Synthesis and electrochemistry of pseudocapacitive multilayer fullerenes and MnO2 nanocomposites - Azhagan, Muniraj Vedi Kuyil; Vaishampayan, Mukta V.; Shelke, Manjusha V. (Journal of Materials Chemistry A, 2014)
Electrode materials with efficient capabilities for ionic and electronic transport are key to high performance supercapacitors. Here, we demonstrate a simple and comparatively low temperature synthesis of functionalized multilayer fullerenes so called carbon nano-onions (CNOs) as the electrode for high performance electrochemical supercapacitors. The exohedral type supercapacitor formed due to nonporous CNOs showed higher specific capacitance than conventional graphitic/mesoporous/activated carbons. Surface redox functionalities of these CNOs add up to significant pseudocapacitance. Further in situ incorporation of MnO2 nanoparticles to these CNOs increased the specific capacitance up to 1207 F g(-1), which is close to the theoretical value of pseudocapacitive MnO2.

Synthesis, characterization and photocatalytic behavior of TiO2-SiO2 mesoporous composites in hydrogen generation from water splitting - Niphadkar, P. S.; Chitale, S. K.; Sonar, S. K.; Deshpande, Suvarna S.; Joshi, P. N.; Awate, S. V. (Journal of Materials Science, 2014)
TiO2-SiO2 mesoporous composite photocatalysts with different proportions (in wt%) of TiO2 and SiO2 (TiO2-SiO2 = 20:80, 40:60, 60:40, 80:20 and 100:0) were prepared by loading TiO2 on as-synthesized Si-MCM-41 using sol-gel method. The physicochemical properties of composites were investigated by powder X-ray diffraction, N-2 adsorption-desorption measurements, transmission electron microscopy and UV-Vis diffuse reflectance spectroscopy. It is revealed that the titanium species are dispersed as TiO2 having interaction with the surface of the support. Even at high TiO2 loading, the mesostructural feature of MCM-41 was found to be intact without pore blockages. The change in morphology of TiO2 particle was observed with increase in TiO2 loading which may be due to different environment for the growth of TiO2. The photocatalytic evaluation of composites was carried out in production of hydrogen by water splitting. Among the prepared samples, mesoporous composite containing 60 % TiO2 (MTi60) has shown the best results (0.08805 mmol of H-2/h/g of TiO2) compared to other composite photocatalysts. The catalytic performance of this sample was further enhanced (similar to 8 times) after loading 1 % Pt in water splitting (0.70161 mmol of H-2/h/g of TiO2). 1 % Pt loaded on pure TiO2 (MTi100) showed hydrogen evolution of the magnitude 0.26 mmol of H-2/h/g of TiO2. TiO2-SiO2 mesoporous composite photocatalyst showed much higher activity (similar to 1.9 times) than amorphous silica-embedded titania catalyst having same composition.

Synthesis of chenopanone - Deore, Prashant S.; N. P. Argade (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2014)
Starting from glyoxalic acid, a facile three step approach to chenopanone has been described utilizing the Barbier reaction as a key step.
Keywords: acid hydrolysis; Barbier reaction; chenopanone; condensation; Glyoxalic acid; isovaleraldehyde; synthesis

Synthesis of (+)-harmicine - Mondal, Pravat; N. P. Argade (Synthesis-Stuttgart, 2014)
A facile convergent access to the important indole alkaloid (+)-harmicine is described, starting from tryptamine and (R)-acetoxysuccinic anhydride via the corresponding acetoxysuccinimide in very good overall yield. Regioselective reduction of an unsymmetrical imide carbonyl group and acid-catalyzed stereoselective intramolecular cyclization were the key features involved. The directing group to induce asymmetry was finally detached via the corresponding iodide by using tributyltin hydride chemistry.
Keywords: alkaloids; cyclization; imides; reduction; stereoselective synthesis

Synthetic precursor to vertical TiO2 nanowires - Mishra, Biswajit; Ghildiyal, P.; Agarkar, Shruti A.; Khushalani, Deepa (Materials Research Express, 2014)
An easy protocol for improvement in formation of the photoanode in a dye sensitized solar cell is addressed. Specifically, a novel synthesis for the formation of a TiO2 precursor: titanium butanediolate, is detailed. This precursor is found to have higher thermal and temporal stability than commercially available TiO2 precursors and it has successfully been employed in the one-pot synthesis of rutile nanowires grown directly on a conducting substrate: fluorine doped tin oxide (FTO). This synthesis has been further extended to directly form a mixed phase TiO2 film consisting of rutile nanowires along with anatase spherical particles on FTO and this assembly has been used as the photoanode in a dye-sensitized solar cell. The synergistic effect of the two phases has provided a net DSSC efficiency of 4.61% with FF = 61%.
Keywords: Nanomaterials; Nanowires; TiO2

Titania nanoparticles stabilized HPA in SBA-15 for the intermolecular hydroamination of activated olefins - Sawant-Dhuri, Dhanashri; Balasubramanian, Veerappan V.; Ariga, Katsuhiko; Park, Dae-Hwan; Choy, Jin-Ho; Cha, Wang Soo; Al-deyab, Salem S.; Halligudi, Shivappa B.; Vinu, Ajayan (ChemCatChem, 2014)
A liquid phase hydroamination (HA) of alpha,beta-ethylenic compounds with amines was investigated with TiO2 nanoparticles stabilized 12-tungstophosphoric acid (TPA) in SBA-15. The catalysts were prepared by wet impregnation of TPA/TiO2 nanoparticles into the SBA-15 and calcined at different temperatures. The characterization results reveal that the textural properties and the acidity of the prepared catalysts can be finely controlled with the simple adjustment of the calcination temperature and the structure of the support, decorated with the TiO2 and TPA nanoparticles, was intact even after the modification. The prepared catalysts were investigated for HA of ethyl acrylate with different aromatic and aliphatic amines over a wide range of reaction conditions to optimize the yield and the selectivity of product. It was found that this process is 100% atom efficient and the catalytic performance depended significantly on the loading of TPA over the catalyst and the calcination temperature. Under optimized reaction conditions, the best catalyst, 15 wt% TPA/22.4 wt% TiO2/SBA-15 calcined at 1123 K, offered the highest conversion of p-ethylaniline (70%) with 100% chemo-selectivity to the anti-Markovnikov product, i.e., the mono-addition product. The reaction was heterogeneously catalyzed and no contribution from leached TPA into the reaction was observed.
Keywords: heteropoly acids; hydroamination; mesoporous materials; nanocatalysts

3D polyaniline porous layer anchored pillared graphene sheets: enhanced interface joined with high conductivity for better charge storage applications - Sekar, Pandiaraj; Anothumakkool, Bihag; Kurungot, Sreekumar (ACS Applied Materials & Interfaces, 2015)
Here, we report synthesis of a 3-dimensional (3D) porous polyaniline (PANI) anchored on pillared graphene (G-PANI-PA) as an efficient charge storage material for supercapacitor applications. Benzoic acid (BA) anchored graphene, having spatially separated graphene layers (G-Bz-COOH), was used as a structure controlling support whereas 3D PANI growth has been achieved by a simple chemical oxidation of aniline in the presence of phytic acid (PA). The BA groups on G-Bz-COOH play a critical role in preventing the restacking of graphene to achieve a high surface area of 472 m(2)/g compared to reduced graphene oxide (RGO, 290 m(2)/g). The carboxylic acid (-COOH) group controls the rate of polymerization to achieve a compact polymer structure with micropores whereas the chelating nature of PA plays a crucial role to achieve the 3D growth pattern of PANI. This type of controlled interplay helps G-PANI-PA to achieve a high conductivity of 3.74 S/cm all the while maintaining a high surface area of 330 m(2)/g compared to PANI-PA (0.4 S/cm and 60 m(2)/g). G-PANI-PA thus conceives the characteristics required for facile charge mobility during fast charge-discharge cycles, which results in a high specific capacitance of 652 F/g for the composite. Owing to the high surface area along with high conductivity, G-PANI-PA displays a stable specific capacitance of 547 F/g even with a high mass loading of 3 mg/cm(2), an enhanced areal capacitance of 1.52 F/cm(2), and a volumetric capacitance of 122 F/cm(3). The reduced charge-transfer resistance (RCT) of 0.67 O displayed by G-PANI-PA compared to pure PANI (0.79 O) stands out as valid evidence of the improved charge mobility achieved by the system by growing the 3D PANI layer along the spatially separated layers of the graphene sheets. The low RCT helps the system to display capacitance retention as high as 65% even under a high current dragging condition of 10 A/g. High charge/discharge rates and good cycling stability are the other highlights of the supercapacitor system derived from this composite material.
Keywords: durability; ionic accessibility; phytic acid; pillaring; polyaniline; restacking

Abiotic stress induces change in cinnamoyl CoA reductase (CCR) protein abundance and lignin deposition in developing seedlings of Leucaena leucocephala - Srivastava, Sameer; Vishwakarma, Rishi K.; Arafat, Yasir Ali; Gupta, Sushim K.; Khan, Bashir Mohammad (Physiology and Molecular Biology of Plants, 2015)
Aboitic stress such as drought and salinity are class of major threats, which plants undergo through their lifetime. Lignin deposition is one of the responses to such abiotic stresses. The gene encoding Cinnamoyl CoA Reductase (CCR) is a key gene for lignin biosynthesis, which has been shown to be over-expressed under stress conditions. In the present study, developing seedlings of Leucaena leucocephala (Vernacular name: Subabul, White popinac) were treated with 1 % mannitol and 200 mM NaCl to mimic drought and salinity stress conditions, respectively. Enzyme linked immunosorbant assay (ELISA) based expression pattern of CCR protein was monitored coupled with Phlorogucinol/HCl activity staining of lignin in transverse sections of developing L. leucocephala seedlings under stress. Our result suggests a differential lignification pattern in developing root and stem under stress conditions. Increase in lignification was observed in mannitol treated stems and corresponding CCR protein accumulation was also higher than control and salt stress treated samples. On the contrary CCR protein was lower in NaCl treated stems and corresponding lignin deposition was also low. Developing root tissue showed a high level of CCR content and lignin deposition than stem samples under all conditions tested. Overall result suggested that lignin accumulation was not affected much in case of developing root however developing stems were significantly affected under drought and salinity stress condition.

Advances and recent applications in LC-MS and HPLC - Azharuddin, Quazi Syed; Mahajan, Devidas T.; Masand, Vijay H.; Alafeefy, Ahmed M.; Gajbhiye, Jayant M.; El-Sayed, Nahed Nasser Eid; Wajid, Abdul; Mohammad, Noor (Elsevier, 2015)
Advances and Recent Applications in LC-MS and HPLC presents the most recent developments in liquid chromatography and mass spectrometry techniques. The book’s content reaches across a range of disciplines and cites several case studies to effectively capture the advanced applications that make LC-MS and HPLC multifunctional and exacting techniques. Liquid chromatography and mass spectrometry systems generate chromatograms of column peaks and can provide molecular weights of separated materials and their solvent complexes. However, while these systems can provide structural information to confirm the identity of the compounds separated, the process is very expensive. This book provides identification of simple compounds resulting from fragmentation studies and their subsequent results, offering the reader access to information unavailable elsewhere and allowing researchers to avoid incurring the costs associated with obtaining the hands-on results that LC-MS systems generate. Applicable to chemical analysis, bioanalysis, and medicinal chemistry, as well as pharmaceutical science, synthetic chemistry, and industrial chemistry, Advances and Recent Applications in LC-MS and HPLC is a multidisciplinary reference that arms scientists with the latest research. Detailed case studies enable researchers to make the book's concepts immediately implementable.

Alumina-supported copper iodide: an efficient and recyclable catalyst for microwave-assisted synthesis of 1,4-disubstituted 1,2,3-triazoles via three-component reaction in water - Agalave, Sandip G.; Pharande, Shrikant G.; Gade, Swapna M.; Pore, Vandana S. (Asian Journal of Organic Chemistry, 2015)
A one-pot procedure for the synthesis of 1,4-disubstituted 1,2,3-triazoles by a three-component reaction of allyl or benzyl halides, sodium azide, and terminal alkynes over a neutral alumina-supported copper iodide catalyst has been developed. The products were isolated by simple filtration followed by washing of the catalyst with acetone. The products were obtained in almost pure form in up to 98% yield (TON 495). The catalyst can be recycled for more than eight subsequent reactions. The halides are directly converted into triazoles via in situ formation of azides and thus handling of hazardous azides can be avoided. The broad scope of this protocol is shown by the synthesis of a variety of diversely substituted 1,2,3-triazoles and also two-component azide-alkyne click reaction. The key features of this procedure are the use of water as a solvent, recyclability of the catalyst up to eight runs without appreciable loss of activity, and high yields of products. The catalyst has been fully characterized by FTIR, solid-state NMR and EDX spectroscopy, ESEM, TGA, and XRD.
Keywords: 1; 2; 3-triazoles; 4; copper(I) iodide; Cycloaddition; disubstituted 1; Microwave chemistry; supported catalysts

Analyzing different acetyl co-a metabolizing enzymes as potential drug targets against mycobacterium tuberculosis - Akhtar, Shamim; Singh, Sheetal; Kumar, Santosh; Sarkar, Dhiman (British Microbiology Research Journal, 2015)
Mycobacterium tuberculosis, the causative agent of tuberculosis, is responsible for the deaths of million people around the globe. The scenario is worse than ever due to the emergence of drug resistant strains which are widely spread throughout the globe in much faster ways. To control this worst situation, we need to speed up the search for novel drugs which can specifically kill drug resistant bacteria in collaborative ways amongst academic, clinician and industry. Among different metabolic pathways, fatty acid synthesis pathway has always been a very attractive area for the drug target because of its crucial role during the infection and further in long term survival of pathogen inside the human host. In this review article, we analyzed the role of important and crucial enzymes, which are responsible for the influx and efflux of acetyl co-A substrate, a central hub of metabolites, as potential drug targets against M. tuberculosis.

Antimycobacterium activity of coumarins from fruit pulp of aegle marmelos (L.) correa - Chinchansure, Ashish A.; Shamnani, Neelam; Arkile, Manisha A.; Sarkar, Dhiman; Joshi, Swati P. (International Journal of Basic and Applied Chemical Sciences, 2015)
Phytochemical investigation of n-butanol fraction of acetone extract of Aegle marmelos fruit has afforded four compounds coumarins marmelosin (1), marmin (2) and xanthotoxol (3) and flavonoid kaempferol 3- O-rhamnoside, afzelin (4). All the isolated compounds were evaluated for their antimycobacterium activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis. Compounds 1 and 2 exhibited antimycobacterium activity against M. tuberculosis H37Ra with an IC50 12.46 µg/mL and 4.31 µg/mL respectively whereas, at 100 µg/mL, 62.5% and 82.4% growth inhibition of M. bovis was observed respectively. Compounds 1 and 2 were also evaluated against two gram positive bacteria Staphylococcus aureus, Bacillus subtilis and one gram negative bacteria Escherichia coli. Compound 1 at 100 µg/mL, showed growth inhibition, 64.6% and 74.9% of E. coli and B. subtilis respectively.

Architecturally designed Pt-MoS2 and Pt-graphene composites for electrocatalytic methanol oxidation - Patit, Sagar H.; Anothumakkool, Bihag; Sathaye, Shivaram D.; Patil, Kashinath R. (Physical Chemistry Chemical Physics, 2015)
Thin films consisting of platinum nanoparticles (Pt NPs) with uniform size and distribution have been successfully prepared at a liquid-liquid interface. Apart from the usual substrates like glass, Si etc. the films were also deposited on the surfaces of MoS2 thin films and graphene nanosheets (GNS) respectively, by using a layer-by-layer (LbL) deposition technique to form Pt-MoS2 and Pt-GNS composites. The loading concentration of Pt NPs on MoS2 and GNS can be adjusted by selecting the number and sequence of the component layers during LbL deposition. The Pt thin films, Pt-MoS2 and Pt-GNS nanocomposite thin films are characterized using transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). TEM results of the composites show that Pt NPs with sizes in the range of 1 to 3 nm are uniformly dispersed on the MoS2/GNS surface. The catalytic activities of Pt and Pt-composites for the reaction of methanol oxidation are studied using cyclic voltammetry and chronoamperometry. Electrochemical studies reveal that both the Pt-MoS2 and Pt-GNS nanocomposites show excellent electrocatalytic activity towards methanol oxidation. Pt-MoS2 and Pt-GNS nanocomposite electrodes show excellent stability for reuse of the catalyst. A probable mechanism of catalysis has been discussed. We propose that the similar architecture reported here would be promising for the synthesis of high performance catalysts for fuel cells, gas phase reactions, and other applications such as sensors.

Bacopa monniera recombinant mevalonate diphosphate decarboxylase: biochemical characterization - Shakeel Abbassi; Vishwakarma, Rishi K.; Patel, Parth; Kumari, Uma; Khan, Bashir Mohammad (International Journal of Biological Macromolecules, 2015)
Mevalonate diphosphate decarboxylase (MDD; EC 4.1.1.33) is an important enzyme in the mevalonic acid pathway catalyzing the Mg2+-ATP dependant decarboxylation of mevalonate 5-diphosphate (MVAPP) to isopentenyl diphosphate (IPP). Bacopa monniera recombinant MDD (BmMDD) protein was overexpressed in Escherichia coli BL21 (DE3) strain and purified to apparent homogeneity. K-m and V-max for MVAPP were 144 mu M and 52 U mg(-1) respectively. The values of turnover (k(cat)) and k(cat)/K-m, for mevalonate 5-diphosphate were determined to be 40 s(-1) and 2.77 x 10(5) M-1 s(-1) and k(cat) and k(cat)/K-m values for ATP were found to be 30 s(-1) and 2.20 x 10(4) M-1 s(-1), respectively. pH activity profile indicated the involvement of carboxylate ion, lysine and arginine for the activity of enzyme. The apparent activation energy for the BmMDD catalyzed reaction was 12.7 kJ mol(-1). Optimum pH and temperature for the forward reaction was found to be 8.0 and 45 degrees C. The enzyme was most stable at pH 7 at 20 degrees C with the deactivation rate constant (K-d(*)) of 1.69 x 10(-4) and half life (t(1/2)) of 68 h. The cation studies suggested that BmMDD is a cation dependant enzyme and optimum activity was achieved in the presence of Mg2+. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Mevalonate diphosphate decarboxylase; pH activity profile; Phylogenetic analysis; stability

Bile acid hydrazides: gelation, structural, physical and spectroscopic properties - Pore, Vandana S.; Agalave, Sandip G.; Pharande, Shrikant G.; Patil, Prashant A.; Kotmale, Amol S. (New Journal of Chemistry, 2015)
Synthesis and gelation properties of a series of novel bile acid hydrazides are presented. These compounds are found to undergo self-assembly leading to organogelation in certain organic solvents. Compound 1 was found to be the most ``effective'' gelator in this series. The properties of this gel have been thoroughly investigated by conventional methods typical for molecular gel studies. Sol gel transition temperature (T-g) of chloroform gels of compounds 1 and 3 was found to increase with increase in the chain length. Sol-gel transition was probed using the isothermal time test and results show that there is instantaneous increase in both the moduli after shear melting, which suggests that the kinetics of formation of the network was very fast. IR and NMR studies revealed hydrogen bonding between amidic carbonyl in the side chain and hydroxyl groups of cholic acid.

Bioactive thermoresponsive polyblend nanofiber formulations for wound healing - Pawar, Mahesh D.; Rathna, G. V. N.; Agrawal, Shubhang; Kuchekar, Bhanudas S. (Materials Science & Engineering C-Materials for Biological Applications, 2015)
The rationale of this work is to develop new bioactive thermoresponsive polyblend nanofiber formulations for wound healing (topical). Various polymer compositions of thermoresponsive, poly(N-isopropylacrylamide), egg albumen and poly(epsilon-caprolactone) blend solutions with and without a drug [gatifloxacin hydrochloride, Gati] were prepared. Non-woven nanofibers of various compositions were fabricated using an electrospinning technique. The morphology of the nanofibers was analyzed by an environmental scanning electron microscope. The morphology was influenced by the concentration of polymer, drug, and polymer blend composition. Fourier transform infrared spectroscopy analysis showed the shift in bands due to hydrogen ion interactions between polymers and drug. Thermogram of PNIPAM/PCL/EA with Gati recorded a shift in lower critical solution temperature (LCST) and glass transition temperature (T-g) of PNIPAM. Similarly T-g and melting temperature (T-m) of PCL were shifted. X-ray diffraction patterns recorded a decrease in the crystalline state of PCL nanofibers and transformed crystalline drug to an amorphous state. In vitro release study of nanofibers with Gati showed initial rapid release up to 10 h, followed by slow and controlled release for 696 h (29 days). Nanofiber mats with Gati exhibited antibacterial properties to Staphylococcus aureus, supported suitable controlled drug release with in vitro cell viability and in vivo wound healing. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Antibacterial; Cell viability; drug release; nanofibers; thermoresponsive; wound Healing

Biochemical characterization of recombinant mevalonate kinase from Bacopa monniera - Kumari, Uma; Vishwakarma, Rishi K.; Sonawane, Prashant; Shakeel Abbassi; Khan, Bashir Mohammad (International Journal of Biological Macromolecules, 2015)
Mevalonate kinase (MK; ATP: mevalonate 5-phosphotransferase; EC 2.7.1.36) plays a key role in isoprenoid biosynthetic pathway in plants. MK catalyzes the phosphorylation of mevalonate to form mevalonate-5-phosphate. The recombinant BmMK was cloned and over-expressed in E. coli BL21 (DE3), and purified to homogeneity by affinity chromatography followed by gel filtration. Optimum pH and temperature for forward reaction was found to be 7.0 and 30 degrees C, respectively. The enzyme was most stable at pH 8 at 25 degrees C with deactivation rate constant (Kd*) 1.398 x 10(-4) and half life (t(1/2)) 49 h. pH activity profile of BmMK indicates the involvement of carboxylate ion, histidine, lysine, arginine or aspartic acid at the active site of enzyme. Activity of recombinant BmMK was confirmed by phosphorylation of RS-mevalonate in the presence of Mg2+, having K-m and V-max 331.9 mu M and 719.1 pKat mu g(-1), respectively. The values of k(cat) and k(cat)/K-m for RS-mevalonate were determined to be 143.82 s(-1) and 0.43332 M-1 s(-1) and k(cat) and k(cat)/K-m values for ATP were found 150.9 s(-1) and 1.023 M-1 s(-1). The metal ion studies suggested that BmMK is a metal dependent enzyme and highly active in the presence of MgCl2. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Bacopa monniera; Enzyme kinetics; Mevalonate kinase; stability

Biomimetic synthesis of phaitanthrin e involving a fragmentation of sp(3) carbon-carbon bond: synthesis and rearrangement of phaitanthrin D to phaitanthrin E - Vaidya, Sagar D.; N. P. Argade (Organic Letters, 2015)
A biogenetic type total synthesis of alkaloids phaitanthrin D and phaitanthrin E has been described. The Csp(3)-Csp(3) bond cleavage with the release of several heteroatoms bearing unexpected leaving groups in intramolecular substitution reactions on an iminium double bond in the quinazolinones has been demonstrated using HMDS/ZnCl2 or NaHMDS. The mechanistic aspects have been supported by isolation and characterization of appropriate intermediates.

c Squalene synthase gene from medicinal herb bacopa monniera: molecular characterization, differential expression, comparative modeling, and docking studies - Vishwakarma, Rishi K.; Patel, Krunal; Sonawane, Prashant; Kumari, Uma; Singh, Somesh; Ruby; Shakeel Abbassi; Agrawal, Dinesh C.; Tsay, Hsin-Sheng; Khan, Bashir Mohammad (Plant Molecular Biology Reporter, 2015)
The widespread pharmaceutically important triterpenoid saponins are synthesized via isoprenoid pathway. The formation of squalene is the key regulatory point in triterpene biosynthesis, catalyzed by squalene synthase (SQS). The present study deals with the detailed characterization of SQS by molecular, biochemical, and computational means from Bacopa monniera, an immensely important medicinal plant rich in triterpenoid saponin, bacosides. A full-length SQS gene was isolated from B. monniera, characterized as B. monniera squalene synthase (BmSQS) (1242 bp) encoding 414 amino acids. Deduced amino acid sequence of BmSQS showed highly conserved consensus aspartate-rich motifs (DXXXD) and catalytic site residues. Phylogenetic analysis showed that BmSQS belongs to dicot group having closest relationship with Salvia miltiorrhiza. Semiquantitative and real-time PCR studies showed that the BmSQS messenger RNA (mRNA) expression level was higher in vegetative parts (roots) as compared to floral parts. Methyl jasmonate induces the BmSQS mRNA expression in all tissues tested, while salicylic acid, cold, and salt induce much higher expression in roots. Homology modeling and docking simulations of BmSQS showed the pivotal roles of Asp77, Asp81, Asp213, Asp217, and Tyr168 in catalysis.
Keywords: Abiotic stress; Bacopa monniera; Comparative modeling and docking; Differential expression; Isoprenoid pathway; Squalene synthase

Chemical and biological metal nanoparticles as antimycobacterial agents: a comparative study - Singh, Richa; Nawale, Laxman U.; Arkile, Manisha A.; Shedbalkar, Utkarsha U.; Wadhwani, Sweety A.; Sarkar, Dhiman; Chopade, Balu Ananda (International Journal of Antimicrobial Agents, 2015)
Resistance among mycobacteria leading to multidrug-resistant and extensively drug-resistant tuberculosis is a major threat. However, nanotechnology has provided new insights in drug delivery and medicine development. This is the first comparative report to determine the activity of chemically and biologically synthesised silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) against mycobacteria. Screening data revealed the high mycobactericidal efficiency of AgNPs, with minimum inhibitory concentrations (MICs) of <3 mu g/mL, whereas no such activity was exhibited by AuNPs at concentrations up to 100 mu g/mL. Moreover, in vitro and ex vivo THP-1 infection model assays showed greater efficacy of chemical AgNPs compared with biogenic AgNPs to inhibit active and dormant stage mycobacterial growth. Up to 40% cytotoxicity against human cell lines was observed at a AgNP concentration of 10 x MIC (30 mu g/mL) after 48 h. AgNPs were shown to have more specificity towards mycobacteria than towards other Gram-negative and Gram-positive pathogenic bacteria. The selectivity index was found to be in the range of 11-23, indicating the potential of these nanoparticles for use in developing new therapeutics for tuberculosis. (C) 2015 Elsevier B.V. and the International Society of Chemotherapy. All rights reserved.
Keywords: Antibiotic resistance; Antimycobacterial agent; Cytotoxicity; Mycobacteria; Nanoparticles; tuberculosis

Chemical sensing in two dimensional porous covalent organic nanosheets - Das, Gobinda; Biswal, Bishnu P.; Kandambeth, Sharath; Venkatesh, V.; Kaur, Gagandeep; Addicoat, Matthew A.; Heine, Thomas; Verma, Sandeep; Banerjee, Rahul (Chemical Science, 2015)
Two new imide-based crystalline, porous, and chemically stable covalent organic frameworks (COFs) (TpBDH and TfpBDH) have been successfully synthesized employing solvothermal crystallization route. Furthermore, thin layered covalent organic nanosheets (CONs) were derived from these bulk COFs by the simple liquid phase exfoliation method. These 2D CONs showcase increased luminescence intensity compared to their bulk counterparts (COFs). Notably, TfpBDH-CONs showcase good selectivity and prominent, direct visual detection towards different nitroaromatic analytes over TpBDH-CONs. Quite interestingly, TfpBDH-CONs exhibit a superior ``turn-on'' detection capability for 2,4,6-trinitrophenol (TNP) in the solid state, but conversely, they also show a ``turn-off'' detection in the dispersion state. These findings describe a new approach towards developing an efficient, promising fluorescence chemosensor material for both visual and spectroscopic detection of nitroaromatic compounds with very low [10(-5) (M)] analyte concentrations.

Chemically chargeable photo battery - Thimmappa, Ravikumar; Paswan, Bhuneshwar; Gaikwad, Pramod; Devendrachari, Mruthyunjayachari Chattanahalli; Kotresh, Harish Makri Nimbegondi; Mohan, Ramsundar Rani; Alias, Joy Pattayil; Thotiyl, Musthafa Ottakam (Journal of Physical Chemistry C, 2015)
Here we show a surrogate strategy for power production, wherein light is used to actuate a discharge Chemistry in the cathode of an aqueous rechargeable battery (ARB). The proposed photo battery consists of a titaninm nitride photoanode, promising. cathode:material iron(III) hexacyanoferrate(II) as the battery active species, and Na2S2O8 as the chemical charging agent The photo battery delivered negligible capacity in the dark and the capacity shot up to 77.8 mAh/g when artificially shined light, confirming that the battery chemistry is light driven. In the ambient light, the device retained 72% of its artificial light discharge capacity with a stable cycling for more than 100 cycles. Further, an unprecedented means for charging the battery rapidly is presented using Na2S2O8 and it revitalized the battery in 30 s without any external bias. This methodology of expending a photoanode extends to a battery that is free from dissolution of active materials, irreversible structural changes, spontaneous deinsertion reactions, and safety concerns commonly encountered in the state of the art anode materials in ARBs. Apart from bringing out a sustainable way for power production, this device opens up avenues for charging the battery in the likely events of electrical input unavailability, while solving the critcial issues of longer charging time and higher charging voltage.

Chemoenzymatic collective synthesis of optically active hydroxyl(methyl)tetrahydronaphthalene-based bioactive terpenoids - Batwal, Ramesh U.; N. P. Argade (Organic & Biomolecular Chemistry, 2015)
Starting from succinic anhydride and 2-methylanisole, a chemoenzymatic collective formal/total synthesis of several optically active tetrahydronaphthalene based bioactive natural products has been presented via advanced level common precursors; the natural product and antipode (-)/(+)-aristelegone B. Regioselective benzylic oxidations, stereoselective introduction of hydroxyl groups at the alpha-position of ketone moiety in syn-orientation, efficient enzymatic resolutions with high enantiomeric purity, stereoselective reductions, samarium iodide induced deoxygenations and tandem acylation-Wittig reactions without racemization and/or eliminative aromatization were the key features. An attempted diastereo-selective synthesis of (+/-)-vallapin has also been described.

Chiral pool approach for the synthesis of functionalized amino acids: synthesis of antiepileptic drug (R)-lacosamide - Aratikatla, Eswar K.; Bhattacharya, Asish K. (Tetrahedron Letters, 2015)
An efficient total synthesis of (R)-lacosamide 1 has been achieved from N-Boc-N,O-isopropylidene-l-serinol 2 which could easily be obtained from natural l-serine. Our synthesis of 1 starting from 2 using chiral pool strategy resulted in 54% overall yield.

Chromerid genomes reveal the evolutionary path from photosynthetic algae to obligate intracellular parasites - Woo, Yong H.; Ansari, Hifzur; Otto, Thomas D.; Klinger, Christen M.; Kolisko, Martin; Michalek, Jan; Saxena, Alka; Shanmugam, Dhanasekaran; Tayyrov, Annageldi; Veluchamy, Alaguraj; Ali, Shahjahan; Bernal, Axel; et al. (Elife, 2015)
The eukaryotic phylum Apicomplexa encompasses thousands of obligate intracellular parasites of humans and animals with immense socio-economic and health impacts. We sequenced nuclear genomes of Chromera velia and Vitrella brassicaformis, free-living non-parasitic photosynthetic algae closely related to apicomplexans. Proteins from key metabolic pathways and from the endomembrane trafficking systems associated with a free-living lifestyle have been progressively and non-randomly lost during adaptation to parasitism. The free-living ancestor contained a broad repertoire of genes many of which were repurposed for parasitic processes, such as extracellular proteins, components of a motility apparatus, and DNA-and RNA-binding protein families. Based on transcriptome analyses across 36 environmental conditions, Chromera orthologs of apicomplexan invasion-related motility genes were co-regulated with genes encoding the flagellar apparatus, supporting the functional contribution of flagella to the evolution of invasion machinery. This study provides insights into how obligate parasites with diverse life strategies arose from a once free-living phototrophic marine alga.

Coherent fusion of water array and protonated amine in a metal-sulfate-based coordination polymer for proton conduction - Manna, Biplab; Anothumakkool, Bihag; Desai, Aamod V.; Samanta, Partha; Kurungot, Sreekumar; Ghosh, Sujit K. (Inorganic Chemistry, 2015)
A new function of metal-sulfate-based co-ordination polymer (CP) for proton,conduction Was investigated through rational integration of a continuous water array and protonated amine in the coordination space of the CP. The H-bonded arrays of watet molecules along with nitrogen-rich aromatic cation (protonated melamine) facilitate proton conduction in the compound under humid conditions. Although several reports of metal-oxalate/phosphate-based CPs showing proton conduction are known, this is the first designed synthesis of a metal sulfate-based CP bearing-Water arrays functioning as a solid-state proton conductor:

Compact polar moieties induce lipid-water systems to form discontinuous reverse micellar phase - Kumar, Manoj; Patil, Naganath G.; Choudhury, Chandan Kumar; Roy, Sudip; Ambade, Ashootosh V.; Kumaraswamy, Guruswamy (Soft Matter, 2015)
The role of molecular interactions in governing lipid mesophase organization is of fundamental interest and has technological implications. Herein, we describe an unusual pathway for monoolein/water reorganization from a bicontinuous mesophase to a discontinuous reverse micellar assembly, directed by the inclusion of polar macromolecules. This pathway is very different from those reported earlier, wherein the Fd3m phase formed only upon addition of apolar oils. Experiments and molecular dynamics simulations indicate that hydrophilic ternary additives capable of inducing discontinuous phase formation must (i) interact strongly with the monoolein head group and (ii) have a compact molecular architecture. We present a detailed investigation that contrasts a monoolein-water system containing polyamidoamine (PAMAM) dendrons with one containing their linear analogs. The Fd3m phase forms only on the addition of PAMAM dendrons but not their linear analogs. Thus, the dendritic architecture of PAMAM plays an important role in determining lipid mesophase behavior. Both dendrons and their linear analogs interact strongly with monoolein through their amine groups. However, while linear polymers adsorb and spread on monoolein, dendrons form aggregates that interact with the lipid. Dendrons induce formation of an intermediate reverse hexagonal phase, which subsequently restructures into the Fd3m phase. Finally, we demonstrate that other additives with compact structures that are known to interact with monoolein, such as branched polyethylenimine and polyhedral silsesquioxane cages, also induce the formation of the Fd3m phase.

Concise enantioselective synthesis of (2S,3S)-3-hydroxypipecolic acid via proline catalyzed alpha-aminooxylation of aldehydes and Pd-catalyzed ether directed aza-Claisen rearrangements - Ahuja, Brij Bhushan; Sudalai, Arumugam (Tetrahedron-Asymmetry, 2015)
An efficient approach to (2S,3S)-3-hydroxypipecolic acid with an overall yield of 10.2% and 98% ee starting from 1,5-pentanediol has been developed. The key steps employed in the synthesis are the D-proline catalyzed sequential alpha-aminooxylation/Horner-Wadsworth-Emmons olefination of an aldehyde and the Pd-catalyzed MOM-ether directed aza-Claisen rearrangement of an allylic trichloroacetimidate. (C) 2014 Elsevier Ltd. All rights reserved.

Controlled micellar disassembly of photo- and pH-cleavable linear-dendritic block copolymers - Kalva, Nagendra; Parekh, Nimisha; Ambade, Ashootosh V. (Polymer Chemistry, 2015)
A linear-dendritic block copolymer with both photo-and pH-cleavable linkages at the junction between the hydrophobic dendron and hydrophilic linear polymer was synthesised. The photocleavable o-nitrobenzyl group attached to alkyne was introduced at the focal point of polyester dendron and acid-degradable acetal linkage with terminal azide was introduced at one end of linear polyethylene glycol. The two segments were connected using click chemistry. The copolymer was found to self-assemble into micelle-like aggregates in dilute aqueous solution. Stimuli-responsive disassembly of the aggregates was studied by monitoring fluorescence emission of the encapsulated hydrophobic dye and dynamic light scattering (DLS). Products of acetal cleavage at acidic pH were analyzed by gel permeation chromatography and NMR spectroscopy. The photo and pH stimuli were applied separately as well as simultaneously to study the rate of dye release. The synergistic effect of the two stimuli on dye release was demonstrated and the non-cytotoxic nature of the polymer was shown using the MTT assay. Cell uptake of DOX-loaded micelles and photo-induced release of the drug resulting in significantly higher cytotoxicity than by free DOX was demonstrated using MDA-MB-231 cells.

Core-shell nanoparticles: synthesis and applications in catalysis and electrocatalysis - Gawande, Manoj B.; Goswami, Anandarup; Asefa, Tewodros; Guo, Huizhang; Biradar, Ankush V.; Peng, Dong-Liang; Zboril, Radek; Varma, Rajender S. (Chemical Society Reviews, 2015)
Core-shell nanoparticles (CSNs) are a class of nanostructured materials that have recently received increased attention owing to their interesting properties and broad range of applications in catalysis, biology, materials chemistry and sensors. By rationally tuning the cores as well as the shells of such materials, a range of core-shell nanoparticles can be produced with tailorable properties that can play important roles in various catalytic processes and offer sustainable solutions to current energy problems. Various synthetic methods for preparing different classes of CSNs, including the Stober method, solvothermal method, one-pot synthetic method involving surfactants, etc., are briefly mentioned here. The roles of various classes of CSNs are exemplified for both catalytic and electrocatalytic applications, including oxidation, reduction, coupling reactions, etc.

Correlations between structure, microstructure, density and dielectric properties of the lead-free ferroelectrics Bi0.5(Na,K)0.5TiO3 - Anjali, K.; Ajithkumar, Thalasseril G.; Joy, Pattayil Alias (Journal of Advanced Dieletrics, 2015)

CoSe2 supported on nitrogen-doped carbon nanohorns as a methanol-tolerant cathode for air-breathing microlaminar flow fuel cells - Unni, SreeKuttan M.; Mora-Hernandez, Juan M.; Kurungot, Sreekumar; Alonso-Vante, Nicolas (Chemelectrochem, 2015)
The synthesis of CoSe2 nanoparticles supported on nitrogendoped carbon nanohorns (CoSe2/NCNH) and the influence of the interaction of the metal centre with the NCNH on the oxygen reduction reaction (ORR) are reported. CoSe2/NCNH shows a 50 mV lower onset overpotential and a 150 mV positive shift in the half-wave potential compared to CoSe2 supported on carbon and carbon nanohorns. This suggests that the intrinsic activity and the density of active reaction centres of CoSe2 are modified by NCNHs. An air-breathing direct meth-anol microlaminar flow fuel cell (mLFFC) is constructed using CoSe2/NCNH as a methanol-tolerant cathode catalyst. A maximum power density of 10.05 mWcm(-2) and a maximum current density of 124.20 mAcm(-2) are achieved with CoSe2/NCNH compared to the non-doped catalyst, CoSe2/C and Pt/C with 5m methanol as the fuel. The improved activity of CoSe2/ NCNH is attributed to the peculiar morphology and the nitrogen doping of the carbon nanohorns. This catalyst could be a suitable alternative to Pt.
Keywords: carbon nanohorns; chalcogenides; fuel cells; oxygen reduction reaction; platinum

Cu-catalyzed debrominative cyanation of gem-dibromoolefins: a facile access to alpha,beta-unsaturated nitriles - Ahuja, Brij Bhushan; Sudalai, Arumugam (Organic & Biomolecular Chemistry, 2015)
An efficient catalytic route for the synthesis of alpha,beta-unsaturated nitriles from easily accessible gem-dibromoolefins has been developed. The method utilized inexpensive reagents such as Cu2O as a catalyst, L-proline as a ligand and NaCN as a cyanide source to afford alpha,beta-unsaturated nitriles in high yields (62-86%). A deuterium exchange study has shown that one of the bromide atoms of gem-dibromoolefins exchanges with cyanide while the other with a deuterium atom.

Design and synthesis of a focused library of diamino triazines as potential mycobacterium tuberculosis DHFR inhibitors - Lele, Arundhati C.; Raju, Archana; Khambete, Mihir P.; Ray, M. K.; Rajan, M. G. R.; Arkile, Manisha A.; Jadhav, Nandadeep J.; Sarkar, Dhiman; Degani, Mariam S. (ACS Medicinal Chemistry Letters, 2015)
We report design of a series of 2,4-diamino triazines as Mycobacterium tuberculosis (Mtb) dihydrofolate reductase inhibitors. The synthesized compounds were evaluated against Mtb (H(37)Rv and Dormant stage H37Ra), their cytotoxicity was assessed (HepG2 and A549 cell lines), and selectivity toward Mtb was evaluated by testing against other bacterial strains. Some derivatives showed promising activity along with low cytotoxicity. The most potent compound in the whole cell assay (MIC 0.325 mu M against H(37)Rv) showed selectivity in the enzyme assay and exhibited synergy with second line anti-TB agent p-amino salicylic acid. This study therefore provides promising molecules for further development as antituberculosis DHFR inhibitors.
Keywords: Diamino triazine; dihydrofolate reductase; enzyme assay; molecular modeling; Mycobacterium tuberculosis; selectivity; synergy

Design and synthesis of new fluconazole analogues - Pore, Vandana S.; Agalave, Sandip G.; Singh, Pratiksha; Shukla, Praveen K.; Kumar, Vikash; Siddiqi, Mohammad I. (Organic & Biomolecular Chemistry, 2015)
We have synthesized new fluconazole analogues containing two different 1,2,3-triazole units in the side chain. The synthesis of new amide analogues using a variety of acids is also described. All the compounds showed very good antifungal activity. A hemolysis study of the most active compounds 6e and 13j showed that both compounds did not cause any hemolysis at the dilutions tested. These compounds did not exhibit any toxicity to L929 cells at MIC and lower concentrations. In the docking study, the overall binding mode of 6e and 13j appeared to be reasonable and provided a good insight into the structural basis of inhibition of Candida albicans Cyp51 by these compounds.

Diffusion of small solute particles in viscous liquids: cage diffusion, a result of decoupling of solute-solvent dynamics, leads to amplification of solute diffusion - Acharya, Sayantan; Nandi, Manoj K.; Mandal, Arkajit; Sarkar, Sucharita; Bhattacharyya, Sarika Maitra (Journal of Physical Chemistry B, 2015)
We study the diffusion of small solute particles through solvent by keeping the solute solvent interaction repulsive and varying the solvent properties. The study involves computer simulations, development of a new model to describe diffusion of small solutes in a solvent, and also mode coupling theory (MCT) calculations. In a viscous solvent, a small solute diffuses via coupling to the solvent hydrodynamic modes and also through the transient cages formed by the solvent. The model developed can estimate the independent contributions from these two different channels of diffusion. Although the solute diffusion in all the systems shows an amplification, the degree of it increases with solvent viscosity. The model correctly predicts that when the solvent viscosity is high, the solute primarily diffuses by exploiting the solvent cages. In such a scenario the MCT diffusion performed for a static solvent provides a correct estimation of the cage diffusion.

Doxorubicin-conjugated beta-NaYF4:Gd3+/Tb3+ multifunctional, phosphor nanorods: a multimodal, luminescent, magnetic probe for simultaneous optical and magnetic resonance imaging and an excellent pH-triggered anti-cancer drug delivery nanovehicle - Padhye, Preeti; Alam, Aftab; Ghorai, Suvankar; Chattopadhyay, Sarnit; Poddar, Pankaj (Nanoscale, 2015)
Herein, we report the fabrication of a multifunctional nanoprobe based on highly monodispersed, optically and magnetically active, biocompatible, PEI-functionalized, highly crystalline beta-NaYF4:Gd3+/Tb3+ nanorods as an excellent multi-modal optical/magnetic imaging tool and a pH-triggered intracellular drug delivery nanovehicle. The static and dynamic photoluminescence spectroscopy showed the presence of sharp emission peaks, with long lifetimes (similar to 3.5 milliseconds), suitable for optical imaging. The static magnetic susceptibility measurements at room temperature showed a strong paramagnetic signal (chi similar to 3.8 x 10(-5) emu g(-1) Oe(-1)). The nuclear magnetic resonance (NMR) measurements showed fair T-1 relaxivity (r(1) = 1.14 s(-1) mM(-1)) and magnetic resonance imaging gave enhanced T-1-weighted MRI images with increased concentrations of beta-NaYF4:Gd3+/Tb3+ making them suitable for simultaneous magnetic resonance imaging. In addition, an anticancer drug, doxorubicin (DOX) was conjugated to the amine-functionalized beta-NaYF4:Gd3+/Tb3+ nanorods via pH-sensitive hydrazone bond linkages enabling them as a pH-triggered, site-specific drug delivery nanovehicle for DOX release inside tumor cells. A comparison between in vitro DOX release studies undertaken in normal physiological (pH 7.4) and acidic (pH 5.0) environments showed an enhanced DOX dissociation (similar to 80%) at pH 5.0. The multifunctional material was also applied as an optical probe to confirm the conjugation of DOX and to monitor DOX release via a fluorescence resonance energy transfer (FRET) mechanism. The DOX-conjugated beta-NaYF4:Gd3+/Tb3+ nanorods exhibited a cytotoxic effect on MCF-7 breast cancer cells and their uptake by MCF-7 cells was demonstrated using confocal laser scanning microscopy and flow cytometry. The comparative cellular uptakes of free DOX and DOX-conjugated beta-NaYF4:Gd3+/Tb3+ nanorods were studied in tumor microenvironment conditions (pH 6.5) using confocal imaging, which showed an increased uptake of DOX-conjugated beta-NaYF4:Gd3+/Tb3+ nanorods. Thus, DOX-conjugated beta-NaYF4:Get(3+)/Tb3+ nanorods combining pH-triggered drug delivery, efficient luminescence and paramagnetic properties are promising for a potential multifunctional platform for cancer therapy, biodetection, and optical and magnetic resonance imaging.

Easy `filter-and-separate' method for enantioselective separation and chiral sensing of substrates using a biomimetic homochiral polymer - Senthilkumar, T.; Asha, S. K. (Chemical Communications, 2015)
We present a polyfluorene appended with protected L-glutamic acid that exhibited a reversible alpha-helix/beta-sheet-like conformation and helical porous fibrous morphology mimicking the super-structure of proteins. The new homochiral polymer probe enabled efficient heterogeneous enantioselective separation and chiral sensing of a wide variety of substrates from their aqueous racemic mixture using an easy `Filter-and-Separate' method.

Effect of nutritional factors on growth and L-asparaginase production by three thermophilic coprophilous fungi - Ajmeera, Shanthi Priya; Rao, Vankudoth Koteswara; Sreelatha, B.; Sivadevuni, Girisham; Reddy, Solipuram Madhusudhan (Current Research in Microbiology Biotechnology, 2015)
The present study aimed to investigate the effect of nutritional factors on L-asparaginase production by three thermophilic caprophilous fungi (Thielavia terrestris, Malbranchea cinnamomea and Scytalidium thermophilum) was assessed in YES medium by substituting starch and L-asparagine so as to supply equal amount of carbon and nitrogen sources respectively. D-glucose, starch, maltose and mannitol were best source for growth and L-asparaginase production by all three thermophilic caprophilous fungi under investigation. Similarly L-asparagine, L-arginine, L-tyrosine and L-histidine were good nitrogen sources for both growth and L-asparaginase production. Production of the variance of the data showed the significant difference (P<0.05) among the three thermophilic caprophilous fungi with regards to carbon and nitrogen source.

Efficient robust fluorite CeZrO4-delta oxide catalyst for the eco-benign synthesis of styrene - Periyasamy, Kaliyappan; Aswathy, Venugopalan T.; Kumar, Venugopal Ashok; Manikandan, Marimuthu; Shukla, Rakesh; Tyagi, Avesh K.; Raja, Thirumalaiswamy (RSC Advances, 2015)
In this work, we have reported CeO2, ZrO2, physically mixed (PH)-CeO2/ZrO2 and fluorite CeZrO4-delta oxides and their catalytic activities for the oxidative dehydrogenation (ODH) of ethyl benzene (EB) to styrene (ST) using molecular oxygen, air and carbon dioxide as oxidants. The catalysts were prepared by a gel-combustion method followed by calcination at 600 degrees C for 6 h and subjected to catalytic activity measurements. All the catalysts were characterized and studied by various physicochemical methods. The reaction parameters were varied systematically such as different catalysts, oxidants, temperatures, EB flow and oxidant flow. CeZrO4-delta accounted for a 47% styrene yield for 72 h without any significant deactivation under optimized reaction conditions. A thorough analysis of the spent catalysts demonstrated the robustness of the catalyst for this reaction under different oxidants and reaction conditions. Pristine CeO2 deactivated easily and the activity decreased with time on stream of the reaction.

Enhancing efficiency of perovskite solar cell via surface microstructuring: superior grain growth and light harvesting effect - Tathavadekar, Mukta C.; Agarkar, Shruti A.; Game, Onkar S.; Bansode, Umesh P.; Kulkarni, Sneha A.; Mhaisalkar, Subodh G.; Ogale, Satishchandra B. (Solar Energy, 2015)
We have introduced a novel approach to enhance the perovskite solar cell efficiency by controlling the grain growth and light harvesting properties of perovskite crystallites. Instead of using a mesoporous TiO2 layer, we have modified the surface microstructuring of the TiO2 film by dispensing nano assembled TiO2 submicron structures (nanobeads, NBs) on TiO2 compact layer. With this new approach solar cell efficiency was improved significantly through an increase in both J(sc) and V-oc. This high efficiency is attributed to crystallite size of the perovskite phase. These also act as light scattering centers giving higher current density and reduced recombination effects giving higher open circuit voltage. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Grain growth; Light harvesting; Perovskite solar cells; TiO2 nanobeads

Environmentally friendly route for grafting of molybdenum carbonyl onto a diaminosilane-modified SBA-15 molecular sieve and its catalytic behaviour in olefin epoxidation - Baskaran, Thangaraj; Kumaravel, Raju; Christopher, Jayaraj; Ajithkumar, Thalasseril G.; Sakthivel, Ayyamperumal (New Journal of Chemistry, 2015)
A simple route has been established for grafting molybdenum carbonyl onto the surface of a diaminosilane-modified SBA-15 molecular sieve. The successful grafting of the molybdenum carbonyl species onto diamine-functionalized SBA-15 was evident from FT-IR studies. The resultant molybdenum-carbonyl-complex-grafted SBA-15 (SBA-DA-Mo) materials show promising activity for the epoxidation of various olefins with good conversion (90-95%) and the formation of epoxide as the major product. The catalytic activity remains constant over several runs.

Exploiting powder x-ray diffraction to establish the solvent-assisted solid-state supramolecular assembly of pillar[5]quinone - Shivakumar, Kilingaru I.; Yan, Yuncheng; Hughes, Colan E.; Apperley, David C.; Harris, Kenneth D. M.; Sanjayan, Gangadhar J. (Crystal Growth & Design, 2015)
We report the solvent-mediated supramolecular assembly of pillar[5]quinone (P[5]Q), a symmetric cyclamer containing five benzoquinone moieties bridged by five alternating methylene units. The supramolecular assembly of P[5]Q is shown to be facilitated by 1,1,2,2-tetrachloroethane (TCE) as solvent, producing a microcrystalline solvate material P[5]Q(.)2TCE with a fluffy texture. Optical and electron microscopy reveal that this material has a rod-shaped morphology, extending to several micrometers in length. Due to the microcrystalline nature of the material, structure determination was carried out directly from powder X-ray diffraction data, augmented by high-resolution solid-state C-13 NMR. The two crystallographically distinct TCE molecules occupy different types of void in the structure and have different dynamic properties. Crystallization of P[5]Q was attempted from a large number of different solvents, but only TCE was found to facilitate the formation of a crystalline phase. Indeed, features of the crystal structure suggest that the TCE component plays an important role in promoting the columnar assembly of P[5]Q molecules.

Extrusion film casting of long chain branched polypropylene - Chikhalikar, Kalyani; Banik, Sourya; Azad, Lal Busher; Jadhav, Kishor; Mahajan, Sunil; Ahmad, Zubair; Kulkarni, Surendra; Gupta, Surendra; Doshi, Pankaj; Pol, Harshawardhan; Lele, Ashish K. (Polymer Engineering and Science, 2015)
Extrusion film casting (EFC) is an important melt processing operation which is extensively used to make polypropylene (PP) films. Linear PP shows significant amount of necking and draw resonance during EFC. One of the ways to reduce necking is to introduce long chain branches (LCB) on the polymer backbone. The long branches impart extensional strain hardening behavior thereby stabilizing the melt flow. In this work, we investigate the influence of long chain branching in polypropylene on the extent of necking in the EFC process. Laboratory scale EFC experiments were performed on homopolymer PP of linear and long chain branched architectures. Simulations of the EFC process were carried out using the one-dimensional flow model of Silagy et al., Polym. Eng. Sci.,36, 2614 (1996) into which we incorporate two different multi-mode molecular constitutive equations namely, the eXtended Pom-Pom' equation (XPP, for long chain branched PP) and the Rolie-Poly' equation (RP-S, for linear PP). Our experimental data confirm that presence of long chain branching in PP reduces the extent of necking and our numerical predictions show qualitative agreement with experimental data, thereby elucidating the role of chain architecture on the extent of necking. POLYM. ENG. SCI., 55:1977-1987, 2015. (c) 2014 Society of Plastics Engineers

Facile biological approach for immobilization, physicochemical characterization and antibacterial activity of noble metals nanocomposites - Parveen, Asra; Ali, Tayyab; Wahid, Malik; Rao, Srinath (Materials Letters, 2015)
The use of biopolymer as template to regulate metallic nanoparticles is promising field in green nanotechnology. We have designed a facile biological way for rapid synthesis and immobilization of gold and silver nanoparticles on alginate films using leaf extract of Cassia auriculata. The prepared gold bio-nanocomposite (Au-BNC) and silver bio-nanocomposite (Ag-BNC) were characterized by UV-vis spectroscopy, Fourier transform infrared spectroscopy, Transmission electron microscopy and Thermal analysis. The bio-nanocomposites exhibited good antibacterial activity against both gram positive (Bacillus subtilis) and gram negative (Escherichia coli) bacteria. The metal nanoparticle embedded films have number of applications in catalysis, optical biosensors, electronic, biomedical devices and environmental remediation. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Alginate; Antibacterial; Bio-nanocomposites; Cassia auriculata; Characterization; Nanoparticles

Fe(III) phytate metallogel as a prototype anhydrous, intermediate temperature proton conductor - Aiyappa, Harshitha Barike; Saha, Subhadeep; Wadge, Pritish; Banerjee, Rahul; Kurungot, Sreekumar (Chemical Science, 2015)
A proton conducting metallogel [FNPA; ferric nitrate (FN)-phytic acid (PA)] is synthesized by immobilizing a protogenic ligand (phytic acid) using iron(III) nitrate in DMF. The xerogel shows high proton conductivity of 2.4 x 10(-2) S cm(-1) at 120 degrees C, the best value known among all metal organic materials (MOMs). Marking the first such attempt in MOMs, an electrode made using the xerogel showed a power density of 0.94 mW cm(-2) at 0.6 V under dry fuel cell conditions.

First enantioselective synthesis of (2S,3S)-3-hydroxy-L-arginine via proline catalyzed alpha-aminooxylation of aldehyde and Pd-catalyzed ether-directed aza-Claisen rearrangement - Ahuja, Brij Bhushan; Sudalai, Arumugam (Tetrahedron-Asymmetry, 2015)
A concise enantioselective synthesis of (2S,3S)-3-hydroxy-L-arginine with an overall yield of 10.9% and 98% ee, starting from commercially available 1,4-butanediol in ten linear steps has been achieved. The key chiral inducing steps are D-proline catalyzed sequential alpha-aminooxylation/Horner-Wadsworth-Emmons olefination of an aldehyde and the subsequent diastereoselective MOM-ether-directed Pd-catalyzed aza-Claisen rearrangement of allylic trichloroacetimidate. (C) 2015 Elsevier Ltd. All rights reserved.

Fluorescent probe for specific detection of cysteine in the lipid dense region of cells - Ali, Firoj; Anila, H. A.; Taye, Nandaraj; Gonnade, Rajesh G.; Chattopadhyay, Samit; Das, Amitava (Chemical Communications, 2015)
A new cysteine (Cys) specific chemodosimetric reagent (ER-F) is used in imaging of endogenous Cys localized in the lipid dense region of the live Hct116 cells and the release of Cys within HepG2 cells from a drug following a biochemical transformation. A silica surface, modified with ER-F, could be used for quantitative estimation of Cys present in aqueous solution (pH 7.2) and in a human blood plasma (HBP).

Fluorescent probes for the detection of cyanide ions in aqueous medium: cellular uptake and assay for beta-glucosidase and hydroxynitrile lyase - Agarwalla, Hridesh; Gangopadhyay, Monalisa; Sharma, Dharmendar Kumar; Basu, Santanu Kumar; Jadhav, Sameer; Chowdhury, Arindam; Das, Amitava (Journal of Materials Chemistry B, 2015)
A chemodosimteric reagent (1) for the efficient detection of cyanide species (CN- and/or HCN) in aq. medium as well as under physiological conditions has been described. Selective reaction of the cyanide species with this reagent in the presence of all common interfering anions, amino acids and glutathione (GSH) led to the generation of the corresponding cyanohydrin derivative. The formation of the cyanohydrin derivative of the probe is associated with a visually detectable change in solution fluorescence in aq. buffer medium with 1.9 mu M NaCN, the threshold limit set by WHO for the safe drinking water and this makes this fluorogenic sensor an ideal candidate for in-field applications. An apparent switch on the luminescence response, ultralow detection limit, low response time, cell membrane permeability and insignificant toxicity are key features of a probe molecule, which gives it a distinct edge over previously reported chemodosimetric reagents for the detection of cyanide species (CN- or HCN) in an aqueous environment. This methodology could be used for developing a generalized and efficient fluorescence-based assay for crucial enzymes like beta-glucosidase and hydroxynitrile lyase. Furthermore, spectrally-resolved fluorescence microscopy measurements on single-cells revealed that this sensor molecule could also be used for imaging the cellular uptake of cyanide species from aq. solution contaminated with NaCN. Our results confirmed that statistical analysis of integrated intensity and transition energy obtained from the emission spectra collected over various microscopic sub-cellular regions can potentially be used to discriminate the effects of local cellular environments and that due to cyanide detection.

Freezing tendency towards 4-coordinated amorphous networks causes an increase in the heat capacity of supercooled Stillinger-Weber silicon - Apte, Pankaj A.; Pingua, Nandlal; Gautam, Arvind Kumar; Kumar, Uday; Willow, Soohaeng Yoo; Zeng, Xiao Cheng; Kulkarni, B. D. (RSC Advances, 2015)
Supercooled liquid silicon (Si), modeled by the Stillinger-Weber (SW) potential, has been shown to undergo transition to low density amorphous phases at 1060 K in previous studies. Furthermore, the constant pressure heat capacity C-p has been found to exhibit a large increase as the liquid is cooled to 1060 K. In this work, we examine the nature of the equilibrium and the relaxation process of supercooled SW Si in the temperature range of 1060 K to 1070 K at zero pressure. We find that the relaxation of the supercooled liquid leads to a sharp irreversible decrease in the fluctuation of the two body energy of the largest connected network of 4-coordinated particles. Such a process implies a tightening of the bonds (i.e. freezing or jamming) of the network, and is accompanied by a sharp increase in the fraction of the 4-coordinated particles in the system. We find that the jamming (or freezing) process shows a sudden acceleration across a dynamical instability point that occurs at a unique potential energy state of the network. Further, we find that the occurrence of the dynamical instability is associated with the appearance of a straight line region in the cumulative potential energy distributions with a configurational temperature close to 1060 K. We conclude that the supercooled liquid state must be regarded as a constrained equilibrium state, since the accessible microstates are constrained by the inherent tendency of the system to approach the dynamical instability point. Thus all properties of supercooled liquid SW-Si, including the rise in C-p at 1060 K, can be attributed to the freezing tendency of the 4-coordinated particle network.

FRET-based probe for monitoring pH changes in lipid-dense region of Hct116 cells - Reddy, Upendar G.; Anila, H. A.; Ali, Firoj; Taye, Nandaraj; Chattopadhyay, Samit; Das, Amitava (Organic Letters, 2015)
A rhodamine conjugate (L) with a pseudo Stokes shift of 165 nm is used for probing changes in solution pH under physiological conditions. This reagent is found to be nontoxic, and the luminescence response could be used for imaging changes in endogenous pH induced by dexamethanose (DMT) in the endoplasmic reticulum.

Gelation landscape engineering using a multi-reaction supramolecular hydrogelator system - Foster, Jamie S.; Zurek, Justyna M.; Almeida, Nuno M. S.; Hendriksen, Wouter E.; le Sage, Vincent A. A.; Lakshminarayanan, Vasudevan; Thompson, Amber L.; Banerjee, Rahul; Eelkema, Rienk; Mulvana, Helen; Paterson, Martin J.; van Esch, Jan H.; et al. (Journal of the American Chemical Society, 2015)
Simultaneous control of the kinetics and thermodynamics of two different types of covalent chemistry allows pathway selectivity in the formation of hydrogelating molecules from a complex reaction network. This can lead to a range of hydrogel materials with vastly different properties, starting from a set of simple starting compounds and reaction conditions. Chemical reaction between a trialdehyde and the tuberculosis drug isoniazid can form one, two, or three hydrazone connectivity products, meaning kinetic gelation pathways can be addressed. Simultaneously, thermodynamics control the formation of either a keto or an enol tautomer of the products, again resulting in vastly different materials. Overall, this shows that careful navigation of a reaction landscape using both kinetic and thermodynamic selectivity can be used to control material selection from a complex reaction network.

Green approach for the decoration of Pd nanoparticles on graphene nanosheets: an in situ process for the reduction of C-C double bonds and a reusable catalyst for the suzuki cross-coupling reaction - Hussain, Najrul; Borah, Ashwini; Darabdhara, Gitashree; Gogoi, Pranjal; Azhagan, Muniraj Vedi Kuyil; Shelke, Manjusha V.; Das, Manash R. (New Journal of Chemistry, 2015)
A new strategy for in situ synthesis of palladium nanoparticles (Pd NPs) decorated on reduced graphene oxide (rGO) nanosheets with controlled size and shape is reported. This strategy was designed as three processes in one pot, namely, (a) reduction of graphene oxide, (b) formation of Pd NPs on the rGO nanosheets and (c) simultaneous reduction of olefin. In this synthesis process, a hydrogen atmosphere was used to develop the Pd NPs-rGO nanocatalyst, which is reusable and easily separable. The influence of the size and morphology of the Pd-rGO-H-2 catalyst on the catalytic activity in the Suzuki cross-coupling reaction was investigated by comparing with other catalysts, Pd-rGO-As and Pd-rGO-Gl, and they were synthesized by different reducing agents, ascorbic acid and glucose, respectively. The catalysts were characterized by electron microscopy (HRTEM, SEM), FT-IR, XRD and XPS. The Pd-rGO-H-2 catalyst was found to possess excellent catalytic activity and recyclability in the Suzuki cross-coupling reaction under mild reaction conditions.

Green synthesis of stable Cu(0) nanoparticles onto reduced graphene oxide nanosheets: a reusable catalyst for the synthesis of symmetrical biaryls from arylboronic acids under base-free conditions - Hussain, Najrul; Gogoi, Pranjal; Azhagan, Muniraj Vedi Kuyil; Shelke, Manjusha V.; Das, Manash R. (Catalysis Science & Technology, 2015)
Highly stable Cu(0) nanoparticles were synthesized on reduced graphene oxide (rGO) sheets using a cost-effective and green method. The synthesized Cu(0)-nanoparticle-rGO composites exhibit excellent catalytic activity for the synthesis of symmetrical biaryls from arylboronic acids under microwave irradiation. The reaction proceeds smoothly in base-free conditions with easy recovery and reuse of the catalyst. The methodology is compatible with various functional groups and provides an attractive protocol for the synthesis of symmetrical biaryls with very good yields. HRTEM, XPS and XRD analyses showed the catalyst to be recyclable. The Cu(0) nanoparticles are stable in the rGO nanosheets, and the particle size distribution and oxidation state of the Cu(0) nanoparticle remain the same after performing the chemical reaction.

Hierarchical CdS nanostructure by Lawesson's reagent and its enhanced photocatalytic hydrogen production - Pandit, Vikram U.; Arbuj, Sudhir S.; Hawaldar, Ranjit R.; Kshirsagar, Pradnya V.; Deshmukh, Amarsinh J.; Ambekar, Jalindar D.; Mulik, Uttam P.; Gosavi, Suresh W.; Kale, Bharat B. (RSC Advances, 2015)
Lawesson's reagent (LR) has been effectively exploited for the synthesis of hierarchical architectures of cadmium sulphide (CdS) nanostructures for the first time. The X-ray diffractograms of the as synthesised CdS nanostructures confirm the formation of hexagonal CdS. The broadness of the XRD peaks clearly indicates the nanocrystalline nature of CdS with average crystallite size of 4 nm. A FESEM study revealed the formation of hierarchical nanostructures, whereas a TEM study showed that the hierarchical arrangement is composed of nanosized CdS particles. A band-gap i.e. 2.4 eV was derived from diffuse reflectance spectroscopy. The photoluminescence spectrum showed an emission peak at 535 and 568 nm which can be attributed to band-edge emission and surface emissions or possible metal vacancies, respectively. Considering the band-gap within the visible region, the photocatalytic hydrogen evolution performance of these CdS nanostructures was performed under visible light irradiation from hydrogen sulphide and water, respectively. Utmost hydrogen evolution i.e. 14 136 mu mol h(-1) g(-1) and 2065 mu mol h(-1) g(-1) was observed over a naked CdS nanostructure via H2S and water decomposition, respectively. The amount of hydrogen obtained by H2S splitting is much higher as compared to earlier reports.

High surface area porous carbon for ultracapacitor application by pyrolysis of polystyrene containing pendant carboxylic acid groups prepared via click chemistry - Chhatre, Shraddha; Aravindan, Vanchiappan; Puthusseri, Dhanya; Banerjee, Abhik; Madhavi, Srinivasan; Wadgaonkar, Prakash P.; Ogale, Satishchandra B. (Materials Today Communications, 2015)

Highly efficient regioselective synthesis of pyrroles via a tandem enamine formation-Michael addition-cyclization sequence under catalyst- and solvent-free conditions - Vivekanand, Thavaraj; Vinoth, Perumal; Agieshkumar, B.; Sampath, Natarajan; Sudalai, Arumugam; Menendez, Carlos; Sridharan, Vellaisamy (Green Chemistry, 2015)
A convenient catalyst-free, three-component procedure was developed for the synthesis of tetrasubstituted pyrroles under solvent-free conditions and in green solvents glycerol, PEG-200 and water. A sequential enamine-formation, Michael addition and intramolecular cyclization of primary amines, 1,3-dicarbonyl compounds and isatin-derived Michael acceptors afforded 3-(1H-pyrrol-3-yl)indolin-2-ones in excellent yields. In this simple one-pot transformation the requirement of column chromatography purification of the products was completely avoided. Besides, the method is highly environmentally benign and atom-economical, and the only side product of this reaction was two molecules of water. A comparative study for the four developed conditions showed that the solvent-free conditions were superior regardless of the nature of the starting materials, and the green solvents were effective for alkyl and benzylamines affording higher yields compared to arylamines. The preliminary in vitro cytotoxic studies of a representative compound against Ehrlich's ascites carcinoma (EAC) tumor cells showed significant activity with a CTC50 value of 15.64 mu M.

Human telomeric RNA G-quadruplex response to point mutation in the G-quartets - Agarwala, Prachi; Kumar, Santosh; Pandey, Satyaprakash; Maiti, Souvik (Journal of Physical Chemistry B, 2015)
Many putative G-quadruplex forming sequences have been predicted to exist in the human genome and transcriptome. As these sequences are subject to point mutations or SNPs (single nucleotide polymorphisms) during the course of evolution, we attempt to understand impact of these mutations in context of RNA G-quadruplex formation using human telomeric RNA (TERRA) as a model sequence. Our studies suggest that G-quadruplex stability is sensitive to substitution of the guanines comprising G-quartets. While central G-quartet plays a crucial role in maintaining the DNA G-quadruplex stability as evident in literature, there is equal importance of three G-quartets in the stability of RNA quadruplex structure. The work here highlights the alterations in the G-quartet are detrimental to the integrity of overall RNA G-quadruplex structure. Furthermore, TmPyP4 molecules are shown to exhibit similar binding behavior toward telomeric RNA G-quadruplex harboring base substitutions employing CD titrations and isothermal titration calorimetry; well indicating that mutation does not influence TmPyP4 recognition ability as it affects the stability of RNA G-quadruplex. Thus, our study implicates that mutation in G-quartets causes destabilization of RNA G-quadruplex without affecting its trans factor binding ability.

Hybrid perovskite films by a new variant of pulsed excimer laser deposition: a room-temperature dry process - Bansode, Umesh P.; Naphade, Rounak; Game, Onkar S.; Agarkar, Shruti A.; Ogale, Satishchandra (Journal of Physical Chemistry C, 2015)
A new variant of the classic pulsed laser deposition (PLD) process is introduced as a room-temperature dry process for the growth and stoichiometry control of hybrid perovskite films through the use of nonstoichiometric single target ablation and off-axis growth. Mixed halide hybrid perovskite films nominally represented by CH(3)NH(3)PbI(3-x)A(x) (A = Cl or F) are also grown and are shown to reveal interesting trends in the optical properties and photoresponse. Growth of good quality lead-free CH3NH3SnI3 films is also demonstrated, and the corresponding optical properties are presented. Finally, perovskite solar cells fabricated at room temperature (which makes the process adaptable to flexible substrates) are shown to yield a conversion efficiency of about 7.7%.

Hydrogen bond and ligand dissociation dynamics in fluoride sensing of Re(I)-polypyridyl complex - Verma, Sandeep; Aute, Sunil; Das, Amitava; Ghosh, Hirendra N. (Journal of Physical Chemistry B, 2015)
Hydrogen bonding interaction plays an essential role in the early phases of molecular recognition and colorimetric sensing of various anions in aprotic media. In this work, the host-guest interaction between fac-[Re(CO)(3)Cl(L)] with L = 4-([2,2'-bipyridin]-4-yl)phenol and fluoride ions is investigated for the hydrogen bond dynamics and the changing local coordination environment. The stoichiometric studies using H-1 NMR and ESI-MS spectroscopies have shown that proton transfer in the H-bonded phenol-fluoride complex activates the dissociation of the CO ligand in the Re(I) center. The phenol-to-phenolate conversion during formation of HF2- ion induces nucleophilic lability of the CO ligand which is probed by intraligand charge transfer (ILCT) and ligand-to-metal charge transfer (LMCT) transitions in transient absorption spectroscopy. After photoexcitation, phenol-phenoxide conversion rapidly equilibrates in 280 fs time scale and the ensuing excited state [ReII(bpy(center dot-)-phenolate(-))(CO)(3)Cl]* undergoes CO dissociation in the ultrafast time scale of similar to 3 ps. A concerted mechanism of hydrogen cleavage and coordination change is established in anion sensing studies of the rhenium complex.

Influence of macromolecular architecture on necking in polymer extrusion film casting process - Pol, Harshawardhan V.; Banik, Sourya; Azad, Lal Busher; Thete, Sumeet; Doshi, Pankaj; Lele, Ashish (30th International Conference of the Polymer-Processing-Society (PPS), 2015)
Extrusion film casting (EFC) is an important polymer processing technique that is used to produce several thousand tons of polymer films/coatings on an industrial scale. In this research, we are interested in understanding quantitatively how macromolecular chain architecture (for example long chain branching (LCB) or molecular weight distribution (MWD or PDI)) influences the necking and thickness distribution of extrusion cast films. We have used different polymer resins of linear and branched molecular architecture to produce extrusion cast films under controlled experimental conditions. The necking profiles of the films were imaged and the velocity profiles during EFC were monitored using particle tracking velocimetry (PTV) technique. Additionally, the temperature profiles were captured using an IR thermography and thickness profiles were calculated. The experimental results are compared with predictions of one-dimensional flow model of Silagy et al(1) wherein the polymer resin rheology is modeled using molecular constitutive equations such as the Rolie-Poly (RP) and extended Pom Pom (XPP). We demonstrate that the 1-D flow model containing the molecular constitutive equations provides new insights into the role of macromolecular chain architecture on film necking. D-1. Silagy, Y. Demay, and J-F. Agassant, Polym. Eng. Sci., 36, 2614 (1996).

Insights into the molecular dynamics in polysulfone polymers from C-13 solid-state NMR experiments - Eldho, Kavalakal Mathai; Rajamohanan, P. R.; Anto, Ralf; Bulakh, Neelima N.; Lele, Ashish K.; Ajithkumar, Thalasseril G. (Journal of Physical Chemistry B, 2015)
The molecular and segmental motions in three different grades of ductile polysulfone polymers; poly(ether sulfone) (PESU), polysulfone (PSU), and poly(phenyl sulfone) (PPSU) are probed using C-13 solid-state NMR experiments. Polarization inversion spin exchange at magic angle (PISEMA) experiments indicates that the phenyl rings in the polymers are undergoing pi-flip motions on the order of 100 kHz. The temperature dependent PISEMA experiments show that the fraction of mobile regions that undergoes aromatic pi-flips is higher in PPSU than in the other two polymers. The center band only detection of exchange (CODEX) experiments was carried out and was unable to detect any slow segmental motions in the chains. A combination of C-13 spin-lattice relaxation time (T-1) and T-1-filtered PISEMA experiments show that the mobile regions in all the polymers are dynamically heterogeneous.

Insights into the unfolding pathway and identification of thermally sensitive regions of phytase from aspergillus niger by molecular dynamics simulations - Kumar, Kapil; Patel, Krunal; Agrawal, Dinesh C.; Khire, Jayant Malhar (Journal of Molecular Modeling, 2015)
Thermal stability is of great importance in the application of commercial phytases. Phytase A (PhyA) is a monomeric protein comprising twelve alpha-helices and ten beta-sheets. Comparative molecular dynamics (MD) simulations (at 310, 350, 400, and 500 K) revealed that the thermal stability of PhyA from Aspergillus niger (A. niger) is associated with its conformational rigidity. The most thermally sensitive regions were identified as loops 8 (residues 83-106), 10 (161174), 14 (224-230), 17 (306-331), and 24 (442-444), which are present on the surface of the protein. It was observed that solvent-exposed loops denature before or show higher flexibility than buried residues. We observed that PhyA begins to unfold at loops 8 and 14, which further extends to loop 24 at the C-terminus. The intense movement of loop 8 causes the helix H2 and beta-sheet B3 to fluctuate at high temperature. The high flexibility of the H2, H10, and H12 helices at high temperature resulted in complete denaturation. The high mobility of loop 14 easily transfers to the adjacent helices H7, H8, and H9, which fluctuate and partially unfold at high temperature (500 K). It was also observed that the salt bridges Asp110-Lys149, Asp205-Lys277, Asp335-Arg136, Asp416-Arg420, and Glu387-Arg400 are important influences on the structural stability but not the thermostability, as the lengths of these salt bridges did not increase with rising temperature. The salt bridges Glu125-Arg163, Asp299-Arg136, Asp266-Arg219, Asp339-Lys278, Asp335-Arg136, and Asp424-Arg428 are all important for thermostability, as the lengths of these bridges increased dramatically with increasing temperature. Here, for the first time, we have computationally identified the thermolabile regions of PhyA, and this information could be used to engineer novel thermostable phytases. Numerous homologous phytases of fungal as well as bacterial origin are known, and these homologs show high sequence similarity. Our findings could prove useful in attempts to increase the thermostability of homologous phytases via protein engineering.
Keywords: Conformational dynamics; Molecular dynamics simulations; PhytaseA; Structurally weak regions; Thermostability

Ionic conductivity probed in main chain liquid crystalline azobenzene polyesters - Nardele, Chinmay G.; Dhavale, Vishal M.; Sreekumar, K.; Asha, S. K. (Journal of Polymer Science Part A-Polymer Chemistry, 2015)
Three main chain thermotropic liquid crystalline (LC) azobenzene polymers were synthesized using the azobenzene twin molecule (P4P) having the structure Phenylazobenzene-tetraethyleneglycol-Phenylazobenzene as the AA monomer and diols like diethylene glycol, tetraethylene glycol (TEG), and hexaethylene glycol as the BB comonomer. Terminal C(O)OMe units on P4P facilitated transesterification with diols to form polyesters. All polymers exhibited stable smectic mesophases. One of the polymers, Poly(P4PTEG) was chosen to prepare composite polymer electrolytes with LiCF3SO3 and ionic conductivity was measured by ac impedance spectroscopy. The polymer/0.3 Li salt complex exhibited a maximum ionic conductivity in the range of 10(-5) S cm(-1) at room temperature (25 degrees C), which increased to 10(-4) S cm(-1) above 65 degrees C. The temperature dependence of ionic conductivity was compared with the phase transitions occurring in the sample and it was observed that the glass transition had a higher influence on the ionic conductivity compared to the ordered LC phase. Reversible ionic conductivity switching was observed upon irradiation of the polymer/0.3 Li salt complex with alternate UV and visible irradiation. (c) 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 629-641
Keywords: azo polymers; glass transition; liquid-crystalline polymers (LCP)

Iron superoxide dismutases in eukaryotic pathogens: new insights from apicomplexa and trypanosoma structures - Phan, Isabelle Q. H.; Davies, Douglas R.; Moretti, Nilmar Silvio; Shanmugam, Dhanasekaran; Cestari, Igor; Anupama, Atashi; Fairman, James W.; Edwards, Thomas E.; Stuart, Kenneth; Schenkman, Sergio; Myler, Peter J. (Acta Crystallographica Section F-Structural Biology Communications, 2015)
Prior studies have highlighted the potential of superoxide dismutases as drug targets in eukaryotic pathogens. This report presents the structures of three iron-dependent superoxide dismutases (FeSODs) from Trypanosoma cruzi, Leishmania major and Babesia bovis. Comparison with existing structures from Plasmodium and other trypanosome isoforms shows a very conserved overall fold with subtle differences. In particular, structural data suggest that B. bovis FeSOD may display similar resistance to peroxynitrite-mediated inactivation via an intramolecular electron-transfer pathway as previously described in T. cruzi FeSOD isoform B, thus providing valuable information for structure-based drug design. Furthermore, lysine-acetylation results in T. cruzi indicate that acetylation occurs at a position close to that responsible for the regulation of acetylation-mediated activity in the human enzyme.
Keywords: Apicomplexa; iron superoxide dismutase; Trypanosoma

Leucas mollissima, a source of bioactive compounds with antimalarial and antimycobacterium activities - Chinchansure, Ashish A.; Arkile, Manisha A.; Shukla, Anurag; Shanmugam, Dhanasekaran; Sarkar, Dhiman; Joshi, Swati P. (Planta Medica Letter, 2015)
A phytochemical investigation of the acetone extract from the aerial parts of Leucas mollissima afforded one new (−)epi-marmelo lactone, (2 S, 4R, 6 S)-2,6-dimethyl-6 hydroxy-7-ene-4-olide (1), along with five known compounds, schensianol A (2), vanillin (3), β-hydroxy propiovanillone (4), lanost-9(11),25-diene-3β,24β-diol (5), and lanost-9(11),23E(24)-diene-3β,25-diol (6). Similarly, an investigation of the methanol extract of the aerial parts of L. mollissima resulted in the isolation of three known compounds, (+)-syringaresinol (7), anisofolin A (8), and apigenin 7-O-β-D(− 6′′-p-E-coumaroyl)-glucoside (9). Structure elucidation of the isolated compounds was carried out using detailed analysis of 1D and 2D nuclear magnetic resonance. All compounds were evaluated for antimalarial activity against Plasmodium falciparum (3D7) and for antimycobacterium activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis. Compound 8 was found to have promising antimalarial activity (IC50 4.39 ± 0.25 µM), promising antimycobacterium activity [IC50 4.50 ± 0.75 µM (3.31 µg/mL)] against M. tuberculosis H37Ra and at 100 µg/mL, showed 55.6 % inhibition of M. bovis. Compound 9 showed moderate inhibition of P. falciparum growth (35 % inhibition at 10 µM) with respect to the positive control atovaquone and 67.4 % inhibition against M. bovis at 100 µg/mL with respect to the positive control rifampicin.

Long chain branched impact copolymer of polypropylene: microstructure and rheology - Chikhalikar, Kalyani; Deshpande, Anushree; Pol, Harshawardhan; Dhoble, Deepa Arun; Jha, Saroj; Jadhav, Kishor; Mahajan, Sunil; Ahmad, Zubair; Kulkarni, Surendra; Gupta, Surendra; Lele, Ashish K. (Polymer Engineering and Science, 2015)
A biphasic impact copolymer of polypropylene (ICP) was modified with peroxide by reactive extrusion process resulting in reduced melt flow index, improved melt strength, and higher die swell. The polymers were for the first time subjected to systematic rheological and microstructural characterization in an effort to understand their structure-property relations. In shear rheological tests, the modified ICP displayed higher flow activation energy, reduced values of loss tangent and nearly equal frequency dependence of storage and loss modulli. The modified ICP also showed strain hardening behaviour in uniaxial extensional rheology and higher crystallization temperature in differential scanning calorimetry (DSC). All these are definitive indications of the presence of long chain branches (LCB). Fitting the rheological data of modified ICPs with the eXtended Pom Pom (XPP) model indicated the presence of LCB on the higher molecular weight fraction in the polymer, a result which was corroborated with multi-detector high temperature gel permeation chromatography (HT-GPC). More importantly, the matrix and rubber phases of the ICP were separately characterized for presence of long chain branching by rheology, DSC and HT-GPC. The results indicate that while LCB existed in the matrix phase, microgels were present in both phases indicating that the reaction with peroxide occurred in both phases. POLYM. ENG. SCI., 55:1463-1474, 2015. (c) 2014 Society of Plastics Engineers

Magnetic and magnetostrictive properties of aluminium substituted cobalt ferrite synthesized by citrate-gel method - Anantharamaiah, P. N.; Joy, P. A. (Journal Of Materials Science, 2015)
Structural, magnetic and magnetostrictive properties of sintered aluminium-substituted cobalt ferrite, CoAlxFe2-xO4 (x = 0.0, 0.1, 0.20, 0.30), derived from nanosized powders synthesized by a citrate-gel method, have been investigated. The sample with x = 0.1 is found to exhibit higher maximum magnetostriction strain at relatively lower magnetic fields (230 ppm at 286 kA/m) than that obtained for the unsubstituted cobalt ferrite (217 ppm, at 446 kA/m). All the Al-substituted compositions show larger strain sensitivity (d lambda/dH) at low magnetic fields compared to that for the unsubstituted cobalt ferrite. The variation of the magnetostriction coefficient as well as the strain sensitivity with Al content is likely to be due to the changes in the cation distribution in the tetrahedral and octahedral sites of the spinel lattice along with the associated changes in the magnetocrystalline anisotropy. The magnetostriction coefficient of x = 0.1 could be further enhanced to 306 ppm (at 220 kA/m) after a magnetic field annealing at 300 degrees C. A very high strain sensitivity of 4.5 x 10(-9) m/A is obtained for the magnetically annealed sample, larger than that reported for any substituted cobalt ferrite samples. The combination of high magnetostriction coefficient and strain sensitivity is suitable for device applications.

Molecular docking and QSAR analyses for understanding the antimalarial activity of some 7-substituted-4-aminoquinoline derivatives - Shibi, I. G.; Aswathy, L.; Jisha, Radhakrishnan S.; Masand, Vijay H.; Divyachandran, A.; Gajbhiye, J. M. (European Journal of Pharmaceutical Sciences, 2015)
The quinoline moiety is one of the widely studied scaffolds for generating derivatives with various pharmacophoric groups due to its potential antimalarial activities. In the present study, a series of 7-substituted-4-aminoquinoline derivatives were selected to understand their antimalarial properties computationally by molecular modeling techniques including 2D QSAR, comparative molecular field analysis (CoMFA), comparative molecular similarity indices analysis (CoMSIA) and molecular docking. The 2D-QSAR model built with four descriptors selected by genetic algorithm technique and CoMFA model showed satisfactory statistical results (Q(2) = 0.540, R-ncv(2) = 0.881, F value = 157.09). A reliable CoMSIA model out of the fourteen different combinations has a Q(2) value of 0.638. The molecular docking studies of the compounds for 1CET as the protein target revealed that ten compounds showed maximum interactions with the binding site of the protein. The present study highlights the unique binding signatures of the ligands within the active site groove of the target and it explains the subtle differences in their EC50 values and their mechanism of inhibition. (C) 2015 Elsevier B.V. All rights reserved.

Molecular mechanism underlying recruitment and insertion of lipid-anchored LC3 protein into membranes - Thukral, Lipi; Sengupta, Durba; Ramkumar, Amrita; Murthy, Divya; Agrawal, Nikhil; Gokhale, Rajesh S. (Biophysical Journal, 2015)
Lipid modification of cytoplasmic proteins initiates membrane engagement that triggers diverse cellular processes. Despite the abundance of lipidated proteins in the human proteome, the key determinants underlying membrane recognition and insertion are poorly understood. Here, we define the course of spontaneous membrane insertion of LC3 protein modified with phosphatidylethanolamine using multiple coarse-grain simulations. The partitioning of the lipid anchor chains proceeds through a concerted process, with its two acyl chains inserting one after the other. Concurrently, a conformational rearrangement involving the alpha-helix III of LC3, especially in the three basic residues Lys(65), Arg(68), and Arg(69), ensures stable insertion of the phosphatidylethanolamine anchor into membranes. Mutational studies validate the crucial role of these residues, and further live-cell imaging analysis shows a substantial reduction in the formation of autophagic vesicles for the mutant proteins. Our study captures the process of water-favored LC3 protein recruitment to the membrane and thus opens, to our knowledge, new avenues to explore the cellular dynamics underlying vesicular trafficking.

Multifaceted core-shell nanoparticles: superparamagnetism and biocompatibility - Sardar, Debasmita; Neogi, S. K.; Bandyopadhyay, Sanjoy; Satpati, Biswarup; Ahir, Manisha; Adhikary, Arghya; Jain, Ruchi; Gopinath, Chinnakonda S.; Bala, Tanushree (New Journal of Chemistry, 2015)
NicoreAgshell nanoparticles were synthesized by redox transmetallation reaction. Reduction potential match was encouraging to attempt the synthesis of the NicoreAushell system too. However, it could be achieved only after an effective surface modification on the Ni-core. Thorough characterization (UV-Vis spectroscopy, fluorescence spectroscopy, XRD, XPS, FTIR, TEM, and EDX) proved the necessity of surface modification and the success of synthesis of both types of core-shell structures. The chemical composition and topography were determined using STEM-HAADF analysis and EFTEM imaging. Fourier transform infrared (FTIR) spectroscopy confirmed the surface modification of Ni nanoparticles and the interactions involved between the ligands and metals (in the core and/or the shell) at various steps of the synthetic process. Even after the formation of the noble metal shell, the magnetic core was found to retain its superparamagnetic nature. In addition, the Au-shell protected the core from aerial oxidation and decreased toxicity as compared to pristine Ni nanoparticles as observed by MTT assay on normal cells (PBMCs).

Multifunctional polyaniline-tin oxide (PANI-SnO2) nanocomposite: synthesis, electrochemical, and field emission investigations - Patil, Sandip S.; Harpale, Kashmira V.; Koiry, Shankar P.; Patil, Kashinath R.; Aswal, Dinesh K.; More, Mahendra A. (Journal of Applied Polymer Science, 2015)
Synthesis of PANI-SnO2 nanocomposite has been performed using a simple two step chemical oxidative polymerization route. The structural, morphological and chemical properties of the as-synthesized PANI-SnO2 nanocomposite have been revealed by various characterization techniques such as SEM, TEM, XRD, FTIR, and XPS. Interestingly the as-synthesized PANI-SnO2 nanocomposite exhibits supercapacitance value of 721 F g(-1) with energy density 64 Wh kg(-1), which is noticed to be higher than that of pristine SnO2 and PANI nanostructures. Furthermore, the galvanostatic charge-discharge characteristics revealed pseudocapacitive nature of the PANI-SnO2 nanocomposite. The estimated values of charge transfer resistance and series resistance estimated from the Nyquist plot are found to be lower. Along with the supercapacitive nature, PANI-SnO2 nanocomposite showed promising field emission behavior. The threshold field, required to draw emission current density of 1 A/cm(2), is observed to be 0.90 V/m and emission current density of 1.2 mA/cm(2) has been drawn at applied field of approximate to 2.6 V/m. The emission current stability investigated at preset values of 0.02 and 0.1 mA/cm(2) is observed to be fairly stable over duration of more than 3 h. The enhanced supercapacitance values, as well as, the promising field emission characteristics are attributed to the synergic effect of SnO2 nanoparticles and PANI nanotubes. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41401.
Keywords: conducting polymers; Electrochemistry; nanostructured polymers; surfaces and interfaces

New imaging reagents for lipid dense regions in live cells and the nucleus in fixed MCF-7 cells - Ramu, Vadde; Ali, Firoj; Taye, Nandaraj; Garai, Bikash; Alam, Aftab; Chattopadhyay, Samit; Das, Amitava (Journal of Materials Chemistry B, 2015)
Two new uracil (U) and 5-flurouracil (5-FU) labeled ruthenium(II)-polypyridyl based cellular imaging reagents are reported. Confocal laser scanning microscopic images with live and paraformaldehyde (PFA) fixed MCF-7 cells are examined using these two low-cytotoxic reagents. Experimental results show that these two complexes, appropriately functionalized with U (1) and 5-FU (2), have specific affinity for the lipid dense regions like the endoplasmic reticulum, cell membrane, and cytoplasmic vacuoles in live MCF-7 cells, and dye internalization in these regions happened following an endocytosis pathway. Interestingly, these two complexes are found to be localized in the nucleus of the PFA fixed cells. For fixed cells, presumably the lipid layer disruption helped in the explicit localization of the complexes 1 and 2 in the cell nucleus through specific interaction with cellular DNA. Poor and non-specific internalization of an analogous model complex 3, without having a U or 5-FU moiety, reveals the definite influence of U or 5-FU as well as the role of lipophilicity of the respective complex 1 and 2 in the cellular internalization process. Apart from these, a large Stokes shift (similar to 160 nm) and an appreciably long lived (MLCT)-M-3 excited state (similar to 320 ns) in aq. buffer medium (pH 7.4) are other key features for complexes 1 and 2. Unlike the common nuclear DNA staining reagents like DAPI, these low-cytotoxic reagents are found to be highly stable towards photo-bleaching upon irradiation with 455 nm at the MLCT band for these complexes.

New poly(ether urethane)s based on lignin derived aromatic chemicals via A-B monomer approach: synthesis and characterization - Kuhire, Sachin S.; Avadhani, C. V.; Wadgaonkar, Prakash P. (European Polymer Journal, 2015)
{omega-Hydroxyalkyleneoxy benzoyl azides were synthesized starting from lignin-derived phenolic acids (vanillic acid and syringic acid) and omega-haloalkanols (6-chlorohexanol and 11-bromoundecanol). These bio-derived A-B monomers were self-polycondensed to afford poly(ether urethane)s which exhibited reasonably high molecular weights (eta(inh) = 0.41-0.69 dL g(-1), and M-n
Keywords: A-B type monomer; Poly(ether urethane)s; Renewable resources; Self-polycondensation

New turn on Pd2+-specific fluorescence probe and its use as an imaging reagent for cellular uptake in Hct116 cells - Reddy, Upendar G.; Ali, Firoj; Taye, Nandaraj; Chattopadhyay, Samit; Das, Amitava (Chemical Communications, 2015)
A new coumarin-rhodamine conjugate is used as a specific probe for Pd2+ ions and this could even delineate Pd(II) from Pd(0) or Pd(IV) in aqueous buffer medium (pH similar to 7). Laser confocal microscopic studies reveal that efficient cellular internalization of this reagent helps in imaging the cellular uptake of Pd2+ as low as 0.1 ppm in Hct 116 cells. This reagent could even be used for estimation of Pd2+ in human urine samples.

Nonomuraea indica sp nov., novel actinomycetes isolated from lime-stone open pit mine, India - Quadri, Syed Raziuddin; Tian, Xin-Peng; Zhang, Jing; Li, Jie; Nie, Guo-Xing; Tang, Shu-Kun; Al Ruwaili, Jamal; Agsar, Dayanand; Li, Wen-Jun; Dastager, Syed Gulam (Journal of Antibiotics, 2015)
A Gram-positive, aerobic, nonmotile actinomycete strain designated DRQ-2(T) was isolated from the soil sample collected from limestone open pit mine from the Gulbarga region, Karnataka province, India. Strain DRQ-2(T) was identified as a member of the genus Nonomuraea by a polyphasic approach. Strain DRQ-2(T) could be differentiated from other members of the genus Nonomuraea on the basis of physiology and 16S rRNA gene sequence analysis. The 16S rRNA gene sequence similarity of strain DRQ-2(T) showed highest sequence similarity to Nonomuraea muscovyensis DSM 45913(T) (99.1%), N. salmonea DSM 43678(T) (98.2%) and N. maheshkhaliensis JCM 13929(T) with 98.0%, respectively. Chemotaxonomic properties showing predominant menaquinones of MK-9 (H-4), MK-9(H-2) and MK-9(H-6), major polar lipids comprised diphosphatidylglycerol, phosphatidylmono methyl ethanolamine (PME), phosphatidylethanolamine (PE), hydroxy-PME (OH-PME), hydroxy PE (OH-PEE), phosphatidylglycerol (PG), ninhydrin-positive phosphoglycolipid and unknown phospholipid, fatty acids with major amounts of i-C-16:0, ai-C-15:0 and ai-C-17:0 supported allocation of the strain to the genus Nonomuraea. Results of DNA-DNA hybridization and physiological tests allowed genotypic and phenotypic differentiation of strain DRQ-2(T) from closely related species. The genomic DNA G+C content of the organism was 72.5 mol%. On the basis of phenotypic, chemotypic and molecular characteristics, strain DRQ-2(T) represents a novel species of the genus Nonomuraea, for which the name N. indica sp. nov. is proposed, with type strain DRQ-2(T) (= NCIM 5480(T) = CCTCC AA 209050(T)).

One-pot highly enantio- and diastereoselective synthesis of anti,anti vinylic 3-amino-1,2 diols via proline catalyzed sequential alpha-amination/benzoyloxyallylation of aldehydes - Ahuja, Brij Bhushan; Sudalai, Arumugam (RSC Advances, 2015)
The first direct asymmetric synthesis of anti, anti vinylic 3-amino-1,2-diols from aldehydes is described via a one-pot sequential L-proline catalyzed alpha-amination/benzoyloxyallylation protocol. The reaction proceeds with exceptionally high diastereoselectivity (>99%) as can be explained based on the Felkin-Ahn transition state model. Its effectiveness is proven unambiguously by demonstrating a short asymmetric synthesis of D-ribo-phytosphingosine tetraacetate (93% ee).

Organocatalytic [4+1]-annulation approach for the synthesis of densely functionalized pyrazolidine carboxylates - Lalwani, Komal G.; Aher, Ravindra D.; Sudalai, Arumugam (RSC Advances, 2015)
A novel one-pot [4+1]-annulation process for the asymmetric synthesis of densely functionalized pyrazolidine carboxylates is described. The in situ generated gamma-hydrazino-alpha,beta-unsaturated ester obtained via proline catalysis acts as a four-atom component, and Corey's sulfur ylide or ethyl bromoacetate acts as a one-atom carbon source to construct pyrazolidine carboxylate units in a highly enantio- and diastereoselective fashion.

Penicillin V acylase from pectobacterium atrosepticum exhibits high specific activity and unique kinetics - Avinash, Vellore Sunder; Ramasamy, Sureshkumar; Suresh, C. G.; Pundle, Archana (International Journal of Biological Macromolecules, 2015)
Penicillin V acylases (PVAs, E.C.3.5.11) belong to the Ntn hydrolase super family of enzymes that catalyze the deacylation of the side chain from phenoxymethyl penicillin (penicillin V). Penicillin acylases find use in the pharmaceutical industry for the production of semi-synthetic antibiotics. PVAs employ the N-terminal cysteine residue as catalytic nucleophile and are structurally and evolutionarily related to bile salt hydrolases (BSHs). Here, we report the cloning and characterization of a PVA enzyme from the Gram-negative plant pathogen, Pectobacterium atrosepticum (PaPVA). The enzyme was cloned and expressed in Escherichia coli attaining a very high yield (250 mg/l) and a comparatively high specific activity (430 IU/mg). The enzyme showed marginally better pH and thermo-stability over PVAs characterized from Gram-positive bacteria. The enzyme also showed enhanced activity in presence of organic solvents and detergents. The enzyme kinetics turned out to be significantly different from that of previously reported PVAs, displaying positive cooperativity and substrate inhibition. The presence of bile salts had a modulating effect on PaPVA activity. Sequence analysis and characterization reveal the distinctive nature of these enzymes and underscore the need to study PVAs from Gram-negative bacteria. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Cooperative; Enzyme kinetics; Gram-negative; Penicillin V acylase; Substrate inhibition

Phosphate enriched polyoxometalate based ionic salts for proton conduction - Dey, Chandan; Kundu, Tanay; Aiyappa, Harshitha Barike; Banerjee, Rahul (RSC Advances, 2015)
A series of [NiMo12O30(PO4)(8)](n-) POM anion and organic cation based ionic composites have been prepared in hydrothermal conditions. The ionic composites with protonated ethylene diamine molecules have been tested for proton conductivity.

Photochemical performance of ZnO nanostructures in dye sensitized solar cells - Das, Partha Pratim; Mukhopadhyay, Soumita; Agarkar, Shruti A.; Jana, Arpita; Devi, P. Sujatha (Solid State Sciences, 2015)
In this work, the photoconversion efficiencies of ZnO having diverse microstructures and structural defects have been investigated. A conversion efficiency of 138% was achieved for the DSSCs fabricated with as prepared ZnO nanorods having minimum vacancy defects and a favourable one dimensional directional pathway for electron conduction. The DSSCs fabricated with ZnO nanoparticles exhibited relatively low conversion efficiency of 1.004% probably due to multiple trapping/detrapping phenomena within the grain boundaries and ZnO flowers though exhibited a high dye adsorption capability exhibited the lowest conversion efficiency of 0.59% due to a high concentration of structural defects. Based on the experimental evidences, we believe that the type of defects and their concentrations are more important than shape in controlling the overall performance of ZnO based DSSCs. (C) 2015 Elsevier Masson SAS. All rights reserved.
Keywords: DSSC; Efficiency; Emission; Structural defects; ZnO

Potent inhibition of miR-27a by neomycin-bisbenzimidazole conjugates - Nahar, Smita; Ranjan, Nihar; Ray, Arjun; Arya, Dev P.; Maiti, Souvik (Chemical Science, 2015)
miRNAs are important components of regulatory networks that control gene expression and have implications in various diseases including cancer. Targeting oncogenic miRNAs with small molecules is currently being explored to develop cancer therapeutics. Here, we report the development of dual binding neomycin-bisbenzimidazole conjugates that target oncogenic miR-27a with high affinity (K-a = 1.2 to 7.4 x 10(8) M-1). These conjugates bring significant reduction (similar to 65% at 5 mu M) in mature miRNA levels and penetrate easily in the cells where they localise both in the cytoplasm and the nucleus. Cell cycle analysis showed significant increase in the G0/G1 phase (similar to 15%) and decrease in the S phase (similar to 7%) upon treatment with neomycin-bisbenzimidazole conjugates, suggesting inhibition of cell proliferation. Using the conjugation approach, we show that moderately binding ligands can be covalently combined into high affinity binders. This study also highlights the role of linker optimization in designing high affinity ligands for miR-27a targeting.

Preparation and characterization of self-photostabilizing UV-durable bionanocomposite membranes for outdoor applications - Kushwaha, Omkar S.; Avadhani, C. V.; Singh, R. P. (Carbohydrate Polymers, 2015)
Here, we report a durable and ultraviolet (UV) resistant nanocomposite membrane of chitosan (CS) with effective photostabilization ascribed to Zinc oxide (ZnO) nanoparticles. Zinc oxide nanoparticles were successfully dispersed in the solution of chitosan polymer. The nanocomposite films with the homogenous dispersion of ZnO nanoparticles in the chitosan matrix were obtained by solution casting method and the influence of ZnO nanoparticles as a photostabilizer was studied. The nanocomposite membranes were photoirradiated by polychromatic radiations with lambda > 300 nm using mercury vapour lamps in SEPAP instrument. The resulting nanocomposite material exhibited excellent UV-resistance in very low percentages of ZnO nanoparticles. The chitosan membranes showed fast degradation attributes than the nanocomposite membranes. ZnO nanoparticles effectively absorbed UV radiations, thus protecting polymer from radiation degradation. The neat and irradiated nanocomposites of chitosan and ZnO nanoparticles (CS/ZnO) were characterized by Fourier Transform Infrared Spectroscopy (FT-IR) spectroscopy for the chemical changes/degradation taking place. Chitosan nanocomposites were further characterized for tensile properties, contact angle measurements and surface morphology. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: Bionanocomposite membrane; Chitosan; Contact angle measurement; Fourier transform infrared spectroscopy; Photostabilization; Zinc oxide nanoparticles

Proline-catalyzed sequential syn-mannich and [4+1]-annulation cascade reactions to form densely functionalized pyrrolidines - Aher, Ravindra D.; Kumar, B. Senthil; Sudalai, Arumugam (Journal of Organic Chemistry, 2015)
A highly efficient one-pot [4 + 1]-annulation process for the asymmetric synthesis of densely functionalized pyrrolidine derivatives is described. The in situ generated syn-Mannich adduct obtained via proline catalysis acts as a four-atom component, and Coreys sulfur ylide or ethyl bromoacetate acts as a one-atom carbon source to construct pyrrolidine units in a highly enantio- and diastereoselective manner.

Reagent for specific recognition of cysteine in aqueous buffer and in natural milk: imaging studies, enzymatic reaction and analysis of whey protein - Anila, H. A.; Reddy, Upendar G.; Ali, Firoj; Taye, Nandaraj; Chattopadhyay, Samit; Das, Amitava (Chemical Communications, 2015)
We report a new chemodosimetric probe (L) for specific recognition of cysteine (Cys) in aqueous buffer and in whey protein isolated from fresh cow's milk. Using this reagent we could develop a luminescence-based methodology for estimation of Cys released from a commercially available Cys-supplement drug by aminoacylase-1 in live cells.

Reduction of graphene oxide by 100 MeV Au ion irradiation and its application as H2O2 sensor - Hareesh, K.; Joshi, R. P.; Shateesh, B.; Asokan, K.; Kanjilal, D.; Late, Dattatray J.; Dahiwale, S. S.; Bhoraskar, Vasant N.; Haram, Santosh K.; Dhole, Sanjay D. (Journal of Physics D-Applied Physics, 2015)
Graphene oxide (GO) synthesized from a modified Hummer's method was reduced (referred, rGO) by using 100 MeV Au ion species and its response to the sense H2O2 was investigated. The changes in the atomic composition and structural properties of rGO after irradiation were studied using x-ray diffraction, Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy. These results suggested that the removal of the oxygen-containing functional groups and the improvement of the electrochemical performance of reduced graphene oxide (rGO) after ion irradiation. Raman spectroscopic results revealed the increase in the disorder parameter (I-D/I-G) after Au ion irradiation and also the formation of a large number of small sp(2) domains due to the electronic energy loss of ion beam. The resultant rGO was investigated for H2O2 sensing using electrochemical techniques and it showed a good response.
Keywords: electronic energy loss; GO; ion beam irradiation; reduction

Regioselective and diastereoselective iodocyclization reaction of alkene-thioureas: an efficient approach to bicyclic beta-lactams - Garud, Dinesh R.; Sonawane, Amol D.; Auti, Jyoti B.; Rode, Navnath D.; Ranpise, Vinod R.; Joshi, Rohini R.; Joshi, Ramesh A. (New Journal of Chemistry, 2015)
Bicyclic beta-lactams, i.e. 3-thia-1-dethiacephams, were synthesized via a highly regioselective and diastereoselective iodocyclization reaction of alkene-thioureas with molecular iodine. Furthermore, the structure of 3-thia-1-dethiacepham was confirmed by a chemical method, the dehydrohalogenation reaction using DBU.

RNA stem-loop to G-quadruplex equilibrium controls mature MicroRNA production inside the cell - Pandey, Satyaprakash; Agarwala, Prachi; Jayaraj, Gopal Gunanathan; Gargallo, Raimundo; Maiti, Souvik (Biochemistry, 2015)
The biological role of the existence of overlapping structures in RNA is possible yet remains very unexplored. G-Rich tracts of RNA form G-quadruplexes, while GC-rich sequences prefer stem-loop structures. The equilibrium between alternate structures within RNA may occur and influence its functionality. We tested the equilibrium between G-quadruplex and stem-loop structure in RNA and its effect on biological processes using pre-miRNA as a model system. Dicer enzyme recognizes canonical stem-loop structures in pre-miRNA to produce mature miRNAs. Deviation from stem-loop leads to deregulated mature miRNA levels, providing readout of the existence of an alternate structure per se G-quadruplex-mediated structural interference in miRNA maturation. In vitro analysis using beacon and Dicer cleavage assays indicated that mature miRNA levels depend on relative amounts of K+: and Mg2+ ions, suggesting an ion-dependent structural shift. Further in cellulo studies with and without TmPyP4 (RNA G-quadruplex destabilizer) demonstrated that miRNA biogenesis is modulated by G-quadruplex to stem-loop equilibrium in a subset of pre-miRNAs. Our combined analysis thus provides evidence of the formation of noncanonical G-quaciruplexes in competition with canonical stem-loop structure inside the cell and its effect on miRNA maturation in a comprehensive manner.

Role of aliovalent cation doping in the activity of nanocrystalline CdS for visible-light-driven H-2 production from water - Korake, Prakash V.; Achary, Srungarpu N.; Gupta, Narendra M. (International Journal of Hydrogen Energy, 2015)
This study was aimed at discerning the enhancement in the visible-light-driven water splitting activity of nanocrystalline CdS photocatalysts because of their doping with a small amount of an aliovalent cation (Ag+ or Cr3+). The CdS/Cr-x (x = 0-2.3 wt%) and CdS/Ag-x (x = 0-1.5 wt%) samples, which were synthesized using a one-step hydrothermal method, were characterized systematically for their crystallographic, morphological, interfacial, and photo-physical properties. The Rietveld refinement of the powder X-ray diffraction data enabled us to quantify the doping-effect on the phase composition and lattice parameters. As compared to pure CdS, the samples containing similar to 0.2 wt% of Cr or Ag showed two or tenfold enhancement in the rate of H-2 evolution from water, respectively, when sulfide-sulfite ions were used as sacrificial electron donors. This pyramidal trend, i.e. maximum activity for a specific impurity content, which decreased on decreasing as well as increasing the amount of doping, did not occur owing to the presence of a secondary-phase metal sulfide or a dispersed metal cocatalyst. Our study revealed that instead of the widely advocated mechanism involving inter-semiconductor or semiconductor-to-metal electron transfer steps, the doping-modified photoactivity of CdS was governed by certain bulk and surface properties such as the cation-dependent particle nucleation, dominance of hex-CdS facets, and structural defects. Additionally, impurity-induced sub-bandgap charge-trapping states also contributed to the overall quantum efficiency. Copyright (C) 2015, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Role of tumor cell surface lysosome-associated membrane protein-1 (LAMP1) and its associated carbohydrates in lung metastasis - Agarwal, Akhil Kumar; Srinivasan, Nithya; Godbole, Rashmi K.; More, Shyam K.; Budnar, Srikanth; Gude, Rajiv P.; Kalraiya, Rajiv D. (Journal of Cancer Research and Clinical Oncology, 2015)
Expression of lysosome-associated membrane protein-1 (LAMP1) on the surface correlates with metastatic potential of B16 melanoma cells. Downregulation of their expression in high metastatic (B16F10) cells reduced their surface expression and metastatic potential. Present investigations explore if overexpression of LAMP1 on the surface of low metastatic (B16F1) cells augment their metastatic ability, and if so, how? B16F1 cells were transduced with lentiviral vector carrying mutant-LAMP1 (Y386A) (mutLAMP1). Surface expression of LAMP1 and carbohydrates was analyzed by flow cytometry, immunofluorescence and/or immunoprecipitation and Western blotting. Cell spreading and motility were assessed on components of extracellular matrix (ECM) (fibronectin) and basement membrane (BM) (matrigel), and galectin-3-coated coverslips/plates. Metastatic potential was assessed using experimental metastasis assay. Pre-incubation with anti-LAMP1 antibodies significantly reduced lung metastasis of B16F10 cells. Overexpression of mutLAMP1 significantly increased its surface expression on B16F1 cells, resulting in increased cellular spreading and motility on fibronectin and matrigel. LAMP1 is the major carrier of poly-N-acetyllactosamine (polyLacNAc) on B16F10 cells. However, significantly higher expression of mutLAMP1 had no effect on galectin-3 binding on cell surface or on spreading or motility of cells on galectin-3-coated coverslips/plates. These cells also failed to show any gain in metastatic ability. This could be because LAMP1 from these cells carried significantly lower levels of polyLacNAc in comparison with B16F10 cells. PolyLacNAc on B16F10 cells and galectin-3 on lungs are the major participants in melanoma metastasis. Although surface LAMP1 promotes interactions with organ ECM and BM, carbohydrates on LAMP1 play a decisive role in dictating lung metastasis.
Keywords: 6 branched N-oligosaccharides; beta 1; Cell surface LAMP1; Galectin-3; Motility; Organ-specific metastasis; Poly-N-acetyllactosamine

Rottlerin derivatives and other compounds from mallotus philippinensis fruits and their potential antimycobactrial activity - Bhardwaj, Rima; Chinchansure, Ashish A.; Kulkarni, Roshan R.; Arkile, Manisha A.; Sarkar, Dhiman; Joshi, Swati P. (Planta Medica Letters, 2015)
The methanolic extract of the fruits of Mallotus philippinensis afforded 13 compounds, 7,11-diketo-lanost-3-ol (1, as acetate), lanosta-8-ene-3β-ol (2, as acetate), pregnenolone (3, as acetate), trans-chalcone (4), kamalachalcone E (5), oleanolic acid (6), gallic acid (7), kaempferol (8), myricetin (9), 1-(5,7-dihydroxy-2,2,6-trimethyl-2 H-1-benzopyran-8-yl)-3-phenyl-2-propen-1-one (10), 4′-hydroxyisorottlerin (11), rottlerin (12), and shikimic acid (13). Compound 1 was isolated as a new natural product and its structure was elucidated by 1D and 2D nuclear magnetic resonance analyses including heteronuclear single quantum correlation, heteronuclear multiple-bond correlation, correlation spectroscopy, and nuclear Overhauser effect spectroscopy experiments. All of the isolated compounds were evaluated for their antimycobacterium activity against Mycobacterium tuberculosis H37Ra. Compounds 11 and 12 exhibited promising inhibitory activity with IC50 values of 0.89 ± 0.33 µg/mL (MIC 2.06 ± 0.41 µg/mL) and 7.59 ± 0.42 µg/mL (MIC 11.56 ± 0.35 µg/mL), respectively.

Selective and sensitive sensing of free bilirubin in human serum using water-soluble polyfluorene as fluorescent probe - Senthilkumar, T.; Asha, S. K. (Macromolecules, 2015)
The adherence of serum protein on conjugated polymer is a major bottleneck in the application of the latter for selective sensing of small biomolecules in blood serum. In this report, we present new polyfluorenes with d-glucuronic acid appendage that is a nonreceptor for any serum protein, thereby providing a platform for selective sensing of free bilirubin in the clinically relevant range of <25 to >50 mu mol/L in human blood serum. The appended d-glucuronic acid formed noncovalent interactions with bilirubin, which in conjunction with favorable spectral overlap between the polymers and bilirubin facilitated efficient FRET process in aqueous solutions. Addition of bilirubin resulted in the quenching of the polyfluorene emission with simultaneous appearance of bilirubin emission exhibiting visual emission color change from blue to light green. The polymer remained stable in serum even under severe basic conditions and exhibited high selectivity with visual sensitivity only toward free bilirubin in human serum in the presence of crucial interferences such as hemoglobin, proteins, biliverdin, glucose, cholesterol, and metal ions. Nanomolar sensing of bilirubin could also be demonstrated successfully using one of the d-glucuronic acid appended polymer (PF-Ph-GlcA), which could sense similar to 150 nm of bilirubin in human serum. The combined role of energy transfer and noncovalent interaction highlights the potential of the new polymer design for highly selective sensing activity in complex biofluids.

Self-assembled vertically aligned gold nanorod super-lattices for ultra-high sensitive detection of molecules - Apte, Amey; Bhaskar, Prashant; Das, Raja; Chaturvedi, Smita; Poddar, Pankaj; Kulkarni, Sulabha (Nano Research, 2015)
We show that self-assembled vertically aligned gold nanorod (VA-GNRs) superlattices can serve as probes or substrates for ultra-high sensitive detection of various molecules. D-glucose and 2,4,6-trinitrotoluene (TNT) have been chosen as model systems due to their very low Raman cross-sections (5.6 x 10(-30) cm(2).molecule(-1).sr(-1) for D-glucose and 4.9 x 10(-31) cm(2). molecule(-1).sr(-1) for TNT) to show that the VA-GNR superlattice assembly offers as low as yoctomole sensitivity. Our experiment on mixed samples of bovine serum albumin (BSA) and D-glucose solutions demonstrate sensitivity for the latter, and the possible extension to real samples. Self-assembled superlattices of VA-GNRs were achieved on a silicon wafer by depositing a drop of solvent containing the GNRs and subsequent solvent evaporation in ambient conditions. An additional advantage of the VA-GNR monolayers is their extremely high reproducible morphology accompanied by ultrahigh sensitivity which will be useful in many fields where a very small amount of analyte is available. Moreover the assembly can be reused a number of times after removing the already present molecules. The method of obtaining VA-GNRs is simple, inexpensive and reproducible. With the help of simulations of monolayers and multilayers it has been shown that superlattices can achieve better sensitivity than monolayer assembly of VA-GNRs.
Keywords: Nanostructures; Raman spectroscopy; self-assemblies; sensors; superlattices

Self-assembly directed template photopolymerization of perylenebisimide-poly (4-vinylpyridine): nano organization - Shinde, Shekhar; Asha, S. K. (Polymer, 2015)
A perylene bisimide derivative (PDP-UPBIAcry) having hydroxyl moieties at one termini and polymerizable acrylic units at the other termini was supramolecularly complexed with the pyridine units of Poly (4-vinyl pyridine) (P4VP), followed by photoinduced polymerization of the acrylic units to obtain lamellar organization in the <10 nm range. H-1 NMR studies including variable temperature (20 degrees C-70 degrees C) measurements were undertaken in DMSO-d(6) (anhydrous, extra dry) to understand the interaction between PDP-UPBIAcry and P4VP. The aromatic perylene protons of PDP-UPBIAcry registered an upfield chemical shift while the pyridine protons of P4VP exhibited small downfield shift in their 1:1 supramolecular complex. The hydrogen bonding interaction between pyridyl nitrogen and phenolic OH group was also traced in non-polar media like CDCl3 in model complexes of 4-vinyl pyridine (4VP) with PDP-UPBIAcry. Wide angle X-ray diffraction (WXRD) technique was used to study the bulk structure. Transmission electron microscopy (TEM) imaging revealed highly ordered layered assembly formed upon complexation. Observation from DFT energy minimization studies were correlated with X-ray diffraction data of the supramolecular complex [P4VP (PDP-UPBIAcry)](1.0) to understand the nature of packing of PDP-UPBIAcry that lead to the formation of highly ordered lamellar stacks alternating with P4VP. The higher ordering in the supramolecular polymer complex was also confirmed by the quenching of fluorescence and reduced fluorescence life times of thin solid films of the [P4VP Poly(PDP-UPBIAcry)](1.0) sample. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: hydrogen bonding; P4VP; Perylenebisimide

Self-similar rupture of thin free films of power-law fluids - Thete, Sumeet Suresh; Anthony, Christopher; Basaran, Osman A.; Doshi, Pankaj (Physical Review E, 2015)
The rupture of a thin free film of a power-law fluid under the competing influences of destabilizing van der Waals pressure and stabilizing surface tension pressure is analyzed. In such a fluid, viscosity decreases with the deformation rate raised to the n - 1 power where 0 < n <= 1 (n = 1 for a Newtonian fluid). When 6/7 < n <= 1, film rupture occurs under a balance between van der Waals pressure, inertial stress, and viscous stress. When n < 6/7, however, the dominant balance changes: Viscous stress becomes negligible and the film ruptures under the competition between van der Waals pressure, inertial stress, and surface tension pressure.

Simple recovery of intracellular gold nanoparticles from peanut seedling roots - Raju, D.; Mehta, Urmil J.; Ahmad, Absar (Journal of Nanoscience and Nanotechnology, 2015)
Fabrication of inorganic nanomaterials via a biological route witnesses the formation either extracellularly, intracellulary or both. Whereas extracellular formation of these nanomaterials is cherished owing to their easy and economical extraction and purification processes; the intracellular formation of nanomaterials, due to the lack of a proper recovery protocol has always been dreaded, as the extraction processes used so far were tedious, costly, time consuming and often resulting in very low recovery. The aim of the present study was to overcome the problems related with the extraction and recovery of intracellularly synthesized inorganic nanoparticles, and to devise a method to increasing the output, the shape, size, composition and dispersal of nanoparticles is not altered. Water proved to be much better system as it provided well dispersed, stable gold nanoparticles and higher recovery. This is the first report, where intracellular nanoparticles have been recovered using a very cost-effective and eco-friendly approach.
Keywords: gold nanoparticles; Peanut; Recovery; Sonication; Water

Single-layer graphene-assembled 3D porous carbon composites with PVA and Fe3O4 nano-fillers: an interface-mediated superior dielectric and EMI shielding performance - Rao, B. V. Bhaskara; Yadav, Prasad; Aepuru, Radhamanohar; Panda, H. S.; Ogale, Satishchandra; Kale, S. N. (Physical Chemistry Chemical Physics, 2015)
In this study, a novel composite of Fe3O4 nanofiller-decorated single-layer graphene-assembled porous carbon (SLGAPC) with polyvinyl alcohol (PVA) having flexibility and a density of 0.75 g cm(-3) is explored for its dielectric and electromagnetic interference (EMI) response properties. The composite is prepared by the solution casting method and its constituents are optimized as 15 wt% SLGAPC and 20 wt% Fe3O4 through a novel solvent relaxation nuclear magnetic resonance experiment. The PVA-SLGAPC-Fe3O4 composite shows high dielectric permittivity in the range of 1 Hz-10 MHz, enhanced by a factor of 4 as compared to that of the PVA-SLGAPC composite, with a reduced loss by a factor of 2. The temperature dependent dielectric properties reveal the activation energy behaviour with reference to the glass transition temperature (80 degrees C) of PVA. The dielectric hysteresis with the temperature cycle reveals a remnant polarization. The enhanced dielectric properties are suggested to be the result of improvement in the localized polarization of the integrated interface system (Maxwell-Wagner-Sillars (MWS) polarization) formed by the uniform adsorption of Fe3O4 on the surface of SLGAPC conjugated with PVA. The EMI shielding property of the composite with a low thickness of 0.3 mm in the X-band (8.2-12.4 GHz) shows a very impressive shielding efficiency of similar to 15 dB and a specific shielding effectiveness of 20 dB (g cm(-3))(-1), indicating the promising character of this material for flexible EMI shielding applications.

Situ preparation of N-TiO2/graphene nanocomposite and its enhanced photocatalytic hydrogen production by H2S splitting under solar light - Bhirud, Ashwini P.; Sathaye, Shivaram D.; Waichal, Rupali P.; Ambekar, Jalindar D.; Park, Chan-J.; Kale, Bharat B. (Nanoscale, 2015)
Highly monodispersed nitrogen doped TiO2 nanoparticles were successfully deposited on graphene (N-TiO2/Gr) by a facile in-situ wet chemical method for the first time. N-TiO2/Gr has been further used for photocatalytic hydrogen production using a naturally occurring abundant source of energy i.e. solar light. The N-TiO2/Gr nanocomposite composition was optimized by varying the concentrations of dopant nitrogen and graphene (using various concentrations of graphene) for utmost hydrogen production. The structural, optical and morphological aspects of nanocomposites were studied using XRD, UV-DRS, Raman, XPS, FESEM, and TEM. The structural study of the nanocomposite shows existence of anatase N-TiO2. Further, the details of the components present in the composition were confirmed with Raman and XPS. The morphological study shows that very tiny, 7-10 nm sized, N-TiO2 nanoparticles are deposited on the graphene sheet. The optical study reveals a drastic change in absorption edge and consequent total absorption due to nitrogen doping and presence of graphene. Considering the extended absorption edge to the visible region, these nanocomposites were further used as a photocatalyst to transform hazardous H2S waste into eco-friendly hydrogen using solar light. The N-TiO2/Gr nanocomposite with 2% graphene exhibits enhanced photocatalytic stable hydrogen production i.e. similar to 5941 mu mol h(-1) under solar light irradiation using just 0.2 gm nanocomposite, which is much higher as compared to P25, undoped TiO2 and TiO2/Gr nanocomposite. The enhancement in the photocatalytic activity is attributed to `N' doping as well as high specific surface area and charge carrier ability of graphene. The recycling of the photocatalyst shows a good stability of the nanocomposites. This work may provide new insights to design other semiconductor deposited graphene novel nanocomposites as a visible light active photocatalyst.

Solid state organic amine detection in a photochromic porous metal organic framework - Mallick, Arijit; Garai, Bikash; Addicoat, Matthew A.; Petkov, Petko St.; Heine, Thomas; Banerjee, Rahul (Chemical Science, 2015)
A new Mg(II) based photochromic porous metal-organic framework (MOF) has been synthesized bearing naphthalenediimide (NDI) chromophoric unit. This MOF (Mg-NDI) shows instant and reversible solvatochromic behavior in presence of solvents with different polarity. Mg-NDI also exhibits fast and reversible photochromism via radical formation. Due to the presence of electron deficient NDI moiety, this MOF exhibits selective organic amine (electron rich) sensing in solid state. The organic amine detection has been confirmed by photoluminescence quenching experiment and visual color change.

Specific reagent for Cr(III): imaging cellular uptake of Cr(III) in Hct116 cells and theoretical rationalization - Ali, Firoj; Saha, Sukdeb; Maity, Arunava; Taye, Nandaraj; Si, Mrinal Kanti; Suresh, E.; Ganguly, Bishwajit; Chattopadhyay, Samit; Das, Amitava (Journal of Physical Chemistry B, 2015)
A new rhodamine-based reagent (L-1), trapped inside the micellar structure of biologically benign Triton-X 100, could be used for specific recognition of Cr(III) in aqueous buffer medium having physiological pH. This visible light excitable reagent on selective binding to Cr(III) resulted in a strong fluorescence turn-on response with a maximum at similar to 583 nm and tail of that luminescence band extended until 650 nm, an optical response that is desired for avoiding the cellular autofluorescence. Interference studies confirm that other metal ions do not interfere with the detection process of Cr(III) in aqueous buffer medium having pH 7.2. To examine the nature of binding of Cr(III) to L-1, various spectroscopic studies are performed with the model reagent L-1 which tend to support Cr(III)-eta(2)-olefin pi-interactions involving two olefin bonds in molecular probe L-1. Computational studies are also performed with another model reagent L-M to examine the possibility of such Cr(III)-eta(2)-olefin pi-interactions. Presumably, polar functional groups of the model reagent L-M upon coordination to the Cr(III) center effectively reduce the formal charge on the metal ion and this is further substantiated by results of the theoretical studies. This assembly is found to be cell membrane permeable and shows insignificant toxicity toward live colon cancer cells (Hct116). Confocal laser scanning microscopic studies further revealed that the reagent L-1 could be used as an imaging reagent for detection of cellular uptake of Cr(III) in pure aqueous buffer medium by Hct116 cells. Examples of a specific reagent for paramagnetic Cr(III) with luminescence ON response are scanty in the contemporary literature. This ligand design helped us in achieving the turn on response by utilizing the conversion from spirolactam to an acyclic xanthene form on coordination to Cr(III).

Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents - Sengupta, Pranesh; Mishra, Raman K.; Soudamini, N.; Sen, D.; Mazumder, S.; Kaushik, Chetan P.; Ajithkumar, Thalasseril G.; Banerjee, K. (Journal of Nuclear Materials, 2015)
Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as `glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. Al-27 and Si-29 NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 degrees C, 800 h exposure) are found to be 0.38 x 10(3) mu my(-1), 0.13 x 10(3) mu my(-1) and 4.75 x 10(3) mu my(-1) respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Interaction between refractory material and hazardous liquid; Nuclear waste immobilization; Vitrification melter

Sulfuryl chloride promoted gem-dichlorination-dehydrochlorination in alkyl benzothiazinylacetates: synthesis of the skeleton of trichochrome pigments - Jangir, Ravi; Gadre, Smita R.; N. P. Argade (Synthesis-Stuttgart, 2015)
Chemo- and stereoselective total synthesis of the basic trichochrome skeleton is described starting from o-aminothiophenol and maleic anhydride in very good overall yield. The process involves the synthesis of the corresponding 1,4-benzothiazin-2-ylacetates followed by their sulfuryl chloride induced dihalogenation-dehydrohalogenation and a second condensation with o-aminothiophenol as key steps.
Keywords: condensations; halogenation; maleic anhydride; o-aminothiophenol; trichochrome framework

Supported imidazole as heterogeneous catalyst for the synthesis of cyclic carbonates from epoxides and CO2 - Sankar, Meenakshisundaram; Ajithkumar, Thalasseril G.; Sankar, Gopinathan; Manikandan, Palanichamy (Catalysis Communications, 2015)
Imidazole anchored onto a silica matrix, by means of a propyl linkage, is found to be an effective heterogeneous catalyst for the synthesis of cyclic carbonates from epoxides and CO2 in near quantitative yield. The versatility of this catalyst is demonstrated by using different substrates (epichlorohydrin, propylene oxide, butylene oxide and styrene oxide) for this cycloaddition reaction. These CO2 insertion reactions were typically carried out in the temperature range of 343 to 403 K at 0.6 MPa CO2 pressure under solvent-free conditions. Several spectroscopic methods were used to characterize the catalyst and study the integrity of the fresh and spent catalysts. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Anchored imidazole; CO2 utilization; cyclic carbonates; epoxides

Supramolecular scaffolds on glass slides as sugar based rewritable sensors for bacteria - Gade, Madhuri; Paul, Ajay; Alex, Catherine; Choudhury, Devika; Thulasiram, Hirekodathakallu V.; Kikkeri, Raghavendra (Chemical Communications, 2015)
We describe here the sugar functionalized beta-cyclodextrin-ferrocene glass slides as fully reversible bacterial biosensors under the influence of external adamantane carboxylic acid. The prototype D-mannose - E. coli ORN 178 and L-fucose - P. aeruginosa interactions serve as a model to illustrate the new approach.

Synthesis and evaluation of thieno[2,3-d]pyrimidin-4(3H)-ones as potential antitubercular agents - Borate, Hanumant B.; Annadate, Ritesh A.; Vagh, Sandip S.; Pisal, Mahesh M.; Deokate, Sagar B.; Arkile, Manisha A.; Jadhav, Nandadeep J.; Nawale, Laxman U.; Sarkar, Dhiman (MedChemComm, 2015)
A number of thieno[2,3-d]pyrimidin-4(3H)-ones were designed, synthesized and screened against Mycobacteria as a part of our program to develop new antitubercular agents. It was observed that some of the compounds have significant antimycobacterial activity against Mycobacterium tuberculosis H37Ra (ATCC 25177) and Mycobacterium bovis BCG (ATCC 35743). The active compounds were studied for cytotoxicity against four cell lines and were found to be non-cytotoxic. The results showed that compounds 13b and 29e were found to exhibit very good antimycobacterial activity (MIC in the range of 6-8 mu M) and the thienopyrimidinones as a class have potential to be developed as antitubercular agents.

Synthesis of N, F and S co-doped graphene quantum dots - Kundu, Sumana; Yadav, Ram Manohar; Narayanan, T. N.; Shelke, Manjusha V.; Vajtai, Robert; Ajayan, Pulickel M.; Pillai, Vijayamohanan K. (Nanoscale, 2015)
Graphene quantum dots (GQDs) are a promising category of materials with remarkable size dependent properties like tunable bandgap and photoluminescence along with the possibility of effective chemical functionalization. Doping of GQDs with heteroatoms is an interesting way of regulating their properties. Herein, we report a facile and scalable one-step synthesis of luminescent GQDs, substitutionally co-doped with N, F and S, of similar to 2 nm average size by a microwave treatment of multi-walled carbon nanotubes in a customized ionic liquid medium. The use of an ionic liquid coupled with the use of a microwave technique enables not only an ultrafast process for the synthesis of co-doped GQDs, but also provides excellent photoluminescence quantum yield (70%), perhaps due to the interaction of defect clusters and dopants.

Synthesis of yangjinhualine A - Deore, Prashant S.; Batwal, Ramesh U.; N. P. Argade (Synthesis-Stuttgart, 2015)
Selective reduction of 3-(4-hydroxyphenyl)-2-methylmaleic anhydride provides access the corresponding gamma-hydroxybutenolide natural product yangjinhualine A.
Keywords: anhydrides; lactones; Natural products; reduction; Regioselectivity

Tale of RNA G-quadruplex - Agarwala, Prachi; Pandey, Satyaprakash; Maiti, Souvik (Organic & Biomolecular Chemistry, 2015)
G-quadruplexes are non-canonical secondary structures found in guanine rich regions of DNA and RNA. Reports have indicated the wide occurrence of RNA G-quadruplexes across the transcriptome in various regions of mRNAs and non-coding RNAs. RNA G-quadruplexes have been implicated in playing an important role in translational regulation, mRNA processing events and maintenance of chromosomal end integrity. In this review, we summarize the structural and functional aspects of RNA G-quadruplexes with emphasis on recent progress to understand the protein/trans factors binding these motifs. With the revelation of the importance of these secondary structures as regulatory modules in biology, we have also evaluated the various advancements towards targeting these structures and the challenges associated with them. Apart from this, numerous potential applications of this secondary motif have also been discussed.

Temperature-dependent raman spectroscopy of titanium trisulfide (TiS3) nanoribbons and nanosheets - Pawbake, Amit S.; Island, Joshua O.; Flores, Eduardo; Ramon Ares, Jose; Sanchez, Carlos; Ferrer, Isabel J.; Jadkar, Sandesh R.; van der Zant, Herre S. J.; Castellanos-Gomez, Andres; Late, Dattatray J. (ACS Applied Materials & Interfaces, 2015)
Titanium trisulfide (TiS3) has recently attracted the interest of the 2D community because it presents a direct bandgap of similar to 1.0 eV, shows remarkable photoresponse, and has a predicted carrier mobility up to 10000 cm(2) V-1 s(-1). However, a study of the vibrational properties of TiS3, relevant to understanding the electron-phonon interaction that can be the main mechanism limiting the charge carrier mobility, is still lacking. In this work, we take the first steps to study the vibrational properties of TiS3 through temperature-dependent Raman spectroscopy measurements of TiS3 nanoribbons and nanosheets. Our investigation shows that all the Raman modes linearly soften (red shift) as the temperature increases from 88 to 570 K due to anharmonic vibrations of the lattice, which also includes contributions from the lattice thermal expansion. This softening with the temperature of the TiS3 modes is more pronounced than that observed in other 2D semiconductors, such as MoS2, MoSe2, WSe2, and black phosphorus (BP). This marked temperature dependence of the Raman spectra could be exploited to determine the temperature of TiS3 nanodevices by using Raman spectroscopy as a noninvasive and local thermal probe. Interestingly, the TiS3 nanosheets show a stronger temperature dependence of the Raman modes than the nanoribbons, which we attribute to lower interlayer coupling in the nanosheets.
Keywords: 2D semiconductors; layered materials; Raman spectroscopy; thermal effect; TiS3 nanoribbons; TiS3 nanosheets

Terahertz spectroscopy and solid-state density functional theory calculations of cyanobenzaldehyde isomers - Dash, Jyotirmayee; Ray, Shaurnik; Nallappan, Kathirvel; Kaware, Vaibhav; Basutkar, Nitin B.; Gonnade, Rajesh G.; Ambade, Ashootosh V.; Joshi, Kavita; Pesala, Bala (Journal of Physical Chemistry A, 2015)
Spectral signatures in the terahertz (THz) frequency region are mainly due to bulk vibrations of the molecules. These resonances are highly sensitive to the relative position of atoms in a molecule as well as the crystal packing arrangement. To understand the variation of THz resonances, THz spectra (2-10 THz) of three structural isomers: 2-, 3-, and 4-cyanobenzaldehyde have been studied. THz spectra obtained from Fourier transform infrared (FTIR) spectrometry of these isomers show that the resonances are distinctly different especially below 5 THz. For understanding the intermolecular interactions due to hydrogen bonds, four molecule cluster simulations of each of the isomers have been carried out using the B3LYP density functional with the 6-31G(d,p) basis set in Gaussian09 software and the compliance constants are obtained. However, to understand the exact reason behind the observed resonances, simulation of each isomer considering the full crystal structure is essential. The crystal structure of each isomer has been determined using X-ray diffraction (XRD) analysis for carrying out crystal structure simulations. Density functional theory (DFT) simulations using CRYSTAL14 software, utilizing the hybrid density functional B3LYP, have been carried out to understand the vibrational modes. The bond lengths and bond angles from the optimized structures are compared with the XRD results in terms of root-mean-square-deviation (RMSD) values. Very low RMSD values confirm the overall accuracy of the results. The simulations are able to predict most of the spectral features exhibited by the isomers. The results show that low frequency modes (<3 THz) are mediated through hydrogen bonds and are dominated by intermolecular vibrations.

Thermodynamic and kinetic characterization of transmembrane helix association - Pawar, Aiswarya B.; Deshpande, Sneha A.; Gopal, Srinivasa M.; Wassenaar, Tsjerk A.; Athale, Chaitanya A.; Sengupta, Durba (Physical Chemistry Chemical Physics, 2015)
The transient dimerization of transmembrane proteins is an important event in several cellular processes and computational methods are being increasingly used to quantify their underlying energetics. Here, we probe the thermodynamics and kinetics of a simple transmembrane dimer to understand membrane protein association. A multi-step framework has been developed in which the dimerization profiles are calculated from coarse-grain molecular dynamics simulations, followed by meso-scale simulations using parameters calculated from the coarse-grain model. The calculated value of Delta G(assoc) is approx. -20 kJ mol(-1) and is consistent between three methods. Interestingly, the meso-scale stochastic model reveals low dimer percentages at physiologically-relevant concentrations, despite a favorable Delta G(assoc). We identify generic driving forces arising from the protein backbone and lipid bilayer and complementary factors, such as protein density, that govern self-interactions in membranes. Our results provide an important contribution in understanding membrane protein organization and linking molecular, nano-scale computational studies to meso-scale experimental data.

Trifunctional mesoporous silica-based, highly active catalyst for one-pot, three-step cascade reactions - Biradar, Ankush V.; Patil, Vijayshinha S.; Chandra, Prakash; Doke, Dhananjay S.; Asefa, Tewodros (Chemical Communications, 2015)
We report the synthesis of a trifunctional catalyst containing amine, sulphonic acid and Pd nanoparticle catalytic groups anchored on the pore walls of SBA-15. The catalyst efficiently catalyzes one-pot three-step cascade reactions comprising deacetylation, Henry reaction and hydrogenation, giving up to similar to 100% conversion and 92% selectivity to the final product.

Triterpenoid profiling and functional characterization of the initial genes involved in isoprenoid biosynthesis in neem (Azadirachta indica) - Pandreka, Avinash; Dandekar, Devdutta S.; Haldar, Saikat; Uttara, Vairagkar; Vijayshree, Shinde G.; Mulani, Fayaj A.; Aarthy, Thiagarayaselvam; Thulasiram, Hirekodathakallu V. (BMC Plant Biology, 2015)
Background: Neem tree (Azadirachta indica) is one of the richest sources of skeletally diverse triterpenoids and they are well-known for their broad-spectrum pharmacological and insecticidal properties. However, the abundance of Neem triterpenoids varies among the tissues. Here, we delineate quantitative profiling of fifteen major triterpenoids across various tissues including developmental stages of kernel and pericarp, flower, leaf, stem and bark using UPLC-ESI (+)-HRMS based profiling. Transcriptome analysis was used to identify the initial genes involved in isoprenoid biosynthesis. Based on transcriptome analysis, two short-chain prenyltransferases and squalene synthase (AiSQS) were cloned and functionally characterized. Results: Quantitative profiling revealed differential abundance of both total and individual triterpenoid content across various tissues. RNA from tissues with high triterpenoid content (fruit, flower and leaf) were pooled to generate 79.08 million paired-end reads using Illumina GA.. platform. 41,140 transcripts were generated by d e novo assembly. Transcriptome annotation led to the identification of the putative genes involved in isoprenoid biosynthesis. Two short-chain prenyltransferases, geranyl diphosphate synthase (AiGDS) and farnesyl diphosphate synthase (AiFDS) and squalene synthase (AiSQS) were cloned and functionally characterized using transcriptome data. RT-PCR studies indicated five-fold and ten-fold higher relative expression level of AiSQS in fruits as compared to leaves and flowers, respectively. Conclusions: Triterpenoid profiling indicated that there is tissue specific variation in their abundance. The mature seed kernel and initial stages of pericarp were found to contain the highest amount of limonoids. Furthermore, a wide diversity of triterpenoids, especially C-seco triterpenoids were observed in kernel as compared to the other tissues. Pericarp, flower and leaf contained mainly ring-intact triterpenoids. The initial genes such as AiGDS, AiFDS and AiSQS involved in the isoprenoids biosynthesis have been functionally characterized. The expression levels of AiFDS and AiSQS were found to be in correlation with the total triterpenoid content in individual tissues.
Keywords: Azadirachta indica; Quantitative profiling; Transcriptome; Triterpenoids

Tuning magnetic behavior of nanoscale cobalt sulfide and its nanocomposite with an engineering thermoplastic - Rumale, Narendra; Arbuj, Sudhir S.; Umarji, Govind; Shinde, Manish; Mulik, Uttam P.; Joy, Pattayil Alias; Amalnerkar, Dinesh P. (Journal of Electronic Materials, 2015)
Nanocomposites containing magnetic nanoparticles embedded in a polymer matrix with good thermal stability (up to 200A degrees C) are technologically important. We report an environmentally benign solid-solid approach for synthesis of cobalt sulfide and its nanocomposite using a thermally stable matrix of polyphenylene sulfide. Physicochemical characterizations reveal the formation of nanoclusters of the hexagonal phase CoS. Even though bulk CoS is nonmagnetic, magnetization studies exhibit anomalous magnetic behavior for phase-pure nanoscale CoS and its nanocomposites.
Keywords: Nanocomposite; polyphenylene sulfide; Solid-solid reaction; superparamagnetic

Tuning of multiple luminescence outputs and white-light emission from a single gelator molecule through an ESIPT coupled AIEE process - Maity, Arunava; Ali, Firoj; Agarwalla, Hridesh; Anothumakkool, Bihag; Das, Amitava (Chemical Communications, 2015)
A unique example of an ESIPT coupled AIEE process, associated with a single molecule (1), is utilized for generating multiple luminescent colors (blue-green-white-yellow). The J-aggregated state of 1 forms a luminescent gel in THF and this luminescent property is retained even in the solid state.

Unimolecular antiparallel G-quadruplex folding topology of 2'-5'-isoTBA sequences remains unaltered by loop composition - Aher, Manisha N. (Organic & Biomolecular Chemistry, 2015)
<div class="block-record-info" style="margin: 0px 22px 22px; list-style: none; padding: 0px; line-height: 20px; font-size: 13px; color: rgb(51, 51, 51); font-family: arial, helvetica, sans-serif; background-color: rgb(248, 248, 248);"> A 2'-5'-linked isoTBA 15 mer sequence with (232) loop composition formed stable antiparallel quadruplex structures similar to the SELEX derived 15 mer TBA sequence with (232) loop composition. A parallel versus antiparallel topology of 3'-5'-G-quadruplexes is largely dictated by the loop length, and it is known that the truncated loops favour parallel quadruplexes. In contrast to TBA, systematic reduction of the loop length in isoTBA from (232) to (222), (131) or even (111) did not alter the antiparallel topology of the resulting 14 mer, 13 mer and 11 mer G-rich modified isoTBA-like sequences.

Vanadium in borosilicate glass - Sengupta, Pranesh; Dey, Krishna K.; Halder, Rumu; Ajithkumar, Thalasseril G.; Abraham, Geogy; Mishra, Raman K.; Kaushik, Chetan P.; Dey, Goutam K. (Journal of the American Ceramic Society, 2015)
Understanding the role of V2O5 within borosilicate glass matrices is important for the development of novel matrices toward immobilization of sulfate containing high-level nuclear wastes. Present investigation shows, within sodium barium borosilicate glass matrix V2O5 can be homogeneously added up to 5mol% and beyond which it separates out into three phases, for example, (i) silica (ii) Barium (Ba) - Vanadium (V) oxide, and (iii) glass matrix. Si-29 MAS NMR (Nuclear Magnetic Resonance) studies of the samples show that below 5mol% V2O5 addition, silicate network is dominantly constituted of Q(2) and Q(3) structural units, whereas above this, the network gets more polymerized through formation of Q(3) and Q(4) units. In case of borate network, B-11 MAS NMR investigations revealed that the concentration of BO4 [(0B, 4Si)] unit increases gradually up to 5mol% and then it decreases at the cost of BO4 [(1B, 3Si)], BO3 (symmetric) and BO3 (asymmetric) units. Micro-Raman analyses of the samples showed that with additions of V2O5 in diluted concentrations, amorphous silicate network remained unaltered, whereas some amplification in signals corresponding to ring-type metaborate and VO5 units exists. It is therefore apparent from both MAS-NMR and micro-Raman studies that with V2O5 additions within the solubility limit (5mol%), borate network gets depolymerized leading to decrease in hardness from an average value of 5.0-4.2GPa.

Visible light-triggered disruption of micelles of an amphiphilic block copolymer with BODIPY at the junction - Patil, Naganath G.; Basutkar, Nitin B.; Ambade, Ashootosh V. (Chemical Communications, 2015)
A visible light-cleavable polymer is synthesised to overcome the limitations of UV-sensitive polymers. Photocleavable BODIPY functionalized with an ATRP initiator and alkyne was used to obtain an amphiphilic block copolymer by conducting the click reaction and polymerization simultaneously. Micellar assembly of the polymer was disintegrated under visible light irradiation with controlled release of cargo.

Whole-cell mediated 11 beta-hydroxylation on the basic limonoid skeleton by cunninghamella echinulata - Haldar, Saikat; Mulani, Fayaj A.; Aarthy, Thiagarayaselvam; Thulasiram, Hirekodathakallu V. (Journal of Organic Chemistry, 2015)
Regio- and stereoselective 11 beta-hydroxylation was achieved on the basic limonoid skeleton through microbial transformation. Whole cells of Cunninghamella echinulata efficiently converted basic limonoids such as epoxyazadiradione, azadiradione, and gedunin to their 11 beta-hydroxy analogues as the sole metabolite. Fermentation conditions affecting the efficiency (96%) of biotransformation including substrate concentration, incubation period, pH, and temperature were optimized. The position and stereochemistry of hydroxyl functionality on the isolated metabolites were established through extensive spectroscopic and spectrometric studies (1D, 2D NMR, ESI-MS, and MS/MS).

Zinc inhibits glycation induced structural, functional modifications in albumin and protects erythrocytes from glycated albumin toxicity - Tupe, Rashmi; Kulkarni, Amruta; Adeshara, Krishna; Sankhe, Neena; Shaikh, Shamim; Dalai, Sayli; Bhosale, Siddharth H.; Gaikwad, Sushama M. (International Journal of Biological Macromolecules, 2015)
The present work aims to investigate the concentration and time dependant effect of zinc on the in vitro non enzymatic modifications of albumin by diabetic levels of glucose. Further, preventive and curative effect of zinc was studied by adding zinc before and after initiation of glycation respectively. Glycation of albumin was done at different concentrations of zinc (125, 250 and 500 mu M) at different time intervals (21,28 and 35 days) with appropriate controls. The antiglycation potential of zinc was assessed by estimating different markers of albumin glycation (fructosamines, carbonyls, bound sugar, AGEs), structural modifications (free amino, thiol group, beta amyloid, native PAGE, ANS binding, fluorescence lifetime decay and CD analysis) and functional properties (antioxidant activity, hemolysis). Zinc at highest concentration (500 mu M) significantly reduced modifications of albumin which was comparable to aminoguanidine and also protected secondary and tertiary structure of albumin after 28 days of incubation. Zinc exhibited significant protective effect on erythrocytes by inhibiting hemolysis. Thus the present study indicate preventive mode of albumin glycation inhibition by zinc. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: Albumin; Erythrocytes; Glycation

10000-Fold enhancement in proton conduction by doping of cesium ions in a proton-conducting zwitterionic metal-organic framework - Shalini, Sorout; Aggarwal, Shubhangi; Singh, Santosh K.; Dutt, Malvika; Ajithkumar, Thallaseril G.; Vaidhyanathan, Ramanathan (European Journal of Inorganic Chemistry, 2016)
Developing metal-organic framework (MOF)-based proton-conducting electrolytes for fuel-cell applications is an important target that has drawn a lot of attention. A key approach involves the selective replacement of the guest species within the pores to enhance performance. The modular and crystalline nature of the MOF permits controlled introduction of such species and characterization of their compositions with high precision, a task which is very difficult to achieve in amorphous polymers. Herein, we partially replaced the protons of a zwitterionic pyridinol in Mg(terephthalate)(pyridinol) MOF 1 with Cs+ ions, which brought about a 10000-fold increase in the proton conductivity (10(-6) to 10(-2) S cm(-1)). Interestingly, Li+ ions could not be loaded, whereas Cs+ ions with smaller hydrated ionic radii could be loaded, and the loading was controlled as a function of time. The Cs+ loading nearly halved the activation energy (from 0.35 for 1 to 0.19 eV for _Cs). The highest conductivities were realized for an optimal loading of Cs+ ions, which was found to be about 10 % in this case.

1000-fold enhancement in proton conductivity of a MOF using post-synthetically anchored proton transporters - Shalini, Sorout; Dhavale, Vishal M.; Eldho, Kavalakal Mathai; Kurungot, Sreekumar; Ajithkumar, Thalasseril G.; Vaidhyanathan, Ramanathan (Scientific Reports, 2016)
Pyridinol, a coordinating zwitter-ionic species serves as stoichiometrically loadable and non-leachable proton carrier. The partial replacement of the pyridinol by stronger hydrogen bonding, coordinating guest, ethylene glycol (EG), offers 1000-fold enhancement in conductivity (10(-6) to 10(-3) Scm(-1)) with record low activation energy (0.11 eV). Atomic modeling coupled with C-13-SSNMR provides insights into the potential proton conduction pathway functionalized with post-synthetically anchored dynamic proton transporting EG moieties.

1D alignment of PEDOT in a buckypaper for high-performance solid supercapacitors - Soni, Roby; Anothumakkool, Bihag; Kurungot, Sreekumar (Chemelectrochem, 2016)
A flexible solid-state supercapacitor is prepared from carbon nanotube (CNT)-based buckypaper after forming a thin layer of polyethylenedioxythiophene (PEDOT) on the surface of the CNTs in the paper. A highly conducting PEDOT phase is obtained by interfacial polymerization, in which polymerization is confined at the interface of two immiscible liquids. The hydrophilic interaction between the functionalized CNTs and the oxidizing agent (iron perchlorate, Fe(ClO4)(3)), which is located in the aqueous phase, and the restricted interaction of the oxidizing agent with the EDOT monomer in the organic layer at the immiscible interface play a vital role in establishing a uniform and aggregate-free growth pattern of PEDOT on CNT. By carefully optimizing the amount of polymer in the paper, an electrode with a sheet resistance of 3.4(-1) and equivalent series resistance of 0.95 can be prepared. A thin and flexible solid-state supercapacitor device with an overall thickness of 210m is made by using this paper as the electrodes and poly(vinyl alcohol)/lithium chloride as the gel electrolyte. The power density and energy density of the electrode are 9.94Wcm(-3) and 8.85mWhcm(-3), respectively. The device also delivers a high volumetric capacitance of 18Fcm(-3) and areal capacitance of 354mFcm(-2). The demonstrated strategy is scalable and hence the process can be conveniently applied to prepare large-area PEDOT-modified buckypapers in a short time.
Keywords: Carbon; Energy storage; nanotubes; polymerization; Supercapacitors

3D interconnected porous graphene sheets loaded with cobalt oxide nanoparticles for lithium-ion battery anodes - Puthusseri, Dhanya; Aravindan, Vanchiappan; Madhavi, Srinivasan; Ogale, Satishchandra (Energy Technology, 2016)
Nanomaterials with high surface-to-volume ratio and tunable electronic and optical properties have expanded their use in variety of applications, especially energy conversion and storage. Here we report on the synthesis of a cobalt oxide (Co3O4)/3D-interconnected porous graphene (PG) nanocomposite by using a simple solvothermal route and its application as a Li-ion battery anode. Among the different compositions investigated, the composite PG-600 (with 50% PG) showed a discharge capacity of 700mAhg(-1) at a current density of 500mAg(-1) and maintained 90% retention after 80cycles. The high surface area of the 3DPG sheets helps the Co3O4 nanoparticles to form a uniform dispersion on the surfaces. The increased surface area (accessibility) and electrical conductivity of the composite result in significant enhancement in the capacity, cycling stability, and rate capability than the native Co3O4 phase.
Keywords: Cobalt oxide; Energy storage; graphene; lithium-ion batteries; Nanocomposites

Actinorectispora indica gen. nov., sp nov isolated from soil, a member of the family pseudonocardiaceae - Quadri, Syed Raziuddin; Tian, Xin-Peng; Zhang, Jing; Al Ruwaili, Jamal; Hozzein, Wael N.; Agsar, Dayanand; Li, Wen-Jun; Dastager, Syed Gulam (International Journal of Systematic and Evolutionary Microbiology, 2016)
The taxonomic positions of three Gram-stain-positive, aerobic strains, designated YIM 75722, 75726 and 75728(T), and isolated from a soil sample collected from Kurnool of Andhra Pradesh province, India, were assessed using a polyphasic approach. Growth was observed at pH 7.0-10.0 (optimum pH 7.0), 15-28 degrees C (optimum 28 degrees C) and 0-8% (w/v) NaCl (grew without NaCl). Strains showed cylindrical spores with straight-chain morphology on aerial mycelium, but did not reveal sporangium-like structures or fragmentation of the substrate mycelium. Whole-cell hydrolysates of all strains contained galactose and ribose as the diagnostic sugars and meso-diaminopimelic acid as the diamino acid. The predominant menaquinone was MK-9(H-4); MK-9 (H-6) and MK-10 (H-4) were present in smaller amounts. The phospholipid pattern consisted mainly of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. The major fatty acids were i-C-15: 0, ai-C-15: 0, i-C-17 : 0 and ai-C-17 : 0. The genomic DNA G+C content was 68.0 mol%. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain YIM 75728(T) should be placed within the family Pseudonocardiaceae, in which the strain formed a distinct lineage. The combination of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data support the conclusion that strain YIM 75728(T) represents a novel species of a novel genus of the family Pseudonocardiaceae for which the name Actinorectispora indica gen. nov., sp. nov., is proposed. Strain YIM 75728(T) (=DSM 45410(T)=CCTCC AA 209065(T)) is the type strain of Actinorectispora indica. Strain YIM 75728(T) was considered as the type strain over the other two strains based on the highest sequence read length of the strain.

Additive mediated syn-anti conformational tuning at nucleation to capture elusive polymorphs: remarkable role of extended pi-stacking interactions in driving the self-assembly - Gawade, Rupesh L.; Chakravarty, Debamitra K.; Kotmale, Amol; Sangtani, Ekta; Joshi, Pranaya V.; Ahmed, Awais; Mane, Manoj V.; Das, Susanta; Vanka, Kumar; Rajamohanan, Pattuparambil R.; Puranik, Vedavati G.; Gonnade, Rajesh G. (Crystal Growth & Design, 2016)
Understanding the process of prenucleation clustering at supersaturating stage is of significant importance to envisage the polymorphism in crystalline materials. Preferential formation of a thermodynamically stable crystal form suggests energetically favored patterns of interactions which control molecular aggregation during nucleation. Introduction of additives during crystallization is sometimes used as a suitable strategy to obtain metastable polymorphs in cases where it is not easy to capture the same by conventional crystallization methods. Comparative analysis of energy relationships and intermolecular interactions between thermodynamically stable and metastable crystal forms provides valuable clues about the nature of growth synthons at prenucleation clustering and preferential crystallization of the thermodynamic form. Conformationally flexible sulfonamide/sulfoester derivatives constituting electron rich and electron deficient aromatic rings were synthesized to study the interplay between pi-stacking and hydrogen bonding synthons. We have identified and characterized the thermodynamically stable and metastable elusive polymorphs of aromatic sulfonamides 1 and 2 and sulfoesters 3 and 4. However, these compounds eluded polymorphism during crystallisation from various common solvents/conditions and only produced thermodynamically stable crystals forms (form I crystals). Surprisingly, exploitation of pyrazinamide as an additive in different stoichiometric ratios during crystallization gave elusive polymorphs [three for 1 (form 1II, form 1III, and form 1IV) and one each for 2 (form 2II), 3 (form 3II), and 4 (form 4II)]. Molecules in stable crystal forms of these compounds are linked via extended chains of parallel displaced pi...pi stacking interactions that seem to play a vital role in driving the self-assembly of molecules and subsequently governing the nucleation process. In contrast, molecules in metastable polymorphs are devoid of such extended pi-stacking assemblies. Interestingly, differential scanning calorimetry, hot stage microscopy, and X-ray crystallographic studies confirmed the thermal crystal-to-crystal transition of all three metastable polymorphs of 1 (form 1II, form 1III, and form 1IV) to its thermodynamically stable crystal form (form 1I). Conformational analysis of molecule 1 using density functional theory calculations also validated higher stability for syn conformation (observed in Form 1I crystals) over anti and midway conformations (seen in metastable polymorphs). Melt crystallization of form 1I crystals of 1 on the larger face (001) of delta-pyrazinamide and lattice matching analysis (GRACE) revealed that the layered arrangement of molecules of delta-pyrazinamide (on 001 face) during heterogeneous nucleation acts as a template (heteroepitaxy) to provide a preferential site for the nucleation of new metastable polymorphs by selectively inhibiting the most preferred crystal form from growing into the nucleus. Solution state one- and two-dimensional (NOESY) H-1 NMR, scanning electron microscopy, and a Cambridge Structural Database survey were conducted to substantiate the role of additives during crystallization.

Amelioration of excision wounds by topical application of green synthesized, formulated silver and gold nanoparticles in albino Wistar rats - Naraginti, Saraschandra; Kumari, P. Lakshmi; Das, Raunak Kumar; Sivakumar, A.; Patil, Sagar Hindurao; Andhalkar, Vaibhav Vilas (Materials Science & Engineering C-Materials for Biological Applications, 2016)
Wound healing, a complex biological process, has attained a lot of attention as dermatologists are primarily interested in stimulated wound closure without formation of scar or a faint scar. The recent upsurgence of nanotechnology has provided novel therapeutic materials in the form of silver and gold nanoparticles which accelerate the wound healing process. The effect of formulated nanoparticles using Coleus forskohlii root extract (green synthesized) has been tried out for ameliorating full thickness excision wounds in albino Wistar male rats. The evaluation of in vivo activity of nanoparticles in wound healing was carried out on open wounds made by excision on the dorsal sides of albino Wistar rats under anesthesia, and the healing of the wounds was assessed. Histological aspects of the healing process were studied by a HE (Hematoxylin and Eosin) staining method to assess various degrees of re-epithelialization and the linear alignment of the granulation tissue whereas Van Gieson's histochemical staining was performed to observe collagen fibers. The healing action shown by the formulated nanoparticles was remarkable during the early stages of wound healing, which resulted in the substantial reduction of the whole healing period. Topical application of formulated gold nanoparticles was found to be more effective in suppressing inflammation and stimulating re-epithelialization compared to silver nanoparticles during the healing process. The results throw light on the amelioration of excision wounds using nanoparticles which could be a novel therapeutic way of improving wound healing in clinical practice. The mechanism of advanced healing action of both types of nanoparticles could be due to their antimicrobial, antioxidant and anti-inflammatory properties. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: collagen; Gold; green synthesis; Nanopraticles; wound Healing

Band edge modulated polymer layer to decrease back electron transfer and increase efficiency in sensitized solar cells - Arulkashmir, Arulraj; Sudhakar, Vediappan; Krishnamoorthy, Kothandam (Advanced Energy Materials, 2016)
Recombination of charges residing in the TiO2 and redox electrolyte is one of the factors affecting the efficiency of dye sensitized solar cells (DSSCs). To circumvent this recombination, inorganic oxide barrier layers and organic silanes have been coated on TiO2/dyes. Due to the insulating nature of these layers, the efficiency increase is not very impressive. Conducting polymers with different band edges are used to suppress the charge recombination. Amongst the four polymers that are used as barrier layers, a polymer with a highest occupied molecular orbital energy at -5.8 eV and lowest unoccupied molecular orbital at -3.1 eV is found to increase the electron life time at TiO2 and decrease the charge recombination. The electron life time is found to be 88 ms. In addition to the long electron life time, the recombination resistance of this polymer is also high (91 Omega). This resistance is 18% higher than that measured for DSSCs without polymer barrier layer. These factors impact the efficiency of DSSCs. DSSCs fabricated with this polymer as barrier layer exhibit an efficiency of 9.2%, which is 22% higher than that of DSSCs without polymer barrier layer.

Bicinchoninic acid-based colorimetric chemosensor for detection of low concentrations of cyanide - Biradar, Archana A.; Biradar, Ankush V.; Sun, Tiffany; Chan, Yung; Huang, Xiaoxi; Asefa, Tewodros (Sensors and Actuators B-Chemical, 2016)
Bicinchoninic acid (BCA) is reagent that is widely used to determine the concentration of proteins in solutions through the colored complex it forms with Cu(I) and the proteins. In this report, we present a new use for BCA, where a highly sensitive method for detection of cyanide ions in solutions by using Cu2+-BCA complex as the chemosensing agent is demonstrated. The detection of cyanide ions is achieved by taking advantage of the nucleophilic attack of the Cu2+-BCA complex by cyanide ions. Upon the addition of cyanide ions, the Cu2+-BCA complex undergoes transformations to free BCA via a series of equilibriums and, as a result, forms different Cu(II)-(BCA)(x)(CN)(y) species depending on the concentrations of cyanide ions in the solution. These different Cu(II)-(BCA)(x)(CN)(y) species, in turn, give different metal-to-ligand charge transfer electronic spectra and colors that are easily detectable both with naked eyes and UV-vis spectroscopy. As the cyanide ion concentration increases, the color of the solution containing the complexes changes from green to purple, red, yellow, and finally colorless, giving a corresponding blue shift in the absorption maxima on their UV-vis spectra. Through this process, the complexes enable detection of cyanide ions with a detection level of up to 0.06 ppm in solutions. Thus, this colorimetric technique based on Cu2+-BCA can make low concentrations of cyanide detectable, well before the concentrations possibly reach lethal amounts. Furthermore, the method is shown to give fast detection response with no interference from other anionic and cationic species and has the potential to be adopted for accurate and convenient analysis of cyanide ions in drinking water sources as well as industrial effluents. (C) 2015 Elsevier B.V. All rights reserved.
Keywords: BCA; Bicinchoninic acid; Chemosensor; Colorimetric sensor; Copper; Cyanide

Bioavailability studies of curcumin-sophorolipid nano-conjugates in the aqueous phase: role in the synthesis of uniform gold nanoparticles - Darne, Priti A.; Mehta, Mihir R.; Agawane, Sachin B.; Prabhune, Asmita (RSC Advances, 2016)
The major limiting factors for curcumin to be accepted as a modern drug, despite its widespread applications, are its low aqueous solubility, low retention time and poor bioavailability. When subjected to a mild physical stress, curcumin is observed to internalize within the micellar hydrophobic core of oleic acid sophorolipid resulting in the formation of curcumin-sophorolipid nanoconjugates (CurSL). These bio-composites show enhanced retention time and increased bioavailability of curcumin in rat models. In the presence of gold salts, CurSL act as potent reducing and capping agents, resulting in the synthesis of monodispersed, spherical gold nanoparticles (CurSL-GNPs) of 8-10 nm in size. Physicochemical, morphological and optical characteristics of both the nanoparticles are discussed based on spectroscopic absorption, photoluminescence (PL), dynamic light scattering (DLS), zeta potential, SEM and TEM measurements. FTIR spectroscopy signatures of these nanoparticles confirm the retention of functional groups in the end products. A retention time of 2 hours in blood plasma and an increase in curcumin recovery by about 150 times that previously reported were observed in the pharmacokinetic (pK(a)) studies performed on Wistar rats. The bio-distribution of gold nanoparticles in rats was studied using EDX, which revealed their presence in different vital organs. The absence of unusual legions or necrosis in histopathological analysis of vital organs in all the rat models suggests the use of curcuminsophorolipid nano-conjugates enhances curcumin bioavailability and the Cur-SL based nano-gold formulation is a good drug delivery carrier.

Biogenic terbium oxide nanoparticles as the vanguard against osteosarcoma - Iram, Sana; Khan, Salman; Ansary, Abu Ayoobul; Arshad, Mohd; Siddiqui, Sahabjada; Ahmad, Ejaz; Khan, Rizwan H.; Khan, Mohd Sajid (Spectrochimica Acta Part A-Molecular and Biomolecular Spectroscopy, 2016)
The synthesis of inner transition metal nanoparticles via an ecofriendly route is quite difficult. This study, for the first time, reports synthesis of terbium oxide nanoparticles using fungus, Fusarium oxysporum. The biocompatible terbium oxide nanoparticles (Tb2O3 NPs) were synthesized by incubating Tb4O7 with the biomass of fungus F. oxysporum. Multiple physical characterization techniques, such as UV-visible and photoluminescence spectroscopy, TEM, SAED, and zeta-potential were used to confirm the synthesis, purity, optical and surface characteristics, crystallinity, size, shape, distribution, and stability of the nanoemulsion of Tb2O3 NPs. The Tb2O3 NPs were found to inhibit the propagation of MG-63 and Saos-2 cell-lines (IC50 value of 0.102 mu g/mL) and remained non-toxic up to a concentration of 0373 gg/mL toward primary osteoblasts. Cell viability decreased in a concentration-dependent manner upon exposure to 10 nmTb(2)O(3) NPs in the concentration range 0.023-0373 mu g/mL Cell toxicity was evaluated by observing changes in cell morphology, cell viability, oxidative stress parameters, and FACS analysis. Morphological examinations of cells revealed cell shrinkage, nuclear condensation, and formation of apoptotic bodies. The level of ROS within the cells an indicator of oxidative stress was significantly increased. The induction of apoptosis at concentrations <= IC50 was corroborated by 4',6-diamidino-2-phenylindole dihydrochloride (DAPI) staining (DNA damage and nuclear fragmentation). Flow-cytometric studies indicated that the response was dose dependent with a threshold effect. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: Biosynthesis; Cytotoxicity; fusarium oxysporum; Osteosarcoma; Tb2O3 nanoparticles

Bioinspired eco-friendly synthesis of ZrO2 nanoparticles - Uddin, I.; Ahmad, A. (Journal of Materials and Environmental Science, 2016)
Here we report the extracellular biosynthesis of zirconia (ZrO2) nanoparticles under ambient conditions by challenging the fungus Humicola sp. with potassium hexafluorozirconate (K2ZrF6) as a precursor. Transmission electron micrograph (TEM) showed that nanoparticles are quasi-spherical in shape with an average particle size of 13 nm. The structural investigation was done using selected area electron diffraction (SAED) and powder XRD which show that the nanoparticles are perfectly crystalline with an orthorhombic structure. XPS and FTIR analysis explained the presence of proteins on the nanoparticles surfaces.

Biomimetic collective total synthesis of bioactive carbazole alkaloids indizoline, mafaicheenamine A, claulamine A, claulansine A, and the proposed claulamine E - Markad, Shivaji B.; N. P. Argade (Journal of Organic Chemistry, 2016)
The common precursor 1-methoxy-2-prenyl-3-carbomethoxycarbazole was synthesized from dimethyl indolylmethylenesuccinate in four steps. Well-planned reductive and/or oxidative transformations and intramolecular cyclizations were performed on a pivotal common precursor to accomplish collective first total synthesis of titled natural products and proposed Claulamine E. Burgess reagent induced formation of kinetically controlled product Claulamine A, and intramolecular cyclizations to form bicyclic claulansine A were the key reactions. An alternatively attempted synthesis failed to provide the structural isomer of proposed Claulamine E.

Bioresponsive carbon nano-gated multifunctional mesoporous silica for cancer theranostics - Prasad, Rajendra; Aiyer, Sandhya; Chauhan, Deepak S.; Srivastava, Rohit; Selvaraj, Kaliaperumal (Nanoscale, 2016)
Designing bioresponsive nanocarriers for controlled and efficient intracellular drug release for cancer therapy is a major thrust area in nanomedicine. With recent recognition by the US FDA as a safe material for human trials, mesoporous silica nanoparticles (MSNPs) are being extensively explored as promising theranostic agents. Green fluorescent carbon quantum dots (CQDs), though known as possible alternatives for their more toxic and relatively less efficient predecessors, are less known as gate keepers for drug release control. We report for the first time an efficient bioresponse of CQDs when judiciously designed using glutathione cleavable (redox responsive) disulphide bonds. When the anticancer drug doxorubicin loaded MSNPs are capped with these CQDs, they display promising drug release control on exposure to a mimicked intracellular cancer environment. Their dual functionality is well established with good control on preventing the premature release and exceptional bio-imaging of HeLa cancer cells. Fluorescence images prove selective targeting of HeLa cells by overexpression of folate receptors from the surface functionalised folic acid ligand. Extensive characterisation using XRD, TEM, BET analysis, drug loading tests, drug release kinetics, MTT assay and fluoroscence cell imaging helps in understanding the multi-functionalities of the successful design, extending its scope with exciting prospects towards non-invasive targeted drug delivery and bio-imaging for effective cancer diagnosis and treatment.

Biosurfactant as a promoter of methane hydrate formation: thermodynamic and kinetic studies - Arora, Amit; Cameotra, Swaranjit Singh; Kumar, Rajnish; Balomajumder, Chandrajit; Singh, Anil Kumar; Santhakumari, B.; Kumar, Pushpendra; Laik, Sukumar (Scientific Reports, 2016)
Natural gas hydrates (NGHs) are solid non-stoichiometric compounds often regarded as a next generation energy source. Successful commercialization of NGH is curtailed by lack of efficient and safe technology for generation, dissociation, storage and transportation. The present work studied the influence of environment compatible biosurfactant on gas hydrate formation. Biosurfactant was produced by Pseudomonas aeruginosa strain A11 and was characterized as rhamnolipids. Purified rhamnolipids reduced the surface tension of water from 72 mN/m to 36 mN/m with Critical Micelle Concentration (CMC) of 70 mg/l. Use of 1000 ppm rhamnolipids solution in C type silica gel bed system increased methane hydrate formation rate by 42.97% and reduced the induction time of hydrate formation by 22.63% as compared to water saturated C type silica gel. Presence of rhamnolipids also shifted methane hydrate formation temperature to higher values relative to the system without biosurfactant. Results from thermodynamic and kinetic studies suggest that rhamnolipids can be applied as environment friendly methane hydrate promoter.

Biosynthesis of anti-proliferative gold using endophytic fusarium oxysporum strain isolated from neem (A-indica) leaves - Siddiqui, Ejaz Ahmad; Ahmad, Absar; Julius, Anju; Syed, Asad; Khan, Shadab; Kharat, Mahesh; Pai, Kalpana; Kadoo, Narendra Y.; Gupta, Vidya (Current topics in medicinal chemistry, 2016)
Here we report a simple, rapid, environment friendly approach for the synthesis of gold nanoparticles using neem (Azadirachta indica A. Juss.) fungal endophyte, which based upon morphological and cultural characteristics was eventually identified as Fusarium oxysporum. The aqueous precursor (HAuCl4) solution when reacted with endophytic fungus resulted in the biosynthesis of abundant amounts of well dispersed gold nanoparticles of 10-40 nm with an average size of 22nm. These biosynthesized gold nanoparticles were then characterized by standard analytical techniques such as UV-Visible spectroscopy, X-ray diffraction, Transmission Electron Microscopy and Fourier Transform Infrared Spectroscopy. Cytotoxic activity of these nanoparticles was checked against three different cell types including breast cancer (ZR-75-1), Daudi (Human Burkitt's lymphoma cancer) and normal human peripheral blood mononuclear cells (PBMC), where it was found that our gold nanoparticles are anti-proliferative against cancer cells but completely safe toward normal cells. In addition to this, assessment of toxicity toward human RBC revealed less than 0.1 % hemolysis as compared to Triton X-100 suggesting safe nature of our biosynthesized gold nanoparticles on human cells. Also, our nanoparticles exhibited no anti-fungal (against Aspergillus niger) or anti-bacterial [against Gram positive (Bacillus subtilis & Staphylococcus aureus) and Gram negative (Escherichia coli & Pseudomonas aeruginosa) bacteria] activity thus suggesting their non-toxic, biocompatible nature. The present investigation opens up avenues for eco-friendly, biocompatible nanomaterials to be used in a wide variety of application such as drug delivery, therapeutics, theranostics and so on.

Biosynthesis of fluorescent Bi2S3 nanoparticles and their application as dual-functionSPECT-CT probe for animal imaging - Uddin, Imran; Ahmad, Absar; Siddiqui, Ejaz Ahmad; Rahaman, Sk. Hasanur; Gambhir, Sanjay (Current Topics In Medicinal Chemistry, 2016)
Bismuth sulphide (Bi2S3) is an excellent semiconductor and its nanoparticles have numerous significant applications including photovoltaic materials, photodiode arrays, bio-imaging, etc. Nevertheless, these nanoparticles when fabricated by chemical and physical routes tend to easily aggregate in colloidal solutions, are eco-unfriendly, cumbrous and very broad in size distribution. The aim of the present manuscript was to ecologically fabricate water dispersible, safe and stable Bi2S3 nanoparticles such that these may find use in animal imaging, diagnostics, cell labeling and other biomedical applications. Herein, we for the first time have biosynthesized highly fluorescent, natural protein capped Bi2S3 nanoparticles by subjecting the fungus Fusarium oxysporum to bismuth nitrate pentahydrate [Bi(NO3)(3).5H(2)O] alongwith sodium sulphite (Na2SO3) as precursor salts under ambient conditions of temperature, pressure and pH. The nanoparticles were completely characterized using recognized standard techniques. These natural protein capped Bi2S3 nanoparticles are quasi-spherical in shape with an average particle size of 15 nm, maintain long term stability and show semiconductor behavior having blue shift with a band gap of 3.04 eV. Semiconductor nanocrystals are fundamentally much more fluorescent than the toxic fluorescent chemical compounds (fluorophores) which are presently largely employed in imaging, immunohistochemistry, biochemistry, etc. Biologically fabricated fluorescent nanoparticles may replace organic fluorophores and aid in rapid development of biomedical nanotechnology. Thus, biodistribution study of the so-formed Bi2S3 nanoparticles in male Sprague Dawley rats was done by radiolabelling with Technitium-99m (Tc-99m) and clearance time from blood was calculated. The nanoparticles were then employed in SPECT-CT probe for animal imaging where these imparted iodine equivalent contrast.

Capsicum annuum proteinase inhibitor ingestion negatively impacts the growth of sorghum pest Chilo partellus and promotes differential protease expression - Jadhav, A. R.; War, A. R.; Nikam, A. N.; Adhav, A. S.; Gupta, V. S.; Sharma, H. C.; Giri, A. P.; Tamhane, V.A. (Biochemistry and Biophysics Reports, 2016)
Background Chilo partellus is an important insect pest infesting sorghum and maize. The larvae internalize in the stem, rendering difficulties in pest management. We investigated the effects of Capsicum annuum proteinase inhibitors (CanPIs) on C. partellus larvae by in-vitro and in-vivo experiments. Methods Recombinant CanPI-7 (with four-Inhibitory Repeat Domains, IRDs), -22 (two-IRDs) and insect proteinase activities were estimated by proteinase assays, dot blot assays and in gel activity assays. Feeding bioassays of lab reared C. partellus with CanPI-7 and -22 were performed. C. partellus proteinase gene expression was done by RT-PCR. In-silico structure prediction of proteinases and CanPI IRDs was carried out, their validation and molecular docking was done for estimating the interaction strength. Results Larval proteinases of C. partellus showed higher activity at alkaline pH and expressed few proteinase isoforms. Both CanPIs showed strong inhibition of C. partellus larval proteinases. Feeding bioassays of C. partellus with CanPIs revealed a dose dependent retardation of larval growth, reduction of pupal mass and fecundity, while larval and pupal periods increased significantly. Ingestion of CanPIs resulted in differential up-regulation of C. partellus proteinase isoforms, which were sensitive to CanPI-7 but were insensitive to CanPI-22. In-silico interaction studies indicated the strong interaction of IRD-9 (of CanPI-22) with Chilo proteinases tested. Conclusions Of the two PIs tested, CanPI-7 prevents induction of inhibitor insensitive proteinases in C. partellus so it can be explored for developing C. partellus tolerance in sorghum. General significance Ingestion of CanPIs, effectively retards C. partellus growth; while differentially regulating the proteinases.

Chemoenzymatic access to (+)-artabotriol and its application in collective synthesis of (+)-grandiamide D, (-)-tulipalin B, (+)-spirathundiol, and (+)-artabotriolcaffeate - Batwal, Ramesh U.; N. P. Argade (Synthesis-Stuttgart, 2016)
Starting from dimethyl (+/-)-2-hydroxy-3-methylenesuccinnate chemoenzymatic collective formal/total synthesis of enantiomerically pure bioactive natural products has been described via the advanced level common precursor (+)-artabotriol. An efficient enzymatic resolution with high enantiomeric purity, selective diester to diol reduction, and requisite dehydrative coupling reactions without any racemization are the significant topographies.
Keywords: (+)-artabotriol; collective synthesis; coupling reactions; dimethyl (+/-)-2-hydroxy-3-methylenesuccinate; Enzymatic resolution; Natural products; reduction

"Click" polymerization: a convenient strategy to prepare designer fullerene materials - Krishnamurthy, Munusamy; Krishnamoorthy, Kothandam; Arulkashmir, Arulraj; Raghavendra, V.; Murali, Adhigan; Jaisankar, Sellamuthu N.; Murugan, P.; Gurusamy-Thangavelu, Senthil A.; Nasar, A. Sultan; Mandal, Asit Baran; Samanta, Debasis (Materials & Design, 2016)
"Click" polymeric assemblies of fullerenes, thiophenes and aryl compounds were prepared for the first time to study their spectroscopic/chemical/electronic characteristics and possible applications in photovoltaic cells. The GPC and NMR spectroscopic data confirmed a moderate to high degree of polymerization while microscopic pictures showed well-defined arrangements of fullerenes. The FTIR studies indicated that the product is free from starting azide materials, whereas thermogravimetric analysis data suggested a good stability. Band gap of the material was determined using UV-Vis spectroscopy, cyclic voltammetric techniques and compared with computational investigation. The fullerene copolymer was fabricated as acceptor material in a bulk heterojunction photovoltaic cell. (C) 2016 Elsevier Ltd. All rights reserved.

Cobalt-modified covalent organic framework as a robust wateroxidation electrocatalyst - Aiyappa, Harshitha Barike; Thote, Jayshri; Shinde, Digambar Balaji; Banerjee, Rahul; Kurungot, Sreekumar (Chemistry of Materials, 2016)
The development of stable, efficient oxygen evolution reaction (OER) catalyst capable of oxidizing water is one of the premier challenges in the conversion of solar energy to electrical energy, because of its poor kinetics. Herein, a bipyridine-containing covalent organic framework (TpBpy) is utilized as an OER catalyst by way of engineering active Co(II) ions into its porous framework. The as-obtained Co-TpBpy retains a highly accessible surface area (450 m(2)/g) with exceptional stability, even after 1000 cycles and 24 h of OER activity in phosphate buffer under neutral pH conditions with an overpotential of 400 mV at a current density of 1 mA/cm(2). The unusual catalytic stability of Co-TpBpy arises from the synergetic effect of the inherent porosity and presence of coordinating units in the COF skeleton.

Comparative functional characterization of eugenol synthase from four different ocimum species: implications on eugenol accumulation - Anand, Atul; Jayaramaiah, Ramesha H.; Beedkar, Supriya D.; Singh, Priyanka A.; Joshi, Rakesh S.; Mulani, Fayaj A.; Dholakia, Bhushan B.; Punekar, Sachin A.; Gade, Wasudeo N.; Thulasiram, Hirekodathakallu V.; Giri, Ashok P. (Biochimica Et Biophysica Acta-Proteins and Proteomics, 2016)
Isoprenoids and phenylpropanoids are the major secondary metabolite constituents in Ocimum genus. Though enzymes from phenylpropanoid pathway have been characterized from few plants, limited information exists on how they modulate levels of secondary metabolites. Here, we performed phenylpropanoid profiling in different tissues from five Ocimum species, which revealed significant variations in secondary metabolites including eugenol, eugenol methyl ether, estragole and methyl cinnamate levels. Expression analysis of eugenol synthase (EGS) gene showed higher transcript levels especially in young leaves and inflorescence; and were positively correlated with eugenol contents. Additionally, transcript levels of coniferyl alcohol acyl transferase, a key enzyme diverting pool of substrate to phenylpropanoids, were in accordance with their abundance in respective species. In particular, eugenol methyl transferase expression positively correlated with higher levels of eugenol methyl ether in Ocimum tenuiflorum. Further, EGSs were functionally characterized from four Ocimum species varying in their eugenol contents. Kinetic and expression analyses indicated, higher enzyme turnover and transcripts levels, in species accumulating more eugenol. Moreover, biochemical and bioinformatics studies demonstrated that coniferyl acetate was the preferred substrate over coumaryl acetate when used, individually or together, in the enzyme assay. Overall, this study revealed the preliminary evidence for varied accumulation of eugenol and its abundance over chavicol in these Ocimum species. Current findings could potentially provide novel insights for metabolic modulations in medicinal and aromatic plants. (C) 2016 Elsevier B.V. All rights reserved.

Constructing covalent organic frameworks in water via dynamic covalent bonding - Thote, Jayshri; Aiyappa, Harshitha Barike; Kumar, Raya Rahul; Kandambeth, Sharath; Biswal, Bishnu P.; Shinde, Digambar Balaji; Roy, Neha Chaki; Banerjee, Rahul (Iucrj, 2016)
The formation of keto-enamine based crystalline, porous polymers in water is investigated for the first time. Facile access to the Schiff base reaction in water has been exploited to synthesize stable porous structures using the principles of Dynamic Covalent Chemistry (DCC). Most credibly, the water-based Covalent Organic Frameworks (COFs) possess chemical as well as physical properties such as crystallinity, surface area and porosity, which is comparable to their solvothermal counterparts. The formation of COFs in water is further investigated by understanding the nature of the monomers formed using hydroxy and non-hydroxy analogues of the aldehyde. This synthetic route paves a new way to synthesize COFs using a viable, greener route by utilization of the DCC principles in conjunction with the keto-enol tautomerism to synthesize useful, stable and porous COFs in water.

Counteranion driven homochiral assembly of a cationic C-3-symmetric gelator through ion-pair assisted hydrogen bond - Maity, Arunava; Gangopadhyay, Monalisa; Basu, Arghya; Aute, Sunil; Babu, Sukumaran Santhosh; Das, Amitava (Journal of the American Chemical Society, 2016)
The helical handedness in achiral self-assemblies is mostly complex due to spontaneous symmetry breaking or kinetically controlled random assembly formation. Here an attempt has been made to address this issue through chiral anion exchange. A new class of cationic achiral C-3-symmetric gelator devoid of any conventional gelation assisting functional units is found to form both right-and left-handed helical structures. A chiral counteranion exchange-assisted approach is successfully introduced to control the chirality sign and thereby to obtain preferred homochiral assemblies. Formation of anion-assisted chiral assembly was confirmed by circular dichroism (CD) spectroscopy, microscopic images, and crystal structure. The X-ray crystal structure reveals the construction of helical assemblies with opposite handedness for (+)- and (-)-chiral anion reformed gelators. The appropriate counteranion driven ion-pair-assisted hydrogen-bonding interactions are found responsible for the helical bias control in this C-3-symmetric gelator.

Cutaneous exposure to clinically-relevant pigeon pea (Cajanus cajan) proteins promote T(H)2-dependent sensitization and IgE-mediated anaphylaxis in Balb/c mice - Gupta, Rinkesh Kumar; Kumar, Sandeep; Gupta, Kriti; Sharma, Akanksha; Roy, Ruchi; Verma, Alok Kumar; Chaudhari, Bhushan P.; Das, Mukul; Ansari, Irfan Ahmad; Dwivedi, Premendra D. (Journal of Immunotoxicology, 2016)
Epicutaneous (EC) sensitization to food allergens may occur when the skin has been lightly damaged. The study here tested whether cutaneous exposure to pigeon pea protein(s) may cause allergic sensitization. BALB/c mice were either orally gavaged or epicutaneously sensitized by repeated application of pigeon pea crude protein extract (CPE) on undamaged areas of skin without any adjuvant; afterwards, both groups were orally challenged with the pigeon pea CPE. Anaphylactic symptoms along with measures of body temperature, MCPT-1, TSLP, pigeon pea-specific IgE and IgG(1), myeloperoxidase (MPO) activity, T(H)2 cytokines, T(H)2 transcription factors (TFs) and filaggrin expression were determined. Mast cell staining, eosinophil levels and histopathological analysis of the skin and intestines were also performed. In the epicutaneously-sensitized mice, elevated levels of specific IgE and IgG(1), as well as of MCPT-1, TSLP, T(H)2 cytokines and TFs, higher anaphylactic scores and histological changes in the skin and intestine were indicative of sensitization ability via both routes in the pigeon pea CPE-treated hosts. Elevated levels of mast cells were observed in both the skin and intestine; increased levels of eosinophils and MPO activity were noted only in the skin. Decreased levels of filaggrin in skin may have played a key role in the skin barrier dysfunction, increasing the chances of sensitization. Therefore, the experimental data support the hypothesis that in addition to oral exposure, skin exposure to food allergens can promote T(H)2-dependent sensitization, IgE-mediated anaphylaxis and intestinal changes after oral challenge. Based on this, an avoidance of cutaneous exposures to allergens might prevent development of food anaphylaxis.

Cysteine-specific fluorescent switch for monitoring oxidative stress and quantification of aminoacylase-1 in blood serum - Anila, H. A.; Ali, Firoj; Kushwaha, Shilpi; Taye, Nandaraj; Chattopadhyay, Samit; Das, Amitava (Analytical Chemistry, 2016)

Decoding the morphological diversity in two dimensional crystalline porous polymers by core planarity modulation - Halder, Arjun; Kandambeth, Sharath; Biswal, Bishnu P.; Kaur, Gagandeep; Roy, Neha Chaki; Addicoat, Matthew A.; Salunke, Jagadish K.; Banerjee, Subhrashis; Vanka, Kumar; Heine, Thomas; Verma, Sandeep; Banerjee, Rahul (Angewandte Chemie - International Edition, 2016)

Design, synthesis and biological evaluation of novel azaspiro analogs of linezolid as antibacterial and antitubercular agents - Gadekar, Pradip K.; Roychowdhury, Abhijit; Kharkar, Prashant S.; Khedkar, Vijay M.; Arkile, Manisha A.; Manek, Hardik; Sarkar, Dhiman; Sharma, Rajiv; Vijayakumar, V.; Sarveswari, S. (European Journal of Medicinal Chemistry, 2016)
The design, synthesis and antimicrobial evaluation of a novel series of azaspiro analogues of linezolid (1) have been described. Linezolid comprises of a morpholine ring which is known for its metabolism related liabilities. Therefore, the key modification made in the linezolid structure was the replacement of morpholine moiety with its bioisostere, 2-oxa-6-azaspiro[3.3]heptane. Furthermore, the replacement of N-acetyl terminal of 1 with various aromatic or aliphatic functionalities was carried out. The title compounds were evaluated against a panel of Gram-positive and Gram-negative bacteria and Mycobacterium tuberculosis. Subsequent structure-activity relationship (SAR) studies identified several compounds with mixed antibacterial and antitubercular profiles. Compound 22 (IC50 0.72, 0.51, 0.88, 0.49 mu g/mL for Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, respectively) exhibited similar antibacterial profile as I. The N-acetyl derivative 18 was similar to 1 in antitubercular profile. Thus, the present study successfully demonstrated the use of azaspiro substructure in the medicinal chemistry of antibacterial and antitubercular agents. (C) 2016 Elsevier Masson SAS. All rights reserved.

Disassembly of micelles to impart donor and acceptor gradation to enhance organic solar cell efficiency - Arulkashmir, Arulraj; Krishnamoorthy, Kothandam (Chemical Communications, 2016)
A transparent, conducting and low surface energy surface was prepared by disassembly of anionic micelles, which altered the orientation of the donor polymer and imparted gradation between the donor and acceptor. This configuration increased the solar cell device efficiency.

Effect of different fixed bed media on the performance of sodium dodecyl sulfate for hydrate based CO2 capture - Arora, Amit; Kumar, Asheesh; Bhattacharjee, Gaurav; Kumar, Pushpendra; Balomajumder, Chandrajit (Materials & Design, 2016)
Sodium Dodecyl Sulfate (SDS) is used as a kinetic promoter in gas hydrate formation. In this work, the performance of SDS for carbon dioxide gas hydrate formation in two different fixed bed media: silica sand and zeolite (5A and 13X) has been evaluated. The concentration of SDS was fixed at 0.5 wt%. The experiments were carried out in batch mode with the initial pressure fixed at 3.0 MPa, and the temperature kept constant at 274.65 K. The results showed that hydrate of carbon dioxide with fixed bed of silica sand was significantly promoted by the addition of SDS as compared to the other fixed bed medium used in this study: zeolite 13X. (c) 2015 Elsevier Ltd. All rights reserved.
Keywords: Carbon dioxide; Fixed bed media; Hydrate formation; Kinetic promoter; Silica sand; Zeolite 5A and 13X

Effect of out-of-plane alkyl group's position in dye-sensitized solar cell efficiency: a structure-property relationship utilizing indoline-based unsymmetrical squaraine dyes - Alagumalai, Ananthan; Fairoos, Munavvar M. K.; Vellimalai, Punitharasu; Sil, Manik Chandra; Nithyanandhan, Jayaraj (ACS Applied Materials & Interfaces, 2016)
Squaraine dyes are promising chromophores to harvest visible and near-infrared (NIR) photons. A series of indoline-based unsymmetrical squaraine (SQ) dyes that contain alkyl chains at sp(3) C- and N- atoms of indoline moieties with a carboxylic acid anchoring group were synthesized. The optical and electrochemical properties of the SQ dyes in solution were nearly identical as there was no change in the D-A-D SQ framework; however, remarkable changes with respect to the power conversion efficiencies (PCE) were observed depending upon the position of alkyl groups in the dye. Introduction of alkyl groups to the indoline unit that was away from anchoring unit were helped in more dye loading with controlled organization of dyes on surface, increased charge transfer resistance, long electron lifetime, and hence higher PCE than that of the corresponding isomer in which the alkyl groups funtionalized indoline unit contains the carboxylic acid anchoring group. Careful analysis of incident photon-to current conversion efficiency (IPCE) profiles indicated the presence of aggregated structure on the TiO2 surface that contributes to the charge injection in the presence of a coadsorbent. A dye-sensitized solar cell (DSSC) device made out of SQ5 was achieved an efficiency of 9.0%, with an open-circuit potential (V-oc) of 660 mV and short-circuit current density (J(sc)) of 19.82 mA/cm 2, under simulated AM 1.5G illumination (100 mW/cm(2)). The IPCE profile of SQ5 shows an onset near to 750 nm with a good quantum efficiency (>80%) in the range of 550-700 nm, indicating the importance of self-organization of dyes on the TiO2 surface for an efficient charge injection. This present investigation revealed the importance of position of alkyl groups in the squaraine-based dyes for the better PCE.

Effect of plug temperature on the strain and thickness distribution ofcomponents made by plug assist thermoforming - Marathe, D.; Rokade, D.; Azad, Lal Busher; Jadhav, Kishor; Mahajan, Sunil; Ahmad, Zubair; Gupta, S.; Kulkarni, S.; Juvekar, Vinay A.; Lele, Ashish K. (International Polymer Processing, 2016)
Plug temperature is a key parameter affecting the thickness distribution of thermoplastic components made by plug assist thermoforming. For a specified pair of plug and plastic sheet, the variation in plug temperature can alter the coefficient of friction (COF) between the pair. We show here how the temperature dependence of COF influences the nature and extent of biaxial stretching of the sheet and consequently the thickness distribution of the thermoformed component. In the present study, high impact polystyrene (HIPS) sheets were thermoformed into axisymmetric cups using a plug-assist process in which the aluminum plug temperature (T-plug) was varied from ambient to above the glass transition temperature of HIPS (similar to 100 degrees C). Biaxial strain maps on the surfaces of the formed cups were measured and quantified using Grid Strain Analysis (GSA). Thickness distributions of the cups were also measured. Temperature dependent COF between HIPS and aluminum was determined independently using a rotational rheometer. The measured COF was low for T < 100 degrees C, whereas it increased appreciably at and above 100 degrees C. We conclude that when T-plug < 100 degrees C the HIPS sheet slips on the plug during forming, and this results in biaxial stretching of the base and walls of the formed cup. In contrast for T-plug > 100 degrees C, a significant reduction in the magnitude of slip is expected. Here the sheet is gripped at the clamp and by the plug during forming which causes reduced biaxial stretching of the base and increased uniaxial stretching of the walls of the cup. Simulations of plug-assist thermoforming using a temperature dependent COF showed qualitative agreement with the GSA data thereby supporting our inferences.

Enantiospecific formal synthesis of inthomycin C - Athawale, Paresh R.; Kashinath, K.; Reddy, D. Srinivasa (Chemistry Select, 2016)
An enantiospecific synthesis of Hatakeyama's intermediate enynol has been accomplished in both enantiomeric forms. As these intermediates can be converted to (3R)-inthomycin C and (3S)-inthomycin C through respective enynol intermediates using reported procedures, present effort may be regarded as formal synthesis of inthomycin C in both enantiomeric forms. Our synthesis highlights the use of pantolactone chiral pool and thus reconfirms the previously assigned absolute stereochemistry as 3R to the natural product inthomycin C.

Encapsulation of yeast (Saccharomyces cereviciae) by spray drying for extension of shelf life - Chandralekha, A.; Tavanandi, A. Hrishikesh; Amrutha, N.; Hebbar, H. Umesh; Raghavarao, K. S. M. S.; Gadre, Ramchandra V. (Drying Technology, 2016)
The objective of the present work was to encapsulate yeast using different carrier materials and examine their efficacy in retaining viability of cells after spray drying. Slurry containing yeast cells along with known amount of carrier material (maltodextrin, corn starch, gum arabic, acacia gum, polyethylene glycol 8000, -cyclodextrin, and skimmed milk powder, one at a time) was added and served as feed. Among these carrier materials attempted, corn starch and maltodextrin showed the best results with respect to powder yield (59%, w/w) and cell survival (80.5%), respectively. However, considering both survival and powder yield (67 and 59% w/w, respectively), corn starch was observed to be the most suitable carrier material.
Keywords: Cell viability; Encapsulation; freeze-drying; spray drying; Yeast

Enhancing the strain sensitivity of CoFe2O4 at low magnetic fields without affecting the magnetostriction coefficient by substitution of small amounts of Mg for Fe - Anantharamaiah, P. N.; Joy, Pattayil Alias (Physical Chemistry Chemical Physics, 2016)
Attaining high magnetostrictive strain sensitivity (d lambda/dH) with high magnetostriction strain (lambda) is desirable for sintered polycrystalline cobalt ferrite for various applications. It is shown that substitution of a small amount of Fe3+ by Mg2+ in CoMgxFe2-xO4 (x < 0.1) gives a comparable maximum magnetostriction coefficient to that of the unsubstituted counterpart, with large improvement in the strain sensitivity at relatively low magnetic fields. A large increase in the magnetostriction coefficient is obtained at low magnetic fields for the substituted compositions. The magnetostriction parameters are further enhanced by magnetic field annealing of the sintered products. The results are analyzed based on powder XRD, Raman spectroscopy, XPS and magnetic measurements and based on the results from these studies, the changes in the magnetostriction parameters are correlated with the changes in the cation distribution, magnetic anisotropy and microstructure.

Epoxide ring-opening reaction by using sol-gel-synthesized palladium supported on a strontium hydroxyl fluoride catalyst - Acham, Vaibhav R.; Dongare, Mohan K.; Kemnitz, Erhard; Umbarkar, Shubhangi B. (Comptes Rendus Chimie, 2016)
Palladium supported on a strontium hydroxyl fluoride catalyst was synthesized by a one-pot fluorolytic sol-gel method. The prepared catalyst was characterized by various physicochemical techniques. The sol-gel method has led to the formation of a high surface area (57 m(2)g(-1)), mesoporous (pore diameter = 13.0 nm) catalyst with uniform dispersion of Pd nanoparticles of size similar to 7 nm on the surface of strontium hydroxyl fluoride. The catalyst was used for epoxide alcoholysis, and 100% conversion was obtained with 96% selectivity for beta-alkoxy alcohols under mild conditions: The catalyst could be recycled for up to three catalytic cycles without any appreciable decrease in conversion and selectivity, indicating the stability of the catalyst under the reaction conditions. Further, the mechanism of alcoholysis was proposed on the basis of the physicochemical characteristics of the catalyst and on the basis of the products formed during the catalytic reaction. (C) 2016 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved.

ESP promoted "on water" click reaction: a highly economic and sustainable protocol for 1,4-disubstituted-1H-1,2,3-triazole synthesis at room temperature - Konwar, Manashjyoti; Ali, Abdul A.; Chetia, Mitali; Saikia, Prakash J.; Khupse, Nageshwar D.; Sarma, Diganta (Chemistryselect, 2016)
A highly economic and green protocol for azide-alkyne cyclo-addition reactions in water has been developed which offers a mild, practical and inexpensive basic alternative to the conventional protocols. The protocol uses readily available, considered as waste material, Egg Shell Powder (ESP) as an additive for CuAAC reaction. The reactions proceeded in water in presence of this basic waste material derived additive under 'external base/ligand/reducing agent/organic solvent' free conditions affording good to excellent yields of the desired products.

Evaluation of uttroside B, a saponin from Solanum nigrum Linn, as a promising chemotherapeutic agent against hepatocellular carcinoma - Nath, Lekshmi R.; Gorantla, Jaggaiah N.; Thulasidasan, Arun Kumar T.; Vijayakurup, Vinod; Shah, Shabna; Anwer, Shabna; Joseph, Sophia M.; Antony, Jayesh; Veena, Kollery Suresh; Sundaram, Sankar; Marelli, Udaya K.; Lankalapalli, Ravi S.; et al. (Scientific Reports, 2016)
We report, for the first time, the remarkable efficacy of uttroside B, a potent saponin from Solanum nigrum Linn, against liver cancer. The compound has been isolated and characterized from the leaves of Solanum nigrum Linn, a plant widely used in traditional medicine and is a rich resource of several anticancer molecules. Uttroside B, that comprises of beta-D-glucopyranosyl unit at C-26 of the furostanol and beta-lycotetraosyl unit at C-3, is ten times more cytotoxic to the liver cancer cell line, HepG2 (IC50: 0.5 mu M) than sorafenib (IC50: 5.8 mu M), the only FDA-approved drug for liver cancer. Moreover, it induces cytotoxicity in all liver cancer cell lines, irrespective of their HBV status, while being non-toxic to normal immortalized hepatocytes. It induces apoptosis in HepG2 cells by down-regulating mainly the activation of MAPK and mTOR pathways. The drastic reduction in HepG2-xenograft tumor size achieved by uttroside B in NOD-SCID mice and substantiation of its biological safety through both acute and chronic toxicity studies in Swiss albino mice warrants clinical validation of the molecule against hepatic cancer, for which, the chemotherapeutic armamentarium currently has limited weapons.

Evidence for dry molten globule-like domains in the pH-induced equilibrium folding intermediate of a multidomain protein - Acharya, Nirbhik; Mishra, Prajna; Jha, Santosh Kumar (Journal of Physical Chemistry Letters, 2016)
The role of van der Waals (vdW) packing interactions compared to the hydrophobic effect in stabilizing the functional structure of proteins is poorly understood. Here we show, using fluorescence resonance energy transfer, dynamic fluorescence quenching, red-edge excitation shift, and near- and far-UV circular dichroism, that the pH-induced structural perturbation of a multidomain protein leads to the formation of a state in which two out of the three domains have characteristics of dry molten globules, that is, the domains are expanded compared to the native protein with disrupted packing interactions but have dry cores. We quantitatively estimate the energetic contribution of vdW interactions and show that they play an important role in the stability of the native state and cooperativity of its structural transition, in addition to the hydrophobic effect. Our results also indicate that during the pH-induced unfolding, side-chain unlocking and hydrophobic solvation occur in two distinct steps and not in concerted manner, as commonly believed

Extension of the effective fragment potential method to macromolecules - Gurunathan, Pradeep Kumar; Acharya, Atanu; Ghosh, Debashree; Kosenkov, Dmytro; Kaliman, Ilya; Shao, Yihan; Krylov, Anna I.; Slipchenko, Lyudmila V. (Journal of Physical Chemistry B, 2016)
The effective fragment potential (EFP) approach, which can be described as a nonempirical polarizable force field, affords an accurate first-principles treatment of noncovalent interactions in extended systems. EFP can also describe the effect of the environment on the electronic properties (e.g., electronic excitation energies and ionization and electron-attachment energies) of a subsystem via the QM/EFP (quantum mechanics/EFP) polarizable embedding scheme. The original formulation of the method assumes that the system can be separated, without breaking covalent bonds, into closed-shell fragments, such as solvent and solute molecules. Here, we present an extension of the EFP method to macromolecules (mEFP). Several schemes for breaking a large molecule into small fragments described by EFP are presented and benchmarked. We focus on the electronic properties of molecules embedded into a protein environment and consider ionization, electron-attachment, and excitation energies (single-point calculations only). The model systems include chromophores of green and red fluorescent proteins surrounded by several nearby amino acid residues and phenolate bound to the T4 lysozyme. All mEFP schemes show robust performance and accurately reproduce the reference full QM calculations. For further applications of mEFP, we recommend either the scheme in which the peptide is cut along the C-alpha-C bond, giving rise to one fragment per amino acid, or the scheme with two cuts per amino acid, along the C-alpha-C and C-alpha-N bonds. While using these fragmentation schemes, the errors in solvatochromic shifts in electronic energy differences (excitation, ionization, electron detachment, or electron-attachment) do not exceed 0.1 eV. The largest error of QM/mEFP against QM/EFP (no fragmentation of the EFP part) is 0.06 eV (in most cases, the errors are 0.01-0.02 eV). The errors in the QM/molecular mechanics calculations with standard point charges can be as large as 0.3 eV.

Facile green synthesis of BCN nanosheets as high-performance electrode material for electrochemical energy storage - Karbhal, Indrapal; Devarapalli, Rami Reddy; Debgupta, Joyashish; Pillai, Vijayamohanan K.; Ajayan, Pulickel M.; Shelke, Manjusha V. (Chemistry-A European Journal, 2016)
Two-dimensional hexagonal boron carbon nitride (BCN) nanosheets (NSs) were synthesized by new approach in which a mixture of glucose and an adduct of boric acid (H3BO3) and urea (NH2CONH2) is heated at 900 degrees C. The method is green, scalable and gives a high yield of BCN NSs with average size of about 1 mm and thickness of about 13 nm. Structural characterization of the as-synthesized material was carried out by several techniques, and its energy-storage properties were evaluated electrochemically. The material showed excellent capacitive behaviour with a specific capacitance as high as 244 F g(-1) at a current density of 1 A g(-1). The material retains up to 96% of its initial capacity after 3000 cycles at a current density of 5 A g(-1).
Keywords: boron; Doping; Electrochemistry; Nanoparticles; nitrides

Facile strategy for accessing 3-alkynylchromones through gold-catalyzed alkynylation/cyclization of o-hydroxyarylenaminones - Akram, Manjur O.; Bera, Saibal; Patil, Nitin T. (Chemical Communications, 2016)
A strategy based on tandem alkynylation of o-hydroxyarylenaminones followed by intramolecular cyclization has been developed to generate a diverse array of 3-alkynyl chromones. The functionality embedded in these key intermediates enables their facile elaboration into more diverse structures by a variety of functionalizations and ring-forming processes.

Facile synthesis of 1,3-thiazolidin-4-ones as antitubercular agents - Subhedar, Dnyaneshwar D.; Shaikh, Mubarak H.; Arkile, Manisha A.; Yeware, Amar; Sarkar, Dhiman; Shingate, Bapurao B. (Bioorganic & Medicinal Chemistry Letters, 2016)
We have developed, highly efficient, one-pot, solvent-free, [Et3NH][HSO4] catalyzed multicomponent reaction protocol for the synthesis of 1,3-thiazolidin-4-ones in excellent yields. For the first time, the 1,3-thiazolidin-4-ones were evaluated in vitro for their antimycobacterial activity against Mycobacterium tuberculosis dormant MTB H37Ra and Mycobacterium bovis BCG strains. Among the synthesized basic 1,3-thiazolidin-4-ones, particularly the compounds 4c, 4d, 4e, 4f, 4h, 4i and 4j displays promising antitubercular activity along with no significant cytotoxicity against the cell lines MCF-7, A549 and HCT-116. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords: Antitubercular; Cytotoxicity; Green protocol; Multicomponent reaction

Fate of inorganic nanoparticles in agriculture - Phogat, N.; Khan, S. A.; Shankar, S.; Ansary, A. A.; Uddin, I. (Advanced Materials Letters, 2016)
In modern world, engineered nanoparticles (ENPs) are increasingly becoming an important component of daily life. They are becoming an integral part of a wide range of man-made products including electronics, paints, biomedical products, sunscreens, clothing, automobiles, etc. Rapid progress in the manufacturing of ENPs and the subsequent increase in its commercial applications always have had an impact on agriculture due to the exposure of living things to these ENPs. Also, human beings are directly dependent on the plants because of their nutritional values. Hence, the impact of nanoparticles on agricultural soil and plants is always of topical interest. It is imperative to be aware of the effects of nanoparticles on soil as well as on the soil ecosystem it supports especially the soil microbes and plants; or more specifically whether they have an influence on the agricultural yield and agri-economy. It is also important to study the effects of man-made nanomaterials on the properties of agricultural soil. This work reviews some of the key features of the impact of ENPs on the environment and the fate of ENPs in agriculture.

Field emission properties of highly ordered low-aspect ratio carbon nanocup arrays - Gupta, Bipin Kumar; Kedawat, Garima; Kumar, Pawan; Singh, Satbir; Suryawanshi, Sachin R.; Agrawal, Neetu; Gupta, Govind; Kim, Ah Ra; Gupta, R. K.; More, Mahendra A.; Late, Dattatray J.; Hahm, Myung Gwan (RSC Advances, 2016)
Herein, we design and develop a field emission device utilizing highly porous carbon nanocup (CNC) films. These three-dimensional (3D) low-aspect ratio CNC structures were fabricated by a combination of anodization and chemical vapor deposition techniques. The low turn-on fields of 2.30 V mu m(-1) were observed to draw an emission current density of 1 mu A cm(-2) and a maximum emission current density of similar to 1.802 mA cm(-2) drawn at an applied field of similar to 4.20 V mu m(-1). The enhanced field emission behavior observed from the CNC films is attributed to an excellent field enhancement factor of 1645. The observed field emission properties of CNC arrays are attributed to a synergistic combination of high aspect ratio, nano-sized radius of curvature, highly organized distribution of the emitters over the whole area of specimen and lower screening effect of the CNC arrays. These observations shed light on the effect of the stacking carbon layers of CNC on their electronic properties and open up possibilities to integrate new morphologies of graphitic carbon in nanotechnology applications. Thus, the low turn on field, high emission current density and better emission current stability enable CNC based future field emission applications.

Fingering instability in the flow of a power-law fluid on a rotating disc - Arora, Akash; Doshi, Pankaj (Physics of Fluids, 2016)
A computational study of the flow of a non-Newtonian power law fluid on a spinning disc is considered here. The main goal of this work is to examine the effect of non-Newtonian nature of the fluid on the flow development and associated contact line instability. The governing mass and momentum balance equations are simplified using the lubrication theory. The resulting model equation is a fourth order non-linear PDE which describes the spatial and temporal evolutions of film thickness. The movement of the contact line is modeled using a constant angle slip model. To solve this moving boundary problem, a numerical method is developed using a Galerkin/finite element method based approach. The numerical results show that the spreading rate of the fluid strongly depends on power law exponent n. It increases with the increase in the shear thinning character of the fluid (n < 1) and decreases with the increase in shear thickening nature of the fluid (n > 1). It is also observed that the capillary ridge becomes sharper with the value of n. In order to examine the stability of these ridges, a linear stability theory is also developed for these power law fluids. The dispersion relationship depicting the growth rate for a given wave number has been reported and compared for different power-law fluids. It is found that the growth rate of the instability decreases as the fluid becomes more shear thinning in nature, whereas it increases for more shear thickening fluids. (C) 2016 AIP Publishing LLC.

Fluorescent carbon nanodots for targeted in vitro cancer cell imaging - Aiyer, Sandhya; Prasad, Rajendra; Kumar, Manoj; Niryikar, K.; Jain, Bhanprakash; Kushwaha, Omkar S. (Applied Materials Today, 2016)
Carbon quantum dots (CQDs or C-dots, <= 10nm in size) are tiny carbon nanoparticles being envisaged in biosensing, bio-imaging and biomolecular/drug delivery. In the present investigation, green fluorescent carbon quantum/nano dots (GCQDs, similar to 3 nm in size) were synthesized through facile chemical slicing method. Further, folic acid (FA) functionalized GCQDs (GCQDs-FA) were obtained to enhance their targeting ability. FA is known to positively influence the binding potential and penetration into the cancer cells because of high abundance of folate receptors (FR) on various cancer cell membranes. We report high biocompatibility, photoluminescence stability and excellent in vitro cancer cell cytoplasm and nucleus targeting performance of GCQDs-FA on MCF-7 breast cancer cells. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords: Cancer cell bio-imaging; Carbon quantum/nano dots; Cell cytoplasm and nucleus targeting; Green fluorescence; Photoluminescence stability; Targeting ability

Fluorescent polystyrene microbeads as invisible security ink and optical vapor sensor for 4-nitrotoluene - Sonawane, Swapnil L.; Asha, S. K. (ACS Applied Materials & Interfaces, 2016)
Color-tunable solid-state emitting polystyrene (PS) microbeads were developed by dispersion polymerization, which showed excellent fluorescent security ink characteristics along with sensitive detection of vapors of nitro aromatics like 4 nitro toluene (4-NT). The fluorophores pyrene and perylenebisimide were incorporated into the PS backbone as acrylate monomer and acrylate cross-linker, respectively. Solid state quantum yields of 94 and 20% were observed for the pyrene and perylenebisimide, respectively, in the PS/Py and PS/PBI polymers. The morphology and solid state fluorescence was measured by SEM, fluorescence microscopy, and absorbance and fluorescence spectroscopy techniques. The ethanol dispersion of the polymer could be used directly as a fluorescent security ``invisible'' ink, which became visible only under ultraviolet light. The color of the ink could be tuned depending on the amounts of the pyrene and perylenebisimide incorporated with blue and orange-green for pyrene alone or perylenebisimide alone beads respectively and various shades in between including pure white for beads incorporating both the fluorophores. More than 80% quenching of pyrene emission was observed upon exposure of the polymer in the form of powder or as spin-coated films to the vapors of 4-NT while the emission of perylenebisimide was unaffected. The limit of detection was estimated at 10(-5) moles (2.7 ppm) of 4-NT vapors. The ease of synthesis of the material along with its invisible ink characteristics and nitro aromatic vapor detection opens up new opportunities for exploring the application of these PS-based materials as optical sensors and fluorescent ink for security purposes.
Keywords: dispersion polymerization; invisible security ink; Perylenebisimide; pyrene; solid state detection

Fluorescent probe for bisulfite ions: its application to two-photon tissue imaging - Agarwalla, Hridesh; Pal, Suman; Paul, Anirban; Jun, Yong Woong; Bae, Juryang; Ahn, Kyo Han; Srivastava, Divesh N.; Das, Amitava (Journal of Materials Chemistry B, 2016)
A benzoxazinone based fluorescent probe for the specific and efficient detection of bisulfite ions in aqueous medium is described. The probe formed a bisulfite/sulphite adduct with an associated turn-on fluorescence response in the red wavelength region. No interference was observed in the detection process from all possible competing anions and molecules, including cyanide ion, cysteine, homocysteine and glutathione. In addition, the probe showed a fast response time, low detection limit, and cell membrane permeability. Furthermore, the probe was two-photon excitable, enabling imaging of endogenous bisulfite ions in HeLa cells as well as in deep tissues from different organs of mouse.

Formal enantioselective synthesis of (-)-epiquinamide by proline-catalyzed one-pot sequential -amination/propargylation of aldehyde and asymmetric dihydroxylation of olefin - Ahuja, Brij Bhushan; Emmanuvel, Lourdusamy; Sudalai, Arumugam (Synlett, 2016)
Two independent routes to the formal synthesis of (-)-epiquinamide, have been described: the first route utilizes an l-proline-catalyzed one-pot sequential -amination/propargylation of aldehyde, while the second one employs asymmetric dihydroxylation as the key reaction to install the stereochemistry. While the first synthesis was accomplished in nine steps with 24.4% overall yield and dr 9:1, the second strategy resulted in the synthesis in eight steps with 36.4% overall yield and with perfect enantiocontrol.
Keywords: Amination; diastereoselective; Dihydroxylation; Proline; quinolizidine

Functional characterization and transient expression manipulation of a new sesquiterpene synthase involved in beta-caryophyllene accumulation in Ocimum - Jayaramaiah, Ramesha H.; Anand, Atul; Beedkar, Supriya D.; Dholakia, Shushan B.; Punekar, Sachin A.; Kalunke, Raviraj M.; Gade, Wasudeo N.; Thulasiram, Hirekodathakallu V.; Giri, Ashok P. (Biochemical And Biophysical Research Communications, 2016)
The genus Ocimum has a unique blend of diverse secondary metabolites, with major proportion of terpenoids including mono- and sesquiterpenes. Although, beta-Caryophyllene, bicyclic sesquiterpene, is one of the major terpene found in Ocimum species and known to possess several biological activities, not much is known about its biosynthesis in Ocimum. Here, we describe isolation and characterization of beta-caryophyllene synthase gene from Ocimum kilimandscharicum Gurke (OkBCS- GenBank accession no. KP226502). The open reading frame of 1629 bp encoded a protein of 542 amino acids with molecular mass of 63.6 kDa and pl value of 5.66. The deduced amino acid sequence revealed 50-70% similarity with known sesquiterpene synthases from angiosperms. Recombinant OkBCS converted farnesyl diphosphate to beta-caryophyllene as a major product (94%) and 6% alpha-humulene. Expression variation of OkBCS well corroborated with beta-caryophyllene levels in different tissues from five Ocimum species. OkBCS transcript revealed higher expression in leaves and flowers. Further, agro-infiltration based transient expression manipulation with OkBCS over-expression and silencing confirmed its role in beta-caryophyllene biosynthesis. These findings may potentially be further utilized to improve plant defense against insect pests. (C) 2016 Elsevier Inc. All rights reserved.
Keywords: beta-Caryophyllene; Natural product biosynthesis; Ocimum; Terpene synthase; Transient expression

GAME9 regulates the biosynthesis of steroidal alkaloids and upstream isoprenoids in the plant mevalonate pathway - Cardenas, Pablo D.; Sonawane, Prashant D.; Pollier, Jacob; Vanden Bossche, Robin; Dewangan, Veena; Weithorn, Efrat; Tal, Lior; Meir, Sagit; Rogachev, Ilana; Malitsky, Sergey; Giri, Ashok P.; Goossens, Alain; et al. (Nature Communications, 2016)
Steroidal glycoalkaloids (SGAs) are cholesterol-derived molecules produced by solanaceous species. They contribute to pathogen defence but are toxic to humans and considered as anti-nutritional compounds. Here we show that GLYCOALKALOID METABOLISM 9 (GAME9), an APETALA2/Ethylene Response Factor, related to regulators of alkaloid production in tobacco and Catharanthus roseus, controls SGA biosynthesis. GAME9 knockdown and overexpression in tomato and potato alters expression of SGAs and upstream mevalonate pathway genes including the cholesterol biosynthesis gene STEROL SIDE CHAIN REDUCTASE 2 (SSR2). Levels of SGAs, C24-alkylsterols and the upstream mevalonate and cholesterol pathways intermediates are modified in these plants. Delta(7)-STEROL-C5(6)-DESATURASE (C5-SD) in the hitherto unresolved cholesterol pathway is a direct target of GAME9. Transactivation and promoter-binding assays show that GAME9 exerts its activity either directly or cooperatively with the SlMYC2 transcription factor as in the case of the C5-SD gene promoter. Our findings provide insight into the regulation of SGA biosynthesis and means for manipulating these metabolites in crops.

Graphene based nanocomposites for alloy (SnO2), and conversion (Fe3O4) type efficient anodes for Li-ion battery applications - Mhamane, Dattakumar; Aravindan, Vanchiappan; Taneja, Divya; Suryawanshi, Anil; Game, Onkar; Srinivasan, Madhavi; Ogale, Satishchandra B. (Composites Science and Technology, 2016)
Two types of trigol reduced one pot synthesized graphene (TRG) based nanocomposites (SnO2-TRG, and Fe3O4-TRG) are examined as potential anodes for Lithium ion battery (LIB) applications. The two specific systems represent different electrode reaction mechanisms, namely alloying, and conversion respectively. The high resolution transmission electron microscopy (HR-TEM) analysis confirms the uniform distribution of SnO2 (similar to 2 nm), and Fe3O4 (similar to 8 nm) particulates on ultrathin TRG nanosheets and highlights the importance of surfactant free synthesis. The SnO2-TRG, and Fe3O4-TRG exhibited the maximum reversible capacity of similar to 947, and similar to 1024 mA h g(-1), respectively. The results show that such graphene based composite materials can be effectively used as prospective anodes for LIB applications. (C) 2016 Elsevier Ltd. All rights reserved.

Graphene oxide sheathed ZIF-8 microcrystals: engineered precursors of nitrogen-doped porous carbon for efficient oxygen reduction reaction (ORR) electrocatalysis - Thomas, Minju; Illathvalappi, Rajith; Kurungot, Sreekumar; Nair, Balagopal N.; Mohamed, Abdul Azeez Peer; Anilkumar, Gopinathan M.; Yamaguchi, Takeo; Hareesh, U. S. (ACS Applied Materials & Interfaces, 2016)
Nitrogen containing mesoporous carbon obtained by the pyrolysis of graphene oxide (GO) wrapped ZIF-8 (Zeolitic Imidazolate Frameworks-8) micro crystals is demonstrated to be an efficient catalyst for the oxygen reduction reaction (ORR). ZIF-8 synthesis in the presence of GO sheets helped to realize layers of graphene oxide over ZIF-8 microcrystals and the sphere-like structures thus obtained, on heat treatment, transformed to highly porous carbon with a nitrogen content of about 6.12% and surface area of 502 m(2)/g. These catalysts with a typical micromeso porous architecture exhibited an onset potential of 0.88Vvs RHE in a four electron pathway and also demonstrated superior durability in alkaline medium compared to that of the commercial Pt/C catalyst. The N-doped porous carbon derived from GO sheathed ZIF-8 core shell structures could therefore be employed as an efficient electrocatalyst for fuel cell applications.
Keywords: alkaline fuel cell; graphene oxide; N-doped carbon; oxygen reduction reaction; porous carbon; ZIF-8

Green synthesis of stable Cu(0) nanoparticles onto reduced graphene oxide nanosheets: a reusable catalyst for the synthesis of symmetrical biaryls from arylboronic acids under base-free conditions (vol 5, pg 1251, 2015) - Hussain, Najrul; Gogoi, Pranjal; Azhagan, Muniraj Vedi Kuyil; Shelke, Manjusha V.; Das, Manash R. (Catalysis Science & Technology, 2016)
Correction for ‘Green synthesis of stable Cu(0) nanoparticles onto reduced graphene oxide nanosheets: a reusable catalyst for the synthesis of symmetrical biaryls from arylboronic acids under base-free conditions’ by Najrul Hussain et al., Catal. Sci. Technol., 2015, 5, 1251–1260.

H2S detection using low-cost SnO2 nano-particle Bi-layer OFETs - Surya, Sandeep G.; Ashwath, B. S. Narayan; Mishra, Sushma; Karthik, A. R. B.; Sastry, A. B.; Bhagavatula L. V. Prasad; Rangappa, Dinesh; Rao, V. Ramgopal (Sensors and Actuators B-Chemical, 2016)
In this article, a unique platform with an organic field-effect transistor (OFET) integrated with metal oxide nanoparticles for sensing of H2S gas is presented. Metal oxide nanoparticles such as SnO2 and ZnO synthesized using herbal techniques were used in the fabrication of OFETs using a bi-layer technique. The as -synthesized nanoparticles were characterized by Field Effect Scanning Electron Microscopy (FESEM), X-ray diffraction (XRD) and UV-vis Spectroscopy (UV-vis) to establish the material properties. We showed that the SnO2 based OFETs displayed better response for H2S at room temperature (25 degrees C) compared to the OFETs fabricated with ZnO. The characterization of the sensors by using extracted electrical parameters like field-effect mobility ([1), On -Current (Ion), threshold voltage (VT) and saturation current (ID]) establish the fact that the SnO2 based OFETs detect H2S gas at room temperature. Plausible mechanisms explaining the H2S gas detection by bi-layer film were discussed. On the other hand, the sensitivity of these OFETs against other reducing gases was less. (C) 2016 Elsevier B.V. All rights reserved.
Keywords: bi-layer; H2S detection; Metal-oxide; OFETs; Sensor

High hydroxide conductivity in a chemically stable crystalline metal-organic framework containing a water-hydroxide supramolecular chain - Nagarkar, Sanjog S.; Anothumakkool, Bihag; Desai, Aamod V.; Shirolkar, Mandar M.; Kurungot, Sreekumar; Ghosh, Sujit K. (Chemical Communications, 2016)
A chemically stable cationic MOF encapsulating an in situ formed water-hydroxide supramolecular anionic chain is realized for high hydroxide (OH-) ion conductivity in the solid-state (Type A). High OH- ion conductivity and low activation energy of the MOF demonstrate the advantage of the in situ incorporation of OH- ions to achieve efficient OH- ion conduction in the solid-state.

High-Performance flexible solid-state supercapacitor with an extended nanoregime interface through in situ polymer electrolyte generation - Anothumakkool, Bihag; Torris, Arun A. T.; Veeliyath, Sajna; Vijayakumar, Vidyanand; Badiger, Manohar V.; Kurungot, Sreekumar (ACS Applied Materials & Interfaces, 2016)
{Here, we report an efficient strategy by which a significantly enhanced electrodeelectrolyte interface in an electrode for supercapacitor application could be accomplished by allowing in situ polymer gel electrolyte generation inside the nanopores of the electrodes. This unique and highly efficient strategy could be conceived by judiciously maintaining ultraviolet-triggered polymerization of a monomer mixture in the presence of a high-surface-area porous carbon. The method is very simple and scalable, and a prototype, flexible solid-state supercapacitor could even be demonstrated in an encapsulation-free condition by using the commercial-grade electrodes (thickness = 150 mu m
Keywords: cyclic voltametry; impedance analysis; in situ polymer generation; interface; polymer electrolyte; supercapacitor

Hydrogen-bonded organic frameworks (HOFs): a new class of porous crystalline proton-conducting materials - Karmakar, Avishek; Illathvalappil, Rajith; Anothumakkool, Bihag; Sen, Arunabha; Samanta, Partha; Desai, Aamod V.; Kurungot, Sreekumar; Ghosh, Sujit K. (Angewandte Chemie-International Edition, 2016)
Two porous hydrogen-bonded organic frameworks (HOFs) based on arene sulfonates and guanidinium ions are reported. As a result of the presence of ionic backbones appended with protonic source, the compounds exhibit ultra-high proton conduction values (sigma) 0.75x 10(-2)Scm(-1) and 1.8x10(-2)Scm(-1) under humidified conditions. Also, they have very low activation energy values and the highest proton conductivity at ambient conditions (low humidity and at moderate temperature) among porous crystalline materials, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs). These values are not only comparable to the conventionally used proton exchange membranes, such as Nafion used in fuel cell technologies, but is also the highest value reported in organic-based porous architectures. Notably, this report inaugurates the usage of crystalline hydrogen-bonded porous organic frameworks as solid-state proton conducting materials.
Keywords: guanidinium; hydrogen-bonded organic frameworks; porous crystalline frameworks; proton conduction; sulfonates

Improved all-polymer solar cell performance of n-type naphthalene diimide-bithiophene P(NDI2OD-T2) copolymer by incorporation of perylene diimide as coacceptor - Sharma, Sandeep; Kolhe, Nagesh B.; Gupta, Vinay; Bharti, Vishal; Sharma, Abhishek; Datt, Ram; Chand, Suresh; Asha, S. K. (Macromolecules, 2016)
Naphthalene diimide-bithiophene P(NDI2OD-T2) is a well-known donor-acceptor polymer, previously explored as n-type material in all-polymer solar cells (all-PSCs) and organic field effect transistor (OFETs) applications. The optical, bulk, electrochemical, and semiconducting properties of P(NDI2OD-T2) polymer were tuned via random incorporation of perylene diimide (PDI) as coacceptor with naphthalene diimide (NDI). Three random copolymers containing 2,2'-bithiophene as donor unit and varying compositions of naphthalene diimide (NDI) and perylene diimide (xPDI, x = 15, 30, and 50 mol % of PDI) as two mixed acceptors were synthesized by Stille coupling copolymerization. Proton NMR spectra recorded in CD Cl-3 showed that the pi-pi stacking induced aggregation among the naphthalene units could be successfully disrupted by the random incorporation of bulky PDI units. The newly synthesized random copolymers were investigated as electron acceptors in BHJ all-PSCs, and their performance was compared with P(NDI2OD-T2) as reference polymer. An enhanced PCE of 5.03% was observed for BHJ all-PSCs (all-polymer solar cells) fabricated using NDI-Th-PDI30 as acceptor and PTB7-Th as donor, while the reference polymer blend with the same donor polymer exhibited PCE of 2.97% efficiency under similar conditions. SCLC bulk carrier mobility measured for blend devices showed improved charge mobility compared to reference polymer, with PTB7-Th:NDI-Th-PDI30 blend device exhibiting the high hole and electron mobility of 4.2 x 10(-4) and 1.5 x 10(-4) cm(2)/(V s), respectively. This work demonstrates the importance of molecular design via random copolymer strategy to control the bulk crystallinity, compatibility, blend morphology, and solar cell performance of n-type copolymers.

In vitro and ex vivo antitubercular activity of diarylheptanoids from the rhizomes of alpinia officinarum hance - Honmore, Varsha S.; Rojatkar, Supada R.; Nawale, Laxman U.; Arkile, Manisha A.; Khedkar, Vijay M.; Natu, Arun D.; Sarkar, Dhiman (Natural Product Research, 2016)
Phytochemical investigation of methanol extract of the rhizomes of Alpinia officinarum Hance afforded four known diarylheptanoids 1,7-diphenylhept-4-en-3-one (1), 5-hydroxy-1,7-diphenyl-3-heptanone (2), 5-hydroxy-7-(4 ''-hydroxy-3 ''-methoxyphenyl)-1-phenyl-3-heptanone (3), and 7-(4 ''-hydroxy-3 ''-methoxyphenyl)-1-phenyl heptan-3-one (4).The acetate derivative of (4), 7-(4 ''-actetate-3 ''-methoxy phenyl)-1-phenyl heptan-3-one (5), was prepared. These diarylheptanoids exhibited promising in vitro and ex vivo antitubercular activity for the first time against dormant Mycobacterium tuberculosis H37Ra with the IC50 values between 0.3447.69 and 0.1322.91 mu M, respectively. All compounds showed comparable activity against Mycobacterium bovis BCG (dormant phage) and did not show any activity against two gram + ve and two gram -ve bacterial strains. These compounds were also weakly cytotoxic up to 300 mu M against three human cancer cell lines THP-1, Panc-1 and A549.

Interplaying intrinsic and extrinsic proton conductivities in covalent organic frameworks - Chandra, Suman; Kundu, Tanay; Dey, Kaushik; Addicoat, Matthew A.; Heine, Thomas; Banerjee, Rahul (Chemistry of Materials, 2016)
A sulfonic-acid-based covalent organic framework (TpPa-SO3H) has been synthesized that exhibits intrinsic proton conductivity under anhydrous conditions. The sulfonic acid groups are aligned on the two-dimensional (2D) layers at periodic intervals and promote the proton hopping inside the hexagonal one-dimensional channel. The intrinsic proton conductivity of TpPa-SO3H was measured as 1.7 X 10(-5) S cm(-1) at 120 degrees C under anhydrous conditions. To enhance the proton conductivity, we have synthesized a hybrid COF TpPa(SO3H-Py) by a ligand-based solid-solution approach that contains sulfonic acid as the acidic site, as well as pyridine as the basic site, in order to immobilize acidic proton carrier molecules. Impregnation of phytic acid molecules inside the framework increases the anhydrous proton conductivity up to 5 x 10(-4) S cm(-1) at 120 degrees C. Such an approach highlights the advantage and first-time use of hybrid COF for interplaying intrinsic to extrinsic proton conductivity.

Isolation and characterization of new lignin streams derived from extractive-ammonia (EA) pretreatment - Sousa, Leonardo da Costa; Foston, Marcus; Bokade, Vijay V.; Azarpira, Ali; Lu, Fachuang; Ragauskas, Arthur J.; Ralph, John; Dale, Bruce E.; Balan, Venkatesh (Green Chemistry, 2016)
One of the key challenges facing lignin conversion to fuels and chemicals is related to the level of carbohydrate and ash impurities found in extracted lignin. Structural modifications of lignin may also occur as a result of biomass pretreatment and harsh lignin extraction protocols. Extractive-Ammonia (EA) is a new pretreatment technology that uses liquid ammonia to cleave lignin-carbohydrate complexes, decrystallize cellulose, solubilize lignin, and selectively extract Lignin from lignocellulosic biomass, enabling better utilization of both lignin and carbohydrate components in a biorefinery. The EA-based biorefinery produces two different lignin-rich streams, with different properties, that could potentially be upgraded to fuels and chemicals using green processes. In this work, a water/ethanol-based fractionation method was developed to enrich the ammonia-soluble extractives, resulting in a major product stream containing 92% lignin. Detailed characterization of the various streams resulting from EA treatment, including compositional analysis, structural characterization by nuclear magnetic resonance (NMR) spectrometry, elemental analysis, molecular weight analysis, and thermo-gravimetric analysis provides a broad evaluation of the EA derived lignin product stream structures and properties, assessing their potential for commercial applications. In summary, EA-derived lignins preserve much of lignin's functionality, including the sensitive (3-aryl ether units. Nitrogen incorporation was observed in the lignin-rich streams, notably due to the presence of hydroxycinnamoyl amides formed during ammonia pretreatment.

Mechanically tunable curcumin incorporated polyurethane hydrogels as potential biomaterials - Divakaran, Anumon V.; Azad, Lal Busher; Surwase, Sachin S.; Torris, Arun A. T.; Badiger, Manohar V. (Chemistry of Materials, 2016)
We report here on the one-pot synthesis and characterization of curcumin incorporated polyethylene glycol polyurethane (PU-CUR) hydrogels using PEG-4000, 4, 4'-methylenebis (cyclohexyl isocyanate), curcumin in the presence of a cross-linker, 1,2,6 hexanetriol (HT). Besides the physical entrapment, curcumin also provides a partial cross linking in the 3-D structure of the hydrogel. The degree of swelling in hydrogels could be controlled by varying the amount of HT as well as curcumin. The structural characterization of hydrogels was performed using Fourier transform infrared spectroscopy, high-resolution mass spectrometry, UV and fluorescence spectroscopy. The wide-angle X-ray scattering studies revealed the existence of crystalline domains of PEG, and the small-angle X-ray scattering studies showed the presence of lamellar microstructures. Porous structure in the hydrogel was created by cryogenic treatment and lyophilization. Scanning electron microscopy and microcomputed tomography imaging of hydrogels showed the presence of interconnected pores. The mechanical strength of the hydrogels was measured using a universal testing machine. The observed tensile and breaking compression strengths for the equilibrium swollen gels were found to be in the range of 0.22-0.73 MPa and 1.65-4.6 MPa, respectively. Detailed in vitro biological experiments showed the biocompatibility of gels, cytostatic dosage of curcumin, selective toxicity toward cancer cell lines, and antibacterial property. These gels show promising applications as scaffolds and implants in tissue engineering.

Mechanochemically synthesized covalent organic framework as a proton-conducting solid electrolyte - Shinde, Digambar Balaji; Aiyappa, Harshitha Barike; Bhadra, Mohitosh; Biswal, Bishnu P.; Wadge, Pritish; Kandambeth, Sharath; Garai, Bikash; Kundu, Tanay; Kurungot, Sreekumar; Banerjee, Rahul (Journal of Materials Chemistry A, 2016)
Mechanochemistry has become an increasingly important synthetic tool for a waste-free environment. However, the poor quality of the so-derived materials in terms of their crystallinity and porosity has been their major drawback for any practical applications. In this report, we have for the first time successfully leveraged such characteristics to show that the mechanochemically synthesized bipyridine based covalent organic framework (COF) outperforms its conventional solvothermal counterpart as an efficient solid-state electrolyte in PEM fuel cells. Marking the first such attempt in COFs, a Membrane Electrode Assembly (MEA) fabricated using the mechanochemically synthesized COF was observed to inhibit the fuel crossover and build up a stable Open Circuit Voltage (OCV = 0.93 V at 50 degrees C), thereby establishing itself as an effective solid electrolyte material (with a proton conductivity of 1.4 x 10(-2) S cm(-1)), while the solvothermally synthesized COF proved ineffective under similar conditions.

Minute-made activated porous carbon from agro-waste for Li-ion battery anode using a low power microwave oven - Agarkar, Shruti; Yadav, Poonam; Fernandes, Rohan; Kothari, Dushyant; Suryawanshi, Anil; Ogale, Satishchandra (Electrochimica ACTA, 2016)
We demonstrate a very simple, cost-effective and superfast process for making Li-ion battery (LIB) anode grade carbon from agro-waste in the form of sugarcane bagasse using a low power microwave system. Activation of this bagasse derived carbon is carefully optimized by using various weight ratios of KOH to obtain the desired properties of functional carbon in terms of porosity and electrical conductivity. Low equivalent series resistance (ESR), low charge transfer resistance with good electrical conductivity, and optimum porosity for efficient ion diffusion make this carbon a good candidate for Li-ion battery anode material rendering a reversible capacity of 757 mAhg (1) at a current density of 100 mAg (1) and a good cycling performance at high current rates. (C) 2016 Elsevier Ltd. All rights reserved.

Mixing studies in unbaffled stirred tank reactor using electrical resistance tomography - Sardeshpande, Madhavi V.; Kumar, Gaurav; Aditya, T.; Ranade, Vivek V. (Flow Measurement and Instrumentation, 2016)
Unbaffled stirred tanks are extensively used in chemical process industries for variety of applications including semi-batch reactions. In un-baffled stirred tanks, impeller rotation generates a vortex and reactants are added into this vortex. There is a growing interest towards understanding the mixing performance of such unbaffled stirred vessels. The present work is aimed at providing experimental results on mixing time and solid particle distribution inside an unbaffled vessel using electrical resistance tomography (ERT). A methodology for using ERT for characterizing vortex and mixing in unbaffled stirred vessel was established. The ERT was used to measure the mixing time with and without solid particles (glass beads, 250 mu m) in a stirred reactor. In this study, ERT technique was effectively applied for imaging solid-liquid flow and developed suitable data processing methodologies. It observed that estimated liquid phase mixing time for Un-baffled vessel was more as compared to baffled vessel. Radial solid concentration profiles showed Gaussian distribution inside the vessel. The presented methodology of using ERT and experimental results will be useful for designing and estimating mixing and solid distribution in unbaffled stirred tanks. (C) 2016 Elsevier Ltd. All rights reserved.
Keywords: ERT; Mixing time; Radial solid concentration; Unbaffled stirred tank

Multifunctional copper dimer: structure, band gap energy, catalysis, magnetism, oxygen reduction reaction and proton conductivity - Sarkar, D.; Chandra Rao, P.; Aiyappa, H. B.; Kurungot, S.; Mandal, S.; Ramanujam, K.; Mandal, S. (RSC Advances, 2016)
A new dimeric copper complex namely, [Cu2(PDA)2(Ald)2(H2O)2]·8H2O, 1, (where PDA = 2,4-pyridine dicarboxylic acid, Ald = aldrithiol) has been synthesized through a slow diffusion technique. Compound 1 is a molecular structure and assembled through H-bonding forming a supramolecular architecture. The CuO2N3 units bridged through an aldrithiol molecule to form the dimeric structure. The lattice water molecules are linked through H-bonding to form the decameric water cluster. The decameric water clusters are H-bonded to each other to form the 1D chain which resulted in excellent water stability and conduction of protons under humid conditions. Band gap energy and magnetic measurements show that compound 1 is a semiconductor and paramagnetic in nature. Further the compound is shown as a selective heterogeneous catalyst for styrene and cyclohexene epoxidation. This also shows a facile oxygen reduction reaction (ORR) and can be used as a promising Pt-free cathode in alkaline Direct Methanol Fuel Cells (DMFC). The present results suggest that compound 1 is a promising multifunctional material

Nanostructure oxygen carrier used in chemical looping combustion process-A review - Badadare, Mansing M.; Adbale, Naina M.; Khomane, Ramdas B.; Kale, Ganesh R. (Advanced Science Letters, 2016)
Chemical looping combustion (CLC) is an emerging technology with inherent separation of CO2 from combustion of fuels. In this technique contact of air and fuel for combustion is restricted by providing oxygen through oxygen carrier (DC). The functional efficiency of CLC process mainly depends on the ability of oxygen carrier and it's reactivity, which undergoes repeated oxidation and reduction cycles. Nanostructure metal oxides have shown great potential application in the field of chemical looping combustion due to their high surface to volume ratio and enhanced structural properties. Synthesis technique of nanostructure metal oxides, their role as oxygen carrier, their reactivity with fuels along with their structural stability are reviewed herein. The contribution of various operating conditions on nanostructure oxygen carrier are considered in this review. These operating conditions and synthesis routes are summarized and classified according to metal oxides.
3rd International Conference on Nanotechnology, Pune, INDIA, OCT 14-15, 2014
Keywords: Chemical looping combustion; CO2 Emission; Metal Oxide; Nanostructure; Oxygen Carrier

Naturally occurring anti-TB agents: isolation, chemical transformations and in vitro antitubercular activities of secondary metabolites of rhizomes of alpinia galanga - Valkute, Tushar R.; Arkile, Manisha A.; Sarkar, Dhiman; Bhattacharya, Asish K. (Planta Medica International Open, 2016)
A bioactivity-guided chemical examination of the acetone extract of the rhizomes of Alpinia galanga led to the isolation of six sec-ondary metabolites, eucalyptol derivative (1)andphenylpropa-noids (2–6). The structures of all of the isolated compounds (1–6)wereelucidatedonthebasisoftheirspectraldata.Theisolatedcompounds (1–6)werein vitro assayed against active and dor-mant phenotypes of Mycobacterium tuberculosis H37Ra, respec-tively. Interestingly, 1′S-1′-acetoxychavicol acetate (2)showedgood antitubercular activities against both active and dormantphenotypes of M. tuberculosis with IC50 values of 1.04 µM and2.69 µM, respectively. Tsuji-Trost and homodimerization reac-tions of the active compound (2)respectivelyresultedinthefor-mation of two analogues, 7and 8.Bothofthesesynthesizedana-logues were also found to be active in vitro against active [IC50 sof3.24 and 3.87 µM, respectively, for compounds 7and 8]anddor-mant [IC50 sof8.33and2.41µM,respectively,forcompounds7and 8]phenotypesofM. tuberculosis H37Ra, respectively.

Nevirapine loaded core shell gold nanoparticles by double emulsion solvent evaporation: invitro and in vivo evaluation - Dalvi, Bhagyashree R.; Siddiqui, Ejaz A.; Syed, Asad S.; Velhal, Shilpa M.; Ahmad, Absar; Bandivdekar, Atmaram B.; Devarajan, Padma V. (Current Drug Delivery, 2016)
Background: HIV/AIDS is a macrophage resident infection localized in the reticuloendothelial system and remote locations of brain and bone marrow. We present core shell nanoparticles of gold(AuNPs) and nevirapine(NVP) for targeted delivery to the multiple HIV reservoirs. The aim of the study was to design core shell NVP loaded AuNPs with high drug loading and to evaluate biodistribution of the nanoparticles in possible HIV reservoirs in vivo. A specific objective was to assess the possible synergy of AuNPs with NVP on anti-HIV activity in vitro. Method: Core shell nanoparticles were prepared by double emulsion solvent evaporation method and characterized. Results: Glyceryl monostearate-nevirapine-gold nanoparticles(GMS-NVP-AuNPs) revealed high entrapment efficiency (> 70%), high loading (similar to 40%), particle size < 250 nm and zeta potential -35.9 +/- 1.41mv and exhibited sustained release with good stability. Surface plasmon resonance indicated shell formation while SEM coupled EDAX confirmed the presence of Au. TEM confirmed formation of spherical core shell nanoparticles. GMS-NVP-AuNPs revealed low hemolysis (< 10 %) and serum stability upto 6 h. GMS-NVP-AuNPs exhibited rapid, high and sustained accumulation in the possible HIV reservoir organs, including the major organs of liver, spleen, lymph nodes, thymus and also remote locations of brain, ovary and bone marrow. High cell viability and enhanced uptake in PBMC's and TZM-bl cells were observed. While uptake in PBMC's proposed monocytes/macrophages enabled brain delivery. GMS-NVP-AuNPs demonstrated synergistic anti-HIV activity. Conclusion: The superior anti-HIV activity in vitro coupled with extensive localization of the nanoparticles in multiple HIV reservoirs suggests great promise of the core shell GMS-NVP-AuNPs for improved therapy of HIV.

New dinor-cis-labdane diterpene and flavonoids with antimycobacterium activity from colebrookea oppositifolia - Chinchansure, Ashish A.; Arkile, Manisha A.; Shinde, Dinesh R.; Sarkar, Dhiman; Joshi, Swati P. (Planta Medica Letters, 2016)
The new 14,15-dinor-cis-labdane diterpene, named (+)-14,15-dinor-9α-hydroxy-cis-labd-11(E)-en-13-one (1), was isolated from the acetone extract of the aerial parts of Colebrookea oppositifolia, along with the known compounds alnustin (2), mosloflavone (3), flindulatin (4), 5,6,7-trimethoxy baicalein (5), tanetin (6), scutellarein 4′-methyl ether (7), apigenin (8), caffeic acid (9), anisofolin A (10), apigetrin (11), and forsythoside A (12). Structures of the new and known compounds were established by detailed analysis of 1D and 2D nuclear magnetic resonance studies. The isolated compounds 1–12 were evaluated for their antimycobacterium activity against Mycobacterium tuberculosis H37Ra and Mycobacterium bovis in both dormant and active phases. Compounds 1, 7, and 8 exhibited inhibitory activity against M. tuberculosis with IC50 values in the range of 8.1–55.0 µM (MIC 14.4–119.7 µM) in the active phase and 7.4–43.5 µM (MIC 11.5–123.3 µM) in the dormant phase. Similarly 1, 7, and 8 exhibited inhibitory activity against M. bovis with IC50 values in the range of 4.1–98.5 µM (MIC 13.7–161.0 µM) in the active phase and 4.1–111.1 µM (MIC 13.0–166.4 µM) in the dormant phase.

Next-generation ammonia pretreatment enhances cellulosic biofuel production - Sousa, Leonardo da Costa; Jin, Mingjie; Chundawat, Shishir P. S.; Bokade, Vijay V.; Tang, Xiaoyu; Azarpira, Ali; Lu, Fachuang; Avci, Utku; Humpula, James; Uppugundla, Nirmal; Gunawan, Christa; Pattathil, Sivakumar; et al. (Energy & Environmental Science, 2016)
A new liquid ammonia pretreatment methodology called Extractive Ammonia (EA) was developed to simultaneously convert native crystalline cellulose I-beta (CI) to a highly digestible cellulose IIII (CIII) allomorph and selectively extract up to B45% of the lignin from lignocellulosic biomass with near-quantitative retention of all polysaccharides. EA pretreated corn stover yielded a higher fermentable sugar yield compared to the older Ammonia Fiber Expansion (AFEX) process while using 60% lower enzyme loading. The EA process preserves extracted lignin functionalities, offering the potential to co-produce lignin-derived fuels and chemicals in the biorefinery. The single-stage EA fractionation process achieves high biofuel yields (18.2 kg ethanol per 100 kg untreated corn stover, dry weight basis), comparable to those achieved using ionic liquid pretreatments. The EA process achieves these ethanol yields at industrially-relevant conditions using low enzyme loading (7.5 mg protein per g glucan) and high solids loading (8% glucan, w/v).

Observation of magnetic anomalies in one-step solvothermally synthesized nickel-cobalt ferrite nanoparticles - Datt, Gopal; Sen Bishwas, Mousumi; Raja, M. Manivel; Abhyankar, A. C. (Nanoscale, 2016)
Magnetic anomalies corresponding to the Verwey transition and reorientation of anisotropic vacancies are observed at 151 K and 306 K, respectively, in NiCoFe2O4 nanoparticles (NPs) synthesized by a modified-solvothermal method followed by annealing. Cationic disorder and spherical shape induced non-stoichiometry suppress the Verwey transition in the as-synthesized NPs. On the other hand, reorientation of anisotropic vacancies is quite robust. XRD and electron microscopy investigations confirm a single phase spinel structure and the surface morphology of the as-synthesized NPs changes from spherical to octahedral upon annealing. Rietveld analysis reveals that the Ni2+ ions migrate from tetrahedral (A) to octahedral (B) sites upon annealing. The Mossbauer results show canted spins in both the NPs and the strength of superexchange is stronger in Co-O-Fe than Ni-O-Fe. Magnetic force images show that the as-synthesised NPs are single-domain whereas the annealed NPs are multi-domain octahedral particles. The FMR study reveals that both the NPs have a broad FMR line-width; and resonance properties are consistent with the random anisotropy model. The broad inhomogeneous FMR line-width, observation of the Verwey transition, tuning of the magnetic domain structure as well as the magnetic properties suggest that the NiCoFe2O4 ferrite NPs may be promising for future generation spintronics, magneto-electronics, and ultra-high-density recording media as well as for radar absorbing applications.

Orientation effect induced selective chelation of Fe2+ to a glutamic acid appended conjugated polymer for sensing and live cell imaging - Senthilkumar, T.; Parekh, Nimisha; Nikama, Shrikant B.; Asha, S. K. (Journal of Materials Chemistry B, 2016)
Intracellular detection and imaging of labile iron(II) pools is very important in tracking physiological processes that demand new and rapid sensing probes. In this report, we present a water soluble polymer based probe for the fluorescence sensing and live cell imaging of labile Fe2+ ions with high selectivity for the first time. The polymer probe was based on conjugated polyfluorene which was appended with amino acid (L-glutamic acid). The biocompatibility of the polymer was confirmed from an MTT assay which demonstrated >90% cell viability even at 300 mu g ml(-1) loading of polymers. Simple glutamic acid did not show selectivity towards any of the divalent ions. However, glutamic acid appended polyfluorene exhibited selective chelation to Fe2+ ions resulting in immediate sensing activity for Fe2+ ions in water and living cells with fluorescence turn-off response. The limit of detection of the PF-Ph-GA polymer probe was 46 (+/- 2) nM which indicated high sensitivity for Fe2+ over other ions reported in the literature. The polymer also exhibited improved sensing activity in the range of intracellular pH (5-9) which is advantageous in differentiating endogenous changes. The probe was successfully applied for the fluorescence imaging of intracellular and supplemented labile iron(II) pools in living HeLa cells.

P4VP and oligo(phenylenevinylene)-perylenebisimide mixed donor-acceptor supramolecular comb polymer complexes with improved charge carrier mobility - Saibal, B.; Chithiravel, Sundaresan; Asha, S. K. (Journal of Polymer Science Part A-Polymer Chemistry, 2016)
Random donor-acceptor (D-A) supramolecular comb polymers were formed when hydroxyl functionalized donor and acceptor small molecules based on Oligo(phenylenevinylene) (named OPVCN-OH) and Perylenebisimide (named UPBI-PDP), respectively, were complexed with Poly(4-vinyl pyridine) (P4VP). A series of random D-A supramolecular comb polymers were formed by varying the ratios of UPBI-PDP and OPVCN-OH with P4VP. A 100% P4VP-donor polymer complex [P4VP(OPV1.00)] and a 100% P4VP-acceptor polymer complex [P4VP(UPBI1.00)] were also synthesized and characterized. Complex formation was confirmed by FT-IR and H-1 NMR spectroscopy. Solid state structural studies carried out using small angle X-ray scattering and wide angle X-ray diffraction experiments revealed altered packing of the D and A molecules in the complexes. Transmission electron microscopy images showed lamellar structures in the <10 nm scale for the P4VP(OPV1.00), P4VP(UPBI1.00), and mixed P4VP (D-A) complexes. The effect of the nanoscopic D-A self-assembly on the bulk mobility of the materials was probed using SCLC measurements. The mixed D-A random complexes exhibited ambipolar charge transport characteristics with higher values for the average bulk hole mobility estimate. P4VP(OPV0.25+UPBI0.75) exhibited an average hole mobility in the order of 10(-2) cm(2) V-1 s(-1) and electron mobility 10(-5) cm(2) V-1 s(-1). (C) 2016 Wiley Periodicals, Inc.
Keywords: donor-acceptor; oligo(phenylenevinylene); P4VP; Perylenebisimide; Self-assembly; structure-property relations; supramolecular comb polymer; supramolecular structures

Pd-catalyzed reductive cleavage of N-N bond in dibenzyl-1-alkylhydrazine-1,2-dicarboxylates with PMHS: application to a formal enantioselective synthesis of (R)-sitagliptin - Dey, Soumen; Gadakh, Sunita K.; Ahuja, Brij Bhushan; Kamble, Sanjay P.; Sudalai, Arumugam (Tetrahedron Letters, 2016)
An environmentally benign approach involving Pd-catalyzed reductive N-N bond cleavage in dibenzyl-1-alkylhydrazine-1,2-dicarboxylates leading to the synthesis of N-(tert-butoxy)carbamates under very mild conditions has been described. PMHS serves as an inexpensive source of hydride in MeOH/deionized H2O medium. This protocol has been successfully applied in the formal synthesis of (R)-sitagliptin, an anti-diabetic drug. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: anti-Diabetic; Environmentally benign; Hydrazine; PMHS; Reductive cleavage

Penicillin acylases revisited: importance beyond their industrial utility - Avinash, Vellore Sunder; Pundle, Archana Vishnu; Ramasamy, Sureshkumar; Suresh, Cheravakkattu Gopalan (Critical Reviews In Biotechnology, 2016)
It is of great importance to study the physiological roles of enzymes in nature; however, in some cases, it is not easily apparent. Penicillin acylases are pharmaceutically important enzymes that cleave the acyl side chains of penicillins, thus paving the way for production of newer semi-synthetic antibiotics. They are classified according to the type of penicillin (G or V) that they preferentially hydrolyze. Penicillin acylases are also used in the resolution of racemic mixtures and peptide synthesis. However, it is rather unfortunate that the focus on the use of penicillin acylases for industrial applications has stolen the spotlight from the study of the importance of these enzymes in natural metabolism. The penicillin acylases, so far characterized from different organisms, show differences in their structural nature and substrate spectrum. These enzymes are also closely related to the bacterial signalling phenomenon, quorum sensing, as detailed in this review. This review details studies on biochemical and structural characteristics of recently discovered penicillin acylases. We also attempt to organize the available insights into the possible in vivo role of penicillin acylases and related enzymes and emphasize the need to refocus research efforts in this direction.
Keywords: beta-lactam; choloyl glycine; in vivo role; Ntn hydrolases; pathogenicity; quorum sensing; regulation; signalling

Photocatalytic degradation of methylene blue on Sn-doped titania nanoparticles synthesized by solution combustion route - Bhange, P. D.; Awate, S. V.; Gholap, Ramkrishna S.; Gokavi, G. S.; Bhange, Deu S. (Materials Research Bulletin, 2016)
Series of tin-doped titania nanoparticles with varying tin content in the range 0-20 mol% have been prepared by solution combustion synthesis route using urea as a fuel. The structure, surface morphology and optical activity of Sn-doped TiO2 nanoparticles were investigated by various analytical techniques such as powder XRD, SEM, TEM, UV-vis and N-2 adsorption study. The crystalline structures of the various phases were studied by rietveld refinement of the XRD data. The photocatalytic performance of Sn-doped titania nanoparticles were tested for degradation of MB under UV and visible light irradiation. The results reveal that the photocatalytic activity increases with increase in tin content which may be due to decrease in crystallite size with increase in surface area. The doping of Sn into TiO2 lattice hinders the recombination of electrons and holes thus enhance the quantum efficiency of photocatalytic reaction. (C) 2015 Elsevier Ltd. All rights reserved.
Keywords: Catalytic properties; composites; Nanostructures; X-ray diffraction

Photoresponsive assemblies of linear-dendritic copolymers containing azobenzene in the dendron interior: the effect of the dendron structure on dye encapsulation and release - Kalva, Nagendra; Basutkar, Nitin B.; Ambade, Ashootosh V. (RSC Advances, 2016)
Hydrophobic dendrons with different numbers and positions of azobenzenes as well as different groups benzyl and dodecyl, on the periphery were synthesised and attached to poly(ethylene glycol) using copper-catalysed azide-alkyne cycloaddition to obtain linear-dendritic copolymers. Self-assembly of the polymers in aqueous solution was characterised using dynamic light scattering (DLS), transmission electron microscopy (TEM) and critical micelle concentration (cmc). Formation of H-aggregates during micellisation was shown for polymers with a higher number of azobenzene units. Photoisomerisation of azobenzene in the assemblies was studied and the rate constant of thermal photoisomerisation was calculated. Release of hydrophobic dye Nile red upon photoisomerisation of azobenzene occurred without disruption of micellar aggregates. Dye release varied with the pathway - thermal or visible light irradiation, followed for cis-trans isomerisation. The encapsulation capacity of the micelles and extent of dye release in either pathway were found to be influenced by the dendron structure. A polymer with a lower number of azobenzenes and aliphatic periphery on the dendron showed significantly different behaviour than polymers with a larger number of aromatic units.