively inhibit the growth of E. coli cells at a concentration of 60 mu g mL(-1). The effect of UV-light exposure on the bacterial-biofilm disruption by the TG-hybrid material was also investigated. It was observed that in the presence of UV-light, the biofilm disruption done by the TG-hybrid was larger in comparison to the TiO2 and GQDs alone, under the same conditions. The increase in the formation of reactive oxygen species (ROS) in the presence of sunlight for the TG-hybrid may be the reason behind its superior antibacterial and biofilm eradication properties. We believe that the TG-hybrid material will have applications in energy, health and environment related technologies.

Sustainable biobutanol production from pineapple waste by using Clostridium acetobutylicum B 527: Drying kinetics study (Bioresource Technology, 2017)
Present investigation explores the use of pineapple peel, a food industry waste, for acetone-butanol-ethanol (ABE) production using Clostridium acetobutylicum B 527. Proximate analysis of pineapple peel shows that it contains 35% cellulose, 19% hemicellulose, and 16% lignin on dry basis. Drying experiments on pineapple peel waste were carried out in the temperature range of 60-120 degrees C and experimental drying data was modeled using moisture diffusion control model to study its effect on ABE production. The production of ABE was further accomplished via acid hydrolysis, detoxification, and fermentation process. Maximum total sugar release obtained by using acid hydrolysis was 97 g/L with 95-97% and 10-50% removal of phenolics and acetic acid, respectively during detoxification process. The maximum ABE titer obtained was 5.23 g/L with 55.6% substrate consumption when samples dried at 120 degrees C were used as a substrate (after detoxification).

Syntheses and single crystal X-ray diffraction studies of hydroxynicotinic acid based complexes involving supramolecular interactions - Singh, S.K. (Polyhedron, 2017)
Aqua-bridged coordination polymers of Cu(II) and Cd(II) and a mononuclear complex of Cu(II) were solvothermally synthesized with hydroxy-decorated ligands such as 2-hydroxynicotinic acid (2-OHNAH) and 6-hydroxynicotinic acid (6-OHNAH) in aqueous-nonaqueous mixed media. All these complexes were characterized by elemental analyses (C, H, N), FT-IR, thermogravimetric analysis (TGA), powder XRD and single crystal X-ray crystallography. They are formulated as [Cu(2-OHNA)2] 1, [Cu(6-OHNA)2(μ-H2O)2]n 2 and [Cd(6-OHNA)2(μ-H2O)2]n 3. Complex 1 is mononuclear 0D square planar complex which extends its dimensionality by weak supramolecular interactions such as π–π stacking interactions and intermolecular hydrogen bonding. Complexes 2 and 3 are polymeric aqua-bridged 1D infinite chain of Cu(II) and Cd(II), respectively. The central metal ions in these two complexes are in octahedral coordination environment. These two complexes are also assembled by π–π stacking interactions, inter- and intramolecular hydrogen bonding interactions.
Keywords: 2-Hydroxynicotinic Acid; 6-Hydroxynicotinic Acid; Coordination polymer; Polymeric Aqua-Bridged; X-ray diffraction

Synthesis and antimycobacterial screening of new thiazolyl-oxazole derivatives - Abhale, Yogita K.; Sasane, Amit V.; Chavan, Abhijit P.; Shekh, Saddam Husen; Deshmukh, Keshav K.; Bhansali, Sujit; Nawale, Laxman; Sarkar, Dhiman; Mhaske, Pravin C. (European Journal of Medicinal Chemistry, 2017)
In the present study a series of 4-methyl-2-aryl-5-(2-aryl/benzyl thiazol-4-yl) oxazole (4a-v) have been synthesized and evaluated for their preliminary antitubercular, antimicrobial and cytotoxicity activity. Among all the synthesized compounds, 4v reported comparable activity against dormant M. tuberculosis H37Ra and M. bovis BCG strains with respect to standard drug rifampicin. The active compounds from the antitubercular study were further tested for anti-proliferative activity against HeLa, A549 and PANC-1 cell lines using MU assay and showed no significant cytotoxic activity at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antibacterial activities with MIC range of 2.1-26.8 mu g/mL. High potency, lower cytotoxicity and promising antimycobacterial activity suggested that these compounds could serve as good leads for further optimisation and development. (C) 2017 Elsevier Masson SAS. All rights reserved.

Synthesis and antitubercular activity of new thiazolidinones with pyrazinyl and thiazolyl scaffolds - Dhumal, Sambhaji T.; Deshmukh, Amarsinh R.; Khillare, Lalit D.; Arkile, Manisha A.; Sarkar, Dhiman; Mane, Ramrao A. (Journal of Heterocyclic Chemistry, 2017)
Emergence of multidrug resistant and extensively drug resistant tuberculosis has prompted to develop new molecular entities to treat the disease. A series of new 4-thiazolidinones with pyrazinyl and thiazolyl scaffolds has been synthesized, and their antitubercular activity is reported. The title 4-thiazolidinones, N-(pyrazinyl substituted thiazoloylamino)-2-aryl-4-thiazolidinones () have been first time prepared using pyrazinamide as a starting material via five successive steps. The purity and the structures of the intermediates (carboethoxythiazole, acid hydrazide, and azomethines) and title thiazolidinones () have been confirmed by TLC and spectral analyses, respectively. An antitubercular screening of the new 4-thiazolidinones has been performed on bacterial strains, Mycobacterium tuberculosis H37Ra and Mycobacterium BCG using the solutions of different concentrations of the compounds () and the screening results are presented. Compound has displayed notable antitubercular activity.

Synthesis and biological evaluation of 1,2,4-triazole-3-thione and 1,3,4-oxadiazole-2-thione as anti-mycobacterial agents - Sonawane, Amol; Rode, Navnath D.; Nawale, Laxman U.; Joshi, Rohini R.; Joshi, Ramesh A.; Likhite, Anjali P.; Sarkar, Dhiman (Chemical Biology & Drug Design, 2017)
Resistance among dormant mycobacteria leading to multi-drug resistant (MDR) and extremely-drug resistant(XDR) tuberculosis is one of the major threats. Hence, a series of 1,2,4-triazole-3-thione and 1,3,4-oxadiazole-2-thione derivatives (4a-5c) have been synthesised and screened for their anti-tubercular activity against Mycobacterium tuberculosis H37Ra (H37Ra). Thetriazolethiones4b and 4v showed high anti-tubercular activity (both MIC and IC50) against the dormant H37Ra by in vitro and ex vivo. They were shown to have more specificity towards mycobacteria than other gram-negative and gram- positive pathogenic bacteria. The cytotoxicity was almost insignificant up to 100 μg/mL against THP-1, A549 and PANC-1 human cancer cell lines, and solubility was high in aqueous solution, indicating the potential of developing these compounds further as novel therapeutics against tuberculosis infection.

Synthesis and biological evaluation of new fluconazole β-lactam conjugates linked via 1,2,3-triazole - Divse, Jaisingh M.; Mhaske, Santosh B.; Charolkar, Chaitanya R.; Sant, Duhita G.; Tupe, Santosh G.; Deshpande, Mukund V.; Khedkar, Vijay M.; Nawale, Laxman U.; Sarkar, Dhiman; Pore, Vandana S. (New Journal of Chemistry, 2017)
Novel 1,2,3-triazole-linked β-lactam–fluconazole conjugates 12(a–l) were designed and synthesized. The compounds showed potent antifungal activity against two pathogenic Candida strains; Candida albicans ATCC 24433 and Candida albicans ATCC 10231 with MIC values in the range of 0.0625–2 μg mL−1. Compounds 12h, 12j and 12k showed promising antifungal activity against all the tested fungal pathogens except C. neoformans ATCC 34554 compared to fluconazole. Compound 12j in which the β-lactam ring was formed using para-anisidine and benzaldehyde was found to be more potent than fluconazole against all the fungal strains with an IC50 value of <0.015 μg mL−1 for Candida albicans (ATCC 24433). Mechanistic studies for active compounds revealed that the antifungal action was due to ergosterol inhibition. Compounds 12h and 12j at a concentration of 0.125 μg mL−1 caused 91.5 and 96.8% ergosterol depletion, respectively, compared to fluconazole which at the same concentration caused 49% ergosterol depletion. The molecular docking study revealed that all the fluconazole β-lactam conjugates 12(a–l) could snugly fit into the active site of lanosterol 14α-demethylase (CYP51) with varying degrees of affinities. As anticipated, the binding energy for compound 12j (−58.961 kcal mol−1) was much smaller than that for fluconazole (−52.92 kcal mol−1). The synthesized compounds have therapeutic potential for the control of candidemia.

Synthesis and cell imaging applications of fluorescent mono/di/tri-heterocycl- yl-2,6-dicyanoanilines - Pisal, Mahesh M.; Annadate, Ritesh A.; Athalye, Meghana C.; Kumar, Dipak; Chavan, Subhash P.; Sarkar, Dhiman; Borate, Hanumant B. (Bioorganic & Medicinal Chemistry Letters, 2017)
Synthesis of 3,4,5-triheterocyclyl-2,6-dicyanoanilines, starting from heterocyclic aldehydes and 1,2-diheterocycle-substituted ethanones, is described. 2,6-Dicyanoanilines with one or two heterocyclic substituents have also been synthesized. It was found that some of these molecules have selective cell-staining properties useful for cell imaging applications. The compounds 1g, 10f and 11 were found to stain cytoplasm of the cells in contact but not the nucleus while the compound 12 showed affinity to apoptotic cells resulting in blue fluorescence. The cell imaging results with compound 12 were similar to Annexin V-FITC, a known reagent containing recombinant Annexin V conjugated to green-fluorescent FITC dye, used for detection of apoptotic cells. These compounds were found to be non-cytotoxic and have potential application as cell imaging agents.

Synthesis and characterization of D-2PA-Pd(II)@SBA-15 catalyst via ``click chemistry'': highly active catalyst for Suzuki coupling reactions - Pathak, Aruna; Singh, A. P. (Journal of Porous Materials, 2017)
Copper catalysed cycloaddition reaction between azide and terminal alkyne, called as ``click reaction'', was found to be modular approach for the synthesis of facile, highly efficient and recoverable D-2PA-Pd(II)@SBA-15 catalyst. In efforts to synthesize the catalyst, the cycloaddition reaction between azido-functionalized mesoporous SBA-15 and N,N-dimethyl-2-propynylamine (D-2PA) has been carried out, followed by the complexation with PdCl2. To analyze physiochemical properties of synthesized materials, various characterization techniques such as CHN elemental analysis, X-ray diffraction, solid state C-13 and Si-29 NMR spectra, FT-IR, XPS, SEM, TEM and N-2 sorption analysis, TGA and DTA, UV-Vis spectroscopy have been carried out. The synthesized catalyst, D-2PA-Pd(II)@SBA-15, exhibited excellent catalytic activities with good product yield and high TON towards Suzuki coupling reaction of various aryl halides with phenylboronic acid. The effect of solvent, base and temperature on coupling reactions has also been described. The developed protocol offers recyclability of catalyst for multiple (four) times without any appreciable loss in stability and catalytic reactivity.
Keywords: Click reaction; Cycloaddition; mesoporous materials; SBA-15; Suzuki coupling

Synthesis and characterization of polyhydrazides and poly(1,3,4-oxadiazole)s containing multiple arylene ether linkages and pendent pentadecyl chains - Tawade, Bhausaheb V.; Valsange, Nitin G.; Wadgaonkar, Prakash P. (High Performance Polymers, 2017)
A new diacylhydrazide monomer, namely, 4-(4-(4-(4-(hydrazinocarbonyl)phenoxy)-2-pentadecylphenoxy)phenoxy) benzohydrazide (HPPDPB), was synthesized starting from 4-(4-hydroxyphenoxy)-3-pentadecylphenol. HPPDPB was polycondensed with terephthalic acid chloride (TPC), isophthalic acid chloride (IPC) and a mixture of TPC and IPC (50:50 mol%) to obtain polyhydrazides containing multiple arylene ether linkages in the backbone and pendent pentadecyl chains. Polyhydrazides were subsequently cyclized in the presence of phosphorus oxychloride to obtain the corresponding poly(1,3,4-oxadiazole)s. Polyhydrazides and poly(1,3,4-oxadiazole)s exhibited inherent viscosities in the range 0.65–0.72 dL g−1 and 0.54–0.62 dL g−1, respectively, which indicated the formation of reasonably high-molecular weight polymers. Polyhydrazides were soluble in polar aprotic solvents such as N,N-dimethylformamide, N,N-dimethylacetamide (DMAc), 1-methyl-2-pyrrolidinone and pyridine whereas poly(1,3,4-oxadiazole)s exhibited excellent solubility even in common organic solvents such as chloroform, dichloromethane and tetrahydrofuran. Tough, transparent and flexible films of polyhydrazides and poly(1,3,4-oxadiazole)s could be cast from DMAc and chloroform solutions, respectively. X-Ray diffraction studies revealed amorphous nature of polyhydrazides and poly(1,3,4-oxadiazole)s and the formation of layered structure was observed due to ordered packing of pentadecyl chains. The 10% decomposition temperature (T 10) values for poly(1,3,4-oxadiazole)s were in the range 425–440°C indicating their good thermal stability. Glass transition temperature (T g) values of polyhydrazides and poly(1,3,4-oxadiazole)s were in the range 175–192°C and 92–103°C, respectively. The excellent solubility characteristics and the large gap between T g (92–103°C) and T 10 (425–440°C) values give poly(1,3,4-oxadiazole)-containing pendent pentadecyl chains better opportunities for processability.

Synthesis and characterization of six-membered pincer nickelacycles and application in alkylation of benzothiazole - Pandiri, H.; Sharma, D.M.; Gonnade, R.G.; Punji, B. (Journal of Chemical Sciences, 2017)
Six-membered pincer nickelacycle complexes have been synthesized and employed for the catalytic C–H bond alkylation of benzothiazole. The pincer nickelacycle, {κP, κC, κP- (2 - iPr 2POCH 2-C 6H 3- 6 -CH 2OP iPr 2)} NiBr , [(iPr4-POCCCOP)NiBr(2)] was synthesized by the reaction of 1,3 - iPr 2POCH 2-C 6H 4-CH 2OP iPr 2[(iPr4-POCCCOP)-H(1)] with (CH3CN)2NiBr2 in the presence of Et 3N via the C(2)–H activation on ligand 1. Treatment of [(iPr4-POCCCOP)NiBr](2) with AgOAc afforded the complex [(iPr 4-POCCCOP) Ni (OAc)] (3) in good yield. Both the complexes 2 and 3 were characterized by 1H , 13C and 31P -NMR spectral analysis. Further, the molecular structures of complexes 2 and 3 were established by X-ray crystallography. The complex 2 was found to be an active catalyst for the C–H bond alkylation of benzothiazole with alkyl halides containing β–hydrogen atoms. Graphical abstract: Synopsis. Six-membered pincer nickelacycles have been synthesized and structurally characterized, which show catalytic activity for the C–H bond alkylation of benzothiazole with alkyl halides containing β–hydrogen atoms.[Figure not available: see fulltext.].
Keywords: Active catalyst; Alkyl halides; Alkylation; Atoms; Benzothiazole; Benzothiazoles; Catalyst activity; Chemical activation; Crystallography; C–H activation; Hydrogen atoms; Nickelacycles; Pincer complex; Pincer complexessix-membered nickelacycle; six-membered nickelacycle; Spectrum analysis; Synthesis (chemical); Synthesis and characterizations; X ray crystallography

Synthesis and tunable thermoresponsive solution morphologies of 2,2-bis-methylolpropionic acid dendron-azobenzene-poly(N-isopropyl acrylamide) copolymers - Kalva, Nagendra; Ambade, Ashootosh V. (Polymer International, 2017)
Amphiphilic temperature- and photoresponsive linear-dendritic block copolymers comprising second-generation acetonide-2,2-bis-methylolpropionic acid-based polyester dendron and linear poly(N-isopropyl acrylamide) (PNIPAM) linked by an azobenzene unit were synthesized using atom transfer radical polymerization (ATRP) followed by click chemistry. Linear PNIPAM precursor was prepared from an azide-functionalized azobenzene containing ATRP initiator. Two polymers obtained by varying the chain length of the PNIPAM block showed different morphologies and lower critical solution temperature (LCST) values in aqueous solution. Complete change in morphology of the two polymers into large spherical aggregates and nanotubes, respectively, was observed upon heating the micellar solution above LCST. The azobenzene unit was found to undergo trans-cis photoisomerization in the assemblies and caused a change in the microenvironment of an encapsulated hydrophobic dye without any release. Acetonide groups on the dendron were deprotected to afford hydroxylated polymer that showed well-defined morphologies above the LCST and after heating-cooling cycle while significant dye encapsulation was seen only above the LCST. (c) 2017 Society of Chemical Industry

Synthesis, antimycobacterial screening and molecular docking studies of 4-aryl-4′-methyl-2′-aryl-2,5′-bisthiazole derivatives - Abhale, Yogita K.; Shinde, Abhijit D.; Deshmukh, Keshav K.; Nawale, Laxman U.; Sarkar, Dhiman; Choudhari, Prafulla B.; Kumbhar, Santosh S.; Mhaske, Pravin C. (Medicinal Chemistry Research, 2017)
A series of 4-aryl-4′-methyl-2′-aryl-2,5′-bisthia- zole derivatives (5a–o) were synthesized and screened for inhibitory activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis BCG (ATCC 35743) strains. Five lead compounds (5e, 5f, 5g, 5h, and 5o) were further confirmed from their dose dependent effect against MTB and Bovine–Calmette–Guerin. The most promising compounds 5f (MIC90: 11.32 μg/mL), 5h (MIC90: 11.59 μg/mL), and 5o (MIC90: 23.64 μg/mL) showed strong antitubercular activity against dormant MTB and BCG as well as almost insignificant cytotoxicity up to 100μg/mL against HeLa, A549, and PANC-1 human cancer cell lines. Further, the synthesized compounds were found to have potential antibacterial activity against Gram-negative bac- teria, Escherichia coli, Pseudomonas flurescence and Gram- positive bacteria, Staphylococcus aureus, Bacillus subtilis. Most of the synthesized compounds showed moderateactivity against fungal strain Candida albicans. Molecular docking studies of these compounds showed significant interactions with crystal structure of the cytochrome P45014α-sterol demethylase (CYP51) PDB ID: 1E9X. Hydrogen bond interactions with SER261 and VAL395 are important interactions for selective inhibition of designed inhibitors. Compounds 5f, 5h, and 5o showed significant interactions with 1E9X. All the experimental results promote us to consider this series as a starting point for the devel- opment of novel, selective and more potent antitubercular agents in the future.

Synthesis, antitubercular and antimicrobial potential of some new thiazole substituted thiosemicarbazide derivatives - Abhale, Y. K.; Shinde, A.; Deshmukh, K. K.; Nawale, L.; Sarkar, D.; Mhaske, P. C. (Medicinal Chemistry Research, 2017)
The increase in antibiotic resistance due to multiple factors has warranted the need for the search of new compounds which are active against multidrug resistant pathogens. In this context a small focused library of thiosemicarbazide derivatives of 2-arylthiazole-4-carbaldehyde, 4-methyl-2-arylthiazole-5-carbaldehyde and 1-(4-methyl-2-arylthiazol-5-yl) ethanone, (5a–l) has been synthesized. The title compounds were screened for inhibitory activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis Bacille Calmette Guerin (ATCC 35743) strains. The synthesized compounds, 5a–l were further assayed for their cytotoxic activity against the two human cancer cell lines, HeLa and human colon carcinoma 116 cell lines and showed no significant cytotoxic activity against these two cell lines at the maximum concentration evaluated. Further, the synthesized compounds were found to have potential antibacterial activity against Gram-negative bacteria, Escherichia coli, Pseudomonas flurescence and Gram-positive bacteria, Staphylococcus aureus, Bacillus subtilis. Most of the synthesized compounds showed moderate activity against fungal strain Candida albicans. This study provides valuable directions to our ongoing endeavor of rationally designing more potent antimycobacterial agent. © 2017, Springer Science+Business Media, LLC.
Keywords: Antimicrobial activity; Antitubercular activit; Cytotoxicity; Thiazole; Thiosemicarbazide

Synthesis, biological evaluation, and molecular docking studies of novel 3-aryl-5-(alkyl-thio)-1H-1,2,4-triazoles derivatives targeting Mycobacterium tuberculosis - Rode, Navnath D.; Sonawane, Amol D.; Nawale, Laxman; Khedkar, Vijay M.; Joshi, Ramesh A.; Likhite, Anjali P.; Sarkar, Dhiman; Joshi, Rohini R. (Chemical Biology & Drug Design, 2017)
A small library of new 3-aryl-5-(alkyl-thio)-1H-1,2,4-triazoles was synthesized and screened for the antimycobacterial potency against Mycobacterium tuberculosis H37Ra strain and Mycobacterium bovis BCG both in active and dormant stage. Among the synthesized library, 25 compounds exhibited promising anti-TB activity in the range of IC(50)0.03-5.88g/ml for dormant stage and 20 compounds in the range of 0.03-6.96g/ml for active stage. Their lower toxicity (>100g/ml) and higher selectivity (SI=>10) against all cancer cell lines screened make them interesting compounds with potential antimycobacterial effects. Furthermore, to rationalize the observed biological activity data and to establish a structural basis for inhibition of M.tuberculosis, the molecular docking study was carried out against a potential target MTB CYP121 which revealed a significant correlation between the binding score and biological activity for these compounds. Cytotoxicity and in vivo pharmacokinetic studies suggested that 1,2,4-triazole analogues have an acceptable safety index, in vivo stability and bio-availability.

Synthesis, characterization and electrochemical investigations of mixed-ligand copper(II)-organic supramolecular frameworks - Singh, Sandeep K.; Srivastava, Ashish Kumar; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish (Journal of Molecular Structure, 2017)
Two mixed-ligand copper(II)-organic coordination compounds with 5,5'-dimethyl-2,2'-bipyridine (5,5'-Me(2)bpy) as a primary ligand while aliphatic malonate (Hmal) and aromatic 2-hydroxynicotinate (2-OHNA) as secondary ligands, were synthesized. These complexes are formulated as: [Cu(Hmal)(5,5'-Me(2)bPY)(H2O)](ClO4) 1 and [Cu-2(2-OHNA)(2)(5,5'-Me(2)bpy)(2)(NO3)KNO3) 2. These two complexes were structurally characterized by single crystal X-ray diffraction analysis. Characterization was further supported by powder X-ray diffraction analysis, elemental analyses, FT-IR, FAB-MASS and TGA, DSC studies. Cyclic voltammetric and UV-visible spectral studies of these two complexes have also been done. The electrochemical studies of complex 1 in DMSO and DMF have shown that this complex undergoes quasi reversible diffusion-controlled one-electron transfer reaction without any chemical complication while complex 2 in DMSO undergoes quasi-reversible diffusion-controlled one electron transfer reaction, following EC mechanism. The electrochemical behaviour of complex 2 in DMF is complicated probably due to presence of more than one species in solution phase. (C) 2017 Elsevier B.V. All rights reserved.
Keywords: 2 '-bipyridine; 3; 5; 5 '-dimethyl-2; 5-Tricarboxylic acid; Benzene-1; classification; Co-ordination-Compounds; Crystal-structures; cyclic voltammetry; magnetic properties; metal organic framework; Mixed-ligand complex; pi-pi stacking interaction; Polymers; Secondery Building Unit; Structural data; Supramolecular framework; Ternare Komplexe; X-ray diffraction

Synthesis of amphiphilic isoindigo co-polymers for organic field effect transistors: A comparative study - Dharmapurikar, Satej S.; Arulkashmir, Arulraj; Mahale, Rajashree Y.; Chini, Mrinmoy Kumar (Journal of the apllied polymer science, 2017)
In this work, the amphiphilic isoindigo (am-iInd) based conjugated polymers namely poly(am-iInd-DT) and poly(am-iInd-TT) and their regular counterpart poly(reg-iInd-DT) and poly(reg-iInd-TT) were synthesized to compare their opto-electronic and charge transport properties. They were used to fabricate organic field effect transistors. Charge transport properties in conjugated polymers depend upon intermolecular interaction which is strongly affected by the nature of side chains. The amphiphilic nature of the conjugated polymers has little impact on the charge transport properties. The charge carrier mobility of amphiphilic conjugated polymers was comparable with the regular polymers except poly(reg-iInd-DT) which can be correlated by X-ray diffraction and thin film morphology. (c) 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45461.
Keywords: Alkyl; Applications; Conducting polymers; Copolymers; Optical and Photovoltaic applications; conjugated polymers; High-performance; mobility; Packaging; Semicondoctors; Side-chains; Solar-cells; Thin-film Transformer

Synthesis of annulated bis-indoles through Au(I)/brønsted acid-catalyzed reactions of (1H-indol-3-yl)(aryl)methanols with 2-(arylethynyl)-1H-indoles - Patil, Nitin T.; Inamdar, Suleman M.; Gonnade, Rajesh Ghanshyam (Organic & Biomolecular Chemistry, 2017)
A general method to access annulated bis-indoles from (1H-indol-3-yl)(aryl)methanols and 2-(arylethynyl)-1H-indoles under the catalysis of the Ph3PAuOTf/Brønsted acid binary catalyst system has been developed. The reaction was found to proceed in a highly efficient manner and benefit from easy-to-make starting materials, broad substrate scope and operational simplicity. The potential of this method has also been exemplified for the synthesis of pyrrole-annulated indoles using 2-(phenylethynyl)-1H-indoles and phenyl(1H-pyrrol-2-yl)methanols. Furthermore, the use of a ternary catalyst system, involving PdCl2/Brønsted acid/Ph3PAuOTf catalysts, has been realized for the synthesis of annulated bis-indoles starting directly from 2-(phenylbuta-1,3-diyn-1-yl)aniline and (1H-indol-3-yl)(aryl)methanol. Mechanistically, this reaction is very interesting since the overall process involves three different catalytic cycles catalyzed by three different catalysts in a relay fashion.

Synthesis of copper nanoparticles in presence of surfactants and evaluation of heat transfer performance of copper nanofluid - Kapadnis, Chetan V.; Gundeli, Kartik P.; Saini, Daulat R.; Bhatkhande, Dhananjay S. (Journal of Nanofluids, 2017)
Copper nanoparticles were synthesized by reduction of copper nitrate hexahydrate using glucose as a green reducing agent. Effect of various synthesis parameters such as the amount of reducing agent, type of surfactant, the concentration of surfactant on particle size and morphology has been studied. Particles thus synthesized were characterized using analytical tools like X-ray Diffraction (XRD), Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). XRD results show copper peaks at 2 angles 43.34, 50.48 and 74.19° corresponding to the planes (111), (200) and (220) respectively and possessing FCC (Face Centred Cubic) crystal lattice and polydispersed particles with crystallite size ranging from 43 to 103 nm. Further Cu nanoparticles were dispersed in water to prepare nanofluid and heat transfer properties such as heat transfer coefficient, viscosity and density were evaluated. Nanofluid models proposed elsewhere were also used for theoretical property evaluations. Nearly 100% increase in heat transfer coefficient was observed at 1% (by volume) particle concentration of copper nanoparticles in water.
Keywords: Chemical Reduction; Copper nanoparticles; green synthesis; Nanofluids; surfactant

Synthesis of extended conjugated indolyl chalcones as potent anti-breast cancer, anti-inflammatory and antioxidant agents - Bhale, Pravin S.; Chavan, Hemant V.; Dongare, Sakharam B.; Shringare, Sadanand N.; Mule, Yoginath B.; Nagane, Samadhan S.; Bandgar, Babasaheb P. (Bioorganic & Medicinal Chemistry Letters, 2017)
In the present investigation, synthesis of a series of extended conjugated delta-chloro-alpha-cyano substituted indolyl chalcones (5a-p) was accomplished by reacting 3-cyanoacetylindole 2 with 3-chloro-3-phenylpropenal 4 in the presence of piperidine. The structural interpretations of newly synthesized compounds were based on chemical and spectroscopic evidences. Anti-tumor evaluation of the synthesized compounds in vitro against MCF-7 (breast carcinoma) cell line revealed that they possess high anti-tumor activities. Among them, compound 5e and 5a demonstrated excellent activity against breast carcinoma (GI(50) <0.1 and mu M respectively) as good as adriamycin (GI(50) <0.1 mu M). The compounds were also screened against the normal Vero monkey cell line, which showed moderate selectivity against inhibition of cancer cells. The effect of extended conjugation on activity authenticated by comparing activity profile of compound 5a, 5i and 5m with their simple analogues. Among the synthesized compounds, 5i and 51 were found to be active anti-inflammatory agents in addition to having noteworthy antioxidant potential. These results suggest the possible use of these compounds for the design and development of novel anti breast cancer agents. (C) 2017 Elsevier Ltd. All rights reserved.

Synthesis of fluorinated heterocycles via multicomponent reactions - Shinde, S. S.; Thore, S. N.; Pawar, R. P.; Ameta, K. L.; Patil, S. N. (Multicomponent reactions: synthesis of bioactive heterocycles, 2017)
Fluorine is one of the most important elements in the periodic table because it is the most electronegative element, makes the strongest C-F bond, and is more polarized in organic synthesis. These unique and distinctive properties of fluorine make it very useful and widely applicable in the pharmaceutical and agrochemical industries. Hydrogen replaced with the fluorine of an organic compound can tune the pharmacokinetic and pharmacological properties of the molecule, which improve solubility, membrane permeability, 184metabolic stability, and receptor-binding properties compared with nonfluorinated analogs.1 Due to these unique properties of fluorine, organofluorine compounds are very applicative in medicinal, pharmaceutical, agrochemical, and material chemistry. This wide applicability of fluorine and organofluorine compounds attracts the attention of researchers and chemists. Labeled fluorine-18 is one of the most commonly used positron emitting radioisotopes in positron emission tomography (PET) imaging technology, which can detect presymptomatic biochemical changes in body tissues. In addition to its use in PET-CT, fluorine is used in preparation of chemically resistant polymer materials such as polytetrafluoroethylene (Teflon) or polarity to piezoelectric material such as polyvinylidene fluoride and organic liquid crystals for displays. Because of these many advantages of fluorine, organic chemists have developed various methods to introduce fluorine in organic molecules. During the last two decades, numerous organofluorine heterocyclics have been developed; in this chapter, we have summarized synthesis of multicomponent reactions (MCRs) in application of fluorine compound synthesis.

Synthesis of functional polymers of polar and nonpolar monomers by living and/or controlled polymerization - Chowdhury, S. R.; Sivaram, S. (Functional polymers: design, synthesis, and applications, 2017)

Synthesis of functionalized β-keto arylthioethers by the aryne induced [2,3] Stevens rearrangement of allylthioethers - Thangaraj, Manikandan; Gaykar, Rahul N.; Roy, Tony; Biju, Akkattu T. (Journal of Organic Chemistry, 2017)
A mild and transition-metal-free synthesis of β-keto arylthioethers has been developed by the aryne triggered [2,3] Stevens rearrangement of allylthioethers. The key sulfur ylide intermediate for the rearrangement was formed by the S-arylation of allylthioethers with arynes generated from 2-(trimethylsilyl)aryl triflates using CsF. Later, the reaction products are converted into valuable heterocycles in two steps.

Synthesis of gamma-WO3 thin films by hot wire-CVD and investigation of its humidity sensing properties - Jadkar, Vijaya; Pawbake, Amit; Waykar, Ravindra; Jadhavar, Ashok; Date, Abhijit; Late, Dattatray; Pathan, Habib; Gosavi, Suresh; Jadkar, Sandesh (Physica Status Solidi A-Applications and Materials Science, 2017)
In this study, monoclinic tungsten oxide (gamma-WO3) have been grown in a single step using HW-CVD method by resistively heating W filaments in a constant O-2 pressure. The formation of gamma-WO3 was confirmed using low angle-XRD and Raman spectroscopy analysis. Low angle-XRD analysis revealed that as-deposited WO3 film are highly crystalline and the crystallites have preferred orientation along the (002) direction. HRTEM analysis and SAED pattern also show the highly crystalline nature of WO3 with d spacing of similar to 0.38 nm, having an orientation along the (002) direction. Surface topography investigated by SEM analysis shows the formation of a uniform and homogeneous cauliflower like morphology throughout the substrate surface without flaws and cracks. A humidity sensing device incorporating WO3 is also fabricated, which shows a maximum humidity sensitivity factor of similar to 3954% along with a response time of similar to 14 s and a recovery time of similar to 25 s. The obtained results demonstrate that it is possible to synthesize WO3 in a single step by HW-CVD method and to fabricate a humidity sensor by using it. (C) 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim

Synthesis of isohexide-di(ether-ene)s and ADMET polymerization - Rajput, Bhausaheb S.; Lekshmy, Kalpakasseril Girija; Menon, Shamal K.; Chikkali, Samir H. (Green Materials, 2017)
As the fossil fuel reserves deplete and the greenhouse gases increase, the scientific community is challenged to provide sustainable solutions. Sugar-based isohexides can be modified to prepare a library of isohexide-diene monomers for polymerization. Such isohexide diene monomers can be subjected to Acyclic Diene Metathesis Polymerization to obtain green materials. Here we report a single step synthetic protocol to access a small family of isohexide-di(ether-ene)s and the corresponding polymers. The isohexide di(ether-ene)s 2a-2c could be isolated in good to excellent yields under optimized conditions. The resultant isohexide-di(ether-ene)s 2a-2c are potential versatile building blocks for pharmaceuticals and material science. The synthetic utility of 2a-2c was demonstrated by subjecting them to ADMET polymerization using Grubbs 1st and 2nd generation catalysts. The resultant viscous material was evaluated using 1H NMR and MALDI-ToF-MS, which suggests the formation of anticipated ADMET polymers

Synthesis of meta-substituted monodentate phosphinite ligands and implication in hydroformylation - Deshmukh, Satej S.; Gaikwad, Shahaji R.; Pandey, Swechchha; Mali, Pramod S.; Chikkali, Samir H. (Journal of Chemical Sciences, 2017)
Synthesis of meta-substituted phosphinite ligands 3,3'-(methoxyphosphanediyl) bis(N, N-diethylaniline) (4a) and methoxybis(3-methoxyphenyl) phosphane (4b), in high yields, has been demonstrated. Typical phosphorus chemical shift between 110-120 ppm, appearance of methoxy protons and corresponding carbon, as well as ESI-MS spectra unambiguously confirmed the existence of phosphinite ligands 4a and 4b. To demonstrate the synthetic usefulness of 4a and 4b, these ligands were tested in the rhodium catalyzed hydroformylation of 1-octene. The diethylamine substituted ligand 4a was found to be highly active, whereas 4bwas less reactive but revealed slightly better regioselectivity of 62% under optimized conditions. Additionally, 4a and 4b were found to catalyze the hydroformylation of styrene, 1-undecenol and 1,1-disubstituted functional olefin, methyl methacrylate. Both the ligands displayed excellent conversion of styrene, and 4b revealed an excellent branch selectivity of 75%. Although 1-undecenol proved to be amenable to hydroformylation (85-90% conversion to aldehyde), both the ligands failed to discriminate between the linear and branched products. Substrate methyl methacrylate proved to be highly challenging and reduced conversion (between 33-42%) was observed under optimized conditions. Ligand 4a was found to be highly selective towards linear aldehyde (81% linear selectivity).

Synthesis of methyl-protected (+/-)-chlorizidine A - Mahajan, Jyoti P.; Mhaske, Santosh B. (Organic Letters, 2017)
The first total synthesis of the methyl-protected (+/-)-chlorizidine A has been achieved in 10 steps. Pd-catalyzed decarboxylative coupling and late-stage oxidation were utilized to, construct the 5H-pyrrolo[2,1-a]isoindol-5-one scaffold. Samarium(II) iodide mediated Reformatsky reaction and intramolecular Mitsunobu reactions were efficiently applied for the synthesis of the 2,3-dihydropyrrolizine ring system. Chlorizidine A is highly prone to degradation; hence, methyl-protected (+/-)-chlorizidine A was prepared.

Synthesis of novel triazole-incorporated isatin derivatives as antifungal, antitubercular, and antioxidant agents and molecular docking study - Shaikh, Mubarak H.; Subhedar, Dnyaneshwar D.; Khan, Firoz A. Kalam; Sangshetti, Jaiprakash N.; Nawale, Laxman; Arkile, Manisha A.; Sarkar, Dhiman; Shingate, Bapurao B. (Journal of Heterocyclic Chemistry, 2017)
A library of 1,2,3-triazoles efficiently prepared via click chemistry and evaluated for their antifungal, antitubercular, antioxidant, cytotoxicity, molecular docking and ADME prediction.

Synthesis of o-methyl trifluoromethyl sulfide substituted benzophenones via 1,2-difunctionalization of aryne by insertion into the C-C bond - Ahire, Milind M.; Khan, Ruhima; Mhaske, Santosh B. (Organic Letters, 2017)
An efficient process for the preparation of valuable o-methyl trifluoromethyi sulfide substituted benzopheriones has been developed. The transition-metal-free method features insertion of aryne into a C-C sigma-bond under mild reaction conditions for the first time to achieve ortho-difunctionalized arenes containing a pharmaceutically important trifluoromethylthio functional group. A wide substrate, scope has been demonstrated for the developed protocol.

Synthesis of orthorhombic-molybdenum trioxide (α-MoO3) thin films by hot wire-CVD and investigations of its humidity sensing properties - Jadkar, Vijaya; Pawbake, Amit S.; Waykar,Ravindra G.; Jadhavar, Ashok Arjun; Mayabadi, Azam; Date, Abhijit; Late, Dattatray J.; Pathan, Habib M.; Gosavi, Suresh W.; Jadkar, Sandesh R. (Journal of Materials Science Materials in Electronics, 2017)
In present work, we report synthesis of orthorhombic-molybdenum trioxide (α-MoO 3) thin films using home-build hot wire-CVD (HW-CVD) method simply by heating the Mo filament in a controlled O 2 atmosphere. The formation of α-MoO 3 was confirmed by low angle-XRD and Raman spectroscopy. Low angle-XRD analysis revealed that α-MoO 3 crystallites have orientations along (110), (101) and (111) directions while Raman spectroscopy analysis shows two prominent vibrational modes ~819 and ~994 cm −1 associated with Mo 2–O and Mo=O respectively. SEM and TEM analysis show the formation of nano-sheets like morphology of α-MoO 3 thin films. The SAED pattern shows highly crystalline nature of α-MoO 3. The humidity-sensing properties were investigated at room temperature by fabricating the two probe device. The humidity sensing results showed n-type behavior of α-MoO 3. The maximum humidity sensitivity of ~6957% along with response time of ~66 s and recovery time of ~5 s were observed for α-MoO 3 thin film humidity sensor device. Our results have opened up a new avenue to grow α-MoO 3 for humidity sensor applications.

Synthesis of succinimide derivatives by NHC-catalyzed stetter reaction of aromatic aldehydes with N-substituted itaconimides - Ahire, Milind M.; Mhaske, Santosh B. (ACS Omega, 2017)
An N-heterocyclic carbene-catalyzed intermolecular Stetter reaction of aromatic aldehydes with N-substituted itaconimides has been developed. A delicate balance between the Stetter reaction and the competing isomerization of the itaconimide double bond has been achieved in this operationally simple reaction to afford valuable new succinimide derivatives containing 1,4 and 1,5 dicarbonyl scaffolds in good to excellent yields. The reaction tolerates variable substituents on both aldehydes and N-substituted itaconimides.

Synthesis of water soluble CdS nanoparticles and study of their DNA damage activity - Prasad, K. S.; Amin, T.; Katuva, S.; Kumari, Madhu; Selvaraj, Kaliaperumal (Arabian Journal of Chemistry, 2017)
This study reports a novel method for preparation of water soluble CdS nanoparticles using leaf extract of a plant, Asparagus racemosus. The extract of the leaf tissue which worked as a stabilizing and capping agent, assisted the formation of nanoparticles. Nanoparticles were characterized using a UV–vis spectrophotometer, Photoluminescence, TEM, EDAX, XRD and FT-IR. Transmission electron microscopy followed by selected area electron diffraction pattern analysis indicated the formation of spherical, polydispersed, crystalline, CdS of diameter ranging from 2 to 8 nm. X-ray diffraction studies showed the formation of 1 1 1, 2 2 0 and 3 1 1 planes of face-centered cubic (fcc) CdS. EDAX analysis confirmed the presence of Cd and S in nanosphere. The cytotoxicity test using MTT assay as well as DNA damage analysis using comet assay revealed that synthesized nano CdS quantum dots (QDs) caused less DNA damage and cell death of lymphocytes than pure CdS nanoparticles.

Synthesis route to pyrrolones from -cyano ,-unsaturated ketones and -isocyano esters by oxidative dearomatization of 2-aminofuran intermediates - Mahida, Anil K.; Kale, Someshwar B.; Das, Utpal (European Journal of Organic Chemistry, 2017)
An efficient method for the catalyst/promoter-free synthesis of tetrasubstituted furan derivatives proceeding through the [4+1] cycloaddition of isocyanoacetates with electron-deficient olefins was developed. The products were obtained in good to excellent yields without any column chromatography. Oxidative dearomatization of these furans was achieved only in the presence of oxygen, which led to pyrrolones in high yields.

Synthesis, structure and DNA interaction studies of bisphosphoramides: theoretical and experimental insights - Goud, E. Veerashekhar; Sivaramakrishna, Akella; Vijayakrishna, Kari; Rao, C. V. S. Brahmmananda; Khedkar, Vijay M.; Jha, Prakash C. (Inorganica Chimica Acta, 2017)
New bisphosphoramides (having phenyl (EDAPOPh(2)) and ethoxy (EDADEP) substituents attached to phosphoryl groups bridged with ethylenediamine spacer) are synthesized and structurally characterized by spectroscopic techniques as well as elemental analysis. The molecular structure of EDAPOPh(2) was determined by single crystal X-ray diffraction technique. The interaction of these bisphosphoramides with calf thymus DNA (ct-DNA) is investigated using UV-Visible absorption and fluorescence spectral data as well as the DFT calculations. These studies reveal that EDAPOPh(2) and EDADEP interact with DNA in a partial intercalation mode. The intrinsic binding constants K-b of two different bisphosphoramides with ct-DNA were determined by fluorescence spectroscopy as 2.08 x 10(4) and 3.86 x 10(4) M-1 respectively. The results indicated that the two compounds bind to ct-DNA with different binding affinities, i.e. EDAPOPh(2) > EDADEP. The binding mechanism of these bisphosphoramides to ct-DNA is also discussed. (C) 2017 Elsevier B.V. All rights reserved.
Keywords: Bisphosphoramides; crystal structure; DNA interaction; Molecular docking

Synthetic manipulation of hybrid perovskite systems in search of new and enhanced functionalities - Naphade, Rounak; Nagane, Satyawan; Bansode, Umesh; Tathavadekar, Mukta; Sadhanala, Aditya; Ogale, Satishchandra (ChemSusChem, 2017)
Over the past few years the organic-inorganic hybrid perovskite systems have emerged as a promising class of materials for photovoltaic and electroluminescent thin-film device applications, in view of their unique set of tunable optoelectronic properties. Importantly, these materials can be easily solution-processed at low temperatures and as such are amenable to facile molecular engineering. Thus, a variety of low-dimensional forms and quantum structures of these materials can be obtained through strategic synthetic manipulations through small molecule incorporation or molecular ion doping. In this Minireview, we specifically focus on these approaches and outline the possibilities of utilizing these for enhanced functionalities and newer application domains.

Systematic comparison of the response properties of protein and RNA mediated gene regulatory motifs - Iyengar, Bharat Ravi; Pillai, Beena; Venkatesh, K. V.; Gadgil, Chetan J. (Molecular BioSystems, 2017)
We present a framework enabling the dissection of the effects of motif structure (feedback or feedforward), the nature of the controller (RNA or protein), and the regulation mode (transcriptional, post-transcriptional or translational) on the response to a step change in the input. We have used a common model framework for gene expression where both motif structures have an activating input and repressing regulator, with the same set of parameters, to enable a comparison of the responses. We studied the global sensitivity of the system properties, such as steady-state gain, overshoot, peak time, and peak duration, to parameters. We find that, in all motifs, overshoot correlated negatively whereas peak duration varied concavely with peak time. Differences in the other system properties were found to be mainly dependent on the nature of the controller rather than the motif structure. Protein mediated motifs showed a higher degree of adaptation i.e. a tendency to return to baseline levels; in particular, feedforward motifs exhibited perfect adaptation. RNA mediated motifs had a mild regulatory effect; they also exhibited a lower peaking tendency and mean overshoot. Protein mediated feedforward motifs showed higher overshoot and lower peak time compared to the corresponding feedback motifs.

Salts and salt cocrystals of the antibacterial drug pefloxacin - Gunnam, Anilkumar; Suresh, Kuthuru; Nangia, Ashwini (Crystal Growth & Design, 2018)
Pefloxacin (PEF) is an amphoteric, antibacterial drug which exists as a neutral molecule in the crystal structure stabilized by C-H center dot center dot center dot O and C-H center dot center dot center dot F interactions. The design of multicomponent solids using crystal engineering was undertaken in a cocrystal/salt screen of PEF with generally recognized as safe (GRAS) dicarboxylic acids to improve the solubility and phase stability of the drug. Ten multicomponent forms, namely, five salts, two salt hydrates, and three salt cocrystals, were prepared by liquid-assisted grinding followed by crystallization. In some cases, salt and salt cocrystals were obtained concomitantly during solution evaporative crystallization. Single crystal X-ray diffraction showed that the structures are stabilized by N+-H center dot center dot center dot O-, O-H center dot center dot center dot O, C-H center dot center dot center dot O, C-H center dot center dot center dot F, and pi-pi stacking interactions. The bulk phase purity of multicomponent forms was characterized by powder X-ray diffraction, spectroscopy, and thermal techniques. The salt/salt cocrystal forms exhibit a faster dissolution rate and higher solubility compared to pure PEF in pH 1.2 (acidic, like gastric environment) and pH 7 phosphate buffer media (neutral, like intestinal passage). Specifically the PEF+-SA(-) salt (SA = succinic acid) showed remarkably high solubility, dissolution rate, and stability compared to the other multicomponent forms and PEF neutral form. The drug formulation compatible pefloxacin succinate is a promising soluble and stable PEF salt.

Selective N-acetylation with concurrent S-oxidation of o-amino thiol at ambient conditions over Ce doped ZnO composite nanocrystallites - Jagtap, Rohidas; Sakate, Sachin; Pardeshi, Satish (Molecular Catalysis, 2018)
The oxidative S-S coupling of thiol to disulfide is an imperative chemical transformation in the domain of biological processes and also finds numerous chemical applications. The CeO2 and ZnO are significant catalysts for oxidation of thiol to disulfide and N-acetylation of amines respectively. Dithiobis(phenylene)bis(benzyldeneimine) moiety containing N-acetyl and disulfide functional groups is a potential antimicrobial agent with Leishmanicidal and antihyperlipidemic activities. Herein, we report a synchronized catalytic application of Ce doped ZnO (Ce-ZnO) and CeO2-Ce-ZnO composites for selective synthesis of Dithiobis(phenylene)bis(benzyldeneimine) from o-amino thiol. The Ce-ZnO samples were synthesized by simple co precipitation method by calcination of hydroxide precursors at 400 degrees C to get 0-10% Ce-ZnO nanocrystallites. The formation of CeO2-Ce-ZnO composite material was observed beyond 1.5% Ce concentration. The synthesized materials were well characterized by IR, XRD, DRS spectroscopy and SEM-EDS analysis. The application of Ce doped ZnO as an efficient catalyst towards the selective N-acetylation and concurrent S-oxidation of o-amino thiol to afford Dithiobis(phenylene)bis(benzyldeneimine) at ambient temperature in acetonitrile was deliberated. Among all screened catalysts, the maximum selectivity was found for 7.5% Ce-ZnO as CeO2-Ce-ZnO composite catalyst. Lewis acidic property of catalyst supported probable mechanism for achieved dual transformations. Also, the 7.5% Ce-ZnO catalyst has demonstrated a versatile S-S coupling ability for variety of thiol substrates with excellent stability.

Selective oxidation of cyclohexane to cyclohexanone using chromium oxide supported mesoporous MCM-41 nanospheres: probing the nature of catalytically active chromium sites - Betsy, Kurisingal J.; Nayak, Chandrani; Lazar, Anish; Krishnan, Athira; Bhattacharyya, Dibyendu; Jha, Shambhu N.; Vinod, Chathakudath P. (ChemCatChem, 2018)
Highly dispersed chromium oxide supported mesoporous MCM-41 nanosphere catalysts have been synthesized using a simple wet impregnation method. This work is devoted to a systematic study to reveal the active Cr sites in chromium oxide supported MCM-41 nanosphere catalysts for the selective oxidation of cyclohexane to cyclohexanone. To probe the nature of the active species, we synthesized 0.5-10wt% Cr loaded catalysts and characterized them by using XRD, UV/Vis spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, extended X-ray absorption fine structure analysis, X-ray absorption near edge structure analysis, N-2 sorption analysis, FTIR spectroscopy, (SiNMR)-Si-29 spectroscopy, SEM, and TEM. The liquid-phase oxidation of cyclohexane to cyclohexanone (99% selectivity) was performed under mild reaction conditions, and the results reveal clearly that the 5wt% Cr loaded catalyst was optimum for the reaction. The initial composition of isolated Cr3+ species in the catalyst is the major factor that influences the enhanced activity for cyclohexane oxidation.
Keywords: chromium; heterogeneous catalysis; Nanostructures; Oxidation; supported catalysts

Selective production of furanic ethers from lignocellulosic biomass over mesoporous Zr-incorporated SBA-15 catalyst - Patil, Chetana R.; Rode, Chandrashekhar, V. (ChemistrySelect, 2018)
Etherification of furanic compounds such as furfuryl alcohol (FA) and 5-(Hydroxymethyl) furfural (5-HMF) to the corresponding ethers was successfully achieved over Zr-SBA-15 catalyst. For this purpose, various Zr-SBA-15 catalysts with different Zr/Si molar ratios in self-generated acidic environment were prepared by one-pot strategy in self-generated acidic environment. XRD analysis revealed the increase in the d-spacing from 9.021 nm for parent SBA-15 to 11.66 nm for Zr-SBA-15, confirming the incorporation of Zr into the framework without disturbing the mesoporous structure of SBA-15. For the lowest Zr concentration of 0.09 M, hexagonally ordered porous structure was found to be retained as confirmed by TEM while, increase in Zr/Si molar ratio to 0.14, resulted in loss of long range order mesoporosity. The presence of both Lewis and Bronsted acid sites in Zr-SBA-15 catalyst as evidenced by py-IR, were due to the introduction of Zr in the frame work of SBA-15. The co-existence of Lewis and Bronsted acid sites in Zr-SBA-15 was responsible to catalyze etherification of FA and esterification of levulinic acid producing 2-(Ethoxymethyl) furan and ethyl levulinate selectively, both of which are bio-derived fuel additives.

Self-assembly of Cis-configured squaraine dyes at the TiO2-dye interface: far-red active dyes for dye-sensitized solar cells - Punitharasu, Vellimalai; Kavungathodi, Munavvar Fairoos Mele; Nithyanandhan, Jayaraj (ACS Applied Materials & Interfaces, 2018)
To synergize both steric and electronic factors in designing the dyes for dye-sensitized solar cells, a series of cis-configured unsymmetrical squaraine dyes P11-P15 with suitably functionalized alkyl groups and squaric acid units containing the electron-withdrawing groups were synthesized, respectively. These dyes capture the importance of (i) the effect and position of branched alkyl groups, (ii) mono- and di-anchoring groups containing dyes, and (iii) further appending the alkyl groups through the cyanoester vinyl unit on the central squaric acid units of DAD-based cis-configured squaraine dyes. All the above factors govern the controlled self-assembly of the dyes on the TiO2 surface which helps to broaden the absorption profile of the dyes with an increased energy-harvesting process. With respect to the position of the branched alkyl groups, dye P11 with the sp(3)-C and N-alkyl groups away from the TiO2 surface showed a better device efficiency of 5.98% (J(sc) of 14.46 mA cm(-2), V-oc of 0.576 V, and ff of 71.8%) than its positional isomer P12 with 3.45% (J(sc) of 8.78 mA cm(-2), V-oc of 0.554 V, and ff of 70.9%). However, with respect to the dyes containing mono- and di-anchoring groups, P13 with two anchoring units exhibited a superior device performance of 7.58% (J(sc) of 17.12 mA cm(-2), V-oc of 0.618 V, and ff of 71.7%) in the presence of optically transparent co-adsorbent CDCA (3 alpha,7 alpha-dihydroxy-5 beta-cholanic acid) than dyes P11 and P12.

Sensitive electrochemical detection of cardiac troponin I in serum and saliva by nitrogen-doped porous reduced graphene oxide electrode - Chekin, Fereshteh; Vasilescu, Alina; Jijie, Roxana; Singh, Santosh K.; Kurungot, Sreekumar; Iancu, Madalina; Badea, Gabriela; Boukherroub, Rabah; Szunerits, Sabine (Sensors and Actuators B-Chemical, 2018)
Cardiovascular diseases pose one of the highest mortality risks among all diseases in developed countries, steadily increasing the burden on the health systems. Early diagnosis of cardiovascular diseases has consequently become highly important to decrease mortality and to use more adapted therapeutic decisions. We demonstrate here the utility of nitrogen-doped reduced graphene oxide (N-prGO) for detecting and quantifying of cardiac troponin I (cTnI), a key human cardiac protein biomarker, under physiologically relevant conditions. Non-covalent modification of N-prGO by 1-pyrenecarboxylic acid (py-COOH) and poly(ethylene glycol) modified pyrene (py-PEG) ligands allowed the covalent integration of Tro4 aptamer, known for its high selectivity towards cTnI. Using differential pulse voltammetry (DPV), a label-free electrochemical sensor for cTnI for concentrations down to 1 pgmL(-1) in human serum could be obtained. This sensitive detection arises from the integration of a porous nanomaterial with excellent electrochemical properties being easily amendable to site-specific surface modification. (C) 2018 Elsevier B.V. All rights reserved.

Sensitizing with short conjugated molecules: multimodal anchoring on ZnO nanoparticles for enhanced electron transfer characteristics, stability and H-2 evolution - George, Leena; Sappati, Subrahmanyam; Ghosh, Prasenjit; Devi, R. Nandini (Catalysis Today, 2018)
Sensitizing semiconductors with organic dyes is usually employed to improve efficiency of semiconductors towards visible light absorption and charge transport. However, till date most of the dyes are either noble metal based with complex and expensive synthesis procedure or have a very narrow absorption band. Further the photostability of the dyes is another important issue. In this work we have studied, using a combination of photophysical and computational methods, ZnO nanoparticles sensitized with transition metal free, cheap and easy to synthesize azoquinoline dye that has been designed to have multiple chelating sites, viz., carboxylic group and hydroxyl imine group as a photocatalyst for water splitting activity. We find that the presence of multiple chelating sites facilitates dual mode of anchoring on ZnO nanoparticles, which leads to enhanced photostability and H-2 generation of the composite. This is attributed to the incorporation of resonance features in the dye that increases electron transfer between ZnO and dye in contrast to the charge accumulation and photo degradation observed in non-conjugated and single site anchoring counterparts. Electron transfer from ZnO to dye under UV light and reverse in visible light could be identified experimentally. Such simple designing aspects can aid in identifying better catalysts for photocatalytic water splitting.

Serum responsive proteome reveals correlation between oxidative phosphorylation and morphogenesis in Candida albicans ATCC10231 - Ahmed, Radfan; Kodgire, Santosh; Santhakumari, B.; Patil, Rajendra; Kulkarni, Mahesh J.; Zore, Gajanan (Journal of Proteomics, 2018)
To understand the impact of fetal bovine serum (FBS) on metabolism and cellular architecture in addition to morphogenesis, we have identified FBS responsive proteome of Candida albicans. FBS induced 34% hyphae and 60% pseudohyphae in C. albicans at 30 C while 98% hyphae at 37 C. LC-MS/MS analysis revealed that 285 proteins modulated significantly in response to FBS at 30 degrees C and 37 degrees C. Out of which 152 were upregulated and 62 were downregulated at 30 degrees C while 18 were up and 53 were downregulated at 37 degrees C. Functional annotation suggests that FBS may inhibit glycolysis and fermentative pathway and enhance oxidative phosphorylation (OxPhos), TCA cycle, amino acid and fatty acid metabolism indicating a use of alternative energy source by C. albicans. OxPhos inhibition assay using sodium azide corroborated the correlation between inhibition of glycolysis and enhanced OxPhos with pseudohyphae formation. C. albicans induced hyphae in response to FBS irrespective of down regulation of Rasl,Asrl/Asr2, indicates the possible involvement of MAPK and cAMP-PKA independent pathway. The Cell wall of cells grown in presence of FBS at 30 degrees C was rich in mannan, Beta 1,3glucan and chitin while membranes were rich in ergosterol compared to those grown at 37 degrees C. Significance of the study: This is the first study suggesting a correlation between OxPhos and morphogenesis especially pseudohyphae formation in C. albicans. Our data also indicate that fetal bovine serum (FBS) induced morphogenesis is multifactorial and may involve MAPK and cAMP-PKA independent pathway. In addition to morphogenesis, our study provides an insight in to the modulation of metabolism and cellular architecture of C. albicans in response to FBS.
Keywords: analysis; Candida albicans; Fetal bovin serum; Liquid chromatography mass spectrometry; morphogenesis; Oxidative phosphorylation; pathogenicity

Silicon oxidation by NAPPES: From dangling bonds to oxygen islands to 2D SiOx layer to the onset of bulk SiO2 formation - Ghosalya, Manoj Kumar; Jain, Ruchi; Reddy, Kasala Prabhakar; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2018)
Valence band and core level photoelectron spectral measurements at near-ambient pressures (NAP; up to 0.5 mbar) were made in the presence of molecular oxygen to explore the various oxidation stages of silicon surfaces. Dangling bonds feature observed on clean Si-surfaces in the valence band at ultrahigh vacuum decreases dramatically due to oxygen adsorption between ambient temperature and up to 400 K at 0.1 mbar of O-2 pressure. The adsorption of oxygen on dangling bonds appears to be localized as islands; this reflects in the surface heterogeneous character and also responsible for the broadening in the oxygen gas phase vibrational features. This is further supported by an increase in the work function and can be correlated to the presence of Hofer (molecular) precursor. When the temperature was increased to 500 K, molecular precursor species dissociates to form Si-=-0 species. This is fully supported by the change in the Si work function as well as from the observation of oxidized Si species from Si 2p core level spectra. At >= 600 K, the Si-=-0 species dissociates to form a uniform 2D oxide layer on the silicon surface, which is characterized by the reappearance of sharp vibration features for gas-phase O-2 molecules. This layer is also quite stable up to 800 K and without any further oxidation in the bulk. On increasing the temperature to 850 K at 0.2 mbar oxygen pressure, bulk Si oxidation begins and the work function increases drastically by 1 eV. An angle-dependent Si 2p spectra recorded map out the presence of elemental Si to Si4+ from bulk to the surface, respectively. A simple model is proposed to show the various stage of silicon oxidation. A continuous change in the work function and electronic states observed due to gas-lattice (O-2-Si) interaction indicates the implications for surface-dependent phenomena, such as heterogeneous catalysis, electrochemistry, 2D layered materials.

Silicon-fluorine chemistry: from the preparation of SiF2 to C-F bond activation using silylenes and its heavier congeners - Sen, Sakya S.; Roesky, Herbert W. (Chemical Communications, 2018)
This feature article is intended to provide a background to the history of the isolation of silicon(II) fluorides and the different synthetic methodologies used to generate them. Although first detected in the 1970s, the chemistry of silicon(II) fluorides has not encountered serious research efforts for a rather long period of time. This is somewhat surprising given the fact that the chemistry of compounds with divalent silicon has undergone a renaissance during last three decades. Recently, the interest in silicon(II) fluorides have been resparked with tremendous progress being achieved in this area, in particular, with respect to their synthesis and structural characterisation. The successful isolation of cyclic alkyl amino carbene (cAAC) stabilized silicon difluoride has completed the classic progression of SiF2, from a transient intermediate to spectroscopically detected molecule to a stable compound. The related germanium(II), tin(II), and lead(II) fluoride chemistry will also be discussed. Apart from the isolation of tetrel(II) fluorides, the use of compounds with low valent group 14 elements for the selective activation and functionalisation of C-F bonds has witnessed some remarkable advances, which will also be summarized in this feature article.

Silk cocoon as counter - electrode substrate in dye - sensitized solar cells - Sudhakar, Vediappan; Das, Chayanika; Krishnamoorthy, Kothandam (ChemistrySelect, 2018)
Electrodes are vital components of energy conversion devices such as dye sensitized solar cells (DSSCs). The widely used electrodes consist of fluorine doped tin oxide (FTO) and platinum. We were interested in identifying a substrate that is available from natural resources and exhibit performance comparable to that of Pt coated FTO (Pt-FTO). Silk fibers are naturally available and they are mechanically stable. The woven silk fibers are known as silk cocoons (SCs) that structurally resemble widely used carbon paper electrodes. To impart conductivity to the insulating SCs, metal film was coated by an electroless metal plating procedure using polyphenols from green tea. The metal coated SCs were conformaly coated with a conjugated polymer and these electrodes were used as flexible electrodes in DSSCs. The flexible electrode based DSSCs exhibited a power conversion efficiency of 7.2% which is comparable to that of the DSSCs with rigid Pt-FTO based devices (7.4%).
Keywords: counter electrode; PEDOT-G-SCs; Recombination; Silk cocoons (SCs)

Silk fibroin micro-particle scaffolds with superior compression modulus and slow bioresorption for effective bone regeneration - Nisal, Anuya; Sayyad, Raeesa; Dhavale, Prachi; Khude, Bhakti; Deshpande, Rucha; Mapare, Vidhyashri; Shukla, Swati; Venugopalan, Premnath (Scientific Reports, 2018)
Silk fibroin (SF), a natural polymer produced by Bombyx mori silkworms, has been extensively explored to prepare porous scaffolds for tissue engineering applications. Here, we demonstrate, a scaffold made of SF, which exhibits compression modulus comparable to natural cancellous bone while retaining the appropriate porosities and interconnected pore architecture. The scaffolds also exhibit high resistance to in-vitro proteolytic degradation due to the dominant beta sheet conformation of the SF protein. Additionally, the scaffolds are prepared using a simple method of microparticle aggregation. We also demonstrate, for the first time, a method to prepare SF micro-particles using a Hexafluoroisopropanol-Methanol solvent-coagulant combination. SF microparticles obtained using this method are monodisperse, spherical, non-porous and extremely crystalline. These micro-particles have been further aggregated together to form a 3D scaffold. The aggregation is achieved by random packing of these microparticles and fusing them together using a dilute SF solution. Preliminary in-vitro cell culture and in-vivo implantation studies demonstrate that the scaffolds are biocompatible and they exhibit the appropriate early markers, making them promising candidates for bone regeneration.

Silver-mediated oxidative decarboxylative intramolecular asymmetric radical cyclization (C sp3 –C sp2 ) via memory of chirality: access to circumdatin alkaloids - Mahajan, Pankaj S.; Mhaske, Santosh B. (Organic Letters, 2018)
A novel silver-mediated oxidative decarboxylative intramolecular asymmetric radical cyclization has been developed to form a Csp3–Csp2 bond via memory of chirality. The application of the process has been demonstrated for the synthesis of the circumdatin class of alkaloids in high enantiopurity with retention of the configuration. The developed protocol is mild and works with an inexpensive silver catalyst in the absence of ligand, base, or additives. The involvement of a monoradical in the reaction has been established by trapping the radical intermediate.

Single pot selective hydrogenation of furfural to 2-methylfuran over carbon supported iridium catalysts - Date, Nandan S.; Hengne, Amol M.; Huang, K-W.; Chikate, Rajeev C.; Rode, Chandrashekhar V. (Green Chemistry, 2018)
Various iridium supported carbon catalysts were prepared and screened for the direct hydrogenation of furfural (FFR) to 2-methyl furan (2-MF). Amongst these, 5% Ir/C showed excellent results with complete FFR conversion and highest selectivity of 95% to 2-MF at a very low H-2 pressure of 100 psig. Metallic (Ir degrees) and oxide (IrO2) phases of Ir catalyzed the first step hydrogenation involving FFR to FAL and subsequent hydrogenation to 2-MF, respectively. This was confirmed by XPS analysis and some control experiments. At a low temperature of 140 degrees C, almost equal selectivities of FAL (42%) and 2-MF (43%) were observed, while the higher temperature (220 degrees C) favored selective hydrodeoxygenation. At optimized temperature, 2-MF was formed selectively while higher pressure and higher catalyst loading favored ring hydrogenation of furfural rather than side chain hydrogenation. With the combination of several control experimental results and detailed catalyst characterization, a plausible reaction pathway has been proposed for the selective formation of 2-MF. The selectivity to various other products in FFR hydrogenation can be manipulated by tailoring the reaction conditions over the same catalyst.

Single step, phase controlled, large scale synthesis of ferrimagnetic iron oxide polymorph nanoparticles by thermal plasma route and their rheological properties - Raut, Suyog A.; Mutadak, Pallavi R.; Kumar, Shiv; Kanhe, Nilesh S.; Huprikar, Sameer; Pol, Harshawardhan V.; Phase, Deodatta M.; Bhoraskar, Sudha V.; Mathe, Vikas L. (Journal of Magnetism and Magnetic Materials, 2018)
In this paper we report single step large scale synthesis of highly crystalline iron oxide nanoparticles viz. magnetite (Fe3O4) and maghemite (gamma-Fe2O3) via gas phase condensation process, where micron sized iron metal powder was used as a precursor. Selective phases of iron oxide were obtained by variation of gas flow rate of oxygen and hence partial pressure of oxygen inside the plasma reactor. Most of the particles were found to possesses average crystallite size of about 20-30 nm. The DC magnetization curves recorded indicate almost super-paramagnetic nature of the iron oxide magnetic nanoparticles. Further, iron oxide nanoparticles were analyzed using Raman spectroscopy, X-ray photoelectron spectroscopy and Mossbauer spectroscopy. In order to explore the feasibility of these nanoparticles for magnetic damper application, rheological studies have been carried out and compared with commercially available Carbonyl Iron (CI) particles. The nanoparticles obtained by thermal plasma route show improved dispersion which is useful for rheological applications. (C) 2017 Elsevier B.V. All rights reserved.
Keywords: Iron oxide; magnetic properties; Nano-crystalline materials; Rheological properties; Thermal plasma

Single-particle tracking to probe the local environment in ice-templated crosslinked colloidal assemblies - Suresh, Karthika; Sharma, D. K.; Chulliyil, Ramya; Sarode, Ketan Dinkar; Kumar, V. Ravi; Choudhary, Arindam; Kumaraswamy, Guruswamy (Langmuir, 2018)
We use single-particle tracking to investigate colloidal dynamics in hybrid assemblies comprising colloids enmeshed in a crosslinked polymer network. These assemblies are prepared using ice templating and are macroporous monolithic structures. We investigate microstructure-property relations in assemblies that appear chemically identical but show qualitatively different mechanical response. Specifically, we contrast elastic assemblies that can recover from large compressive deformations with plastic assemblies that fail on being compressed. Particle tracking provides insights into the microstructural differences that underlie the different mechanical response of elastic and plastic assemblies. Since colloidal motions in these assemblies are sluggish, particle tracking is especially sensitive to imaging artifacts such as stage drift. We demonstrate that the use of wavelet transforms applied to trajectories of probe particles from fluorescence microscopy eliminates stage drift, allowing a spatial resolution of about 2 nm. In elastic and plastic scaffolds, probe particles are surrounded by other particles—thus, their motion is caged. We present mean square displacement and van Hove distributions for particle motions and demonstrate that plastic assemblies are characterized by significantly larger spatial heterogeneity when compared with the elastic sponges. In elastic assemblies, particle diffusivities are peaked around a mean value, whereas in plastic assemblies, there is a wide distribution of diffusivities with no clear peak. Both elastic and plastic assemblies show a frequency independent solid modulus from particle tracking microrheology. Here too, there is a much wider distribution of modulus values for plastic scaffolds as compared to elastic, in contrast to bulk rheological measurements where both assemblies exhibit a similar response. We interpret our results in terms of the spatial distribution of crosslinks in the polymer mesh in the colloidal assemblies.

Single-pot reductive rearrangement of furfural to cyclopentanone over silica-supported Pd catalysts - Date, Nandan S.; Kondawar, Sharda E.; Chikate, Rajeev C.; Rode, Chandrashekhar V. (ACS Omega, 2018)
Direct one-pot hydrogenation of furfural (FFR) to cyclopentanone (CPO) was investigated over different silica-supported Pd catalysts. Among these, 4% Pd on fumed silica (4%Pd/f-SiO2) showed remarkable results, achieving almost 98% furfural (FFR) conversion with similar to 89% selectivity and 87% yield to cyclopentanone at 165 degrees C and 500 psig H-2 pressure. More interestingly, the fumed-silica-supported catalyst tuned the selectivity toward the rearrangement product, i.e, cyclopentanone, whereas all of the other supports were found to give ring hydrogenation as well as side chain hydrogenation products due to their parent Bronsted acidity and specific support properties. X-ray diffraction data revealed the presence of different phases of the face-centered cubic lattice of metallic Pd along with lowest crystallite size of 15.6 nm in the case of the silica-supported Pd catalyst. However, Pd particle size was found to be in the range of 5-13 nm with even dispersion over the silica support, confirmed by high-resolution transmission electron microscopy analysis. While studying the effect of reaction parameters, it was observed that lower temperature gave low furfural conversion of 58% with only 51% CPO selectivity.. Similarly, higher H-2 pressure lowered CPO selectivity with subsequent increase in 2-methyl furan and ring hydrogenation product 2-methyl furan and 2-methyl tetrahydrofuran. Thus, as per the requirement, the product selectivity can be tuned by varying the type of support and/or the reaction parameters suitably. With the help of several control experiments and the characterization data, a plausible reaction pathway was proposed for the selective formation of cyclopentanone.

Solid state auto-inversion of C-centrochirality: enantioselective total synthesis of furocarbazolones (-)-epi-claulansine D and (-)-claulansine D and pyranocarbazolone (+)-epi-claulansine C - Markad, Shivaji B.; N. P. Argade (Journal of Organic Chemistry, 2018)
Starting from dimethyl (E)-2-{[(1-tert-butoxycarbonyl)-1H-indol-3-yl]methylene}succinate and (R)-2,2,5,5-tetramethyl-1,3-dioxolane-4-carbaldehyde, facile synthesis of (-)-epi-claulansine D was accomplished via condensation and two intramolecular cyclizations. The (-)-epi-claulansine D in the solid state exists in a metastable form, and after an induction period of 30-90 days, it underwent complete epimerization to exclusively deliver the desired natural product (-)-claulansine D in quantitative yield. The witnessed inversion of C-centrochirality in the solid state is conceptually novel and takes place for relatively higher crystal stability reasons. Base-catalyzed ring expansion of both (+/-)/(-)-epi-claulansine D and (+/-)/(-)-claulansine D resulted in (+/-)/(+)-epi-claulansine C in very good yields.

Soluble polybenzimidazoles with intrinsic porosity: synthesis, structure, properties and processability - Kumar, Vikas; Chatterjee, Shyambo; Sharma, Pragati; Chakrabarty, Suman; Avadhani, Chilukuri V.; Sivaram, Swaminathan (56Journal of Polymer Science Part A-Polymer Chemistry, 2018)
We have explored two novel comonomers, namely, 4,16-dicarboxyl[2.2]paracyclophane and 5,5,6,6-tetraamino-3,3,3,3-tetramethyl-1,1-spirobi[indane], for the synthesis of co-polybenzimidazoles (co-PBIs) with intrinsic porosity. Both these monomers possess twisted structures that can lead to awkward macromolecular shapes that cannot pack efficiently. The consequences of introducing these two monomers on the structure and properties of PBIs are reported. The random copolymers synthesized are amorphous and possess glass transition temperatures (T(g)s) greater than 400 degrees C. T-g decreases with increasing comonomer content indicating an increase in fractional free volume. The copolymers have low surface area. TEM and BET measurements show evidence of mesopore formation. The copolymers show significant carbon dioxide adsorption. Single chain molecular dynamics simulation of 24-mer repeat units shows intramolecular void spaces arising as a result of distorted polymer chain with reduced conformational mobility. These studies define a new synthetic strategy for bottoms-up synthesis of PBIs with intrinsic porosity. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1046-1057

Solvent and pH-stable poly(2,5-benzimidazole) (ABPBI) based UF membranes: preparation and characterizations - Lohokare, Harshada R.; Chaudhari, Harshal D.; Kharul, Ulhas. K. (Journal of Membrane Science, 2018)
Poly(2,5-benzimidazole), commonly known as ABPBI, is an excellent thermo-chemically stable polymer that is widely evaluated as a proton exchange membrane material in a fuel cell. Its niche intrinsic characteristics could be highly useful in the membrane preparation for various separation applications, especially under harsher environments. To gain insights towards this feasibility, ABPBI based supported membranes were prepared by phase inversion method. Effects of the nonwoven porous support material (polypropylene/polyester), non-solvent (water/0.5 N NaOH) and polymer concentration (6 or 4 wt%) on the membrane properties (water flux, rejection and porosity) were investigated. The stability of these membranes towards common organic solvents, concentrated acid (25 N H2SO4), base (2.5 N NaOH) and an autoclave condition was analyzed. ABPBI membrane showed a pore collapse after drying. In order to avoid this, the glycerol treatment was not only found to be suitable but also repeatable, without significant deviations in the water flux.
Keywords: ABPBI membrane; Pore size distribution; Solvent stable membranes; Ultrafiltration

Solvent degradation studies using hydrodynamic cavitation - Suryawanshi, Pravin G.; Bhandari, Vinay M.; Sorokhaibam, Laxmi Gayatri; Ruparelia, Jayesh P.; Ranade, Vivek V. (Environmental Progress & Sustainable Energy, 2018)
Hydrodynamic cavitation for the degradation of organic solvents was investigated in detail using a newer form of cavitating device-vortex diode. The results were also compared with that using conventional cavitating device orifice. Removal of three different organic solventsacetone, methyl ethyl ketone (MEK), and toluene were studied on a pilot plant with capacity of 1m(3)/h. The effect of different operating parameters such as inlet pressure, initial concentration, and reactor type on the degradation rate of solvent was investigated in detail. The results revealed that efficiency of solvent removal varies substantially with the change in physical operating conditions and nature of the solvent. It was found that up to 80% degradation could be achieved for toluene (cavitational yield 32.2 x 10(-3) mg/J), substantially higher than that for acetone and MEK indicating the effect of molecular weight/structure in the degradation process. Further, the results clearly indicated chemical oxidation as a predominant mechanism for degradation and not physical destruction. Vortex diode that works on the principle of vortex generation for cavitation, was found to be far superior over conventional cavitating device-orifice- approximate to up to eight times higher cavitational yield could be obtained for toluene as compared to orifice. The results of this study provide newer insight into solvent removal using hydrodynamic cavitation and would have bearing on the treatment of solvent containing wastewaters. (C) 2017 American Institute of Chemical Engineers
Keywords: Effluent treatment; industry; pollution; Vortex diode; wastewater

Solvent-less solid state synthesis of dispersible metal and semiconducting metal sulfide nanocrystals - Bera, Abhijit; Busupalli, B.; Bhagavatula L. V. Prasad (ACS sustainable chem. eng, 2018)
Monolayer protected metal and metal sulfide nanocrystals (NCs) have mainly two constituents; the inorganic metal or metal chalcogenide complex as core and organic molecule as shell. Noticing that metal thiolates have these ingredients inbuilt in their structure, we investigated them as possible precursors for the preparation of monolayer protected metal and metal sulfide NCs via solid state grinding method. Accordingly silver and gold NCs have been prepared using a solvent less green approach, by the simple and convenient solid state grinding of the corresponding metal thiolate with sodium borohydride. Similarly, a large variety of uniform-sized semiconducting NCs of metal sulfides including PbS, CdS, ZnS, MnS, Ag2S, and CuS could also be synthesized by the same solid state route by grinding the metal thiolates with octyl dithiocarbamic acid (C8DTCA) and in some cases C8DTCA plus small amount of oleylamine as sulfur source. Interestingly, this simple technique could be used to prepare sub-3 nm NCs like Ag2S, PbS, and CuS which are otherwise difficult to prepare by the conventional high temperature solution routes also. Most gratifyingly, all these NCs, though were prepared by a solvent less grinding method, could be easily dispersed in nonpolar solvents as the preparation method ensued the formation of organic molecule capped NCs.

Spatial-temporal spectroscopy characterizations and electronic structure of methylammonium perovskites - Liu, Zhaoyu; Bhamu, K. C.; Luo, Liang; Shah, Satvik; Park, Joong-Mok; Cheng, Di; Long, Men; Biswas, Rana; Fungara, F.; Shiner, Ruth; Shiner, Joseph; Vela, Javier; et al. (MRS Communications, 2018)
Using time-resolved laser-scanning confocal microscopy and ultrafast optical pump/THz probe spectroscopy, we measure photoluminescence (PL) and THz-conductivity in perovskite micro-crystals and films. PL quenching and lifetime variations occur from local heterogeneity. Ultrafast THz-spectra measure sharp quantum transitions from excitonic Rydberg states, providing weakly bound excitons with a binding energy of similar to 13.5 meV at low temperatures. Ab-initio electronic structure calculations give a direct band gap of 1.64 eV, a dielectric constant of similar to 18, heavy electrons, and light holes, resulting in weakly bound excitons, consistent with the binding energies from the experiment. The complementary spectroscopy and simulations reveal fundamental insights into perovskite light-matter interactions.

Specific stereoisomeric conformations determine the drug potency of cladosporin scaffold against malarial parasite - Das, Pronay; Babbar, Palak; Malhotra, Nipun; Sharma, Manmohan; Jachak, Goraknath R.; Gonnade, Rajesh G.; Shanmugam, Dhanasekaran; Harlos, Karl; Yogavel, Manickam; Sharma, Amit; Reddy, D. Srinivasa (Journal of Medicinal Chemistry, 2018)
The dependence of drug potency on diastereomeric configurations is a key facet. Using a novel general divergent synthetic route for a three-chiral center antimalarial natural product cladosporin, we built its complete library of stereoisomers (cladologs) and assessed their inhibitory potential using parasite-, enzyme-, and structure-based assays. We show that potency is manifest via tetrahyropyran ring conformations that are housed in the ribose binding pocket of parasite lysyl tRNA synthetase (KRS). Strikingly, drug potency between top and worst enantiomers varied 500-fold, and structures of KRS-cladolog complexes reveal that alterations at C3 and C10 are detrimental to drug potency whereas changes at C3 are sensed by rotameric flipping of glutamate 332. Given that scores of antimalarial and anti-infective drugs contain chiral centers, this work provides a new foundation for focusing on inhibitor stereochemistry as a facet of antimicrobial drug development.

Specificity of amino acid-aluminum cluster interaction and subsequent oxygen activation by the above complex - Samanta, Bipasa; Sengupta, Turbasu; Pal, Sourav (Journal of Physical Chemistry C, 2018)
Amino acid aluminum cluster complex has been shown to be a promising oxygen molecule activator and has the potential to dissociate O-O bond on the cluster surface. The study of the complex also reveals specificity of amino acid to aluminum cluster in the above complex, which can be used in the detection of amino acid. The results have been obtained by the density functional theory at the B3LYP/6-311++g(d,p) level of calculation.

Spin state engineered ZnxCo3-xO4 as an efficient oxygen evolution electrocatalyst - Ramsundar, Rani Mohan; Pillai, Vijayamohanan Kunjukrishna; Joy, Pattayil Alias (Physical Chemistry Chemuical Physics, 2018)
Oxygen evolution is the key step in the oxidation of water in electrolyzers and photoelectrochemical cells for the production of hydrogen. Developing a non-precious metal oxide catalyst with good electrocatalytic activity for the oxygen evolution reaction (OER) is very challenging. In this work, nanostructured ZnxCo3-xO4 has been shown as an efficient catalyst with a low overpotential for the OER in 0.1 M KOH solution. Substitution of Co2+ in the spinel oxide Co3O4 with Zn2+ creates a higher number of high-spin Co3+, which is found to be directly correlated with the OER activity of ZnxCo3-xO4. Zn0.8Co2.2O4 (x = 0.8) with the optimum amount of Co2+/Co3+ and high-spin Co3+ content showed a very low overpotential of approximate to 250 mV, at 10 mA cm(-2), with a turnover frequency of approximate to 3 x 10(-3) s(-1) for the OER. The high Faradaic efficiency along with the stability of Zn0.8Co2.2O4 and electrocatalytic activity comparable with that of precious metal oxides indicate that this composition is a promising catalyst for water oxidation.

Spinel‐type mixed oxides for stable and selective partial oxidation of benzyl alcohol - Gurrala, Lakshmiprasad; Nagpure, Atul S.; Gurav, Hanmant R.; Chilukur, Satyanarayana (ChemistrySelect, 2018)
Benzaldehyde is an important chemical intermediate, which need to be prepared through an eco‐friendly process. Manganese oxides are active as catalysts for its preparation through partial oxidation of benzyl alcohol. In this study, Cu, Co and Mn containing spinel based mixed oxides (CuxMn3−xO4) were prepared and tested for partial oxidation of benzyl alcohol to get benzaldehyde with high selectivity. The catalytic activity strongly depended on chemical composition, acid‐base properties and oxygen uptake. The influence of chemical composition, reaction temperature, oxygen partial pressure and the weight hourly space velocity (WHSV) were investigated to optimize benzaldehyde yield and to stabilize the catalyst activity. A high benzaldehyde selectivity of 98%, accompanied with benzyl alcohol conversion of 84.5% was obtained over Cu0.25Mn2.75O4 catalyst at 300 °C. It was evident from temperature programmed desorption (TPD) of CO2 that this catalyst was found to have optimum basicity and high oxygen uptake, thus imparting high activity and stability. Activity and catalyst life could be attributed to appropriate acid‐base properties. Supporting Information

Spiro [fluorene-9,9 '-xanthene]-containing copolymers of intrinsic microporosity: synthesis, characterization and gas permeation properties - Shrimant, Bharat; Kharul, Ulhas K.; Wadgaonkar, Prakash P. (Reactive & Functional Polymers, 2018)
In the present study, a new bis(catechol) containing spiro[fluorene-9,9'-xanthene], namely, 4,4'-(spiro(fluorene9,9'-xanthene]-2',7'-diyl)bis(benzene-1,2-diol) (THSFX) was designed and synthesized. Polycondensation reactions of THSFX and varying compositions of THSFX and 5,5',6,6'-tetrahydroxy-3,3,3',3'-tetramethyl-1,1'-spirobisindane (TTSBI) were carried out with 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) to obtain a homopolymer and copolymers, respectively. The organo-soluble polymers exhibited reasonably high molecular weights (23300-34,100 g/mol) and could be cast into self-standing films from their chloroform solutions. X-Ray diffraction studies indicated that PIMs were amorphous in nature. These polymers exhibited high thermal stability (T-10 = 490-510 degrees C) and possessed intrinsic microporosity with high BET surface area (360-796 m(2)/g). The gas permeation properties of SFX-PIM-25 and SFX-PIM-33 were evaluated and they exhibited high gas permeability (CO2 = 3595-4034 Barrer). The gas permeability data of SFX-PIM-25 and SFX-PIM-33 was located close to 1991 Robson upper bound for CO2/N-2, CO2/CH4 and O-2/N-2 gas pairs

Spreading dynamics of superposed liquid drops on a spinning disk - Sahoo, Subhadarshinee; Orpe, Ashish V.; Doshi, Pankaj (Physics of Fluids, 2018)
We have experimentally studied simultaneous spreading of superposed drops of two Newtonian liquids on top of a horizontal spinning disk using the flow visualization technique. An inner drop of high surface tension liquid is placed centrally on the disk followed by a drop of outer liquid (lower surface tension) placed exactly above that. The disk is then rotated at a desired speed for a range of volume ratios of two liquids. Such an arrangement of two superposed liquid drops does not affect the spreading behavior of the outer liquid but influences that of the inner liquid significantly. The drop spreads to a larger extent and breaks into more fingers (Nf) as compared to the case where the same liquid is spreading in the absence of outer liquid. The experimentally observed number of fingers is compared with the prediction using available theory for single liquid. It is found that the theory over-predicts the value of Nf for the inner liquid while it is covered by an outer liquid. We provide a theoretical justification for this observation using linear stability analysis. Our analysis demonstrates that for small but finite surface tension ratio of the two liquids, the presence of the outer interface reduces the value of the most unstable wave number which is equivalent to the decrease in the number of fingers observed experimentally. Finally, sustained rotation of the disk leads to the formation of droplets at the tip of the fingers traveling outwards. Published by AIP Publishing.

Steering the ester and gamma-valerolactone selectivities in levulinic acid hydrogenation - Kasar, Gayatri B.; Date, Nandan S.; Bhosale, P. N.; Rode, Chandrashekhar V. (Energy Fuels, 2018)
Both alkyl esters and γ-valerolactone (GVL) derived from levulinic acid (LA) have applications as renewable transportation fuel/fuel additives. Non-noble metal cobalt supported on La2O3 catalyst was developed for efficient cascade LA hydrogenation to GVL via esterification. LA hydrogenation in methanol alone yielded methyl levulinate (MeLA) as a major product along with 43% of GVL. Interestingly, hydrogenation in water gave almost complete selectivity to GVL; nevertheless, it was associated with significant metal leaching. Suppression of metal leaching and enhancement in selectivity to GVL could be achieved by a methanol/water (95:5) solvent system. XRD analysis of La2O3-supported catalysts evidenced the characteristic peaks of a mixture of La2O3 and La(OH)3 phases. Basicity, as well as acidity, of the catalyst as determined by CO2 and NH3 TPD was due to these La2O3, Co–La, and La(OH)3 phases which played an important role in directing the product selectivity in levulinic acid hydrogenation. At the low temperature of 160 °C, almost equal selectivities of MeLA (47%) and GVL (43%) were observed, while higher temperature (200 °C) favored further hydrogenation of MeLA to GVL (75%). Similarly, with an increase in reaction time to 9 h, the GVL selectivity achieved was as high as 80%. The selectivity to MeLA and GVL in LA hydrogenation over Co/La2O3 catalyst can be altered by suitably adjusting the reaction conditions.

Strategies to reduce necking and drawdown defects in polymer melt extrusion film casting process - Rokade, Dhammaraj; Chougale, Sanket; Pol, Harshawardhan (256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond, 2018)
256th National Meeting and Exposition of the American-Chemical-Society (ACS) - Nanoscience, Nanotechnology and Beyond

Streptomyces sp metabolite(s) promotes Bax mediated intrinsic apoptosis and autophagy involving inhibition of mTOR pathway in cervical cancer cell lines - Dan, Vipin Mohan; Muralikrishnan, Balaji; Sanawar, Rahul; Vinodh, J. S.; Burkul, Bhushan Bapusaheb; Srinivas, Kalanghad Puthankalam; Lekshmi, Asha; Pradeep, N. S.; Dastager, Syed G.; Santhakumari, B.; Santhoshkumar, Thankayyan R.; Kumar, R. Ajay; et al. (Scientific Reports, 2018)
In cervical cancer, the association between HPV infection and dysregulation of phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway (PI3K/AKT/mTOR pathway) places mTOR as an attractive therapeutic target. The failure of current treatment modalities in advanced stages of this cancer and drawbacks of already available mTOR inhibitors demand for novel drug candidates. In the present study we identified the presence of a mTOR inhibitor in an active fraction of the ethyl acetate extract of Streptomyces sp OA293. The metabolites(s) in the active fraction completely inhibited mTORC1 and thereby suppressed activation of both of its downstream targets, 4E-BP1 and P70S6k, in cervical cancer cells. In addition, it also stalled Akt activation via inhibition of mTORC2. The mechanism of mTOR inhibition detailed in our study overcomes significant drawbacks of well known mTOR inhibitors such as rapamycin and rapalogs. The active fraction induced autophagy and Bax mediated apoptosis suggesting that mTOR inhibition resulted in programmed cell death of cancer cells. The molecular weight determination of the components in active fraction confirmed the absence of any previously known natural mTOR inhibitor. This is the first report of complete mTOR complex inhibition by a product derived from microbial source.

Structural and functional analysis of UGT92G6 suggests an evolutionary link between mono- and disaccharide glycoside-forming transferases - Huang, Fong-Chin; Giri, Ashok; Daniilidis, Melina; Sun, Guangxin; Härtl, Katja; Hoffmann, Thomas; Schwab, Wilfried (Plant and Cell Physiology, 2018)
Glycosylation mediated by UDP-dependent glycosyltransferase (UGT) is one of the most common reactions for the biosynthesis of small molecule glycosides. As glycosides have various biological roles, we characterized UGT genes from grapevine (Vitis vinifera). In silico analysis of VvUGT genes that were highly expressed in leaves identified UGT92G6 which showed sequence similarity to both monosaccharide and disaccharide glucoside-forming transferases. The recombinant UGT92G6 glucosylated phenolics, among them caffeic acid, carvacrol, eugenol and raspberry ketone, and also accepted geranyl glucoside and citronellyl glucoside. Thus, UGT92G6 formed mono- and diglucosides in vitro from distinct compounds. The enzyme specificity constant Vmax/Km ratios indicated that UGT92G6 exhibited the highest specificity towards caffeic acid, producing almost equal amounts of the 3- and 4-O-glucoside. Transient overexpression of UGT92G6 in Nicotiana benthamiana leaves confirmed the production of caffeoyl glucoside; however, the level of geranyl diglucoside was not elevated upon overexpression of UGT92G6, even after co-expression of genes encoding geraniol synthase and geraniol UGT to provide sufficient precursor. Comparative sequence and 3-D structure analysis identified a sequence motif characteristic for monoglucoside-forming UGTs in UGT92G6, suggesting an evolutionary link between mono- and disaccharide glycoside UGTs. Thus, UGT92G6 functions as a mono- and diglucosyltransferase in vitro, but acts as a caffeoyl glucoside UGT in N. benthamiana.

Structural and magnetic properties of La2Ni1-xCoxMnO6 compounds - Pramanik, Debabrata; Mukherjee, S.; Dan, Shovan; Nandy, A.; Pradhan, S. K.; Dasgupta, Papri; Poddar, Asok; Mukherjee, Manabendra; Manjunath, B.; Joy, P. A. (Materials Research Bulletin, 2018)
Single phase monoclinic La2Ni1-xMnO6 (x = 0.2, 0.4, 0.8) compounds, henceforth, referred as LNCxMO (x = 0.2, 0.4, 0.8) have been prepared by Sol-gel technique. The structural study and redox titration suggest that the samples are both La and O deficient. The generated atomic models using Rietveld refined structural parameters show octahedral distortion In the double perovskite structure. X-ray photoelectron spectroscopy (XPS) study has been used to determine the predominant valence states of Ni, Mn and Co ions. LNCxMO (x = 0.2, 0.4) are found to be Heisenberg ferromagnets whereas LNC0.8MO is a phase segregated system. In LNC0.4MO and LNO0.8MO, at temperatures above T-c, chi(-1)(T) curve shows the characteristics of Griffiths phase. The study of ac susceptibility and Isothermal remanent magnetization (IRM) discard the possibility of any glassy state at low temperatures. The antiphase boundaries (APBs), antisite disorders (ASDs) and oxygen vacancies play important roles in this system.

Structural characterization and magnetic properties of undoped and copper-doped cobalt ferrite nanoparticles prepared by the octanoate coprecipitation route at very low dopant concentrations - Kamta Tedjieukeng, H.M.; Tsobnang, P.K.; Fomekong, R.L.; Etape, E.P.; Joy, P.A.; Delcorte, A.; Lambi, J.N. (RSC Advances, 2018)
Nanoparticles of undoped and copper-doped cobalt ferrite Co1−xCuxFe2O4 at very low dopant concentrations (x = 0; 0.02; 0.04; 0.06; 0.08) were successfully synthesized by pyrolysis of the corresponding hetero metal octanoate precursors obtained via coprecipitation using the octanoate ligand as precipitating agent. The precursors were then characterized by FTIR, ICP-AES and TG-DTA analyses and the results reveal the formation of a copper-cobalt-iron hydroxooctanoate represented by the formula [Co1−xCuxFe2(C8H15O2)6(OH)2·2H2O]. The decomposition products obtained upon pyrolysis in air at 400 °C for 3 h were characterized by FTIR, XRD, SEM, TEM, XPS and VSM analyses. FTIR and XRD analyses showed the formation of a single phase mixed spinel ferrite while TEM analysis showed that the particles have a spherical shape with a mean size of 20 nm and form spherical agglomerates with sizes reaching 500 nm in some cases as the SEM images show. The chemical states of the metallic species in the samples were revealed by XPS to be Cu2+, Co2+ and Fe3+. These results combined with XRD confirmed the mixed spinel structure, Co1−xCuxFe2O4 in which Cu2+ ions substitute Co2+ ions in tetrahedral sites for x lower than 0.06 and in octahedral sites for x between 0.06 and 0.08. Magnetic parameters such as saturation magnetization (Ms), coercivity (Hc), remanent magnetization (Mr), magnetocrystalline anisotropy constant (K) and reduced magnetization (Mr/Ms), obtained from magnetic hysteresis loops measured at room temperature, are in agreement with this mixed spinel structure and also indicate that these materials are ferromagnetic and could be good candidates for applications in biomedicine and in microwave devices.

Structural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium - Allu, Amarnath R. (RSC Advances, 2018)
Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries. In the research reported in this paper, NASICON-based NCAP glass (Na2.8Ca0.1Al2P3O12) was selected as the parent glass. The present study demonstrates the changes in the Na+ ion conductivity of NCAP bulk glass with the substitution of boron (NCABP: Na2.8Ca0.1Al2B0.5P2.7O12) and gallium (NCAGP: Na2.8Ca0.1Al2Ga0.5P2.7O12) for phosphorus and the resulting structural variations found in the glass network. For a detailed structural analysis of NCAP, NCABP and NCAGP glasses, micro-Raman and magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopic techniques (for 31P, 27Al, 23Na, 11B and 71Ga nuclei) were used. The Raman spectrum revealed that the NCAP glass structure is more analogous to the AlPO4 mesoporous glass structure. The 31P MAS-NMR spectrum illustrated that the NCAP glass structure consists of a high concentration of Q0 (3Al) units, followed by Q0 (2Al) units. The 27Al MAS-NMR spectrum indicates that alumina exists at five different sites, which include AlO4 units surrounded by AlO6 units, Al(OP)4, Al(OP)5, Al(OAl)6 and Al(OP)6, in the NCAP glass structure. The 31P, 27Al and 11B MAS-NMR spectra of the NCABP glass revealed the absence of B–O–Al linkages and the presence of B3–O–B4–O–P4 linkages which further leads to the formation of borate and borophosphate domains. The 71Ga MAS-NMR spectrum suggests that gallium cations in the NCAGP glass compete with the alumina cations and occupy four (GaO4), five (GaO5) and six (GaO6) coordinated sites. The Raman spectrum of NCAGP glass indicates that sodium cations have also been substituted by gallium cations in the NCAP glass structure. From impedance analysis, the dc conductivity of the NCAP glass (∼3.13 × 10−8 S cm−1) is slightly decreased with the substitution of gallium (∼2.27 × 10−8 S cm−1) but considerably decreased with the substitution of boron (∼1.46 × 10−8 S cm−1). The variation in the conductivity values are described based on the structural changes of NCAP glass with the substitution of gallium and boron.

Structural elucidation of the binary mixtures of [emim][bf4] and [bmim][bf4] in ethyl-substituted solvents by isothermal titration calorimeter. - Jain, Preeti (ChemistrySelect, 2018)
In order to address the issue whether both ionic liquids and solvents influence the enthalpy of their solutions, highly accurate excess partial molar enthalpy, urn:x-wiley:23656549:media:slct201800976:slct201800976-math-0001 values have been measured using Isothermal Titration Calorimeter (ITC). Therefore, thermodynamic behavior has been observed in the mixtures containing ionic liquids. It essentially depends on the molecular structure of the constituents of the mixture. The hydrogen bonding between ionic liquids and ethyl‐substituted solvents (2‐ethoxyethanol, ethylene glycol, diethylamine, ethyl acetate and N,N‐ diethylacetamide) may lead to strong ion‐solvent interactions. In the present study, an effort has been made to quantify various interactions between ionic liquid and solvent, based on the urn:x-wiley:23656549:media:slct201800976:slct201800976-math-0002 values. Linear solvation free relation shows dependence of limiting excess partial molar enthalpies, urn:x-wiley:23656549:media:slct201800976:slct201800976-math-0003 upon the solvent properties. Structural orientation of solvent molecules and ionic liquids also described by the urn:x-wiley:23656549:media:slct201800976:slct201800976-math-0004 values. The ion‐ion, ion‐solvent interactions have also been investigated in terms of the enthalpic interaction parameters, urn:x-wiley:23656549:media:slct201800976:slct201800976-math-0005 and relative apparent molar enthalpy, φL of ionic liquid‐ethyl‐substituted solvent systems.

Structural, functional and evolutionary diversity of 4-coumarate-CoA ligase in plants - Lavhale, Santosh G.; Kalunke, Raviraj M.; Giri, Ashok P. (Planta, 2018)
Main conclusions The 4-coumarate-CoA ligases (4CL) contribute in channelizing flux of different phenylpropanoid biosynthetic pathways. Expression of 4CL is optimized at developmental stages and in response to environmental triggers such as biotic and abiotic stresses. The enzyme is valuable in metabolic pathway engineering for curcuminoids, resveratrol, biofuel production and nutritional improvement. Vigorous analysis of regulation at functional and expression level is obligatory to attain efficient commercial production of candidate metabolites using 4CL. Phenylpropanoid pathway provides precursors for numerous secondary metabolites in plants. In this pathway, 4-coumarate-CoA ligase (EC 6.2.1.12, 4CL) is the main branch point enzyme which generates activated thioesters. Being the last enzyme of three shared common steps in general phenylpropanoid pathway, it contributes to channelize precursors for different phenylpropanoids. In plants, 4CL enzymes are present in multiple isoforms and encoded by small gene family. It belongs to adenylate-forming enzyme family and catalyzes the reaction that converts hydroxy or methoxy cinnamic acid derivatives to corresponding thioesters. These thioesters are further utilized for biosynthesis of phenylpropanoids, which are known for having numerous nutritional and medicinal applications. In addition, the 4CL enzymes have been characterized from various plants for their role in plant physiology or in biotic and abiotic stresses. Furthermore, specific isoforms are differentially regulated upon exposure to diverse stimuli leading to flux diversion toward the particular metabolite biosynthesis. Evolutionary studies showed that 4CL separately evolved after monocot and dicot segregation. Here, we provide a comprehensive review on 4CL, which includes evolution, function, gene/protein structure, role in metabolite biosynthesis and cellular partition, and their regulation. Based on the available data, we have explored the scope for pathway engineering by utilizing 4CL enzymes.

Structural insights into the unique inhibitory mechanism of Kunitz type trypsin inhibitor from Cicer arietinum L. - Bendre, A.D.; Suresh, C.G.; Shanmugam, D.; Ramasamy, S. (Journal of Biomolecular Structure and Dynamics, 2018)
Kunitz-type trypsin inhibitors bind to the active pocket of trypsin causing its inhibition. Plant Kunitz-type inhibitors are thought to be important in defense, especially against insect pests. From sequence analysis of various Kunitz-type inhibitors from plants, we identified CaTI2 from chickpea as a unique variant lacking the functionally important arginine residue corresponding to the soybean trypsin inhibitor (STI) and having a distinct and unique inhibitory loop organization. To further explore the implications of these sequence variations, we obtained the crystal structure of recombinant CaTI2 at 2.8Å resolution. It is evident from the structure that the variations in the inhibitory loop facilitates non-substrate like binding of CaTI2 to trypsin, while the canonical inhibitor STI binds to trypsin in substrate like manner. Our results establish the unique mechanism of trypsin inhibition by CaTI2, which warrant further research into its substrate spectrum. Abbreviations BApNA Nα-Benzoyl-L-arginine 4-nitroanilide BPT bovine pancreatic trypsin CaTI2 Cicer arietinum L trypsin inhibitor 2 DrTI Delonix regia Trypsin inhibitor EcTI Enterolobium contortisiliquum trypsin inhibitor ETI Erythrina caffra trypsin inhibitor KTI Kunitz type inhibitor STI soybean trypsin inhibitor TKI Tamarindus indica Kunitz inhibitor Communicated By Ramaswamy H. Sarma.

Structure and function of a highly active Bile Salt Hydrolase (BSH) from Enterococcus faecalis and post-translational processing of BSH enzymes - Chand, D. (Biochim Biophys Acta., 2018)
Bile Salt Hydrolase (BSH), a member of Cholylglycine hydrolase family, catalyzes the de-conjugation of bile acids and is evolutionarily related to penicillin V acylase (PVA) that hydrolyses a different substrate such as penicillin V. We report the three-dimensional structure of a BSH enzyme from the Gram-positive bacteria Enterococcus faecalis (EfBSH) which has manifold higher hydrolase activity compared to other known BSHs and displays unique allosteric catalytic property. The structural analysis revealed reduced secondary structure content compared to other known BSH structures, particularly devoid of an anti-parallel β-sheet in the assembly loop and part of a β-strand is converted to increase the length of a substrate binding loop 2. The analysis of the substrate binding pocket showed reduced volume owing to altered loop conformations and increased hydrophobicity contributed by a higher ratio of hydrophobic to hydrophilic groups present. The aromatic residues F18, Y20 and F65 participate in substrate binding. Thus, their mutation affects enzyme activity. Docking and Molecular Dynamics simulation studies showed effective polar complementarity present for the three hydroxyl (-OH) groups of GCA substrate in the binding site contributing to higher substrate specificity and efficient catalysis. These are unique features characteristics of this BSH enzyme and thought to contribute to its higher activity and specificity towards bile salts as well as allosteric effects. Further, mechanism of autocatalytic processing of Cholylglycine Hydrolases by the excision of an N-terminal Pre-peptide was examined by inserting different N-terminal pre-peptides in EfBSH sequence. The results suggest that two serine residues next to nucleophile cysteine are essential for autocalytic processing to remove precursor peptide. Since pre-peptide is absent in EfBSH the mutation of these serines is tolerated. This suggests that an evolution-mediated subordination of the pre-peptide excision site resulted in loss of pre-peptide in EfBSH and other related Cholylglycine hydrolases.
Keywords: autocatalytic processing; Bile salt hydrolase; molecular dynamics; Mutagenesis; Polar complementarity; X-ray crystallography

Studies on CL-20/HMX (2:1) cocrystal: a new preparation method and structural and thermokinetic analysis - Ghosh, Mrinal; Sikder, Arun K.; Banerjee, Shaibal; Gonnade, Rajesh G. (Crystal Growth & Design, 2018)
A new preparation method for CL-20/HMX (2:1) cocrystal has been established at the laboratory level that is amenable for scale up. Solvent evaporation from a saturated solution of the stoichiometric mixture in the presence of a high boiling antisolvent, comparatively a very efficient and cheaper method, yielded pure cocrystals. Cocrystals were well characterized by spectroscopic, thermoanalytical tools, X-ray diffraction, and microscopic techniques. A correlation of percentage of cocrystal formation with evaporation rate has been obtained through quantitative analysis using Raman spectrometry. An evaporation rate of <1 mL/min consistently produced pure cocrystal confirmed by Raman and powder X-ray diffraction analysis. Thermokinetic analysis suggests the cocrystal to be more stable than CL-20 with an energy of activation of 65 kcal/mol, higher than CL-20 but inferior to HMX. Significant augmentation in the values of k and A over CL-20 justified a faster decomposition rate. Enhanced insensitivity toward friction and impact forces and higher measured velocity of detonation indicate improved performance on incorporation into high explosive formulations.

Study of photoelectrochemical conductivity mechanism and electrochemical impedance spectroscopy of bulk CuInTe2 – Electrolyte interface - Lakhe, M. G.; Rohom, A. B.; Londhe, P. U.; Bhand, G. R.; Chaure, N. B. (Surfaces and interfaces, 2018)
CuInTe2 (CIT) thin films were electrochemically deposited in an aqueous electrolyte on fluorine doped tin oxide (FTO) coated glass substrates for potentials ranging from −0.6 V to −0.9 V at pH 4. Films were annealed at 400 °C for 15 min in air ambient. Both as-deposited and annealed layers were characterized by various characterization techniques. The conductivity type of the CIT layers was studied by photoelectrochemical (PEC) response and solid–electrolyte interface by impedance spectroscopy. As-deposited samples confirmed amorphous nature of CIT in contrast to that of polycrystalline films obtained upon annealing. Three prominent reflections (1 1 2), (2 2 0)/(2 0 4) and (3 1 2)/(1 1 6) of chalcopyrite CIT were obtained upon annealing. The optical band gap values ∼0.90 eV and 1.08 eV and ∼0.88 eV and 1.01 eV were estimated for as-deposited and annealed CIT layers deposited at −0.7 V and −0.8 V respectively. The most prominent A1 mode observed at 123 cm−1 in the Raman spectra of chalcopyrite CIT was shifted towards lower wavelengths due to the development of tensile strain. Very compact, well adhesive and void free globular layers were deposited at pH 4. The indium content was found to be increased with increasing the deposition potential which agrees well with the overpotential deposition of indium. Photoelectrochemical (PEC) study confirms the growth of p-type CIT layers. The negative resistance at higher frequency domain (3 MHz to 10 kHz) from electrochemical impedance spectroscopy (EIS) confirms the power/energy giving nature of CIT/electrolyte interface at higher frequency and diffusion mechanism of ionic species dominate at lower frequency region

Study the effect of impact angle on slurry erosion wear of four different ductile materials - Nandre, Bhushan D.; Desale, Girish R. (Materials Today: Proceedings, 2018)
The test rig fabricated for the present work has an ability to study the effect of orientation angle of erosion wear. The particles of Indian Standard sand (Quartz) selected as erodent for the present investigation because it is the most widely occurs in natural slurries. Experimental investigations on erosion behavior of ductile materials AISI SS304, AA 6063, Copper and Brass have been carried out using solid-water mixtures of the above erodent. The erosion wear due to solid-liquid mixture of IS Sand and tap water at different impact angles shows typical ductile erosion behavior for the selected materials. The maximum erosion is observed at 22.5° angle for AISI SS 304, 45o for AA 6063, 22.5o for Copper and 30o for Brass. The minimum erosion is observed at 90o orientation angle for all the materials. The eroded specimens were examined under the Scanning Electron Microscope (SEM) at minimum and maximum wear orientation angles. The SEM micrographs of eroded specimens depict the mechanism of material removal.
Keywords: AA 6063; AISI SS304; brass; Copper; Quart; SEM; Slurry erosion

Substituent‐induced deformed ni–porphyrin as an electrocatalyst for the electrochemical conversion of water into dioxygen - Krishna, J. V. S.; Krishna, Narra Vamsi; Singh, Santosh K.; Shaw, Pankaj K.; Dhavale, Vishal M.; Vardhaman, Anil Kumar; Giribabu, Lingamallu (European Journal of Inorganic Chemistry, 2018)
The electrochemical water oxidation ability of complexes 5,15‐diphenylporphinatonickel(II) (A) and 5,15‐bis(3,5‐di‐tert‐butylphenyl)porphinatonickel(II) (B) in the oxygen evolution reaction (OER) have been investigated in an alkaline medium. Complex B was found to be kinetically and thermodynamically more active than complex A. The overpotential and Tafel slope of complex B are lower than those of complex A by 30 mV and around 45 mV/decade, respectively, which supports the higher activity of B. Moreover, stability tests endorse the sustainability of both samples under alkaline conditions. It has been found that the 3,5‐di‐tert‐butylphenyl substituent in B plays a decisive role in achieving a better OER onset potential and current than that obtained with A, which is a result of the modulation of the structural parameters of B. Furthermore, the measured OER activities of A and B have been correlated with their molecular arrangement as well as differences in their bonding characteristics and dipole moments. For further insight, the obtained results have been confirmed by a theoretical study.

Subtle interaction between Ag and O 2 : a near ambient pressure UV photoelectron spectroscopy (NAP-UPS) investigations - Ghosalya, Manoj Kumar (Journal of Chemical Sciences, 2018)
The Ag-O2 interaction, which is at the center-stage of Ag-catalyzed partial oxidation reactions, is studied with NAP-UPS up to 0.2 mbar O2 pressure between 295 and 550 K. Three temperature regimes were identified for distinct Ag-O2 interaction, which are (a) 295–390 K, where mainly dissociative chemisorption of O2 happens, (b) 390–450 K, where diffusion of O-atoms into the sub-surfaces of Ag is prominent, and (c) >450 K, where metastable oxide forms on polycrystalline Ag surfaces. The work function (WF) of Ag changed from 4.95 (≤390 K) to 5.30 eV (390–450 K), and then to 5.7 eV (≥450 K) at 0.1 mbar O2 pressure. Oxygen population in the sub-surfaces imparts crucial modifications to Ag at 390–450 K; it makes the surface to be electron-deficient that relates to the change in the WF of Ag and facilitates the formation of space charge layer on Ag surface. Oxygen adsorbed on such modified Ag-surfaces is electrophilic in nature, and this appears at a higher binding energy in core level XPS than the chemisorbed oxygen on metallic Ag. This is supported by angle-dependent NAP-XPS studies. The subsurface population of oxygen in Ag no longer persists at >410 K when the O2 supply is removed. A high ratio of antibonding/bonding O 2p bands suggests the unique silver-oxygen interaction under the measurement conditions.
Keywords: Electronic Structure; epoxidation; heterogeneous catalysis; Surface Science

Sucrose capped gold nanoparticles as a plasmonic chemical sensor based on non-covalent interactions: application for selective detection of vitamins B-1 and B-6 in brown and white rice food samples - Shrivas, Kamlesh; Nirmalkar, Nidhi; Thakur, Santosh Singh; Deb, Manas Kanti; Shinde, Sandip S.; Shankar, Ravi (Food Chemistry, 2018)
We report simple and selective method for detection of vitamins B-1 and B-6 in brown and white rice samples using localized surface plasmon resonance (LSPR) of sucrose capped gold nanoparticles (AuNPs) as a chemical sensor colorimetrically. Here, detection is based on the color change of AuNPs from pink to blue followed by a red shift of LSPR absorption band in UV-vis region with the addition of vitamins B-1 and B-6 into the NPs solution. A good linear range was observed in the range of 25-1000 ngmL(-1) with detection limit of 8 ngmL(-1) for B-1 and 50-1000 ngmL(-1) with detection limit of 15 ngmL(-1) for vitamins B-6. The employment of AuNPs for detection of B-1 and B-6 vitamins in rice food samples showed remarkable abilities in terms of the simplicity, low cost, stability, reproducibility and sensitivity.

Superior HIV-1 TAR binders with conformationally constrained R52 arginine mimics in the Tat(48-57) peptide - Bhosle, Govind S.; Kharche, Shalmali; Kumar, Santosh; Sengupta, Durba; Maiti, Souvik; Fernandes, Moneesha (Chemmedchem, 2018)
We report a 100-fold increase in binding affinity of the Tat(48-57) peptide to HIV-1 transcriptional activator-responsive element (TAR) RNA by replacing Arg52, an essential and critical residue for Tat's specific binding, with (2S,4S)-4-guanidinoproline. The resulting Tat1M peptide is a far superior binder than Tat1M, a peptide containing another conformationally constrained arginine mimic, (2S,4S)-4-amino-N-(3-guanidinopropyl)proline, or even the control Tat peptide (CtrlTat) itself. Our observations are supported by circular dichroism (CD), isothermal titration calorimetry (ITC), gel electrophoresis and UV spectroscopy studies. Molecular dynamics simulations suggest increased interactions between the more compact Tat1M and TAR RNA, relative to CtrlTat. The CD signature of the RNA itself remains largely unchanged upon binding of the peptides. The Tat mimetics further have better cell uptake properties than the control Tat peptide, thus increasing their potential application as specific TAR-binding molecules.
Keywords: antiviral agents; arginine mimics; RNA; Tat peptide analogues; Tat-TAR binding

Superprotonic conductivity in flexible porous covalent organic framework membranes - Banerjee, Rahul; Sasmal, Himadri Sekhar; Harshitha, B. A.; Bhange, Siddheshwar; Karak, Suvendu; Halder, Arjun; Kurungot, Sreekumar (Angewandte Chemie, 2018)
Poor mechanical stability of the polymer electrolyte membranes (PEMs) remains one of the bottlenecks towards improving the performance of the proton exchange membrane (PEM) fuel cells. The present work proposes a unique way to utilize crystalline covalent organic frameworks (COFs) as a self‐standing, highly flexible membrane to further boost the mechanical stability of the material without compromising its innate structural characteristics. The as‐synthesized p‐toluene sulfonic acid loaded covalent organic framework membranes (COFMs) showing the highest proton conductivity amongst all crystalline porous organic polymeric materials reported till date, as high as 7.8 x 10‐2 S cm‐1, have been further tested under real PEM operating conditions to ascertain their practical utilization as proton exchange membranes. Attainment of 24 mW cm‐2 power density, which is the highest among COFs and MOFs, highlights the possibilityof using a COF membrane over the other state‐of‐the‐art crystalline porous polymeric materials reported to date.

Supramolecular complexes of poly(3‐Hexylthiophene)‐block (and random)‐poly[3‐(2‐(6‐carboxyhexyl)methyl)thiophene] copolymers with perylene bisimide - Shinde, Shekhar (Journal of Polymer Science Part A: Polymer Chemistry, 2018)
Block and random copolymers of poly(3‐hexylthiophene) and poly[3‐(2‐(6‐carboxyhexyl)methyl)thiophene] with side‐chain carboxylic functionality ((P3HT‐b‐P3COOH) and (P3HT‐r‐P3COOH) were developed by Grignard Metathesis (GRIM) polymerization. The carboxylic functionality was introduced in the side chain via the oxazoline route. Both the block and random polythiophene copolymers were complexed with pyridine functionalized perylene bisimide to obtain supramolecular block and random polymer complexes. The complex formation in both systems was confirmed by 1H NMR, WXRD and SAXS studies. An expansion of d spacing upon complex formation was observed in both the block and random copolymer, which could be traced by WXRD. Hole and electron mobilities measured for the supramolecular complexes indicated values which were higher by an order of magnitude for the supramolecular block complex (μh ≈ 2.9 × 10−4 cm2/Vs; μe ≈ 3.1 × 10−6 cm2/Vs) as compared to the random (μh ≈ 1.4 × 10−5 cm2/Vs; μe ≈ 4.7 × 10−7 cm2/Vs) copolymer. These results are indicative of the higher degree of disorder prevailing in the films of random copolymer system compared to the block copolymer.
Keywords: block and random polythiophene; perylene bisi-mide; Self-assembly

Supramolecular reassembly of self-exfoliated ionic covalent organic nanosheets for label-free detection of double-stranded DNA - Mal, Arindam; Mishra, Rakesh K.; Praveen, Vakayil K.; Khayum, M. Abdul; Banerjee, Rahul; Ajayaghosh, Ayyappanpillai (Angewandte Chemie-International Edition, 2018)
Ionic covalent organic nanosheets (iCONs), a member of the two-dimensional (2D) nanomaterials family, offer a unique functional platform for a wide range of applications. Herein, we explore the potential of an ethidium bromide (EB)-based covalent organic framework (EB-TFP) that self-exfoliates in water resulting in 2D ionic covalent organic nanosheets (EB-TFP-iCONs) for the selective detection of double-stranded DNA (dsDNA). In an aqueous medium, the self-exfoliated EB-TFP-iCONs reassemble in the presence of dsDNA resulting in hybrid EB-TFP-iCONs-DNA crystalline nanosheets with enhanced fluorescence at 600 nm. Detailed steady-state and time-resolved emission studies revealed that the reassembly phenomenon was highly selective for dsDNA when compared to single-stranded DNA (ssDNA), which allowed us to use the EB-TFP-iCONs as a 2D fluorescent platform for the label-free detection of complementary DNA strands.
Keywords: Covalent organic framework; DNA; ionic assembly; ionic covalent organic nanosheets; label-free detection

Surface colonized silver nano particles over chitosan poly-electrolyte micro-spheres and their multi-functional behavior - Prakash, B. (Materials Research Express, 2018)
hitosan/tripolyphosphate polyelectrolyte (TPP) microspheres, decorated and surface functionalized with silver nanoparticles (NPs) of average diameter of 15 nm, were synthesized following a simple two-step procedure. These Ag NP-functionalized polyelectrolyte microspheres (Ag-CSPMs) are found to be biocompatible and enhancing the reactive oxygen species in curcumin with excellent anti-bacterial activity for selected Gram-positive and negative bacterial strains, making them much attractive relative to bare surface counterparts; the well-stabilized silver NPs do not form any agglomerations on the surface of the chitosan microspheres. They also show excellent cytotoxic behavior towards MCF7 cell lines, showing a half-maximal inhibitory concentration (IC50) of 32 μg ml-1. Therefore, Ag-CSPMs exhibit multi-functional ability having potential towards theranostics applications.
Keywords: antibacterial properties; Chitosan; Cytotoxicity; reactive oxygen species; silver nanoparticles; theranostics

Surface functionalized fluorescent PS nanobead based dual-distinct solid state sensor for detection of volatile organic compounds - Makkad, Sarabjot Kaur (Analytical Chemistry, 2018)
Solid state emitting, distinctly dual vapor sensors with high quantum yield was developed using polystyrene incorporating two fluorophores following a miniemulsion polymerization method. Selective functionalization with carboxy and amine functionality was used to decorate the resulting polystyrene nanobeads having both perylenebisimide (PBI) and oligo (p-phenylenevinylene) (OPV) fluorophores. These nanobeads with a size of 70–180 nm showed near white emission under UV light. On contact with vapors of specific electron deficient nitroaromatics OPV emission got selectively quenched to show yellow emission from the nanobeads under UV radiation. Exposure to amine vapor quashed PBI emission selectively resulting in blue emission under UV lamp. Such a vast range of color alteration from white to either blue or yellow from the same sensor makes it a true dual analyte sensor with two distinct outputs. Control of surface functionality (−COOH, −NH2, and neutral) on the nanobeads played a pivotal role in boosting the sensing efficiency; introduction of functionality on the surface facilitated analyte-sensor interaction through hydrogen bonding, prompting their fast responsiveness. Real time, potential device based application was demonstrated with free-standing films which was capable of efficient detection with fast analyte exchange from dilute solutions. Recyclability of the film sensor was demonstrated with 8 cycles of reuse.

Surface modification of polymers for tissue engineering applications: arginine acts as a sticky protein equivalent for viable cell accommodation - Sengupta, Poulomi (ACS Omega, 2018)
Hydrophobic polymers, for their favorable mechanical properties, are a popular choice as permanent bioimplants. These materials remain absolutely bioinert for years, but throw up challenges when it comes to fast integration with healthy tissue. Addressing this, herein, we present a surface-modification technique of converting the hydrophobic surface of a polymeric film into a hydrophilic one using a layer-by-layer assembly process involving gold nanoparticles and small molecules like amino acids. These films showed much improved animal cell (murine fibroblast) adherence properties compared to commercially available tissue culture plates. Moreover, arginine-modified films exhibited a nearly equivalent cell viability compared to the films modified with the natural extracellular matrix component fibronectin. The surface hydrophilicity and roughness of our novel film were characterized by contact angle measurement and atomic force microscopy. Cell counting, fluorescence microscopy, cell viability, and collagen estimation assay were employed to demonstrate that our film favored a much improved cell adherence, and accommodation in comparison to the commercially available tissue culture plates.
Keywords: Cell and Molecular biology; Extracellular matrix proteins; Nanoparticles; Physical and chemical properties; Polymers; Proteins; Surface structure; Surface treatment; Thin films; tissue engineering

Sustainability assessment of brick work for low-cost housing: a comparison between waste based bricks and burnt clay bricks - Joglekar, S. N. (Sustainable Cities and Society, 2018)
Manufacturing of bricks, using clay or fly ash, is one of the major contributors to greenhouse gas emissions as their manufacturing involves utilization of coal and cement. To overcome this limitation, alternative construction materials are developed by author using industrial and agro wastes like cotton mill waste, recycled paper mill waste, and rice husk ash. This work aims at performing a sustainability assessment of burnt clay bricks and bricks made of industrial and agro wastes used for brickwork in a low-cost house. The criteria considered for the assessment are economic, environmental, social, and technical aspects for manufacture of bricks and use of different bricks for brickwork. For the evaluation of environmental criterion, a life cycle assessment (LCA) tool is used. Overall sustainability index (SI) is calculated for alternatives based on the various criteria using MIVES approach. The relative SIs of clay and fly ash bricks, were 0.25 and 0.26, respectively. Overall, bricks made of industrial and agro wastes are found more sustainable with the highest SI for cotton waste bricks (0.94). Sensitivity analysis also confirmed that brickwork from waste based bricks is more sustainable compared to brickwork made from clay brick or fly ash brick.
Keywords: Life cycle assessment; Low cost housing; Multicriteria decision; Sustainability index; Sustainable construction material

Syntheses and single crystal X-ray diffraction analysis of five isostructural 2D MOCCs - Singh, Sandeep K.; Srivastava, Krishna; Banerjee, Rahul; Prasad, Jagdish (Polyhedron, 2018)
Five two-dimensional metal-organic coordination compounds (MOCCs) have been solvothermally synthesized by the combination of 2-aminonicotinic acid (ANA) and transition metal ions, viz. Co(II), Ni (II), Cu(Il), Zn(II) and Cd(II), in water-ethanol mixed solvent. They are formulated as [CoC6H5N2O2)(2)], (Co-ANA); [Ni(C6H5N2O2)(2)], (Ni-ANA) [Cu(C6H5N2O2)(2)], (Cu-ANA), [Zn(C6H5N2O2)(2)], (Zn-ANA) and [Cd(C6H5N2O2)(2)], (Cd-ANA). Single crystal X-ray diffraction studies for the complexes Co-ANA, Ni-ANA and Cd-ANA have also been carried out. These three complexes crystallize in the tetragonal crystal system with the space group P4(1)2(1)2. The metal ions in all these complexes have an octahedral coordination environment. The six coordinations are satisfied by two pyridine N-atoms from two different ANA ligands and four oxygen atoms from two chelating carboxylate groups of another two ANA ligands. The topological motif of the coordination network is defined as 2-periodic net or square lattice (sql). These complexes were further characterized by elemental, FT-IR spectral, thermal and powder X-ray diffraction analyses. (C) 2018 Elsevier Ltd. All rights reserved.

Synthesis and anticancer activity of conformationally constrained Smac mimetics containing pseudo beta turns - Baravkar, Sachin B.; Wagh, Mahendra A.; Paul, Debasish; Santra, Manas; Sanjayan, Gangadhar J. (Tetrahedron Letters, 2018)
Herein, we report synthesis and in vitro anticancer activity of conformationally constrained Smac mimetics containing reverse turn inducing motifs "Ant-Pro" and "sAnt-Pro". The synthesis of Smac analogs with diverse hydrophobic groups at the C-terminus was carried out using solution phase peptide synthesis. The synthesis of Ant-Pro containing analogs 3a-j was carried out by ring opening of benzoxazinones 7a-c, whereas, their sulfonamide counterparts 4a-h were synthesized by using routine acid-amine coupling reaction. In vitro anticancer studies against breast cancer cell line MDA-MB-231 revealed that some of the new analogs had better anticancer activity than the standard AVPI Smac tetrapeptide. (C) 2018 Published by Elsevier Ltd.

Synthesis and anticancer studies of michael adducts and heck arylation products of sesquiterpene lactones, zaluzanin D and zaluzanin C from vernonia arborea - Valkute, T.R.; Aratikatla, E.K.; Gupta, N.A.; Ganga, S.; Santra, M.K.; Bhattacharya, A.K. (RSC Advances, 2018)
Sesquiterpene lactones containing α-methylene-γ-lactones, zaluzanin D 1 and zaluzanin C 2 were isolated from the leaves of Vernonia arborea. Several diverse Michael adducts (3–22) and Heck arylation analogs (23–34) of 1 have been synthesized by reacting with various amines and aryl iodides, respectively and were assayed for their in vitro anticancer activities against human breast cancer cell lines MCF7 and MDA-MB-231. Among all the synthesized analogs, Michael adducts 9 and 10 showed better anticancer activities as compared to 1. However, among these compounds, only 10 has minimal cytotoxic effect on normal breast epithelial MCF10A cells. Our detailed mechanistic studies reveal that compounds 9 and 10 execute their antiproliferative activity through induction of apoptosis and thereby inhibit the cancer cells proliferation and compound 10 could be a lead compound for designing potential anti-cancer compound.

Synthesis and antitumor activity evaluation of 2-aminothiazoles appended 5-methylisoxazoline and pyridine-piperazine hybrid molecules - Suresh, G.; Nadh, R.V.; Srinivasu, N.; Yennity, D. (Letters in Organic Chemistry, 2018)
A highly efficient and milder protocol for the syntheses of novel series of 2-aminothiazoles bearing 5-methylisoxazoline and pyridine-piperazine hybrid molecules has been developed. The target compounds 13a-e were screened for their in vitro cytotoxicity activity against various tumor cell lines including MCF-7 (human breast adenocarcinoma), HCT-116 (colorectal carcinoma), Jurkat (human T-cell leukemia) and THP-1 (human acute monocytic leukemia). The bioactive assay showed that the most of the new compounds exhibited promising results in comparison with the parental Sunitinib. The synthesized compounds could well be used in the future as lead anticancer drugs in drug development studies. The synthesized compounds were fully characterized by IR,1 H NMR,13 C NMR, elemental analysis and mass spectral data.

Synthesis and biological evaluation of new 2-aryl-4-((4-aryl-1H-1,2,3-triazol-1-yl)methyl)thiazole derivatives - Shinde, Vikas; Mahulikar, Pramod; Mhaske, Pravin C.; Nawale, Laxman; Sarkar, Dhiman (Research on Chemical Intermediates, 2018)
A series of 2-aryl-4-((4-aryl-1H-1,2,3-triazol-1-yl)methyl)thiazole derivatives (8a-p) have been synthesized. The structure of the newly synthesized compounds was determined by spectral analysis. The title compounds were screened for their preliminary antitubercular activity against Mycobacterium tuberculosis H37Ra (MTB, ATCC 25177) and Mycobacterium bovis BCG (BCG, ATCC 35743). Further, the synthesized compounds were screened for antimicrobial activity against standard Gram-negative bacteria Escherichia coli (NCIM 2576) and Pseudomonas flurescence (NCIM 2059) and Gram-positive bacteria Staphylococcus aureus (NCIM 2602) and Bacillus subtilis (NCIM 2162). Among all the synthesized compounds, 8a-c, f-h, m exhibited good activity against dormant M. bovis BCG strain. Compounds 8h, j exhibited good activity against all tested bacterial strains. All active compounds were screened for cytotoxicity and found inactive. Their high potency and promising antimycobacterial activity suggest that these compounds could serve as good leads for further optimization and development.
Keywords: 1; 2; 3-Triazole; antibacterial activity; Antitubercular activity; Thiazole

Synthesis and biological evaluation of novel triazole-biscoumarin conjugates as potential antitubercular and anti-oxidant agents - Danne, Ashruba B. (Research on Chemical Intermediates, 2018)
The synthesis of a new series of triazole-biscoumarin conjugates by using a molecular hybridization approach is described. The newly synthesized compounds 6a–k were evaluated for their in vitro antitubercular activity against active and dormant Mtb H37Ra and anti-oxidant activity against DPPH radical scavenging. Molecular docking simulations for the antitubercular activity showed that the conjugates 6a–k bind in the pocket of the DprE1 enzyme. Most of the conjugates displayed good antitubercular activity against both the active and dormant Mtb H37Ra strain. The compound 6h displayed very good antitubercular activity against dormant Mtb H37Ra with an IC50 value of 1.44 μg/mL. Most of the synthesized conjugates exhibit excellent anti-oxidant activity with an IC50 of less than the standard BHT. Compound 6b is the most active among all the conjugates with an IC50 value of 08.17 ± 0.11 μg/mL. The molecular docking study shows good agreement between the observed antitubercular activity and the binding affinity.
Keywords: 1; 2; 3-triazoles; Anti-oxidant activity; Antitubercular activity; Biscoumarins; Molecular docking

Synthesis and biological evaluation of some bicyclic [2-(2,4-dimethylphenylthio)phenyl] aniline and its amide derivatives as potential antitubercular agents - Patil, Yogesh; Shingare, Ramesh (Journal of Chemical Sciences, 2018)
In the present investigation, a series of bicyclic [2-(2,4-dimethylphenylthio)phenyl] aniline analogues were synthesized and characterized by IR, NMR (1H and 13C) and mass spectra. All newly synthesized 15 compounds were inspected for their in vitro antitubercular activity against Mycobacterium tuberculosis (MTB) H37Ra in both active and dormant state using an established XTT Reduction Menadione assay (XRMA). The titled compounds exhibited minimum inhibitory concentration (MIC90) ranging from 0.05 to >30 (μg/mL). The potent four compounds were further evaluated in THP-1 infection model where they demonstrated significant antitubercular activity. All the ex vivo active were further evaluated for cytotoxic activity against THP-1, MCK7 and HeLa cell lines in order to check selectivity index. All compounds were further screened against four different bacteria to assess their selectivity towards MTB. These derivatives could be considered as a precursor structure for further design of antituberculosis agent.
Keywords: 4-dimethylphenylthio)phenyl] aniline; antituberculosis activity; Cytotoxicity; [2-(2

Synthesis and biological evaluation of some new tricyclic pyrrolo[3,2-e]tetrazolo[1,5-c]pyrimidine derivatives as potential antitubercular agents - Patil, Yogesh; Shingare, Ramesh; Choudhari, Amit; Borkute, Rachana; Sarkar, Dhiman; Madje, Balaji R. (Archiv Der Pharmazie, 2018)
A series of new tricyclic pyrrolo[3,2-e]tetrazolo[1,5-c]pyrimidines 8a-l were synthesized and characterized by IR, NMR (H-1 and C-13), and mass spectral analysis. The newly synthesized compounds 8a-l were inspected for their in vitro antitubercular activity against Mycobacterium tuberculosis (MTB) H37Ra using an established XTT reduction menadione assay (XRMA). The title compounds exhibited minimum inhibitory concentrations (MIC90) ranging from 0.09 to >30g/mL. Five compounds (8c, 8i-l) were further confirmed for their dose-dependent effect against MTB. These compounds were evaluated in the THP-1 infection model, where 8i (MIC90=0.35g/mL), 8j (MIC90=1.17g/mL), 8k (MIC90=2.38g/mL), and 8l (MIC90=1.17g/mL) demonstrated significant antitubercular activity. All the ex vivo active compounds showed insignificant cytotoxicity against the human cancer cell lines, HeLa, MCF-7, and THP-1. Inactivity of all these compounds against Gram positive and Gram negative bacteria indicates their specificity. Molecular docking studies in the active site of the sterol 14alpha-demethylase (CYP51) enzyme revealed a similar binding mode to the native ligand in the crystal structure, thereby helping to understand the ligand-protein interactions and to establish a structural basis for inhibition of MTB. The results suggest novel pharmacophores as selective and specific inhibitors against MTB that can be explored further to synthesize lead compounds against tuberculosis. In summary, the results clearly indicate the identification of some novel, selective, and specific inhibitors against MTB that can be explored further for potential antitubercular drugs.
Keywords: 2-e]tetrazolo[1; 5-c]pyrimidine; Antituberculosis; Cytotoxicity; Molecular docking; tricyclic pyrrolo[3

Synthesis and characterization of partially bio-based polyimides based on biphenylene-containing diisocyanate derived from vanillic acid - Kuhire, Sachin S.; Ichake, Amol B.; Grau, Etienne; Cramail, Henri; Wadgaonkar, Prakash P. (European Polymer JOurnal, 2018)
A new bio-based biphenylene-containing diisocyanate, namely, 5,5'-diisocyanato-2,2',3,3'-tetramethoxy-1,1'-biphenyl (BDI) was synthesized starting from vanillic acid - a lignin-derived phenolic acid. A series of new partially bio-based polyimides was prepared by polycondensation of BDI with five commercially available aromatic dianhydrides. Polyimides exhibited good solubility in organic solvents and medium molecular weights (Mn (GPC, polystyrene standard) = 25,100-32,200 g mol(-1)). Polyimides showed good thermal stability with 10% degradation temperature and glass transition temperature in the range 459-473 degrees C and 262-329 degrees C, respectively.

Synthesis, biological evaluation, and molecular docking study of pyridine clubbed 1,3,4-oxadiazoles as potential antituberculars - Desai, N. C. (Synthetic Communications, 2018)
A series of pyridine clubbed 1,3,4-oxadiazole derivatives were efficiently synthesized, characterized by standard spectral techniques and evaluated for their in vitro antitubercular activity against Mycobacterium tuberculosis (MTB) H37Ra and Mycobacterium bovis BCG in active and dormant state using an established methods. Compounds 5a, 5m, and 5t were identified as the most active compounds against MTB. Molecular docking was performed against MTB enoyl-ACP (CoA) reductase (FabI/ENR/InhA) enzyme to predict the binding modes and affinity. The theoretical predictions from molecular docking could establish a link between the observed biological activity and the binding affinity shedding light into specific bonded and non-bonded interactions influencing the activity. The active compounds were studied for cytotoxicity against three cell lines and were found to be non-cytotoxic. Specificity of these compounds was checked by screening them for their antibacterial activity against four bacterial strains.
Keywords: antibacterial activity; antituberculosis activity; cytotoxicity activity

Synthesis, characterization, and gas permeation properties of adamantane-containing polymers of intrinsic microporosity - Shrimant, Bharat; Shaligram, Sayali V.; Kharul, Ulhas K.; Wadgaonkar, Prakash P. (Journal of Polymer Science Part A-Polymer Chemistry, 2018)
A new bis(catechol) monomer, namely, 4,4-((1r,3r)-adamantane-2,2-diyl)bis(benzene-1,2diol) (THADM) was synthesized by condensation of 2-adamantanone with veratrole followed by demethylation of the formed (1r,3r)-2,2-bis(3,4 dimethoxyphenyl)adamantane. Polycondensation of THADM and various compositions of THADM and 5,5,6,6-tetrahydroxy-3,3,3,3-tetramethylspirobisindane was performed with 2,3,5,6-tetrafluoroterephthalonitrile (TFTPN) to obtain the homopolymer and copolymers. These polymers demonstrated good solubility in common organic solvents such as dichloromethane, chloroform, and tetrahydrofuran and could be cast into tough films from their chloroform solutions. GPC analysis revealed that number average molecular weights of polymers were in the range 48,100-61,700 gmol(-1), suggesting the formation of reasonably high molecular weight polymers. They possessed intrinsic microporosity with Brunauer-Emmett-Teller (BET) surface area in the range 703-741 m(2)g(-1). Thermogravimetric analysis of polymers indicated that 10% weight loss temperature was in the range 513-518 degrees C demonstrating their excellent thermal stability. THADM-based polymer of intrinsic microporosity (PIM) showed P(CO2)=1080, P(O-2)=232 and appreciable selectivity [(CO2/CH4)=22.6, (CO2/N-2)=26.7, and (O-2/N-2)= 5.7]. The gas permeability measurements revealed that with increase in the content of adamantane units in PIMs, selectivity increased and permeability decreased, following the trade-off relationship. The gas separation properties of PIMs containing adamantane units were located close to 2008 Robeson upper bound for gas pairs such as CO2/CH4, CO2/N-2, H-2/N-2, and O-2/N-2. (c) 2017 Wiley Periodicals, Inc.
Keywords: adamantane; Gas permeation; intrinsic microporosity; membranes; structure-property relations

Synthesis of 3-azidopiperidine skeleton employing ceric ammonium nitrate (CAN)-mediated regioselective azidoalkoxylation of enol ether: total synthesis of d-2 receptor agonist (+/-)-quinagolide - Chavan, Subhash P.; Kadam, Appasaheb L.; Lasonkar, Pradeep B.; Gonnade, Rajesh G. (Organic letters, 2018)
The total synthesis of (+/-)-quinagolide, which is a D-2 receptor agonist, was accomplished via a ceric ammonium nitrate (CAN)-mediated regioselective azidoalkoxylation of enol ether route. Key features of the synthesis include Claisen rearrangement, PPTS (pyridinium p-toluene-sulfonate)-catalyzed one-pot acetal deprotection, followed by a diastereoselective Henry reaction, which enables construction of the required trans ring junction and CAN-mediated regioselective azidoalkoxylation of enol ether. The PPTS-catalyzed intramolecular diastereoselective Henry reaction to fix three contiguous stereocenters on tetrahydronaphthalene and the first-of-its-kind synthesis of the 3-azidopiperidine skeleton, using a CAN -mediated regioselective azidoalkoxylation of enol ether, are important findings of the present work.

Synthesis of 4-difluoromethylquinolines by NHC-catalyzed umpolung of imines - Patra, Atanu (Organic Letters, 2018)
The N-heterocyclic carbene (NHC)-catalyzed umpolung of aldimines for the synthesis of 4-difluoromethylquinoline derivatives is reported. In the presence of NHCs, the intramolecular cyclization of aldimines bearing a moderately electron-poor double bond due to the presence of the −CF3 group likely proceeds via the intermediacy of the aza-Breslow intermediate. The key to the success of this aza-Stetter type transformation is the NHC generated from the bicyclic triazolium salt using DBU as the base.

Synthesis of biomass waste derived activated carbon-NBR composites for automobile application - Jadhav, A.; Mohanraj, G.T.; Gokarn, A.; Mayadevi, S. (Chemistry and Chemical Technology, 2018)
This paper reports on usability of activated carbon obtained from areca nut shell, coconut shell, and coconut leaves as a filler to prepare NBR based composite for automobile based application. The carbon was activated by phosphoric acid (H3PO4) as dehydrating agent. The stoichiometric ratio of biomass and phosphoric acid was found to be 3:1 for the batch size of 300 g. As compared to commercially available carbon filler, the activated carbon derived from biomass waste responded better to the petrol swelling test. Among three biomass waste sources, namely, areca nut shell, coconut shell, and coconut leaves, activated carbon derived from coconut shell was appeared to be the best for percent swelling and percent deviation in hardness. The results obtained are confirmed by proximate analysis.
Keywords: activated carbon; composites; hardness; NBR; Phosphoric acid

Synthesis of diesel additives from fructose over PWA/SBA-15 catalyst - Patil, Chetana R. (Fuel, 2018)
A series of composites of phosphotungstic acid (PWA) H3PW12O40 with SBA-15 were prepared by varying PWA amount from 5% to 30% by one-step sol-gel hydrothermal as well as by impregnation methods. Successful incorporation of PWA into the SBA-15 framework by sol-gel method was confirmed by 31P NMR in which a shifting of the peak due to tetrahedral ‘P’ atom of PWA from −14.32 and −14.49 ppm was observed. The composites exhibited both Brønsted and Lewis acidity, large and well distributed three dimensional interconnected pores with high surface areas exhibiting excellent activity for one pot synthesis of 5-(hydroxymethyl) furfural (5-HMF) and 5-(ethoxymethyl) furfural (EMF) from fructose. The minimum loading of 5% of PWA in SBA-15, gave 78% fructose conversion with the highest yield of 70% towards 5-HMF. Increase in PWA loading up to 20% resulted in the enhanced fructose conversion of 95% accompanied by further etherification of 5-HMF to 67 and 12% yield towards EMF and ethyl levulinate (EL), respectively. Increasing the % of PWA in SBA-15 matrix resulted in increase in the acidity of the composites giving the yield trend as 5-HMF < EMF < EL. Catalyst prepared by sol-gel method showed excellent recyclability up to 3 reuses
Keywords: 5-(Ethoxymethyl) furfural; 5-(Hydroxymethyl) furfural; Phosphotungstic acid; SBA-15

Synthesis of ecofriendly fluorescent carbon dots and their biomedical and environmental applications - Joshi, Preeti Nigam; Mathias, Anjelica; Mishra, Abhishek (Materials Technology, 2018)
Green Synthesis of nanoparticles is an emerging field with enormous advantages over conventional synthesis methods. Herein we have reported a green method for the preparation of water soluble polydisperse carbon dots (c-dots) from Cocos nucifera frond pinnae by a modified version of the `single step hydrothermal carbonization'. C-dots having blue emission were obtained with this method and we further evaluated the effect of metal ions interactions on c-dots, as a sharp decrease in photoluminescence was observed. The synthesized c-dots were found bioactive against B.subtilis, M. smegmatis and S. aureus as determined by the well diffusion assay. We also explored nanotheranostic applications of c-dots as biosensor matrix in DNA hybridization sensor for pancreatic cancer and in bioimaging of cancer cells. This study demonstrated that c-dots can be explored for numerous biomedical and environmental applications in a variety of fields owing to the cost effective synthesis, biocompatibility and excellent physico-chemical properties.
Keywords: Carbon dots; differential pulse voltammetry; DNA hybridization sensor; green synthesis; Pancreatic Cancer

Synthesis of furo[2,3-b]pyran-2-ones through Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols and alpha-ketoesters - Thorat, Sagar S.; Kataria, Priyanka; Kontham, Ravindar (Organic Letters, 2018)
Ag(I)- or Ag(I)-Au(I)-catalyzed cascade annulation of alkynols (5-hexyn-1-ol systems) with a-ketoesters involving a dual activation process (pi and sigma) has been developed for the first time. This reaction proceeds through cycloisomerization of alkynol to give the 6-endo-enol ether followed by annulation with an alpha-ketoester to furnish furo[2,3-b]pyran-2-ones in good yields. Chemical structures of all products were rigorously confirmed by single crystal X-ray analysis and analogy.

Synthesis of heterogeneous Ru(II)-1,2,3-triazole catalyst supported over SBA-15: application to the hydrogen transfer reaction and unusual highly selective 1,4-disubstituted triazole formation via multicomponent click reaction - Sharma, Priti; Rathod, Jayant; Singh, A. P.; Kumar, Pradeep; Sasson, Yoel (Catalysis Science & Technology, 2018)
In the present study, we demonstrate a simple and efficient method for ligand formation and covalent anchoring to a heterogeneous support via click reaction. The complex tris(triphenylphosphine) ruthenium(II) dichloride [RuCl2(PPh3)(3)] anchored over the click modified ligand of SBA-15 forms a new highly efficient heterogeneous SBA-15-Tz-Ru(II) TPP catalyst. Solid state C-13, Si-29, and P-31 CP-MAS NMR spectra provide evidence for the formation of the heterogeneous catalyst. SBA-15-Tz-Ru(II) TPP catalyst was screened for the multicomponent click cycloaddition reaction in water medium as a green solvent and it exhibited unusual and excellent selectivity for the formation of 1,4-disubstituted triazole product under mild reaction condition. In addition, SBA-15-Tz-Ru(II) TPP catalyst also catalyzed the hydrogen transfer reaction of various carbonyl compounds with excellent catalytic activity to give the corresponding alcohols. The heterogeneous catalyst can be recycled and reused several times (five) without a loss in reactivity.

Synthesis of hyaluronic acid hydrogels using click chemistry approach for biomedical applications - Gupta, N.; Tiwari, N.; Badiger, M. (Trends in carbohydrate research, 2018)
Hyaluronic acid (HA) is one of the most versatile biomaterial which forms an essential component of an extracellular matrix (ECM) and plays a vital role in wide variety of biological processes. Inherent biocompatibility, biodegradability and presence of functional groups for modification make it an attractive material for the synthesis of hydrogels for biological applications. In the present work, we have explored an azide-alkyne click chemistry approach for the preparation of HA hydrogels. Furthermore, we incorporated the hydrolysable carbonate ester linkages which are known to cleave in the physiological environment. The hydrogels with carbonate ester linkages and incubated with drug molecules can be used for the slow release of drug molecules. The hydrogels synthesized using azide alkyne click chemistry was characterized using NMR and IR spectroscopy.

Synthesis of key intermediate for (+)-tofacitinib through CoIII(salen)-catalyzed two stereocentered hydrolytic kinetic resolution of (Â±)-methyl-3-(oxiran-2-yl)butanoate - Kamble, Rohit B. (Synthetic Communications, 2018)
An enantiopure piperidine, a key intermediate for the synthesis of (+)-tofacitinib, has been achieved in high optical purity (98% ee) from readily available crotyl alcohol. The key steps involved is a CoIII(salen)-OAc-catalyzed two stereocentered hydrolytic kinetic resolution of (±)-methyl-3-(oxiran-2-yl)butanoate.
Keywords: enantioselective; Hydrolytic kinetic resolution; iodolactonization; γ-Butyralactone

Synthesis of novel alpha-aminophosphonate derivatives, biological evaluation as potent antiproliferative agents and molecular docking - Deshmukh, Satish U. (ChemistrySelect, 2018)
A series of novel fluorine containing α‐aminophosphonate derivatives (4 a–4 q) were synthesized in excellent yield and high purity. All these novel Fluorinated α‐aminophosphonate compounds were screened for antiproliferative and apoptosis activity on human non small cell lung carcinoma cells (A549) and human skin melanoma cells (SK‐MEL‐2). Compounds 4 a, 4 b, 4 c, 4 f, 4 i, 4 j and 4 m were found to be more active antiproliferative agent against A549 and SK‐MEL‐2 cells with IC50 value 0.22 to 1.25 μM. Molecular docking study related to binding affinity and binding mode analysis showed that synthesized compounds had potential to inhibit human Topoisomerase IIa enzyme system. Flow cytometric study showed some of these derivatives also induced cell apoptosis and arrest cell cycle at G1 and at G2/M phase. Overall, this study provides future perspective of lead candidate for the future anticancer drug discovery initiatives.

Synthesis of quinolinyl based pincer copper (II) complexes: an efficient catalyst system for Kumada coupling of alkyl chlorides and bromides with alkyl Grignard reagents - Pandiri, Hanumanprasad; Gonnade, Rajesh G.; Punji, Benudhar (Dalton Transactions, 2018)
Quinolinamide-based pincer copper(ii) complexes, (N),(N),(N)-{C9H6N-(-N)-C(O)CH2NEt2}CuX [((NNN2Et)-N-Q)CuX (X = Cl, 2; X = Br, 3; X = OAc, 4)], were synthesized by the reaction of ligand ((NNN2Et)-N-Q)-H (1) with CuX2 (X = Cl, Br or OAc) in the presence of Et3N. The reaction of ((NNN2Et)-N-Q)-H with CuX (X = Cl, Br or OAc) also afforded the Cu(ii) complexes 2, 3 and 4, respectively, instead of the expected Cu(i) pincer complexes. The formation of Cu(ii) complexes from Cu(i) precursors most likely occurred via the disproportionation reaction of Cu(i) into Cu(0) and Cu(ii). A cationic complex [((NNN2Et)-N-Q)Cu(CH3CN)]OTf (5) was synthesized by the treatment of neutral complex 2 with AgOTf. On the other hand, the reaction of ((NNN2Et)-N-Q)-H (1) with [Cu(MeCN)(4)]ClO4 produced cationic Cu(i) complex, [((NN)-N-Q(H)N-2(Et))Cu(CH3CN)]ClO4 (6), in good yield. All complexes 2-5 were characterized by elemental analysis and HRMS measurements. Furthermore, the molecular structures of 2, 3 and 4 were elucidated by X-ray crystallography. Complex 4 crystallizes in a dimeric and catemeric pattern. The cationic complex 5 was found to be an efficient catalyst for the Kumada coupling reaction of diverse nonactivated alkyl chlorides and bromides with alkyl magnesium chloride under mild reaction conditions.

Synthetic control on structure/dimensionality and photophysical properties of low dimensional organic lead bromide perovskite - Haris, Muhammed P. U.; Bakthavatsalam, Rangarajan; Shaikh, Samir; Kore, Bhushan P.; Moghe, Dhanashree; Gonnade, Rajesh G.; Sarma, D. D.; Kabra, Dinesh; Kundu, Janardan (Inorganic chemistry, 2018)
Low dimensional lead halide perovskites have attracted huge research interest due to their structural diversity and remarkable photophysical properties. The ability to controllably change dimensionality/structure of perovskites remains highly challenging. Here, we report synthetic control on structure/dimensionality of ethylenediammonium (ED) lead bromide perovskite from a two dimensionally networked (2DN) sheet to a one dimensionally networked (1DN) chain structure. Intercalation of solvent molecules into the perovskite plays a crucial role in directing the final dimensionality/structure. This change in dimensionality reflects strongly in the observed differences in photophysical properties. Upon UV excitation, the 1DN structure emits white light due to easily formed “self-trapped” excitons. 2DN perovskites show band edge blue emission (∼410 nm). Interestingly, Mn2+ incorporated 2DN perovskites show a highly red-shifted Mn2+ emission peak at ∼670 nm. Such a long wavelength Mn2+ emission peak is unprecedented in the perovskite family. This report highlights the synthetic ability to control the dimensionality/structure of perovskite and consequently its photophysical properties.

Synthetic studies towards Pseudoxylallemycin B, an antibiotic active against gram-negative bacteria: total synthesis of 3-epi-Pseudoxylallemycin B - Gunjal, Vidya B. (Tetrahedron Letters, 2018)
In an attempt towards the total synthesis of Pseudoxylallemycin B, a homo dimeric, N-methylated macrocyclic tetrapeptidic natural product, synthesis of its epimer at position 3 (d-Tyr instead of l-Tyr) is described here. During the course of synthesis we came across a striking yet unusual observation of complete epimerization which led to the formation of 3-epi-Pseudoxylallemycin B.
Keywords: Cyclic tetrapeptides; Epimerization; Gram-negative bacteria; Macrolactamization; Propyl phosphonic anhydride (T3P)

Systematic synthesis of a 6-component organic-salt alloy of naftopidil, and pentanary, quaternary and ternary multicomponent crystals - Dandela, Rambabu; Tothadi, Srinu; Marelli, Udaya Kiran; Nangia, Ashwini (IUCrJ, 2018)
The single-crystal X-ray structure of a 6-component organic-salt alloy (hexanary) of naftopidil (1) (an active pharmaceutical ingredient) with benzoic acid (2) and four different hydroxy-substituted benzoic acids, i.e. salicylic acid (3), 2,3-dihydroxybenzoic acid (4), 2,4-dihydroxybenzoic acid (5) and 2,6-dihydroxybenzoic acid (6), is reported. The hexanary assembly originates from the observation that the binary salts of naftopidil with the above acids are isostructural. In addition to the 6-component solid, we also describe five 5-component, ten 4-component, and ten 3-component organic-salt alloys of naftopidil (1) with carboxylic acids (2)-(6). These alloys were obtained from different combinations of the acids with the drug. The synthetic design of the multicomponent organic alloys is based on the rationale of geometrical factors (shape and size) and chemical interactions (hydrogen bonds). The common supramolecular synthon in all these crystal structures was the cyclic N+ - H center dot center dot center dot O- and O-H center dot center dot center dot O hydrogen-bonded motif of R-2(2) (9) graph set between the 2-hydroxyammonium group of naftopidil and the carboxylate anion. This ionic synthon is strong and robust, directing the isostructural assembly of naftopidil with up to five different carboxylic acids in the crystal structure together with the lower-level multicomponent adducts. Solution crystallization by slow evaporation provided the multicomponent organic salts and alloys which were characterized by a combination of single-crystal X-ray diffraction, powder X-ray diffraction, NMR and differential scanning calorimetry techniques.

Saturated N-heterocyclic carbene based thiele's hydrocarbon with a tetrafluorophenylene linker - Kundu, Gargi; De, Sriman; Tothadi, Srinu; Das, Abhishek; Koley, Debasis; Sen, Sakya S. (Chemistry-A European Journal, 2019)
The synthesis of a SIPr [1,3-bis(2,6-diisopropylphenyl)-imidazolin-2-ylidene] derived Kekule diradicaloid with a tetrafluorophenylene spacer (3) has been described. Two synthetic routes have been reported to access 3. The cleavage of C-F bond of C6F6 by SIPr in the presence of BF3 led to double C-F activated compound with two tetrafluoro borate counter anions (2), which upon reduction by lithium metal afforded 3. Alternatively, 3 can be directly accessed in one step by reacting SIPr with C6F6 in presence of Mg metal. Compounds 2 and 3 were well characterized spectroscopically and by single-crystal X-ray diffraction studies. Experimental and computational studies support the cumulenic closed-shell singlet state of 3 with a singlet-triplet energy gap (Delta ES-T) of 23.7 kcal mol(-1).
Keywords: C-F activation; Density functional calculations; fluorine; Kekule diradicaloids; saturated NHC

Scalable microwave-assisted continuous flow synthesis of CuO nanoparticles and their thermal conductivity applications as nanofluids - Nikam, Arun V.; Dadwal, Arun H. (Advanced Powder Technology, 2019)
We have demonstrated the novel and scalable synthesis of CuO nanoparticles by an integration of microwave and flow synthesis. The shape and size of CuO nanoparticles were tuned by changing the concentration of copper precursor. The production rate of CuO nanoparticles was found to be 5 g/h with 70% conversion of copper acetate into the CuO nanoparticles. The thermal conductivity of CuO nanofluid prepared in ethylene glycol showed linear enhancement with increase in the volume content of CuO nanoparticles produced in batch and flow reactors. (C) 2018 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.
Keywords: Flow synthesis; Microwave; Nanofluids; Nanoparticles; scale-up; Thermal conductivity

Scalable synthesis of both enantiomers of vigabatrin, an antiepileptic drug - Jachak, G.R.; Reddy, D.S. (European Journal of Organic Chemistry, 2019)
Vigabatrin is a potent inhibitor of gamma‐aminobutyric acid (GABA) catabolism used for the treatment of epilepsy. Here we have synthesized both enantiomers of the drug vigabatrin in five steps from known intermediates using Wittig olefination and pyrolytic elimination as key steps. The target compounds are synthesized in gram scale amounts with >98 % enantiopurity.

Scalable synthesis of cladosporin - Das, Pronay; Mankad, Yash; Reddy, D. Srinivasa (Tetrahedron Letters, 2019)
Cladosporin, a secondary metabolite isolated from fungal sources like Cladosporium cladosporioides and Aspergillus flavus was found to exhibit selective nano-molar activity against malarial parasite Plasmodium falciparum by inhibiting parasitic protein biosynthesis. In addition, this natural product has a broad range of bioactivities including, antiparasitic, antifungal, antibacterial as well as plant growth inhibition. However, it has limited availability from the natural sources for further development. Herein, we report a modified and improved synthetic route which led us to produce this potent natural product in a gram scale. Conversion of the undesired diastereomer to desired one via Mitsunobu inversion of secondary alcohol and carbon monoxide insertion reaction towards the construction of isocoumarin unit are the key features of the present synthesis. (C) 2019 Elsevier Ltd. All rights reserved.
Keywords: Anti-malarials; Cladosporin; Mitsunobu; Total synthesis

Scope and mechanistic aspect of nickel-catalyzed alkenylation of benzothiazoles and related azoles with styryl bromides - Patel, Ulhas N.; Jagtap, Rahul A.; Punji, Benudhar (Organometallics, 2019)
Alkenylation of benzothiazoles and related azoles with alkenyl bromides is achieved employing the well-defined and air-stable nickel complexes, (bpy)NiBr2 and [Ni(bpy)(3)] [NiBr4], as catalysts. Numerous electronically distinct alkenyl bromides efficiently coupled with substituted benzothiazoles, oxazoles, and benzimidazoles under the catalytic conditions to afford 2-alkenylated azoles. An extensive mechanistic study of the alkenylation of benzothiazole using (bpy)NiBr2 highlights a single-electron transfer process for the reaction involving the two-step one-electron oxidative addition of alkenyl bromide. The substrate benzothiazole plays a significant and diverse role in the reaction, and C-H bond cleavage is reversible in nature. Detailed kinetic analysis and control reactivity studies are indicative of a Ni(I)/Ni(III) pathway for the alkenylation comprising the rate-influencing reductive elimination step.

Secondary structure of the internal transcribed rDNA (ITS) regions of cosmopolites sordidus (Germar) and odoiporus longicollis (Olivier): a first report in family Curculionidae - Kumar, Lalitha Sunil (International Journal of Tropical Insect Science, 2019)
In the present work the consensus secondary structure of the internal transcribed rDNA spacers ITS1 and ITS2 of two weevils i.e. Cosmopolites sordidus (Germar) and Odoiporus longicollis (Olivier) has been described. The secondary structures of the ITS1 region of C.sordidus and O.longicollis have ten and five helices respectively, emerging from a central core. Two and five helices emerge from a central core in the ITS2 secondary structures of C.sordidus and O.longicollis respectively, and do not conform to the `paneukaryotic' four domain model. The ITS2 sequences of these two weevils share three regions with maximum sequence identity. Of these, two are present at the 5' and 3' end and share structural similarity, suggesting their possible role in the processing of the rRNA. This is the first report of the secondary structure of the ITS region in family Curculionidae which can serve as a valuable resource for homology modelling and phylogenetic studies.
Keywords: Cosmopolites sordidus (Germar); Curculionidae; ITS1; ITS2; Odoiporus longicollis (Olivier); Secondary structure

Selective hydrogenation of 5-HMF to 2,5-DMF over a magnetically recoverable non-noble metal catalyst - Solanki, Bhanupratap Singh; Rode, V. Chandrashekhar (Green Chemistry, 2019)
A non-noble bimetallic catalyst Cu-Fe (1 : 2) was magnetically recoverable, highly selective and efficient for 5-(hydroxymethyl) furfural (5-HMF) hydrogenation to 2,5-dimethyl furan (DMF). The structure-activity correlation was established by characterising the prepared catalyst by XRD, XPS, TEM, ESEM, BET surface area, N-2-adsorption, NH3-TPD, pyridine-IR and H-2-TPR measurements. The high catalytic efficiency was attributed to the oxophilic nature and Lewis acidity of Fe, whereas the selectivity towards DMF was attributed to the Bronsted acidity of CuO and its affinity towards the C-O bond which was further confirmed by NH3-TPD and Py-IR analyses. XPS and XRD revealed the presence of Cu/CuFe2O4 species which catalyzed the hydrogenolysis pathway. TEM and SEM images evidenced the presence of a Cu-Fe nanomorph in which Cu/CuFe2O4 was present. The size of the Cu-Fe nanomorph was found to be between 15.4-17.6 nm. Under the optimised reaction conditions, the highest conversion of 97% and selectivity of 93% were achieved.

Selective hydrogenolysis of 5-(hydroxymethyl)furfural over Pd/C catalyst to 2,5-dimethylfuran - Solanki, B. S.; Rode, C. V. (Journal of Saudi Chemical Society, 2019)
everal metal supported catalysts were prepared and evaluated for 5-(hydroxymethyl)furfural (5-HMF) hydrogenolysis to 2,5-dimethylfuran (2,5-DMF) which is a renewable potential fuel additive. Among the prepared catalysts, 3%Pd/C showed excellent performance in terms of complete conversion of 5-HMF along with the highest selectivity of 99% to 2,5-DMF. Detailed physico-chemical characterisation was done in order to understand structure-activity correlation. Uniformly dispersed Pd nanoparticles on activated carbon provided the adsorption surface to enhance the hydrogenation of 5-HMF. Reaction was well optimised and established by extensive study of different reaction parameters like temperature, pressure, reaction time, stirring effect, substrate loading and metal loading.
Keywords: Biomass; Fuel additive; heterogeneous catalysis; Hydrogenolysis; Palladium

Selective synthesis of dimethyl carbonate via transesterification of propylene carbonate with methanol catalyzed by bifunctional Li-Al Nano-composite - Nivangune, Nayana; Kelkar, Ashutosh (Chemistryselect, 2019)
A series of binary mixed metal oxides (MMOs) were synthesized by combination of Mn+/Al3+ (Mn+= Li, Mg, Co, Ni, Zn) via co-precipitation method and screened for transesterification of propylene carbonate (PC) with methanol. The aim of this study was to understand the role of acid-base properties of MMOs on the activity and selectivity towards dimethyl carbonate (DMC) synthesis. The MMOs were characterized in detail by XRD, BET, TEM, NH3 and CO2-TPD techniques. Catalysts synthesized by various combination of Mn+/Al3+ showed different textural and surface properties and the strength of acid-base sites were also found to be significantly altered. These changes in physicochemical properties significantly affected the PC conversion and selectivity to DMC. Li+ incorporated in Al3+ showed the formation of octahedral alpha-LiAlO2 phase having more amounts of active sites (O2-) present on the edges and corner of the structure. This resulted in easy accessibility of active sites and higher activity compared to other catalysts screened. Furthermore the catalyst retained high activity and selectivity for six consecutive recycle experiments; which is highly desirable for large-scale application.

Selective synthesis of secondary amines from nitriles by a user-friendly cobalt catalyst - Sharma, Dipesh M.; Punji, Benudhar (Advanced Synthesis & Catalysis, 2019)
Selective hydrogenation/reductive amination of nitriles to secondary amines catalyzed by an inexpensive and user-friendly cobalt complex, (Xantphos)CoCl2, is reported. The use of (Xantphos)CoCl2 and ammonia borane (NH3-BH3) combination affords the selective reduction of nitriles to symmetrical secondary amines, whereas the employment of (Xantphos)CoCl2 and dimethylamine borane (Me2NH-BH3) along with external amines produce unsymmetrical secondary amines and tertiary amines. The general applicability of this methodology is demonstrated by the synthesis of 43 symmetrical and unsymmetrical secondary and tertiary amines bearing diverse functionalities.

Selective targeting of integrin alpha v beta 8 by a highly active cyclic peptide - Reichart, Florian; Maltsev, Oleg V.; Kapp, Tobias G.; Raeder, Andreas F. B.; Weinmueller, Michael; Marelli, Udaya Kiran; Notni, Johannes; Wurzer, Alexander; Beck, Roswitha; Wester, Hans Juergen; Steiger, Katja; Di Maro, Salvatore; et al. (Journal of Medicinal Chemistry, 2019)
Integrins play important roles in physiological and pathophysiological processes. Among the RGD-recognizing integrin subtypes, the alpha v beta 8 receptor is emerging as an attractive target because of its involvement in various illnesses, such as autoimmune diseases, viral infections, and cancer. However, its functions have, so far, not been investigated in living subjects mainly because of the lack of a selective alpha v beta 8 ligand. Here, we report the design and potential medical applications of a cyclic octapeptide as the first highly selective small-molecule ligand for alpha v beta 8. Remarkably, this compound displays low nanomolar alpha v beta 8 binding affinity and a strong discriminating power of at least 2 orders of magnitude versus other RGD-recognizing integrins. Peptide functionalization with fluorescent or radioactive labels enables the selective imaging of alpha v beta 8-positive cells and tissues. This new probe will pave the way for detailed characterization of the distinct (patho)physiological role of this relatively unexplored integrin, providing a basis to fully exploit the potential of alpha v beta 8 as a target for molecular diagnostics and personalized therapy regimens.

Self-assemblies of nucleolipid supramolecular synthons show unique self-sorting and cooperative assembling process - Nuthanakanti, Ashok; Walunj, Manisha B.; Torris, Arun; Badiger, Manohar V.; Srivatsan, Seergazhi G. (Nanoscale, 2019)
The inherent control of the self-sorting and co-assembling process that has evolved in multi-component biological systems is not easy to emulate in vitro using synthetic supramolecular synthons. Here, using the basic component of nucleic acids and lipids, we describe a simple platform to build hierarchical assemblies of two component systems, which show an interesting self-sorting and co-assembling behavior. The assembling systems are made of a combination of amphiphilic purine and pyrimidine ribonucleoside-fatty acid conjugates (nucleolipids), which were prepared by coupling fatty acid acyl chains of different lengths at the 2 `-O- and 3 `-O-positions of the ribose sugar. Individually, the purine and pyrimidine nucleolipids adopt a distinct morphology, which either supports or does not support the gelation process. Interestingly, due to the subtle difference in the order of formation and stability of individual assemblies, different mixtures of supramolecular synthons and complementary ribonucleosides exhibit a cooperative and disruptive self-sorting and co-assembling behavior. A systematic morphological analysis combined with single crystal X-ray crystallography, powder X-ray diffraction (PXRD), NMR, CD, rheological and 3D X-ray microtomography studies provided insights into the mechanism of the self-sorting and co-assembling process. Taken together, this approach has enabled the construction of assemblies with unique higher ordered architectures and gels with remarkably enhanced mechanical strength that cannot be derived from the respective single component systems.

Self-assembly of Di-guanine peptide nucleic acid amphiphiles into fractal patterns - Abraham, Jancy N.; Pawar, Prabhakar; Kootteri, Dilna K. (ChemistrySelect, 2019)
Peptide nucleic acids (PNAs) amphiphiles have been reported to assemble into different nanostructures; however, there is immense untapped potential to control their supramolecular assemblies by altering their lipid chain. Here, we functionalized di-guanine PNA with various hydrophobic appendages, namely dodecyl, p-dodecylbenzoyl and pentadecyl phenol groups, to investigate the effect of aromatic linkers, long alkyl and alkoxyl substituents on hierarchical self-assembly of di-guanine PNA. Systematic electron microscopy and atomic force microscopy studies revealed that while all three derivatives of di-guanine-PNA formed nanospheres, only nanospheres of dodecylamide and pentadecyl phenol derivatives matured into nanorods, these later formed higher order fractal assemblies. Furthermore, we observed that inclusion of a positively charged lysine at the C-terminus prevented fractal assembly, possibly due to electrostatic repulsion between the head groups. Thus, the findings of the present work might guide rational design of PNA amphiphiles to obtain specific self-assembled morphology.
Keywords: Fractal pattern; Guanine; pentadecylphenol; Peptide nucleic acid; Self-assembly

Semirational design and engineering of grapevine glucosyltransferases for enhanced activity and modified product selectivity - Joshi, Rakesh; Trinkl, Johanna; Haugeneder, Annika; Haertl, Katja; Franz-Oberdorf, Katrin; Giri, Ashok; Hoffmann, Thomas; Schwab, Wilfried (Glycobiology, 2019)
Uridine diphosphate-dependent glycosyltransferases (UGTs) catalyze the transfer of a diversity of sugars to several acceptor molecules and often exhibit distinct substrate specificity. Modulation of glycosyltransferases for increased catalytic activity and altered substrate or product specificity are the key manipulations for the biotechnological use of glycosyltransferases in various biosynthetic processes. Here, we have engineered the binding pocket of three previously characterized Vitis vinifera glycosyltransferases, UGT88F12, UGT72B27 and UGT92G6, by structure-guided in silico mutagenesis to facilitate the interactions of active site residues with flavonol glucosides and thus modify substrate specificity and activity. Site-directed mutagenesis at selected sites, followed with liquid chromatography-mass spectrometry based activity assays, exhibited that mutant UGTs were altered in product selectivity and activity as compared to the wild-type enzymes. Mutant UGTs produced larger amounts of flavonol di-monosaccharide glucosides, which imply that the mutations led to structural changes that increased the volume of the binding pocket to accommodate a larger substrate and to release larger products at ease. Mutants showed increased activity and modified product specificity. Thus, structure-based systematic mutations of the amino acid residues in the binding pocket can be explored for the generation of engineered UGTs for diverse biotechnological applications.
Keywords: flavonol; Glycosyltransferase; in silico analysis; Mutagenesis; selectivity

On the sensitivity of alginate rheology to composition - Suresh, Karthika; Haering, Marleen; Kumaraswamy, Guruswamy; Diaz Diaz, David (Soft Matter, 2019)
The linear response of alginate-phenyl boronic acid (Alg-PBA) esters shows a universal, composition-independent viscoelastic fluid-like behaviour. Reversible association of alginates governs their rheology at all compositions (viz. at all alginate concentrations and solution pH). However, their high strain behaviour is very sensitive to composition. Tuning composition affords liquids that neck to form filaments capable of being drawn to large elongations without failure. We interpret our data by invoking strain-dependent association and dissociation rates for the alginates. High association rates at high strain result in materials with viscoelastic liquid like behaviour.

Separation of nitroaromatics from wastewater by using supported ionic liquid membranes - Bhosale, Vikas K.; Chana, Harpreet K.; Kamble, Sanjay P.; Kulkarni, Prashant S. (Journal of Water Process Engineering, 2019)
Nitroaromatics have been released into wastewater during its production and application, thus, contaminating the ecosystem. The stringent discharge limits of industrial effluents have led to the development of sustainable technologies for removal of nitroaromatics from wastewater. In the present investigation, separation of nitroaromatic compounds such as TNT, TNP and Tetryl from model wastewater was investigated by using supported ionic liquid membrane (SILM) process. Various aliquat 336 based ionic liquids (ILs) were synthesised and characterized, and immobilized in PTFE and PVDF supports for the preparation of SILMs. The key parameters such as type of IL and striping phase, feed phase pH, selectivity for SILM, extraction kinetics and reuse of SILM were studied, in detail. The size of IL-anion plays an important role in removal process. The SILM was found to be selective for TNP over other nitroaromatics. Maximum separation of TNP (< 95%) was achieved with IL, [A336][SCN] within 12 h. Selectivity and reuse of the membrane indicate the potential of SILM technology as a sustainable chemical process for the treatment of nitroaromatics contaminated wastewater.
Keywords: Ionic liquid; Membrane; Nitroaromatics; Separation; wastewater

Separator membranes for lithium-sulfur batteries: design principles, structure, and performance - Gupta, Aritrajit; Sivaram, Swaminathan (Energy Technology, 2019)
Improvement in electrical energy storage systems is one of the most recent research topics of great academic and industrial interest. Lithium-sulfur (Li-S) battery systems offer a theoretical energy density an order of magnitude larger than the popular Li-ion batteries. The principle of working, inherent challenges in utilizing this system for commercial applications, and the various approaches taken to address these challenges are herein discussed in detail. The polysulfide shuttle effect is a major concern that deteriorates electrochemical performance in this system. In the recent past, electrodes have been intricately engineered to tackle this problem. However, more recently, the focus has shifted to the critical role of the separator. Modifying conventional separators or fabricating novel structures to enhance the cell performance appears to be a more feasible option. Some design principles that are critical to the functioning of a separator in Li-S batteries, namely physisorption, chemisorption, and electrostatic repulsion, are discussed. Many recent papers proposed novel cell configurations with specifically designed functional separators. These reports are classified according to three design principles, analyzed critically, and compared with a view to assess their relative merits and efficacy. Some thoughts on the future directions in the development of an efficient separator are described.
Keywords: lithium-sulfur batteries; polysulfides; rechargeable batteries; separators; shuttle effect

Silk fibroin-sodium dodecyl sulfate gelation: molecular, structural, and rheological insights - Hirlekar, Swarali; Ray, Debes; Aswal, Vinod K.; Prabhune, Asmita; Nisal, Anuya; Ravindranathan, Sapna (Langmuir, 2019)
A gelling agent is necessary to accelerate sol to gel transition in an aqueous solution of silk fibroin (SF), which otherwise takes several days to complete. In this paper, we investigate the mechanism of gelation of Bornbyx mori SF by a model anionic surfactant, sodium dodecyl sulfate (SOS). Even though interactions between SDS and proteins have been extensively investigated, most of these studies have focused on globular proteins, which undergo denaturation. The interaction with a fibrous protein such as SF is different and results in an altered secondary structure leading to gelation. In this work, the concentration-dependent gelation process of the SF-SDS system is examined using rheology, SANS, FTIR, and NMR. We observed preferential binding of SDS to specific regions on the SF chain, which aids structural changes favoring beta-sheet formation. We propose a mechanism for the accelerated sol-gel transition in the SF-SDS system.

Silylene induced cooperative B-H bond activation and unprecedented aldehyde C-H bond splitting with amidinate ring expansion - Swamy, V. S. V. S. N.; Raj, K. Vipin; Vanka, Kumar; Sen, Sakya S.; Roesky, Herbert W. (Chemical Communications, 2019)
The addition of HBpin to PhC(NtBu)(2)SiN(SiMe3)(2) (1) results in the cleavage of the B-H bond in a cooperative fashion across the Si and amidinate-C sites. The reaction of 1 with benzaldehyde led to C-H bond activation with amidinate ring expansion leading to a five-membered heterocycle. In case of 4-fluorobenzaldehyde, a C-C bond coupling takes place leading to a dioxasilolane derivative as the major product.

Size-controlled cobalt ferrite nanocrystals: magnetically separable reusable nanocatalysts for selective oxidation of styrene - Jeyavani, Vijayakrishnan; Pawar, Sayali; Dadwal, Arun; Joy, Pattayil Alias; Mukherjee, Shatabdi Porel (ChemistrySelect, 2019)
Superparamagnetic cobalt ferrite (CFO) nanocrystals (NCs) with sizes similar to 6 nm and similar to 4 nm were synthesized using a facile solvothermal method using fatty acids, lauric acid and stearic acid, as the capping agents. The synthesized nanocrystals were well characterized by XRD, FT-IR, XPS, SEM and TEM. The formation mechanism was explored and it was shown that the fatty acid was actually chemisorbed as a carboxylate onto the surface of CFO NCs. The experimental results specify that the size and size distribution of the CFO NCs were highly dependent on the length of fatty acid hydrophobic chain. Corresponding changes of the magnetic properties were investigated by measuring magnetization as a function of field and temperature, which suggest that the CFO NCs were superparamagnetic in nature. The catalytic properties for the oxidation of styrene in organic medium were examined by using the synthesized CFO NCs with sizes similar to 6 nm and similar to 4 nm. The synthesized CFO NCs, well dispersible in organic media, were demonstrated to be highly catalytically active, reached 100% conversion of styrene in 12 h with similar to 77% and similar to 82% selectivity for styrene oxide respectively. The magnetic CFO nanocatalysts were easily separated and recovered from the reaction medium by an external magnet, and reused for several cycles without losing catalytic selectivity for styrene oxide.
Keywords: Cobalt ferrite; epoxidation; Fatty acids; magnetic properties; nanocrystals

Slow motion protein dance visualized using red-edge excitation shift of a buried fluorophore - Mishra, Prajna; Jha, Santosh Kumar (Journal of Physical Chemistry B, 2019)
It has been extremely challenging to detect protein structures with a dynamic core, such as dry molten globules, that remain in equilibrium with the tightly packed native (N) state and that are important for a myriad of entropy-driven protein functions. Here, we detect the higher entropy conformations of a human serum protein, using red-edge excitation shift experiments. We covalently introduced a fluorophore inside the protein core and observed that in a subset of native population, the side chains of the polar and buried residues have different spatial arrangements than the mean population and that they solvate the fluorophore on a timescale much slower than the nanosecond timescale of fluorescence. Our results provide direct evidence for the dense fluidity of protein core and show that alternate side-chain packing arrangements exist in the core that might be important for multiple binding functions of this protein.

Solvothermal growth of PbBi2Se4 nano-flowers: a material for humidity sensor and photodetector applications - Aher, Rahul; Bhorde, Ajinkya; Nair, Shruthi; Borate, Haribhau; Pandharkar, Subhash; Naik, Dhirsing; Vairale, Priti; Karpe, Smita; Late, Dattatray; Prasad, Mohit; Jadkar, Sandesh (Physica Status Solidi A-Applications and Materials Science, 2019)
In the present work, lead bismuth selenide (PbBi2Se4) nano-flowers are synthesized by using a simple solvothermal method. Humidity sensor and photodetector based on PbBi2Se4 nano-flowers are fabricated on indium tin oxide (ITO) substrates and their sensing properties are investigated. Formation of PbBi2Se4 is confirmed by XRD, EDS, and XPS whereas formation of nano-flowers is confirmed by SEM and TEM analysis. XRD analysis reveals the hexagonal crystal structure of PbBi2Se4 phase with a = b = 4.22 angstrom, and c= 17.42 angstrom. The surface morphology of PbBi2Se4 clearly shows the formation of well-organized flower-like nanostructures which closely resembles the shape of Dahlia. The elemental mapping of chemical constituents obtained from SEM-EDS analysis shows uniform distribution of chemical constituents for the Pb, Bi, and Se in PbBi2Se4 nano-flowers. The PbBi2Se4 nano-flowers based humidity sensor has a typical response time of approximate to 65s and recovery time of approximate to 75 s. In case of PbBi2Se4 nano-flowers-based photodetector, the response and recovery time are observed approximate to 121 and approximate to 123 s, respectively, under visible light illumination with photoresponsivity (5 x 10(-6)), photosensitivity (2.16%), and quantum efficiency (1.5 x 10(4)). The obtained results demonstrate the potential applications of solvothermally grown PbBi2Se4 nano-flowers-based devices for humidity sensors and photodetectors. The ease of the present work is to develop novel material to obtain device quality humidity sensors and photodetectors.
Keywords: humidity sensor; PbBi2Se4; photodetector; XPS; XRD

Special issue: membrane and receptor dynamics - Prakash, Shikha; Sengupta, Durba (Journal of Membrane Biology, 2019)

Squaraine-linked metalloporphyrin two-dimensional polymer photocatalyst for hydrogen and oxygen evolution reactions - Ranjeesh, K. C.; George, L.; Wakchaure, V. C.; Goudappagouda; Devi, R. N.; Babu, S. S. (Chemical Communications, 2019)
Efficient water splitting photocatalysts are an energetically demanding and cost-effective method for generating renewable energy. Significant research has been reported to advance this approach. However, the use of organic photocatalysts and the presence of residual catalysts trapped in the porous frameworks present major concerns about the efficiency of this strategy. Herein, we report the photocatalytic evolution of H2 and O2 by a multi-hydroxyl group-decorated metalloporphyrin-based two-dimensional catalyst developed via metal catalyst-free synthetic route. Though metalloporphyrins have long been used for catalytic functions, a heterogeneous photocatalyst delivering both H2 and O2 has not yet been realized. This polymer catalyst design enables the photocatalytic diatomic O2 release, a bottleneck in water splitting, in a facile way. Photocatalytic release of H2 as well as O2 occurs with long-term durability of 20 cycles in 300 days with negligible decrease in efficiency, thus demonstrating the excellent performance of this new catalyst.

Stabilization of bis(chlorogermyliumylidene)s within bifunctional PNNP ligand frameworks and their reactivity studies - Sahoo, Padmini; Raut, Ravindra K.; Maurya, Devesh; Kumar, Vikas; Rani, Pooja; Gonnade, Rajesh G.; Majumdar, Moumita (Dalton Transactions, 2019)
The diiminodiphosphine (L-im) and diaminodiphosphines (l-NH and l-NMe) with a bifunctional PNNP ligand framework have been employed to host two [GeCl](+) units leading to the formation of bis(chlorogermyliumylidene) 1-3, respectively. The synthetic route involves a 1:2 stoichiometric reaction between the PNNP ligand and GeCl(2)dioxane and the subsequent addition of two equivalents of chloride abstracting agent. Compound 1 is unstable towards coordinating solvents and Lewis bases, resulting in the displacement of the GeCl unit and the formation of rearranged products 4 and 5. However, the diaminodiphosphine coordinated Ge(ii) bis(monocation)s 2 and 3 proved to be stable and revealed their electrophilic behaviour towards the Lewis bases studied.

Stealth emulsion based on natural rubber latex, core-shell ferrofluid/carbon black in the S and X bands - Vinayasree, S.; Nair, Ajalesh Balachandran; Mani, Manoj; Archana, V. N.; Joseph, Rani; Mohanan, P.; Joy, P. A.; Anantharaman, M. R. (Nanotechnology, 2019)
A lossy dielectric with an appropriate magnetic property is one of the requirements of a stealth material. The thickness of the absorber and the corresponding bandwidth of absorption are also other deciding factors that determine the choice of the material as microwave absorbers. A stable emulsion, which is lossy as well as magnetic, is promising, since it can be coated on surfaces with required thickness in the desired band. A magnetic nanofluidic emulsion serves the purpose. A microwave absorbing emulsion based on natural rubber latex with core-shell magnetic nanoparticles, based on superparamagnetic iron oxide nanoparticles (SPIONs), was developed. The effect of additives like carbon black on the bandwidth of absorption was also studied as a function of weight percentage of carbon black. The complex dielectric permittivity and magnetic permeability were evaluated using a vector network analyser in the S and X bands. Furthermore, these results were modelled using surface impedance equations. These investigations revealed that the incorporation of carbon black enhances the bandwidth of absorption and an emulsion with the required dielectric permittivity and magnetic permeability can be tailored for stealth applications.
Keywords: carbon black; core-shell nanoparticles; ferrofluid; microwave absorbing paint; natural rubber latex

Stereoselective aromatic ring hydrogenation over supported rhodium catalysts in supercritical carbon dioxide solvent - Shirai, M.; Hiyoshi, N.; Rode, C. V. (Chemical Record, 2019)
The combination of supported rhodium metal catalysts and supercritical carbon dioxide solvent was effective for the stereoselective ring hydrogenations of aromatic compounds at low temperature. Higher solubility of hydrogen in supercritical carbon dioxide provides higher concentration of hydrogen on the rhodium surface, but lower that of the intermediate on rhodium surface, which suppresses the flipping of surface intermediate, leading to higher catalyst activities and cis selectivities to the corresponding ring-hydrogenated products as compared with those in organic solvents.

Stereoselective construction of deoxy-cruciferane alkaloids by NHC-catalyzed intramolecular annulation of homoenolate with quinazolinone - Ahire, Milind M.; Pol, Mahesh D.; Kavale, Dattatry S; Gonnade, Rajesh G.; Mhaske, Santosh B. (Organic & Biomolecular Chemistry, 2019)
Chiral N-heterocyclic carbene (NHC)-catalyzed intramolecular [3 + 2] annulation of enals with an unactivated imine moiety of quinazolinone via formal homoenolate cycloaddition has been demonstrated. It is an excellent approach for stereoselective syntheses of deoxy-cruciferane alkaloids comprising a biologically important pyrroloindoline scaffold. Notably, this is the first report on the NHC-catalyzed asymmetric intramolecular homoenolate annulation with cyclic N-acyl amidine.

Stereoselective synthesis of subincanadine alkaloids framework - Kalshetti, Manojkumar G.; Argade, Narshinha P. (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2019)
Starting from, N-tosyltryptamine and (S)-acetoxysuccinic anhydride, a facile synthesis of (-)-indolizinoindolone has been demonstrated as a basic structural outline of bioactive subincanadine alkaloids. Regioselective Grignard reaction with (S)-acetoxysuccinimide, stereoselective intramolecular cyclization to form (-)-indolizinoindolone skeleton and TiCl4 induced condensation with acetaldehyde for stereoselective generation of exocyclic carbon carbon double bond are the key features.
Keywords: (S)-Acetoxysuccinimide; alane reduction; condensation; Grignard reaction; indolizinoindolone; PCC-oxidation; stereoselective Pictet-Spengler cyclization

Steroidal thiazolidinone derivatives: design, synthesis and their molecular interaction with human serum albumin - Ansari, Anam; Ali, Abad; Asif, Mohd; Shamsuzzaman (Steroids, 2019)
A series of steroidal thiazolidinone derivatives have been synthesized through one-pot multicomponent reaction involving steroidal ketone, thiosemicarbazide/methyl-thiosemicarbazide and DMAD in presence of AlCl3 as a Lewis acid catalyst. Among all the synthesized steroidal thiazolidinone derivatives, compound 7-9 (ST 7-9) were investigated for their in vitro molecular interaction with human serum albumin. Intrinsic fluorescence spectroscopy, constant wavelength synchronous fluorescence spectroscopy, circular dichroism and UV-visible absorption techniques have been exploited to characterize the binding phenomena in phosphate buffer solution at pH 7.4. The experimental results indicated that ST 7-9 bind to HSA and the intrinsic fluorescence of HSA was quenched through static quenching mechanism. The binding parameters were calculated and the binding constants obtained were 1.44 x 10(5) M-1 for ST 7, 0.84 x 10(5) M-1 for ST 8 and 1.06 x 10(5) M-1 for ST 9. Circular dichroism analysis confirms that the presence of ST 7-9, altered the secondary structure of HSA due to partial unfolding of the polypeptide chain. Furthermore, hemolytic activity assay demonstrated that the synthesized steroidal thiazolidinone derivatives have good compatibility towards human red blood cells. Finally, molecular docking studies revealed that the steroidal thiazolidinones can bind in the hydrophobic cavity of HSA, by hydrophobic and hydrogen bonding interaction. These results provided valuable information about the binding mechanism of ST 7-9 with HSA and play a pivotal role in the development of steroidal heterocycle inspired compounds.
Keywords: heterocycles; Human serum albumin; steroids; Thiazolidinone

Structural insight into a membrane intrinsic Acyltransferase from Chlorobium tepidum - Boral, Debjyoti; Vankudoth, Koteswara Rao; Ramasamy, Sureshkumar (Current Microbiology, 2019)
The Lipid A component of the outer membrane of Gram-negative bacteria is an integral part of the permeability barrier known as LPS, which actively prevents the uptake of bactericidal compounds. It is clinically very significant, as it is known to elicit a strong immune response in the humans, through the TLR4 complex. The Lipid A species are synthesized through a highly conserved multistep biosynthetic pathway. The final step is catalyzed by acyltransferases of the HtrB/MsbB family, which are members of a superfamily of enzymes, present in all domains of life with important roles to play in various biological processes. The investigation of a putative dual functioning enzyme which can add both laurate and myristate residues to the (Kdo)(2)-lipid IVA (precursor of Lipid A) would give a snapshot into the versatility of substrates that these enzymes catalyze. In this study we have cloned and purified to homogeneity, such a putative dual functional acyltransferase from Chlorobium tepidum, and attempted to study the enzyme in more details in terms of its sequence and structural aspects, as it lacks conserved residues with other enzymes of the same family.

Structural insights into the unique inhibitory mechanism of Kunitz type trypsin inhibitor from Cicer arietinum L. Vol. 37 - Bendre, Ameya D.; Suresh, C. G.; Shanmugam, Dhanasekaran; Ramasamy, Sureshkumar (Journal of Biomolecular Structure & Dynamics, 2019)
Kunitz-type trypsin inhibitors bind to the active pocket of trypsin causing its inhibition. Plant Kunitz-type inhibitors are thought to be important in defense, especially against insect pests. From sequence analysis of various Kunitz-type inhibitors from plants, we identified CaTI2 from chickpea as a unique variant lacking the functionally important arginine residue corresponding to the soybean trypsin inhibitor (STI) and having a distinct and unique inhibitory loop organization. To further explore the implications of these sequence variations, we obtained the crystal structure of recombinant CaTI2 at 2.8 angstrom resolution. It is evident from the structure that the variations in the inhibitory loop facilitates non-substrate like binding of CaTI2 to trypsin, while the canonical inhibitor STI binds to trypsin in substrate like manner. Our results establish the unique mechanism of trypsin inhibition by CaTI2, which warrant further research into its substrate spectrum.
Keywords: Chickpea; crystal structure; inhibitory loop; Kunitz trypsin inhibitor; Trypsin

Structure-property relations in regenerated cellulose fibers: comparison of fibers manufactured using viscose and lyocell processes - Sharma, Aakash; Nagarkar, Shailesh; Thakre, Shirish; Kumaraswamy, Guruswamy (Cellulose, 2019)
Regenerated cellulose fibers are produced using two industrially dominant technologies: the viscose and lyocell processes. Here, we compare commercially available fibers, prepared using the viscose and lyocell processes. Single fibers are subjected to a variety of mechanical deformations to obtain stress-strain, stress relaxation and stress recovery data. These are fitted to a phenomenological model, whose parameters are interpreted in terms of the fiber semicrystalline microstructure. This simple model does not incorporate the complexities of semicrystalline microstructure. Rather, it represents structure in a semicrystalline polymer fiber in terms of an elastic crystalline phase that coexists with a viscoelastic Voigt-like glassy amorphous phase. Lyocell fibers are characterized by higher values of crystalline modulus relative to viscose. Lyocell fibers also have a higher amorphous phase modulus and a wider relaxation spectrum than viscose, suggesting that amorphous and crystalline phases are dispersed in close connectivity in lyocell. Viscose and lyocell fibers exhibit qualitative similarities in their mechanical response. On stretching, there is a transition in the stress-strain curve from a low strain elastic response at a critical value of strain. This critical strain has been incorrectly attributed to yielding of the fiber. We establish that this critical value corresponds to an apparent yield. When subjected to strains higher than this apparent yield point, the fibers develop a memory of the mechanical deformation. This memory decays slowly, logarithmically with time and is lost over about a day as the fiber structure transitions back to the original as spun fiber. Finally, we demonstrate that on wetting the fibers with water, there is an increase in the apparent yield strain for viscose fibers, but not for lyocell. We interpret these results in terms of the semicrystalline microstructure of the fibers.
Keywords: mechanical properties; Model; Regenerated cellulose; Yielding

Studies on nano composites of SPEEK/ethylene glycol/cellulose nanocrystals as promising proton exchange membranes - Bano, Saleheen; Negi, Yuvraj S.; Illathvalappil, Rajith; Kurungot, Sreekumar; Ramya, K. (Electrochimica Acta, 2019)
The present work deals with fabrication and characterisations of nano-composite membranes composed of sulfonated poly (ether ether ketone) (SPEEK) cross-linked and reinforced with ethylene glycol (EG) and cellulose nanocrystals (CNCs) respectively. The thin films of cross-linked composite membranes were prepared by solvent casting method and further analysed for physicochemical and electrochemical properties to execute their applicability as promising proton exchange membrane (PEM) in fuel cells. The process of cross-linking helps to improve the strength and dimensional stability of bare SPEEK membranes without compromising with conductivity. However, presence of CNCs further improves the strength and provides an effective pathway for the conduction of protons in membranes by interacting through their surface hydroxyl and sulfonic acid groups with ionic moieties of polymer matrix. All prepared composite membranes showed good oxidative and thermal stability along with good proton conductivity. The cross-linked SPEEK membranes with 4 wt% loading of CNCs possess an appreciable proton conductivity of 0.186 S/cm at 95 degrees C and 95% RH which is comparable to Nafion 117. From the view point of above studies, the prepared nano-composite can be described as promising proton exchange membrane for fuel cells. (c) 2018 Elsevier Ltd. All rights reserved.
Keywords: Cellulose nanocrystals; Cross-linked SPEEK; fuel cell; oxidative stability; proton conductivity

Studies on the use of sodium polyacrylate (SPA) for low-salt animal skin preservation - Balasubramanian, Venkatakrishnan; Velappan, Brindha; Vijayan, Sandhya Kurvilla; Jabamani, Hepzibah; Nagarajan, Vedaraman; Victor, John Sundar; Ranganath, Suresha P.; Badiger, Manohar V.; Chinnaraj, Velappan kandukalpatti; Chellappa, Muralidharan (Environmental Science and Pollution Research, 2019)
Salt-based preservation is practiced for decades in the leather industry because of its versatility, cost-effectiveness, and availability. The salt removed from the soaking process causes significant pollution including organic and elevated total dissolved solids (TDS). Hence, a low-salt skin preservation method using commercial sodium polyacrylate with a reduced quantity of sodium chloride aiming to retain leather properties and pollution reduction was the principal focus of the study. Commercial sodium polyacrylate initially characterized for water absorption capacity along with structural and functional properties is confirmed by NMR and IR spectroscopic techniques. In preliminary experiments, the process parameters attained optimized conditions of sodium polyacrylate (SPA) quantity (5%), a minimal amount of salt (15%), and contact time (4 h) required for skin preservation. Besides, reusability studies after SPA recovery (95%) were applied to skins with an optimized quantity of SPA and salt subsequently stored for 15 days along with control (40% salt). The results revealed that SPA with low salt aided an adequate curing efficiency with a substantial reduction (> 65%) of TDS and comparable physical and organoleptic properties on par with the conventional method. Overall, SPA supported low-salt skin preservation reduces pollutant load (TDS) caused due to using of 40% sodium chloride in the conventional curing process.

Studies toward the total synthesis of parvifolals A/B: an intramolecular o-quinone methide [4 + 2]-cycloaddition to construct the central tetracyclic core - Paymode, D. J.; Ramana, C. V. (ACS Omega, 2019)
Two different approaches funded upon the intramolecular [4 + 2]-cycloaddition of in situ generated o-quinone methides have been explored to construct the central tetracyclic core of parvifolals A/B. At the outset, a cross-pinacol coupling of 2-formyl tri-O-methyl resveratrol with 4-methoxysalicylaldehyde followed by acid treatment was found to provide the desired tetracyclic core with an internal olefin. The requisite pendant aryl group has been introduced by a Pd-catalyzed direct coupling of corresponding diazonium salt.

Study of rheology and plug assist thermoforming of linear and branched pp homopolymer and impact copolymer - Marathe, D.; Shelar, S.; Mahajan, S.; Ahmad, Z.; Gupta, S.; Kulkarni, S.; Juvekar, V; Lele, A. (International Polymer Processing, 2019)
Polypropylene (PP) is one of the fastest growing thermoplastic polymers in the world, second only to polyethylene. This is primarily due to its excellent balance of physical and chemical properties at a lower cost. PP however possesses low melt strength on account of its linear structure and hence is not easily amenable to processing techniques that involve free surface stretching deformations like thermoforming, blow molding and extrusion film casting. One way to enhance the melt strength of PP is to incorporate long chain branches in its molecular architecture. The present study focuses on the impact of rheology of linear and branched PP on their thermoforming characteristics. Two grades each of linear and long chain branched (LCB) PP homopolymer and impact copolymer (ICP) were used. It was observed that the LCB-PP homopolymer and LCB-ICP showed higher flow activation energy, reduced value of loss tangent and nearly equal frequency dependence of storage and loss moduli in shear rheology. Also, a strong strain hardening behavior was displayed in extensional rheology by the LCB grades. Plug assist thermoforming experiments were carried out to assess the effect of long chain branching on surface strain and thickness distribution for axisymmetric cups of two draw ratios. Biaxial surface strain maps of the formed cups were quantified using Grid Strain Analysis (GSA). Thermoformed cups made from LCB-PP homopolymer and LCB-impact copolymer showed lower surface strain and overall higher thickness as compared to cups made from their linear counterparts, which is in accordance with what might be expected from their rheology.

Superfluous glutamine synthetase activity in Chinese Hamster Ovary cells selected under glutamine limitation is growth limiting in glutamine-replete conditions and can be inhibited by serine - Maralingannavar, Vishwanathgouda; Parmar, Dharmeshkumar; Panchagnula, Venkateswarlu; Gadgil, Mugdha (Biotechnology Progress, 2019)
Passaging and expansion of animal cells in lean maintenance medium could result in periods of limitation of some nutrients. Over time, such stresses could possibly result in selection of cells with metabolic changes and contribute to heterogeneity. Here, we investigate whether selection of Chinese Hamster Ovary (CHO) cells under glutamine limitation results in changes in growth under glutamine-replete conditions. In glutamine-limiting medium, compared to control cells passaged in glutamine-rich medium, the selected cells showed higher glutamine synthetase (GS) activity and attained a higher peak viable cell density (PVCD). Surprisingly, in glutamine-replete conditions, selected cells still showed a higher GS activity but a lower PVCD. We show that in glutamine-replete medium, PVCD of selected cells was restored on (a) inhibition of GS activity with methionine sulfoximine, (b) supplementation of aspartate-without affecting GS activity, and (c) supplementation of serine, which is reported to inhibit GS in vitro. Consistent with the reported effect of serine, inhibition of GS activity was observed upon serine supplementation along with reduced growth of cells under glutamine-limiting conditions. The latter observation is important for the design of glutamine-free culture medium and feed used for GS-CHO and GS-NS0. In summary, we show that CHO cells selected under glutamine limitation have superfluous GS activity in glutamine-replete medium, which negatively affects their PVCD. This may be due to its effect on availability of aspartate which was the limiting nutrient for the growth of selected cells in glutamine-replete conditions.
Keywords: C-13 tracer analysis; CHO cells; glutamine limitation; Glutamine synthetase; GS-CHO; GS-NS0; selection under nutrient limitation; serine

Superior humidity sensor and photodetector of mesoporous ZnO nanosheets at room temperature - Gupta, Shobhnath P.; Pawbake, Amit S.; Sathe, Bhaskar R.; Late, Dattatray J.; Walke, Pravin S. (Sensors and Actuators B-Chemical, 2019)
Miniaturized sensor technology is vastly demanding multifunctional materials to fulfill many requirements simultaneously; instead of integrating various sensors into a single device. Efficient operation of these miniaturized sensors at room temperature is highly feasible and cost-effective. The humidity sensing and photodetection is precise merit of sensing in special usage like artificial skin. Sensitivity enhancement in both humidity and photodetection required the high surface area for adsorption as well as a high charge transfer mechanism. The two dimensional (2D) zinc oxide nanosheets (ZnO NS) is the ultimate structure for dimensionally confined transport properties owing to the specific surface atomic configuration that results in high sensitivity, low operating temperature, fast response and recovery, and improved selectivity. Furthermore, introducing porosity into 2D nanostructures has opened new opportunities to enhance the efficiency of sensors and detectors via increasing large surface area and tunable physical and chemical properties. Here we report preparation of mesoporous and highly crystalline 2D ZnO NS by a single step, template free, cost-effective chemical method. The structural and morphological characterizations of ZnO NS are carried out using XRD, FESEM, XPS, TEM respectively. The high-resolution TEM images emphasize sheet-like morphology with a thickness of around 18-22 nm. Further the mesoporous ZnO NS (MZNS) with the pore size between 5-10 nm are achieved by simple heat-treatment. XPS and PL study is confirming the oxygen deficiency in MZNS. The MZNS exhibits an excellent responsivity than PZNS with a fast response and rapid recovery time of 25 s and 5 s respectively along with good cyclic stability which is highly crucial for smart humidity sensor. Furthermore, it considerably enhances photo-sensor performance than pristine ZnO NS (PZNS) with (similar to)1 s response time as well as (similar to)1 s recovery time along with better stability. These promising results illustrate the great potential of MZNS for next-generation humidity sensors and photodetectors.
Keywords: humidity sensor; Mesoporous; nanosheets; Photo-detector

Supramolecular synthon hierarchy in sulfonamide cocrystals with syn-amides and N-oxides - Bolla, Geetha; Nangia, Ashwini (IUCRJ, 2019)
Sulfonamide drugs are well known antibacterial and antimicrobial molecules for pharmaceutical development. Building a library of suitable supramolecular synthons for the sulfonamide functional group and understanding their crystal structures with partner coformer molecules continues to be a challenge in crystal engineering. Although a few sulfonamide cocrystals with amides and N-oxides have been reported, the body of work on sulfonamide synthons is limited compared with those that have carboxylic acids and carboxamides. To address this structural gap, the present work is primarily focused on sulfonamide-lactam and sulfonamide-syn-amide synthons with drugs such as celecoxib, hydrochlorothiazide and furosemide. Furthermore, the electrostatic potential of previously reported cocrystals has been recalculated to show that the negative electrostatic potential on the lactam and syn-amide O atom is higher compared with the charge on carboxamide and pyridine N-oxide O atoms. The potential of sulfonamide molecules to form cocrystals with syn-amides and lactams are evaluated in terms of the electrostatic potential energy for the designed supramolecular synthons.
Keywords: cocrystals; crystal engineering; sulfonamides; supramolecular synthons; syn-amides

Surfactant free synthesis of Au@Ni core-shell nanochains in aqueous medium as efficient transfer hydrogenation catalyst - Vysakh, A. B.; Shebin, K. J.; Jain, Ruchi; Sumanta, P.; Gopinath, Chinnakonda S.; Vinod, C. P. (Applied Catalysis A-General, 2019)
A surfactant free aqueous phase synthesis method is reported for the generation of highly lattice mismatched Au@Ni core-shell nanochains without using any expensive and hazardous organic ligands. As synthesised Au@Ni nanochain structures showed high thermal stability and bulk oxidation resistance up to 300 degrees C. In situ near ambient pressure XPS (NAPXPS) analysis has been done for the bare Au@Ni nanochain surfaces under oxygen atmosphere and at different temperatures which showed evidence for the surface oxidation resistance of naked Au@Ni nanochains up to 200 degrees C. Ligand or capping agent free Au@Ni nanochain surfaces are found to be highly active for transfer hydrogenation of acetophenone to 1-phenyl ethanol an important commodity in perfumery industry.
Keywords: Au@Ni nanochains; core-shell; NAPXPS; Surfactant free; synergistic effects; transfer hydrogenation

Sustained release insect repellent microcapsules using modified cellulose nanofibers (mCNF) as pickering emulsifier - Kadam, Sandip L.; Yadav, Prashant; Bhutkar, Siddhant; Patil, Vishal D.; Shukla, Parshuram G.; Shanmuganathan, Kadhiravan (Colloids and Surfaces A-Physicochemical and Engineering Aspects, 2019)
We report here an approach to encapsulate N, N-diethyl-3-methylbenzamide (DEET), an insect repellent, through interfacial polycondensation using modified cellulose nanofiber (CNF) as pickering emulsifier. We found that stearic acid functionalized CNF (mCNF) can be used to form stable pickering emulsions (oil-in-oil and water-in-oil), and further encapsulate DEET using interfacial polycondensation with very high encapsulation efficiency of about 98%. Another major advantage of this approach is that mCNF can act both as pickering emulsifier and also strengthen the barrier properties of microcapsules resulting in significant reduction in release rate of DEET. Interpretation of the release profiles using standard mathematical models proposed by Ritger-Peppas show a factor of three reduction in release rate constant for the microcapsules reinforced with mCNF.
Keywords: Cellulose nanofiber; Controlled release; Microcapsules; Nanocomposite; nanoparticle; Pickering emulsion

Synergetic combination of H2Zr1PW12O40 and Sn-Beta as potential solid acid catalyst for direct one-step transformation of glucose to ethyl levulinate, a biofuel additive - Mulik, N.; Niphadkar, P.; Bokade, V. (Environmental Progress and Sustainable Energy, 2019)
Ethyl levulinate (EL) has found wide applications as chemicals and biofuel additives. Efficient catalytic conversion of abundantly available glucose to ELs over solid acid catalyst having optimum Brønsted (B) and Lewis (L) acidity is highly appreciated. Present work demonstrated, direct one‐step synthesis of EL from glucose over synergized Brønsted (H2Zr1PW12O40) and Lewis (Sn‐Beta) acid catalyst. H2Zr1PW12O40 is prepared by exchanging H+ of tungstophosphoric acid (H3PW12O40‐heteropolyacid) with Zr, improves the heterogeneity in polar medium by 50%. The combination of a physical mixture of H2Zr1PW12O40 + Sn‐Beta with 80:20 weight ratio was found to be optimum for the maximum EL yield formation of 54% from glucose at 180°C for 3 h, which is probably the highest than reported over the heterogeneous catalyst in ethanol medium. An optimal combination of B and L catalyst and its ratio is found to be crucial for the direct transformation of glucose to EL in one step. The present study also explored that this combined physical mixture of H2Zr1PW12O40 + Sn‐Beta can tolerate glucose concentration up to 30 g/L, which is probably the higher than reported. © 2019 American Institute of Chemical Engineers Environ Prog, 2019

Synthesis and antimycobacterial evaluation of new 5-(1-benzyl-1H-1,2,3-triazol-4-yl)-4-methyl-2-arylthiazole derivatives - Shinde, Vikas; Mahulikar, Pramod; Mhaske, Pravin C.; Chakraborty, Shakti; Choudhari, Amit; Phalle, Siddharth; Choudhari, Prafulla; Sarkar, Dhiman (Medicinal Chemistry Research, 2019)
A new series of 5-(1-benzyl-1H-1,2,3-triazol-4-yl)-4-methyl-2-arylthiazole derivatives, 6a-w have been synthesized by click reaction of substituted benzylazide, 5a-d with 5-ethynyl-4-methyl-2-substituted phenylthiazole, 4a-f. The starting compounds 4-ethynyl-2-substituted phenylthiazole (4a-f) were synthesized from the corresponding thiazole aldehyde by using the Ohira-Bestmann reagent. The structure of the synthesized compounds was determined by spectral analysis. All the synthesized compounds were screened for their preliminary antitubercular activity against Mycobacterium tuberculosis H37Ra (MTB, ATCC 25177). Most of the synthesized compounds reported good activity against M. tuberculosis H37Ra strain with IC50 range of 0.58-8.23 mu g/mL. Compounds 6g and 6k reported good antitubercular activity with MIC90 values of 4.71 and 2.22 mu g/mL, respectively. Potential antimycobacterial activity suggested that these compounds could serve as good lead compounds for further optimization and development of a newer antitubercular candidate. [GRAPHICS] .
Keywords: 1; 2; 3-Triazole; Antitubercular activity; Molecular docking; Ohira-Bestmann reagent; Thiazole

Synthesis and biological evaluation of 2,4,5-trisubstituted thiazoles as antituberculosis agents effective against drug-resistant tuberculosis - Karale, Uttam B.; Krishna, Vagolu Siva; Krishna, E. Vamshi; Choudhari, Amit S.; Shukla, Manjulika; Gaikwad, Vikas R.; Mahizhaveni, B.; Chopra, Sidharth; Misra, Sunil; Sarkar, Dhiman; Sriram, Dharmarajan; Dusthackeer, V. N. Azger; et al. (European Journal of Medicinal Chemistry, 2019)
The dormant and resistant form of Mycobacterium tuberculosis presents a challenge in developing new anti-tubercular drugs. Herein, we report the synthesis and evaluation of trisubstituted thiazoles as antituberculosis agents. The SAR study has identified a requirement of hydrophobic substituent at C2, ester functionality at C4, and various groups with hydrogen bond acceptor character at C5 of thiazole scaffold. This has led to the identification of 13h and 13p as lead compounds. These compounds inhibited the dormant Mycobacterium tuberculosis H37Ra strain and M. tuberculosis H37Rv selectively. Importantly, 13h and 13p were non-toxic to CHO cells. The 13p showed activity against multidrug-resistant tuberculosis isolates. (C) 2019 Elsevier Masson SAS. All rights reserved.

Synthesis and biological evaluation of new 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)phenyl)-2-phenylthiazole derivatives - Shinde, Vikas; Mhaske, Pravin C.; Singh, Aakriti; Sarkar, Dhiman; Mahulikar, Pramod (Journal of Heterocyclic Chemistry, 2019)
A novel series of 4-(4-(1-benzyl-1H-1,2,3-triazol-4-yl)phenyl)-2-substitutedthiazole derivatives (8a-l) have been synthesized by [3 + 2] cycloaddition reaction of 4-(4-ethynylphenyl)-2-substitutedthiazole with substituted benzyl azide in aqueous DMF. Starting compounds 4-(4-ethynylphenyl)-2-substitutedthiazole (6a-d) were synthesized by reaction of 4-(2-substitutedthiazol-4-yl)benzaldehyde with Ohira-Bestmann reagent in methanol. The structures of these novel triazole-thiazole clubbed derivatives were confirmed by the spectral analysis. The title compounds (8a-l) were tested for antimycobacterial activity against Mycobacterium tuberculosis H37Ra active and dormant (MTB, ATCC 25177) and antimicrobial activity against standard Gram-positive bacteria, Staphylococcus aureus (NCIM 2602) and Bacillus subtilis (NCIM 2162), and Gram-negative bacteria, Escherichia coli (NCIM 2576) and Pseudomonas flurescence (NCIM 2059). Compounds 8a, 8b, 8c, and 8h reported good activity against B subtilis, compounds 8a, 8b, and 8c showed good activity against S aureus, and compound 8b showed good activity against dormant M tuberculosis H37Rv strain. Compounds 8b and 8c found more potent against Gram positive and dormant M tuberculosis H37Rv strains. These novel triazole-thiazole clubbed analogues found to be a capable leads for further optimization and development.

Synthesis and characterization of zinc oxide nanoparticles by using polyol chemistry for their antimicrobial and antibiofilm activity - Mahamuni, P. P.; Patil, P. M.; Dhanavade, M. J.; Badiger, M. V.; Shadija, P. G.; Lokhande, A. C.; Bohara, R. A. (Biochemistry and Biophysics Reports, 2019)
The present investigation deals with facile polyol mediated synthesis and characterization of ZnO nanoparticles and their antimicrobial activities against pathogenic microorganisms. The synthesis process was carried out by refluxing zinc acetate precursor in diethylene glycol(DEG) and triethylene glycol(TEG) in the presence and in the absence of sodium acetate for 2 h and 3 h. All synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), UV visible spectroscopy (UV), thermogravimetric analysis (TGA), fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy(FESEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) technique. All nanoparticles showed different degree of antibacterial and antibiofilm activity against Gram-positive Staphylococcus aureus (NCIM 2654)and Gram-negative Proteus vulgaris (NCIM 2613). The antibacterial and antibiofilm activity was inversely proportional to the size of the synthesized ZnO nanoparticles. Among all prepared particles, ZnO nanoparticles with least size (~ 15 nm) prepared by refluxing zinc acetate dihydrate in diethylene glycol for 3 h exhibited remarkable antibacterial and antibiofilm activity which may serve as potential alternatives in biomedical application.

Synthesis and reactivity of a hypersilylsilylene - Bisai, Milan Kumar; Swamy, V. S. V. S. N.; Das, Tamal; Vanka, Kumar; Gonnade, Rajesh G.; Sen, Sakya S. (Inorganic chemistry, 2019)
Stabilization of an amidinatosilylene with a bulky tris(trimethylsilyl)silyl substituent was realized with the preparation of PhC(NtBu)(2)Si{Si(SiMe3)(3)} (1) from PhC(NtBu)(2)SiHCl2 with K{Si(SiMe3)(3)} in more than 90% yield. The highly deshielded Si-29 NMR resonance (delta = 76.91 ppm) can be attributed to the absence of a pi-donating substituent. The molecular structure of 1 shows a trigonal-planar geometry around the Si-II center with a Si-II-Si-IV bond length of 2.4339(13) angstrom. A series of reactions of 1 with Me3NO, S, Se, and Te were performed. While siloxane derivatives (2 and 3) are obtained from reactions with Me3NO, silachalcogenones (4-6) are formed with other chalcogens. The presence of Si=E (E = S, Se, and Te) bonds in 4-6 have been confirmed by single crystal X-ray studies. Silaoxirane (7) formation was observed when 1 was treated with acetone, demonstrating the importance of the tris(trimethylsilyl)silyl group to kinetically and thermodynamically protect the silaoxirane derivative with less bulky substituents on the C atom.

Synthesis, biological evaluation and molecular modeling studies of novel chromone/Aza-Chromone fused alpha-aminophosphonates as src kinase inhibitors - Bapat, S.; Viswanadh, N.; Mujahid, M.; Shirazi, A. N.; Tiwari, R. K.; Parang, K.; Karthikeyan, M.; Muthukrishnan, M.; Vyas, Renu (Journal of Scientific & Industrial Research, 2019)
A series of novel chromone/aza-chromone fused alpha-aminophosphonate derivatives were synthesized in good yields using silica chloride as the catalyst. All the synthesized compounds were tested for their c-Src kinase inhibitory activity. Aza-chromone compound showed Src kinase inhibition with an IC50 value of 15.8 mu M. The compounds were subjected to molecular docking and dynamics simulations to study the atomic level interactions with an unphosphorylated proto-oncogenic tyrosine protein kinase Src (PDB code 1Y57) as well as phosphorylated tyrosine protein kinase Src (PDB code 2H8H). Docking and molecular dynamic results revealed phosphorylated Src tyrosine kinase protein better results than unphosphorylated tyrosine Src kinase protein. Chemoinformatics study revealed the compounds had lead like properties. Machine learning (SVR) models were built to study the structure activity correlations. A CC of 0.835 was obtained when the SVR model was applied to the 17 synthesized compounds. It is envisaged that the work will provide guidelines for future drug design efforts for Src kinase inhibitors.

Synthesis, biological evaluation and molecular modeling studies of novel chromone/Aza-chromone fused α-aminophosphonates as Src kinase inhibitors - Bapat, Sanket; Viswanadh, N.; Mujahid, M.; Shirazi, Amir Nasrolahi; Tiwari, Rakesh; Parang, Keykavous; Karthikeyan, Muthukumarasamy; Muthukrishnan, M.; Vyas, Renu (Journal of Scientific and Industrial Research, 2019)
A series of novel chromone/aza-chromone fused α-aminophosphonate derivatives were synthesized in good yields using silica chloride as the catalyst. All the synthesized compounds were tested for their c-Src kinase inhibitory activity. Aza-chromone compound showed Src kinase inhibition with an IC50 value of 15.8 µM. The compounds were subjected to molecular docking and dynamics simulations to study the atomic level interactions with an unphosphorylated proto-oncogenic tyrosine protein kinase Src (PDB code 1Y57) as well as phosphorylated tyrosine protein kinase Src (PDB code 2H8H). Docking and molecular dynamic results revealed phosphorylated Src tyrosine kinase protein better results than unphosphorylated tyrosine Src kinase protein. Chemoinformatics study revealed the compounds had lead like properties. Machine learning (SVR) models were built to study the structure activity correlations. A CC of 0.835 was obtained when the SVR model was applied to the 17 synthesized compounds. It is envisaged that the work will provide guidelines for future drug design efforts for Src kinase inhibitors.

Synthesis, characterization, Hirshfeld surface, cytotoxicity, DNA damage and cell cycle arrest studies of N, N-diphenyl-N `-(biphenyl-4-carbonyl/4-chlorobenzoyl) thiocarbamides - Pandey, Sunil K.; Pratap, Seema; Rai, Sunil K.; Marverti, Gaetano; Kaur, Manpreet; Jasinski, Jerry P. (Journal of Molecular Structure, 2019)
The condensation reaction of biphenyl-4-carbonyl isothiocyanate/4-chlorobenzoyl isothiocyanate with diphenylamine yielded two new compounds; N-diphenyl-N'-(biphenyl-4-carbonyl) thiocarbamide (1) and N, N-diphenyl-N'-(4-chlorobenzoyl) thiocarbamide (2). Structure of the compounds were determined by analytical, spectroscopic (UV-Visible, FT-IR, H-1, & C-13 NMR), powder and single-crystal X-ray diffraction methods. Hirshfeld surface analysis and their associated two dimensional fingerprint plots of compounds were used as theoretical approach to assess driving force for crystal structure formation via the intermolecular interactions in their crystal lattices. The compounds were screened for their in vitro cytotoxicity activity against a panel of five human cancer cell lines namely; cervical (2008 and C13*) and ovarian carcinoma (A2780, A2780/CP and IGROV-1). Both the compounds exhibited promising activity against cervical and IGROV-1 cancer cells whereas for the other two cell lines appreciable activities were observed. The cell cycle arrest at G(0)/G(1) phase is supported by the DNA damage and apoptosis studies of the compounds against 2008, C13* and IGROV-1 cell lines. (C) 2019 Elsevier B.V. All rights reserved.
Keywords: DNA damage and cell cycle arrest; Hirshfeld surface analysis; In vitro cytotoxicity; Thiocarbamide; X-ray crystal structure

Synthesis, characterization, pharmacological and computational studies of 4, 5, 6, 7-tetrahydro-1, 3-benzothiazole incorporated azo dyes - Maliyappa, M. R.; Keshavayya, J.; Mallikarjuna, N. M.; Krishna, P. Murali; Shivakumara, N.; Sandeep, Telkar; Sailaja, Krishnamurty; Nazrulla, Mohammed Azeezulla (Journal of Molecular Structure, 2019)
The present work describes the synthesis of five novel heterocyclic azo dyes (4a-4e) through conventional diazo-coupling reaction of 4, 5, 6, 7-tetrahydro-1, 3-benzothiazole with various coupling compounds at 0-5 degrees C. The chemical structures of the synthesized azo dyes were characterized by both theoretical and experimental techniques. All the synthesized molecules were evaluated for their antioxidant activity by two different techniques such as DPPH and FRAP. The results indicated that all the synthesized compounds proved to be potent antioxidants. The anti-mycobacterial activity of the azo dyes was tested against M. tuberculosis and the compounds 4a and 4e showed higher activity among the tested dyes. The DNA binding studies showed effective intercalation properties between the azo dyes and CT-DNA. Finally, the molecular docking studies indicated a possible interaction of the azo dyes with target receptor RpsA. (C) 2018 Elsevier B.V. All rights reserved.
Keywords: Azo dyes; Benzothiazole; CT-DNA; DFT; tuberculosis

Synthesis of 2-Aryl naphthoquinones by the cross-dehydrogenative coupling involving an NHC-catalyzed endo-stetter reaction - Ghosh, Arghya; Patra, Atanu; Mukherjee, Subrata; Biju, Akkattu T. (Journal of Organic Chemistry, 2019)
An N-heterocyclic carbene (NHC)-catalyzed intramolecular Stetter reaction proceeding via the endo-fashion was the key step for the transition-metal-free and mild cross-dehydrogenative coupling of 2-cinnamoyl benzal-dehydes allowing for the synthesis of 2-aryl naphthoquinones. In this transformation, the carbene generated from the triazolium salt using Na2CO3 catalyzes the intramolecular Stetter reaction, which was followed by air oxidation to reinstall the C-C double bond.

Synthesis of a 3D free standing crystalline NiSex matrix for electrochemical energy storage applications - Dinara, Syed Mukulika; Samantara, Aneeya K.; Das, Jiban K.; Behera, J. N.; Nayak, Saroj K.; Late, Dattatray J.; Rout, Chandra Sekhar (Dalton Transactions, 2019)
The electrochemical performance for energy storage of three-dimensional (3D) self-supported heterogeneous NiSex cubic-orthorhombic nanocrystals grown by a facile one-step chemical vapour deposition (CVD) approach on Ni foam substrates has been explored. NiSex shows a high specific capacitance of 1333 F g(-1) with ultra-high energy (105 W h kg(-1)) and power (54 kW kg(-1)) densities. Furthermore, by integrating the as-grown NiSex as the anode and reduced graphene oxide as the cathode, a hybrid super-capacitor (HSC) prototype with a coin cell configuration has been fabricated. The device shows better capacitance (40 F g(-1)) with high energy (22 W h kg(-1)) and power (5.8 kW kg(-1)) densities and robust cycling durability (similar to 88% capacitance retention after 10 000 repeated cycles). For practical reliability of the as-fabricated HSC, a red LED has been illuminated by connecting it with two charged coin cells. These outstanding performances of the HSC prove to be promising for applications in high energy storage systems.

Synthesis of artemisinin derived glycoconjugates inspired by click chemistry - Goswami, Lakshmi; Paul, Sayantan; Kotammagari, Tharun K.; Bhattacharya, Asish K. (New Journal of Chemistry, 2019)
Herein we describe the synthesis of artemisinin based glycoconjugates (9a-i) through employing a Cu(i)-catalysed reaction between -propargylated dihydroartemisinin (7a) and azido sugars (8a-i), with moderate to excellent yields. Our synthesized artemisinin based glycoconjugates (9a-i) could prove to be an interesting class of bioactive molecules, suitable for the study of their various biological activities.

Synthesis of biodiesel using the Mg/Al/Zn hydrotalcite/SBA-15 nanocomposite catalyst - Prabu, Marimuthu; Manikandan, Marimuthu; Kandasamy, Prabu; Kalaivani, P. R.; Rajendiran, Nagappan; Raja, Thirumalaiswamy (Acs Omega, 2019)
Biodiesel production is an enchanting and eccentric pathway for the reduction of use of fossil fuels and is procured from biologically available renewable sources such as oils and fats. A novel Mg/Al/Zn-based hydrotalcite/SBA-15 composite material having a high catalytic activity was developed and investigated for the transesterification of vegetable oil. The rationally developed composites were systematically characterized and assessed in the transesterification of soybean oil in the presence of methanol. The physicochemical evaluation of the nanocomposites demonstrated the influence of Zn in the textural characteristics, density of the basic sites, and successively the catalytic activity. The catalytic efficiency of the MAZ-x/SBA-15 composite could be linked with the basic site density determined by the temperature-programmed desorption of CO2. Among all the composites used, the MAZ-1/SBA-15 nanocomposite showed the highest activity for biodiesels, with a yield of around 90% under economical reaction conditions. The catalytic studies conferred that the fatty acid methyl ester yield is significantly influenced by various experimental conditions such as the catalyst molar ratio, reaction temperature, pressure, and contact time. It was also found that the incorporation of hydrotalcite into SBA-15 pore channels can enhance the catalyst efficiency and stability of the nanocomposite. Moreover, under mild reaction conditions, a remarkably stable catalytic performance was achieved for more than 200 h of time on stream with no catalyst deactivation.

Synthesis of biphasic nanomaterials based on ZnO and SnO2: application towards photocatalytic degradation of acid red dye - Kudale, Ananada S.; Kamble, Santosh B.; Gore, Anil H.; Pisal, Mahesh M.; Salokhe, Anil T.; Kolekar, Govind B.; Helavi, Vasant B. (Nano-Structures & Nano-Objects, 2019)
Zn2SnO4/SnO2 and ZnO/SnO2 biphasic nanocatalysts have been synthesized by a facile solvothermal method using ethylene glycol (EG) as solvent in three different ways maintaining the pH of the solution at either 3 or 9 followed by calcination at 700 °C. The nanocatalysts are characterized by different techniques to investigate their structure, composition, morphology and optical properties. The XRD results indicate the formation of pristine biphasic composites. The UV-absorbance and photoluminescence spectra confirms the formation of biphasic composites as well as presence of large number of defects in the prepared nanocatalysts. The biphasic nanocomposites possess better photocatalytic activity towards the degradation of Acid Red-183 (AR-183) dye than pristine SnO2 and ZnO nanoparticles. This is mainly due to better charge separation, minimal recombination rate of charge carriers and defect-riched structures of nanocatalysts.

Synthesis of chiral tetrahydrofuran building blocks from pantolactones: application in the synthesis of empagliflozin and amprenavir analogs - Athawale, Paresh R; Kumari, Neeta; Kashinath, K; Reddy, D. Srinivasa (Europen Journal of Organic Chemistry, 2019)
Chiral 4,4-dimethyl tetrahydrofuran (THF) derivatives were synthesized from commercially available D-(-)/ l-(+) pantolactones, which can serve as chiral building blocks in medicinal chemistry. In addition, two of the synthesized building blocks were utilized for the synthesis of new amprenavir (HIV protease inhibitor) and empagliflozin (anti-diabetic) analogs. The synthesized analogs may have beneficial effects in terms of pharmacokinetics and modulation of bioactivity.

Synthesis of deuterated isopentyl pyrophosphates for chemo-enzymatic labelling methods: GC-EI-MS based 1,2-hydride shift in epicedrol biosynthesis - Said, Madhukar S.; Navale, Govinda R.; Gajbhiye, Jayant M.; Shinde, Sandip S. (RSC Advances, 2019)
A sesquiterpene epicedrol cyclase mechanism was elucidated based on the gas chromatography coupled to electron impact mass spectrometry fragmentation data of deuterated (H-2) epicedrol analogues. The chemo-enzymatic method was applied for the specific synthesis of 8-position labelled farnesyl pyrophosphate and epicedrol. EI-MS fragmentation ions compared with non-labelled and isotopic mass shift fragments suggest that the H-2 of C6 migrates to the C7 position during the cyclization mechanism.

Synthesis of hexaphenylbenzene-based template assembled synthetic proteins - Madhu, Suresh; Madica, Krishnaprasad; Gonnade, Rajesh; Sanjayan, Gangadhar J (Tetrahedron Letters, 2019)
Template-assembled synthetic proteins (TASPs) synthesized from rigid templates have attracted attention due to their interesting structural architectures and potential biomedical applications. Herein, we report the design, synthesis and characterizations of TASPs based on hexaphenylbenzene template (HPB) having twelve peptide attachable axial-arms in its structure. The peptides were attached to all the axial-arms of the template in a single step using simple solution phase peptide coupling strategy. The reaction conditions were standardized systematically using simple amines from smaller size to larger ones. (C) 2019 Elsevier Ltd. All rights reserved.

Synthesis of high surface area porous carbon from anaerobic digestate and it's electrochemical study as an electrode material for ultracapacitors - Chaturvedi, Vikash; Usangonvkar, Saurabh; Shelke, Manjusha V. (RSC Advances, 2019)
The remnants of the anaerobic digestion process, `the digestate,' mainly consist of fibrous lignin and cellulose like molecules, as a significant carbon repository along with some other inorganic impurities. The present work demonstrates the potential use of anaerobically treated fruit and vegetable waste (FVW) as a source of porous carbon for supercapacitor electrode materials. This work suggests that the FVW digestate can inherit silicon (Si) and calcium (Ca) based inorganic impurities, which play an essential role as structure directing agents for digestate derived carbon. These contaminants act as hard templates during carbonization to create hierarchical pores and contribute to an enhancement in surface area. Different batches from an anaerobic biogas digester plant are converted to porous carbon and examined as a potential supercapacitor electrode material. A maximum capacitance of 235 F g(-1) is achieved from DDHPC-4kh carbon with a specific surface area of 2502 m(2) g(-1) at a current density of 1 A g(-1) in an acidic aqueous electrolyte. The results are significant in comparison to other bio-sourced precursors studied previously.

Synthesis of nanogate structure in GO-ZnS sandwich material - Kumar, Praveen; Luwang, Meitram Niraj (Scientific Reports, 2019)
Graphite Oxide (multi-layer) composite with other materials has a huge application in various field of science, due to its excellent and unique properties. Even though from past decade, immense research has been done by materials scientists in this field, but the chemistry is still not yet satisfactory. Here, in this work, through the discovery of Nanogate structure, we have reported for the first time the experimental results that enlightened the clear chemistry between the GO and ZnS which is further supported by the DFT calculations. This novel synthesis method led to the discovery of nanogate structure sandwiched between the GO layers. The nanogate formation also shows enhanced properties for various applications like photocatalytic activities, etc. Due to the nanogate formation, there might be a possibility of enormous generation of electrons on excitation of the composite materials, which can be a boom for various applications like photocatalysis, water splitting, solar cell, etc.

Synthesis of new 1,3,4-oxadiazole and benzothiazolylthioether derivatives of 4-arylmethylidene-3-substituted-isoxazol-5(4H)-one as potential antimycobacterial agents - Chavan, Abhijit P.; Deshpande, Rujuta R.; Borade, Nandkumar A.; Shinde, Abhijit; Mhaske, Pravin C.; Sarkar, Dhiman; Bobade, Vivek D. (Medicinal Chemistry Research, 2019)
A new series of 4-[(substituted benzylidene)-3-[(5-(pyridine-4-yl)-1,3,4-oxadiazole-2-ylthio)-methyl]i soxazol-5(4H)-one (6a-g) and 4-(substituted benzylidene)-3-((benzo[d]thiazol-2-ylthio)methyl)isoxazol-5(4H)-one (8a-g) was synthesized. All the synthesized compounds were screened for antitubercular activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis BCG (ATCC 35743) and antibacterial activity against Escherichia coli (NCIM 2576), Pseudomonas flurescence (NCIM 2059), Staphylococcus aureus (NCIM 2602), Bacillus subtilis (NCIM 2162). Amongst the synthesized 1,3,4-oxadiazole and benzothiazoyl thioether derivatives, compounds 6b and 8b showed excellent antimycobacterial activity and compounds 6b, 8a, 8b, and 8d showed excellent antibacterial activity against all tested antibacterial strains. The synthesized compounds were further evaluated for their cytotoxic activity against the HCT 116 and HeLa cancer cell lines. The 1,3,4-oxadiazole and benzothiazoyl thioether derivatives 6a-g and 8a-g did not show cytotoxicity.
Keywords: 1; 3; 4-Oxadiazole; antibacterial activity; Antitubercular activity; Benzothiazol; Isoxazol-5(4H)-one; Thioeteher

Synthesis of ultrathin PEDOT on carbon nanotubes and shear thinning xanthan Gum-H2SO4 gel electrolyte for supercapacitors - Soni, Roby; Bhange, Siddheshwar N.; Athira, E.; Chetry, Rashmi; Kurungot, Sreekumar (ChemElectroChem, 2019)
Resistance of the electrode material play a vital role for applications in supercapacitors, where lowering the resistance leads to improved performance. Poly(3,4-ethylene dioxythiophene) (PEDOT) possesses high theoretical conductivity; however, the high density of grain boundaries, low accessible surface area, and low rate capability have been pervasive issues affecting the PEDOT-based supercapacitors. To this end, a hydrothermal method is proposed in this work where oxygen functional groups incorporated on the surface of carbon nanotubes (CNTs) are utilized to polymerize 3,4-ethylenedioxythiophene (EDOT). PEDOT forms an ultrathin, well-aligned coating on the surface of CNTs. This arrangement minimizes the number of grain boundaries and increases the electrochemically active surface area. Additionally, a shear-thinning Xanthan gum-H2SO4 gel electrolyte is introduced to overcome the low impregnation of the conventional polyvinyl-based electrolyte due to the hydrophobicity of the CNT-PEDOT composite. A supercapacitor based on this material showed a very low Equivalent Series Resistance (ESR) of 0.31 which leads to a high power density of 74 W cm(-3).
Keywords: gel electrolyte; PEDOT; shear thinning; supercapacitor; xanthan gum

Salts and cocrystal of etodolac: advantage of solubility, dissolution, and permeability - Rai, Sunil K.; Allu, Suryanarayana; Nangia, Ashwini K. (Crystal Growth & Design, 2020)
{Etodolac (ETD) is a nonsteroidal anti-inflammatory drug (NSAID) approved by the United States Food and Drug Administration (US-FDA) in 1991 for the treatment of rheumatoid arthritis. Because of its poor aqueous solubility and high permeability, ETD falls under Biopharmaceutics Classification System (BCS) Class II drug. The present study was aimed to screen stable salts and cocrystals of ETD using Generally Recognized as Safe (GRAS) and a few non-GRAS coformers. Crystallization of five salts (i.e.

Scalable synthesis of 3-Ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one: an important building block of the antidiabetic drug glimepiride - Chavan, Subhash P.; Pawar, Ambaji A.; Patil, Niteen B.; Kadam, Appasaheb L.; Shinde, Shrikrishna S. (Synthesis-Stuttgart, 2020)
A four-step, practical, and easily scalable synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one, an important building block of the antidiabetic drug glimepiride, has been accomplished. Key features are the synthesis of 3-methyl-4-hydroxy-2-butenolide in water and triflic acid mediated N-benzyl lactam N-deprotection. The main advantages of this process are the scalable synthetic route and decreased number of reaction steps, which paves the way for the industrial-scale synthesis of 3-ethyl-4-methyl-1,5-dihydro-2H-pyrrol-2-one.
Keywords: antidiabetic drug; Butenolide; glimepiride; lactams; scalable synthesis

Scalable synthesis of manganese-doped hydrated vanadium oxide as a cathode material for aqueous zinc-metal battery - Ghosh, Meena; Dilwale, Swati; Vijayakumar, Vidyanand; Kurungot, Sreekumar (ACS Applied Materials & Interfaces, 2020)
Rechargeable aqueous zinc-metal batteries (ZMBs) are considered as potential energy storage devices for stationary applications. Despite the significant developments in recent years, the performance of ZMBs is still limited due to the lack of advanced cathode materials delivering high capacity and long cycle life. In this work, we report a low-temperature and scalable synthesis method following a surfactant-assisted route for preparing manganese-doped hydrated vanadium oxide (MnHVO-30) and its application as the cathode material for ZMB. The as-prepared material possesses a porous architecture and expanded interlayer spacing. Therefore, the MnHVO-30 cathode offers fast and reversible insertion of Zn2+ ions during the charge/discharge process and delivers 341 mAh g(-1) capacity at 0.1 A g(-1). Moreover, the MnHVO-30 parallel to Zn cell retains 82% of its initial capacity over 1200 stability cycles, which is higher compared to that of the undoped system. Besides, a quasi-solid-state home-made pouch cell with an area of 3.3 x 1.6 cm(2) and 3.6 mg cm(-2) loading is assembled, achieving 115 mAh g(-1) capacity over 100 stability cycles. Therefore, this work provides an easy and attractive way for preparing efficient cathode materials for aqueous ZMBs.
Keywords: anionic surfactant; hydrated vanadium pentoxide; Nafion ionomer membrane; post-lithium battery; quasi-solid-state battery

Screening of zero valent mono/bimetallic catalysts and recommendation of Raney Ni (without reducing agent) for dechlorination of 4-chlorophenol - Raut, Sandesh S.; Shetty, Rohit; Raju, Nikhi Maria; Kamble, Sanjay P.; Kulkarni, Prashant S. (Chemosphere, 2020)
Chlorophenol (CP) is considered as environmentally hazardous material due to its acute toxicity, persistent nature and strong bioaccumulation. The dechlorination of 4-CP was investigated by using various catalysts such as bimetallic (Fe-0/Cu-0, Al-0/Fe-0), Pd/C, Raney Ni and Fe-0 at room temperature. Among the catalysts studied, Raney Ni proved to be very economical and efficient catalyst that worked without the use of an external reducing agent. The dechlorination of 4-CP by Raney Ni was therefore further explored. Complete dechlorination of 4-CP (30 mg L-1) was achieved in 6 hat an optimum Raney Ni catalyst loading of 3 g L-1. The effect of triethylamine (TEA) and tripropylamine (TPA) was also investigated and it was observed that 100% dechlorination is possible in presence of 45 mg L-1 of TEA. The kinetics of dechlorination of 4-CP was investigated and found to be first order with a rate constant of 0.017 min(-1) at 50 degrees C, and it enhances to 0.109 min(-1) with addition of TEA. In the absence of a reducing agent, acidic to neutral pH favors dechlorination of 4-CP. The final product of dechlorination was estimated to be phenol by performing HPLC, LCMS and NMR analysis. Based on the results, a probable dechlorination mechanism of 4-CP is also proposed. It can be concluded that the catalytic hydrodechlorination is an effective and economical technique for dechlorination of 4-CP and it has a potential for the dechlorination of other toxic derivatives of chlorinated aromatics. (C) 2020 Elsevier Ltd. All rights reserved.
Keywords: 4-Chlorophenol; Cl- scavenger; Hydrodechlorination; Raney Ni; Recycling of catalyst; Without reducing agent

Selective, bifunctional Cu-WOx/Al2O3 catalyst for hydrodeoxygenation of fatty acids - Janampelli, Sagar; Sethia, Govind; Darbha, Srinivas (Catalysis Science & Technology, 2020)
Selective hydrodeoxygenation of oleic acid (OA; in a batch reactor, at 300 degrees C, 30 bar H-2 pressure, reaction time of 1 h and reactant-to-catalyst weight ratio of 2 g OA/0.2 g) forming n-octadecane in yields as high as 93% over a non-noble metal, sulfur-free, bimetallic Cu-WOx/Al2O3 catalyst is reported for the first time. Several Cu-WOx/Al2O3 compositions were prepared by a sequential wet-impregnation method and evaluated. A catalyst with 10 wt% Cu and 4 wt% W enabled the highest activity and selectivity. Upon adding WOx, the amount of moderate and strong acid sites increased and more Cu in the catalyst was in reduced electron-rich metallic (Cu-0) state. The crystallite size and dispersion of Cu were little affected. WOx promoted the fatty acid hydrodeoxygenation activity of Cu. While a monometallic Cu catalyst (10Cu/Al2O3) yielded n-octadecane and n-heptadecane along with high amounts of intermediate octadecanol and octadecanal products, the bimetallic catalyst (10Cu-4WO(x)/Al2O3) gave mainly n-octadecane. Acidity and the high amount of reduced Cu-0 species are responsible for the high catalytic hydrodeoxygenation performance of this bimetallic catalyst.

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

Selectivity engineering of Meerwein arylation in a continuous flow reactor: a modelling approach - Shukla, Chinmay A.; Atapalkar, Ranjit S.; Kulkarni, Amol A. (Reaction Chemistry & Engineering, 2020)
This paper presents a methodology for selectivity engineering of Meerwein arylation in a flow reactor. The reaction was optimized in batch mode and reaction kinetics were obtained over a range of temperatures and catalyst concentrations. A lumped kinetic model was formulated and the parameters were estimated using nonlinear regression. Furthermore, telescopic flow synthesis for Meerwein arylation via in situ diazonium salt generation and coupling was demonstrated. A non-isothermal model was developed and experimentally validated. The effect of initial concentration and inlet temperature on the yield of the desired product was estimated for various catalyst concentrations. The results from the simulations in terms of nondimensional numbers were used to find suitable operating conditions for Meerwein arylation.

Self-assembled helical arrays for the stabilization of the triplet state - Nidhankar, Aakash D.; Goudappagouda; Kumari, Divya S. Mohana; Chaubey, Shailendra Kumar; Nayak, Rashmi; Gonnade, Rajesh G.; Kumar, G. V. Pavan; Krishnan, Retheesh; Babu, Sukumaran Santhosh (Angewandte Chemie-International Edition, 2020)
Room-temperature phosphorescence of metal and heavy atom-free organic molecules has emerged as an area of great potential in recent years. A rational design played a critical role in controlling the molecular ordering to impart efficient intersystem crossing and stabilize the triplet state to achieve room-temperature ultralong phosphorescence. However, in most cases, the strategies to strengthen phosphorescence efficiency have resulted in a reduced lifetime, and the available nearly degenerate singlet-triplet energy levels impart a natural competition between delayed fluorescence and phosphorescence, with the former one having the advantage. Herein, an organic helical assembly supports the exhibition of an ultralong phosphorescence lifetime. In contrary to other molecules, 3,6-phenylmethanone functionalized 9-hexylcarbazole exhibits a remarkable improvement in phosphorescence lifetime (>4.1 s) and quantum yield (11 %) owing to an efficient molecular packing in the crystal state. A right-handed helical molecular array act as a trap and exhibits triplet exciton migration to support the exceptionally longer phosphorescence lifetime.
Keywords: carbazole; helicity; phenylmethanone; ultralong phosphorescence; waveguiding

Self-assembly of bispentadecylphenol substituted perylenediimide with PS-b-P4VP for structure-property insight into the core of core-shell micelles - Roy, Moumita; Rajamohanan, Pattuparambil R.; Ravindranathan, Sapna; Asha, S. K. (ACS Applied Polymer Materials, 2020)
We report the use of a ditopic molecular probe bispentadecylphenol substituted perylenediimide (PBI-PDP) to examine the molecular level self-assembly of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) in tetrahydrofuran (THF). A series of complexes were prepared between PS-b-P4VP copolymers with varying lengths of the 4-vinylpyridine chain and PBI-PDP. Light scattering and NMR spectroscopic studies reveal that the self-assembled structures of the solid complexes are not fully disrupted when the complexes are dissolved in THF. NMR experimental parameters measured for the small probe molecule provide detailed insights into the structure of the assemblies in solution as well as the interaction between the small molecule and the block copolymer. Such insights can have important implications in manipulating the nanostructure of block copolymer micelles to suit various application requirements. The dynamics and distribution of the PBI-PDP molecules within the assemblies in solution show a dependence on the length of the P4VP block. Transmission electron microscopy was employed to study the evolution of morphologies in films prepared from the self-assembled structures in THF solutions.
Keywords: core corona interface; ditopic molecular probe; environment; micelles; perylenediimide; PS-b-P4VP; Self-assembly

Self-assembly of novel Fmoc-cardanol compounds into hydrogels - analysis based on rheological, structural and thermal properties - Kadeeja, Aliya; Joseph, Seena; Abraham, Jancy Nixon (Soft Matter, 2020)
Hydrogels of low molecular weight molecules are particularly appealing for various biomedical applications such as drug delivery, tissue engineering, and antitumor therapy due to their excellent biocompatibility, biodegradability, and easy availability. Fmoc-peptide hydrogels form an essential category of these hydrogels. Herein we report a new class of Fmoc hydrogels in which cardanol (3-pentadecyl phenol (PDP)) is covalently linked with fluorenylmethyloxycarbonyl group. Cardanol is a plant-based renewable raw material, readily obtained from Cashew Nut Shell Liquid (CNSL). The long aliphatic chain of pentadecyl phenol helps in bringing a structural incompatibility and generates different nanostructures such as nanospheres, nanotapes, and nanofibers depending on Fmoc substitution and the solvents used. Stable hydrogels were formed from Fmoc-PDP in DMSO/H2O, and the critical aggregation concentration (CAC) and critical gelation concentration (CGC) were determined. The role of non-covalent forces such as hydrogen-bonding, hydrophobicity, and pi-pi stacking interactions in governing self-assembly to hydrogel formation was studied for Fmoc, DiFmoc and Boc groups attached to PDP. The thermal properties were analyzed, and smectic and nematic phases were identified for the molecules depending on the substitutions involved. Overall the study supports the mechanisms of aggregation and gelation in novel Fmoc-cardanol derivatives.

Shape resonance of sulphur dioxide anion excited states using the CAP-CIP-FSMRCCSD method - Basumallick, Suhita; Bhattacharya, Sumantra; Jana, Irina; Vaval, Nayana; Pal, Sourav (Molecular Physics, 2020)
We have studied the shape resonance of excited states of sulphur dioxide (SO2) anion by using the correlated independent particle Fock space multi-reference coupled cluster (CAP-CIP-FSMRCCSD) method augmented by complex absorption potential. These resonant states have been trapped experimentally in recent years by electron collision. In particular, we have investigated e(-)-SO2 scattering and computed the negative-ion resonance states of the anion responsible for the two resonances around 4.45 and 6.56 eV and compared the results with the existing experimental observations. From the computational results using the CAP-CIP-FSMRCCSD method, it has been observed that both the resonances near 4.45 and 6.56 eV result from A(1) symmetries. [GRAPHICS] .
Keywords: CAP augmented correlated independent particle (CAP-CIP-FSMRCCSD); complex absorption potential (CAP); coupled cluster; Fock space multireference coupled cluster (FSMRCCSD); shape resonance

"Shape-coding'': morphology-based information system for polymers and composites - Pansare, V, Amol; Chhatre, Shraddha Y.; Khairkar, Shyam R.; Bell, Jeffrey G.; Barbezat, Michel; Chakrabarti, Subhananda; Nagarkar, Amit A. (ACS Applied Materials & Interfaces, 2020)
Fiber-reinforced composites have become the material of choice for aerospace structures because of their favorable strength-to-weight ratio. Given the increasing amounts of counterfeit composite parts showing up in the complex aerospace supply chain, it is absolutely vital to track a composite part throughout its lifecycle-from production to usage and to disposal. Existing barcoding methods are invasive, affect the structural properties of composites, and/or are vulnerable to tampering. We describe a universal method to store information in fiber-reinforced composites based on solid-state in situ reduction leading to embedded nanoparticles with controlled morphologies. This simple, cost-effective, mild, surfactant-free, and one-step protocol for the fabrication of embedded platinum nanostructures leads to morphology-based barcodes for polymeric composites. We also describe a coding methodology wherein a 1 x 1 cm code can represent 3.4 billion parts to 95 trillion parts, depending on the resolution required along with access to morphology-based chemical encryption systems.
Keywords: barcoding chemical encryption; epoxy composites; nanoparticle morphology control; solid-state synthesis