Synthesis and structural characterization of homochiral homo-oligomers of cis-gamma-methoxy-substituted cis- and trans-furanoid-beta-amino acids - Giri, Awadut G.; Jogdand, Ganesh F.; Rajamohanan, Pattuparampil R.; Pandey, Sunil K.; Ramana, Chepuri V. (European Journal of Organic Chemistry, 2012)
Herein we describe the synthesis of cis-/trans-3-aminotetrahydrofuran-2-carboxylic acids (cis-/trans-FAA) having a ?-methoxy group cis to the amine. The homo-oligomers of these two diastereomeric FAAs have been prepared. Preliminary investigation of their solution secondary structures revealed that they are the same as the homo-oligomers of the parent cis-/trans-FAA with the methoxy group only being a spectator substituent.
Keywords: Amino acids; helical structures; Oxygen heterocycles; Peptides

Synthesis of glycidol from glycerol and dimethyl carbonate using ionic liquid as a catalyst - Gade, Swapna M.; Munshi, Mudassir K.; Chherawalla, Batul M.; Rane, Vilas H.; Kelkar, Ashutosh A. (Catalysis Communications, 2012)
Transesterification of dimethyl carbonate with glycerol has been investigated using various ionic liquids as catalysts. Synthesis of glycidol with high selectivity (78%) has been achieved using tetramethylammonium hydroxide ([TMA][OH]) as a catalyst at 80 degrees C. Effect of various reaction conditions on the activity and selectivity was investigated and catalyst concentration had a significant influence on conversion as well as selectivity to glycidol. Activity as well as selectivity of the catalyst decreased significantly with increase in moisture content. Recycle experiment indicated slight drop in glycerol conversion and selectivity to glycidol because of dilution of reaction mixture and also the presence of products from the initial experiment. (C) 2012 Elsevier B.V. All rights reserved.
Keywords: Glycerol carbonate; Glycidol; Ionic liquid; Transesterification of glycerol

Synthesis of isomeric corniculatolides - Raut, Gajanan N.; Chakraborty, Kasturi; Verma, Priyanka; Gokhale, Rajesh S.; Reddy, D. Srinivasa (Tetrahedron Letters, 2012)
Synthesis of three natural macrolides 11-O-methylcorniculatolide A, 11-O-methylisocorniculatolide A and isocorniculatolide A is reported using a simple, straight forward and high-yielding route. The present synthesis confirms the assigned molecular structures and provides an access to sufficient quantities of the natural products for the biological evaluation. In addition, we have determined the anti-TB potential of the three natural compounds using Alamar-Blue assay (H(37)Rv) and found no significant inhibitory activity at 100 mu g/ml. Excellent yields, short sequence and useful SAR information are the highlights of the present work. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: Diaryl ether; Isocorniculatolide; Macrocyclization; Mitsunobu reaction; Total synthesis

TDR Targets: a chemogenomics resource for neglected diseases - Magarinos, Maria P.; Carmona, Santiago J.; Crowther, Gregory J.; Ralph, Stuart A.; Roos, David S.; Shanmugam, Dhanasekaran; Van Voorhis, Wesley C. (Nucleic Acids Research, 2012)
The TDR Targets Database (http://tdrtargets.org) has been designed and developed as an online resource to facilitate the rapid identification and prioritization of molecular targets for drug development, focusing on pathogens responsible for neglected human diseases. The database integrates pathogen specific genomic information with functional data (e.g. expression, phylogeny, essentiality) for genes collected from various sources, including literature curation. This information can be browsed and queried using an extensive web interface with functionalities for combining, saving, exporting and sharing the query results. Target genes can be ranked and prioritized using numerical weights assigned to the criteria used for querying. In this report we describe recent updates to the TDR Targets database, including the addition of new genomes (specifically helminths), and integration of chemical structure, property and bioactivity information for biological ligands, drugs and inhibitors and cheminformatic tools for querying and visualizing these chemical data. These changes greatly facilitate exploration of linkages (both known and predicted) between genes and small molecules, yielding insight into whether particular proteins may be druggable, effectively allowing the navigation of chemical space in a genomics context.

Total synthesis and structural revision of stagonolide D - Vadhadiya, Paresh M.; Puranik, Vedavati G.; Ramana, Chepuri V. (Journal of Organic Chemistry, 2012)
The total synthesis of the putative structure of stagonolide D has been completed. The relative and absolute configuration of stagonolide D was established by synthesizing its optical antipode. The adopted strategy involves the construction of the central macrolide employing ring-closing metathesis (RCM), followed by selective protecting group manipulations and a final concomitant −OTBS deprotection and displacement of an −OMs placed next to it, resulting in the formation of the epoxide ring.

Total synthesis of (-)-isatisine A - Patel, Pitambar; Ramana, C. V. (Journal of Organic Chemistry, 2012)
A modular total synthesis of (-)-isatisine A is described in which four consecutive metal-mediated transformations have been employed at the final stage. These include [Pd]-catalyzed Sonogashira coupling, [Pd]-catalyzed nitroalkyne cycloisomerization leading to isatogens, and addition of indoles to isatogens using InCl3- and [Rh]-catalyzed oxidative N-heterocyclization of amino alcohol to form the key amide bond. In addition to these, the removal of the protecting groups has also been carried out in a selective fashion employing either catalytic or stoichiometric metal/metal-based reagents.

Total synthesis of (–)-sacidumlignans B and D - Rout, Jeetendra Kumar; Ramana, Chepuri V. (Journal of Organic Chemistry, 2012)
The first total synthesis of naturally occurring sacidumlignans A (1), B (2), and D (4) was executed and the absolute configuration of 2 and 4 was determined. A diastereoselective α- methylation of a lactone was used as the key step for the control of the chiral centers of the central lignan core. An acid mediated dehydrative cyclization of an aldehyde to construct the dihydronaphthalene unit of 2 and the aromatization of the intermediate dihydronaphthalene derivative to synthesize 1 are the key reactions employed in this regard.

Transformation of (+/-)-lavandulol and (+/-)-tetrahydrolavandulol by a fungal strain Rhizopus oryzae - Daramwar, Pankaj P.; Rincy, Raju; Niloferjahan, Siddiqui; Krithika, Ramakrishnan; Gulati, Arvind; Yadav, Amit; Sharma, Rakesh; Thulasiram, Hirekodathakallu V. (Bioresource Technology, 2012)
Biotransformation of an irregular monoterpene alcohol, (+/-)-lavandulol [(+/-)-5-methyl-2-(1-methylethenyl)-4-hexen-1-ol] (I) and its tetrahydro derivative, (+/-)-tetrahydrolavandulol [(+/-)-2-isopropyl-5-methylhexan-1-ol] (II) were studied using a soil isolated fungal strain Rhizopus oryzae. Five metabolites, 2-((3,3-dimethyloxiran-2-yl)methyl)-3-methylbut-3-en-1-ol (Ia), 2-methyl-5-(prop-1-en-2-yl)hex-2ene-1,6-diol (Ib), 2-methyl-5-(prop-1-en-2-yl)hexane-1,6-diol (Ic), 2-(3-methylbut-2-enyl)-3-methylenebutane-1,4-diol (Id), 5-methyl-2-(2-methyloxiran-2-yl)hex-4-en-1-01 (Ie) have been isolated from the fermentation medium and characterized with lavandulol as a substrate. When tetrahydrolavandulol used as a substrate, two metabolites 2-isopropyl-5-methylhexane-1,5-diol (IIa) and 2-isopentyl-3-methylbutane-1,3-diol (lib) have been isolated from the fermentation medium. Biotransformation studies with R. oryzae clearly indicate that the organism initiates the transformation either by hydroxylation at allylic methyl groups or epoxidation of double bond. GC and GCMS analyses indicated that both (R)and (S)-enantiomers of I and II have been transformed into corresponding hydroxylated or epoxy derivatives, when racemic I and II were used as substrates. (C) 2011 Elsevier Ltd. All rights reserved.
Keywords: Biotransformation; Fungus; Lavandulol; Rhizopus oryzae; Tetrahydrolavandulol

Trends in bioconversion of lignocellulose: biofuels, platform chemicals & biorefinery concept - Menon, Vishnu; Rao, Mala (Progress in Energy and Combustion Science, 2012)
Bioconversion of renewable lignocellulosic biomass to biofuel and value added products are globally gaining significant prominence. Market forces demonstrate a drive towards products benign to natural environment increasing the importance of renewable materials. The development of second generation bioethanol from lignocellulosic biomass serves many advantages from both energy and environmental point of views. Biomass an inexpensive feedstock considered sustainable and renewable, is an option with the potential to replace a wide diversity of fossil based products within the energy sector; heat, power, fuels, materials and chemicals. Lignocellulose is a major structural component of woody and non-woody plants and consists of cellulose, hemicellulose and lignin. The effective utilization of all the three components would play a significant role in the economic viability of cellulosic ethanol. Biomass conversion process involves five major steps, choice of suitable biomass, effective pretreatment, production of saccharolytic enzymes-cellulases and hemicellulases, fermentation of hexoses and pentoses and downstream processing. Within the context of production of fuels from biomass, pretreatment has come to denote processes by which cellulosic biomass is made amenable to the action of hydrolytic enzymes. The limited effectiveness of current enzymatic process on lignocellulose is thought to be due to the relative difficulties in pretreating the feedstocks. The present review is a comprehensive state of the art describing the advancement in recent pretreaments, metabolic engineering approaches with special emphasis on the latest developments in consolidated biomass processing, current global scenario of bioethanol pilot plants and biorefinery concept for the production of biofuels and bioproducts. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: Consolidated biomass processing; Lifecycle assessment; Lignocellulose; Pre-treatment; Saccharifying enzymes; Value-added products

Unusual conformational similarity of two peptide folds featuring sulfonamide and carboxamide on the backbone - Vijayadas, Kuruppanthara N.; Davis, Hilda C.; Kotmale, Amol S.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Chemical Communications, 2012)
Two folded peptides featuring carboxamide and sulfonamide at the core of the peptide fold have been shown to possess almost similar conformational features, despite the well-known fact that carboxamides and sulfonamides have strikingly different hydrogen-bonding and geometrical preferences.

Visible light photoredox catalysis: generation and addition of N-aryltetrahydroisoquinoline-derived alpha-amino radicals to michael acceptors - Kohls, Paul; Jadhav, Deepak; Pandey, Ganesh; Reiser, Oliver (Organic Letters, 2012)
The photoredox-catalyzed coupling of N-aryltetrahydroisoquinoline and Michael acceptors was achieved using Ru(bpy)(3)Cl-2 or [Ir(ppy)(2)-(dtb-bpy)]PF6 in combination with irradiation at 455 nm generated by a blue LED, demonstrating the trapping of visible light generated alpha-amino radicals. While intermolecular reactions lead to products formed by a conjugate addition, in intramolecular variants further dehydrogenation occurs, leading directly to 5,6-dihydroindolo[2,1-a]tetrahydroisoquinolines, which are relevant as potential immunosuppressive agents.

Active sites in modified copper catalysts for selective liquid phase dehydration of aqueous glycerol to acetol - Mane, Rasika B.; Yamaguchi, Aritomo; Malawadkar, Atul V.; Shirai, Masayuki; Rode, Chandrashekhar V. (RSC Advances, 2013)
We report here the influence of oxides of various metals viz. Ba, Mg, Zr, Zn, Al, and Cr in modified copper catalysts, on the formation of different copper species and acid sites responsible for dehydration of aqueous glycerol to acetol. These catalysts were prepared by a co-precipitation method, among which the catalysts having higher acid strength and predominant Bronsted acidity (Cu-Mg, Cu-Zr and Cu-Al) gave the highest acetol selectivity (76-92%), while the catalysts with lower acidity such as Cu-Zn showed very poor (25%) selectivity to acetol in spite of the highest conversion of 68%. Nevertheless, catalysts exhibiting higher activity and acetol selectivity also showed the presence of metallic Cu confirmed by XRD and XANES-EXAFS characterization. Based on these results, two different catalytic pathways have been proposed highlighting the role of Lewis and Bronsted acidity along with the metal sites in individual steps of glycerol dehydration reaction.

Aminosilicate sol-gel stabilized N-doped TiO2-Au nanocomposite materials and their potential environmental remediation applications - Pandikumar, Alagarsamy; Sivaranjani, Kumarsrinivasan; Gopinath, Chinnakonda S.; Ramaraj, Ramasamy (RSC Advances, 2013)
A facile chemical reduction method to synthesize amine functionalized silicate sol-gel-supported gold-deposited nitrogen-doped Degussa-TiO2 nanocomposite materials (APS/(N-P25-Au)(NCM)) is reported and the materials are characterized by DRS, PL, XRD, TEM, Raman, XPS and BET surface area analysis. The application of the synthesized APS/(N-P25-Au)(N)CM towards environmental remediation processes are investigated by studying the catalytic oxidation of carbon monoxide (CO) and photocatalytic reduction of toxic mercuric (Hg(II)) ions. The catalytic and photocatalytic activity of the prepared catalysts are found to be in the order of APS/(N-P25-Au)(NCM) >> APS/(P25-Au)(NCM) > N-P25 > P25. The enhanced catalytic and photocatalytic activities of the APS/(N-P25-Au)(NCM) can be attributed to the synergistic effect of Au-nps and N-doped P25. The catalytic activities of the APS/(N-P25-Au)(NCM) are very promising in the field of green technology for the environmental cleaning applications.

Antimycobacterial agent, (E)-phytol and lauric amide from the plant Lagascea mollis - Bhattacharya, Asish K.; Rana, Kalpeshkumar C. (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2013)
Chemical examination of aerial parts of the plant, Lagascea mollis has resulted in the isolation of two compounds, an acyclic diterpene alcohol which has been identified as (E)-phytol 1 and lauric amide 3. Their structures have been elucidated by spectral data and chemical transformations. This is the first report of isolation of both these compounds from this plant It is noteworthy that compound 1 has been found to be a potent antimycobacterial agent and thus, L. mollis could be exploited as an alternative source.
Keywords: amide; chemical transformation; diterpene; Lagascea mollis; structure elucidation

Ant-pro reverse-turn motif. structural features and conformational characteristics - Thorat, Vijaykumar H.; Ingole, Tukaram S.; Vijayadas, Kuruppanthara N.; Nair, Roshna V.; Kale, Sangram S.; Ramesh, Veera V. E.; Davis, Hilda C.; Prabhakaran, Panchami; Gonnade, Rajesh G.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; et al. (European Journal of Organic Chemistry, 2013)
This article details the characteristic conformational features of the Ant-Pro reverse turn ? a folded pseudo -turn motif that displays a closed nine-membered-ring hydrogen-bonded network involving just two amino acid residues, namely anthranilic acid (Ant; a constrained -amino acid), and proline (Pro; a constrained -amino acid). The results from the extensive investigation of ten crystal structures and their NMR conformations in the solution state provide a clear idea about the conformational characteristics of the Ant-Pro reverse turn. The Ant and Pro residues, which form the turn segment, maintain a perfect antiperiplanar orientation throughout, leaving little possibility for the formation of the otherwise possible six-membered hydrogen-bonding that requires a coplanar disposition of the two amino acid residues, as clearly evident from investigation of several crystal structures. The closed hydrogen-bonded network observed in the Ant-Pro reverse turn motif, formed in the forward direction of the sequence (12 amino acid interactions) involving only two amino acid residues, is in stark contrast to the native -turns that involve four residues to form hydrogen-bonded network featuring backward 14 amino acid interactions. The readily available two-residue Ant-Pro motif raises the possibility of a practical utility, particularly in the application of rigidifying flexible peptide backbones by inserting the robust Ant-Pro reverse turn motifs into their backbone.
Keywords: Peptides; Peptidomimetics; Protein folding; Protein structures

Applications of lithium zirconium silicate at high temperature for the carbon dioxide sorption and conversion to syn-gas - Raskar, Reshma; Rane, Vilas; Gaikwad, Abaji G. (Water Air and Soil Pollution, 2013)
The applications of different samples of lithium zirconium silicate contributing to CO2 sorption and conversion of CO2 to syn-gas at high temperatures were investigated. Several samples of lithium zirconium silicate prepared by solid-solid fusion method were calcined in air or nitrogen atmosphere at 900 degrees C for 3 h. The lithium zirconium silicate samples were characterized by acidity/alkalinity, surface area, XRD pattern, SEM images, and CO2 sorption. The alkalinity and surface area of the samples of lithium zirconium silicate were found to be in the range of 15.1 to 20.0 mmol g(-1) and 0.05 to 2.13 m(2) g(-1), respectively. The temperature profile of CO2 sorption by samples of lithium zirconium silicate was given for the range 100 to 700 degrees C. The CO2 sorption was found to be in the range of 12.81 to 18.04 wt.% at 550 degrees C for samples of lithium zirconium silicate with different Li/Zr/Si mole ratios from 1 to 6. The crystalline phases in the samples of the lithium zirconium silicate, Li6Si2O7, ZrSiO4, Li2SiO3, Li2ZrO3, Li4ZrO4, and Li4SiO4 could contribute to CO2 capture. The conversion of CO2 by methane to syn-gas over the lithium silicate samples and PdO (5 wt.%)/Al2O3 at 500 degrees C with the gas hourly space velocities 6,000, 12,000, and 36,000 mL h(-1) g(-1) of methane and 6,000 mL h(-1) g(-1) of CO2 was explored. However, the higher conversion of CO2 to syn-gas was observed at the low gas hourly space velocity of 6,000 mL h(-1) g(-1) of methane.
Keywords: Applications of lithium zirconium silicate; CO2 sorption; Solid-solid fusion method; Syn-gas; Temperature profile

Approach towards biocatalytic valorisation of barley beta-glucan for bioethanol production using 1,3-1,4 beta-glucanase and thermotolerant yeast - Divate, Rupesh; Menon, Vishnu; Rao, Mala (International Biodeterioration & Biodegradation, 2013)
The exploitation of renewable resource containing polymers other than cellulose and hemicellulose are critically important for the feasibility of biofuel production. The potential of 1,3-1,4 glucan 4-gluconohydrolyase mediated saccharification of barley beta-glucan (BG) was investigated for ethanol production using thermotolerant Saccharomyces sp. A maximum hydrolysis of 71% was obtained in 24 h using in-house produced 1,3-1,4 beta-glucanase from an alkalothermophilic Thermomonospora sp. whereas the hydrolysis was 100% with Accellerase (TM) 1000. The synergistic effect of beta-glucosidase and 1,3-1,4 beta-glucanase was demonstrated by the exogenous addition of beta-glucosidase to Thermomonospora 1,3-1,4 beta-glucanase which resulted in complete hydrolysis of BG. The hydrolysates of BG obtained using Accellerase or a cocktail of Thermomonospora 1,3-1,4 beta-glucanase and beta-glucosidase when fermented with free cells of Saccharomyces at 40 degrees C produced an ethanol yield of 0.44 g g(-1) and 0.46 g g(-1) respectively and when fermented with immobilized cells produced a yield of 0.49 g g(-1). The Ca-alginate immobilized yeast cells were reused nine times at 40 degrees C with 100% fermentation efficiency. The economics of barley-to-fuel ethanol program will ameliorate if in addition to barley starch, beta-glucan is also utilized. (c) 2013 Elsevier Ltd. All rights reserved.
Keywords: 1; 3-1; 4 Glucan 4-gluconohydrolyase; Barley beta-glucan; Ethanol; Hydrolysis; Synergism; Thermotolerant yeast

Ascertaining universal features of yielding of soft materials - Kamble, Samruddhi; Pandey, Anurag; Rastogi, Sanjay; Lele, Ashish K. (Rheologica Acta, 2013)
Many metastable complex fluids, when subjected to oscillatory shear flow of increasing strain amplitude at constant frequency, are known to show a characteristic nonlinear rheological response which consists of a monotonic decrease in the elastic modulus and a nonmonotonic change in the loss modulus. In particular, the loss modulus increases from its low strain value, crosses the elastic modulus, and then decreases with further increase in the strain amplitude. Miyazaki et al. (Europhys Lett 75:915-921, 2006) proposed a qualitative argument to explain the origin of the nonmonotonic nature of the loss modulus and suggested that in fact this response could be universal to all complex fluids if they are probed in a certain frequency window in which the fluid is dominantly elastic in the small strain limit. In this letter, we confirm their hypothesis by showing that a wide variety of complex fluids, irrespective of their thermodynamic state under quiescent conditions, indeed show the aforementioned characteristic nonlinear response. We also show that the maximum relative dissipation during yielding occurs when the imposed frequency resonates with the characteristic beta relaxation frequency of the fluid.
Keywords: Colloidal suspensions; Entangled melts; Gels; Glasses; Microgels; Rheology; Yielding

Biodegradation of chlorobenzene and chlorophenols by pseudomonas cultures - Bhaskar, Gaikwad G.; Rita, Varma J. (Research Journal of Chemistry and Environment, 2013)
Cultures from NCIM culture collection (National Chemical Laboratory, Pune, India) were screened for biodegradation chlorobenzene (CB). A strain, Pseudomonas sp. NCIM 2303, was found to be most effective. The biodegradation was carried out in aqueous solution by resting cells. The decomposition of 0.02% CB was 96.64% in 24h. We have screened cultures for biodegradation of o-chlorophenol and p-chlorophenol. Pseudomonas sp. NCIM 2668 has shown 94.59% degradation of 0.15% o-chlorophenol. Pseudomonas sp. NCIM 2668 has shown 31.42% degradation of 0.2% p-chlorophenol.
Keywords: Biodegradation; chloride; chlorobenzene; etc.; pollution; Pseudomonas sp

Biodegradation of phenol by the yeast candida tropicalis: an investigation by NMR spectroscopy - Phalgune, U. D.; Rajamohanan, P. R.; Gaikwad, B. G.; Varma, R. J.; George, S. (Applied Biochemistry and Biotechnology, 2013)
The process of phenol biodegradation by the yeast Candida tropicalis NCIM 3556 in aqueous medium was studied by H-1, C-13, and DOSY NMR techniques. Samples at regular intervals were centrifuged to separate the cells, and H-1 spectral data were collected at 400 MHz. Though a gradual decrease in the concentration of phenol was observed, after an incubation period of similar to 8 h, formation of any intermediate products could not be detected. Experiments carried out with uniformly C-13-labeled phenol also failed to detect formation of any carboxylic acid intermediates during degradation. The studies indicated that the phenol was completely degraded to carbon dioxide and water in approximately 20 h. Self-diffusion coefficient measurements showed that the lifetime of phenol in the bound form is too small to impart any change in its diffusion behavior and the intermediates formed are converted to carbon dioxide and water at a very fast rate.
Keywords: biocatalysis; Carboxylic acid; Diffusion; Enzyme; NMR spectroscopy; phenol

Biosynthesis of antinutritional alkaloids in solanaceous crops is mediated by clustered genes - Itkin, M.; Heinig, U.; Tzfadia, O.; Bhide, Amey J.; Shinde, B.; Cardenas, Pablo D.; Bocobza, S. E.; Unger, T.; Malitsky, Sergey; Finkers, R.; Tikunov, Y.; Bovy, A.; et al. (Science, 2013)
Steroidal glycoalkaloids (SGAs) such as alpha-solanine found in solanaceous food plants-as, for example, potato-are antinutritional factors for humans. Comparative coexpression analysis between tomato and potato coupled with chemical profiling revealed an array of 10 genes that partake in SGA biosynthesis. We discovered that six of them exist as a cluster on chromosome 7, whereas an additional two are adjacent in a duplicated genomic region on chromosome 12. Following systematic functional analysis, we suggest a revised SGA biosynthetic pathway starting from cholesterol up to the tetrasaccharide moiety linked to the tomato SGA aglycone. Silencing GLYCOALKALOID METABOLISM 4 prevented accumulation of SGAs in potato tubers and tomato fruit. This may provide a means for removal of unsafe, antinutritional substances present in these widely used food crops.

Carboxamide versus sulfonamide in peptide backbone folding: a case study with a hetero foldamer - Ramesh, Veera V. E.; Kale, Sangram S.; Kotmale, Amol S.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, P. R.; Sanjayan, Gangadhar J. (Organic Letters, 2013)
Strikingly dissimilar hydrogen-bonding patterns have been observed for two sets of closely similar hetero foldamers containing carboxamide and sulfonamides at regular intervals. Although both foldamers maintain conformational ordering, the hydrogen-bonding pattern and backbone helical handedness differ diametrically.

Catalytic activity of ZIF-8 in the synthesis of styrene carbonate from CO2 and styrene oxide - Zhu, Minqi; Srinivas, Darbha; Bhogeswararao, Seemala; Ratnasamy, Paul; Carreon, Moises A. (Catalysis Communications, 2013)
The catalytic activity of ZIF-8 in the synthesis of styrene carbonate from carbon dioxide and styrene oxide is presented. ZIF-8 crystals displayed catalytic activity even at temperatures as low as 50 degrees C, with styrene carbonate yields as high as similar to 54% at 100 degrees C. In contrast to many prior-art catalysts, solvents or co-catalysts were not required. Pyridine and ammonia were used as probe molecules to estimate the type and density of acid sites in fresh and reused ZIF-8 catalysts. DRIFT spectroscopy of adsorbed pyridine revealed the presence of both Bronsted (B) and Lewis (L) acid sites. The B-sites have nearly vanished in the case of recycled ZIF-8 catalysts. The simultaneous presence of both the acid sites and the nitrogen basic moieties from the imidazole linker in ZIF-8 promoted the adsorption of the CO2 on the solid surface and its further conversion to the cyclic carbonate. The ZIF-8 catalysts could be recycled and reused without significant loss in catalytic activity. Published by Elsevier B.V.
Keywords: CO2 conversion; cyclic carbonates; Styrene carbonate; Zeolitic imidazolate frameworks; ZIF-8

Characterisation and determination of in vitro antioxidant potential of betalains from talinum triangulare (Jacq.) willd. - Swarna, J.; Lokeswari, T. S.; Smita, M.; Ravindhran, R. (Food Chemistry, 2013)
Talinum triangulare (Jacq.) Willd is an erect, succulent, perennial herb belonging to the family Portulacaceae. Under extreme environmental conditions, the plant produces betalain pigments which get accumulated in the stem region. Hence, in the present study, the betaxanthin and betacyanin patterns from different samples of T. triangulare have been investigated by applying high-performance liquid chromatography photo-diode array detection (HPLC-PDA) coupled with positive ion electro-spray mass spectrometry. Two betacyanins and two betaxanthins were identified in aqueous methanolic extract of flower, stem and leaf. Betanin, isobetanin, immonium conjugates of betalamic acid with dopamine and tyrosine were elucidated. The total betalain content was estimated by photometric analysis. In vitro antioxidant activity for the betalain extract determined by various methods revealed potent scavenging ability. The current work may possibly be considered beneficial in utilisation of the plant T. triangulare as a natural colourant in food and beverage industries. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: Antioxidant; Betalains; HPLC-MS; Portulacaceae; Waterleaf

Characterization of conformation and interaction of gene delivery vector polyethylenimine with phospholipid bilayer at different protonation state - Choudhury, Chandan Kumar; Kumar, Abhinaw; Roy, Sudip (Biomacromolecules, 2013)
Polyethylenimine (PEI) is a pH sensitive polymer possessing stretched and coiled conformation at low and high pH, respectively. It is an efficient gene delivery agent. Thus, the interaction of PEI with the biomembrane is very crucial to understand the gene delivery mechanism. In this report, we have investigated the structural properties of PEI and bilayer due to the interaction of PEI with lipid molecules. PEI has coil structure at high pH while at low pH it is elongated. The neutral PEI chain predominately settles itself at the bilayer water interface. We do not find any disruption or pore formation on the bilayer due to interaction of neutral PEI chain. PEI at low pH gets elongated due to electrostatic interaction between charges of the protonated sites. This protonated PEI chain interacts with bilayer membrane, which leads to formation of water/ion channel through the membrane. We have analyzed the structure of the channel and water dynamics along the channel.

Characterization of the structures and dynamics of phosphoric acid doped benzimidazole mixtures: a molecular dynamics study - More, Minal; Pahari, Swagata; Roy, Sudip; Venkatnathan, Arun (Journal of Molecular Modeling, 2013)
Benzimidazole-based polymer membranes like poly(2,5-benzimidazole) (ABPBI) doped with phosphoric acid (PA) are electrolytes that exhibit high proton conductivity in fuel cells at elevated temperatures. The benzimidazole (BI) moiety is an important constituent of these membranes, so the present work was performed in order to achieve a molecular understanding of the BI-PA interactions in the presence of varying levels of the PA dopant, using classical molecular dynamics (MD) simulations. The various hydrogen-bonding interactions, as characterized based on structural properties and hydrogen-bond lifetime calculations, show that both BI and PA molecules exhibit dual proton-acceptor/donor functionality. An examination of diffusion coefficients showed that the diffusion of BI decreases with increasing PA uptake, whereas the diffusion of PA slightly increases. The hydrogen-bond lifetime calculations pointed to the existence of competitive hydrogen bonding between various sites in BI and PA.
Keywords: Diffusion coefficient; Hydrogen bond; molecular dynamics; Radial distribution functions

Charge storage and electron transport properties of gold nanoparticles decorating a urethane-methacrylate comb polymer network - Patil, Sumati; Datar, Suwarna; Rekha, N.; Asha, S. K.; Dharmadhikari, C. V. (Nanoscale, 2013)
We propose enhanced charge storage capacity of nanoparticles based polymer films. A flat band voltage window varying from 5-7 V is obtained leading to a trapped charge density of the order of 10(13) cm(-2). These results vary for two distinct morphologies obtained due to decoration of a urethane-methacrylate comb polymer (UMCP) network by gold nanoparticles (AuNPs). Films have been further investigated for morphology, optical, charge storage, and electron transport properties using techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), absorption spectroscopy (UV-Vis), scanning tunneling microscopy/spectroscopy (STM/STS) and capacitance versus voltage (C-V) measurements. SEM and AFM confirm either the deposition of AuNPs inside the UMCP network or the formation of ring like structures depending on the deposition sequence. STS measurements performed on both films are compared with bare UMCP and AuNPs films. Current versus voltage (I-V) characteristics so obtained are discussed in the light of electron transport mechanisms in such materials.

Cloning and sequence analysis of three variants of the gene encoding alkaline xylanase C from the alkaliphilic bacillus sp (NCL 87-6-10) - Sharma, Poonam; Rele, Meenakshi V.; Kumar, Lalitha Sunil (Biochemical Genetics, 2013)
Alkaline xylanase C from the alkaliphilic Bacillus sp. (NCL 87-6-10) has a low molecular weight and alkaline pI and is cellulase-free, properties compatible with its use in the prebleaching of pulp. We report here the cloning and sequence analysis of three variants of the gene encoding xylanase C; xyl C1, xyl C2, and xyl C3. In phylogenetic analysis, the three xylanase C variants clustered into a single group along with other reported alkaline xylanases. Residues contributing to the alkaline pH were present in all three variants. DNA and protein sequence comparison of these variants with other reported alkaline xylanases revealed silent mutations, some of which are due to codon preference in the respective organisms. The recombinant Xyl C1 that was successfully expressed in E. coli BL21 (DE3) had properties similar to the native enzyme.
Keywords: Alkaline xylanase C; Alkaliphilic Bacillus sp (NCL 87-6-10); Cloning; E. coli BL21 (DE3) expression; Sequence analysis

Cloning, overexpression, crystallization and preliminary X-ray crystallographic analysis of a slow-processing mutant of penicillin G acylase from Kluyvera citrophila - Varshney, Nishant Kumar; Ramasamy, Sureshkumar; Brannigan, James A.; Wilkinson, Anthony J.; Suresh, C. G. (Acta Crystallographica Section F-Structural Biology and Crystallization Communications, 2013)
{Kluyvera citrophila penicillin G acylase (KcPGA) has recently attracted increased attention relative to the well studied and commonly used Escherichia coli PGA (EcPGA) because KcPGA is more resilient to harsh conditions and is easier to immobilize for the industrial hydrolysis of natural penicillins to generate the 6-aminopenicillin (6-APA) nucleus, which is the starting material for semi-synthetic antibiotic production. Like other penicillin acylases, KcPGA is synthesized as a single-chain inactive pro-PGA, which upon autocatalytic processing becomes an active heterodimer of alpha and beta chains. Here, the cloning of the pac gene encoding KcPGA and the preparation of a slow-processing mutant precursor are reported. The purification, crystallization and preliminary X-ray analysis of crystals of this precursor protein are described. The protein crystallized in two different space groups, P1, with unit-cell parameters a = 54.0

CN? specific turn-on phosphorescent probe with probable application for enzymatic assay and as an imaging reagent - Reddy, Upendar G.; Das, Priyadip; Saha, Sukdeb; Baidya, Mithu; Ghosh, Sudip K.; Das, Amitava (Chemical Communications, 2013)
A new “turn-on” luminescence probe for imaging the uptake of 0.2 ppm inorganic CN− in live HeLa cells as well as for probing the CN− generation through an enzymatic process in a virtual aqueous medium at appropriate pH.

Concise synthesis of (5R,6S)-tert-butyl 5-acetoxy-6-(hydroxymethyl)-5,6-dihydropyridine-1(2H)-carboxylate - Ramalingam, S.; Bhise, Ankushkumar D.; Show, Krishanu; Kumar, Pradeep (Arkivoc, 2013)
An efficient synthesis of (5R,6S)-tert-butyl 5-acetoxy-6-(hydroxymethyl)-5,6-dihydropyridine-1(2H)-carboxylate 1, a common intermediate for various polyhydroxylated piperidines is reported in six steps with 32% overall yield starting from Garner's aldehyde. The key steps include the diastereoselective nucleophilic addition and intramolecular cyclization. (5R,6S)-tert-butyl 5-acetoxy-6-(hydroxymethyl)-5,6-dihydropyridine-1(2H)-carboxylate is a common precursor for the synthesis of 1-deoxy-L-mannojirimycin, 1-deoxy-L-idonojirimycin, L-fagomycin and related analogues.
Keywords: cyclization; Garner's aldehyde; nucleophilic addition; polyhydroxy piperidines

Crystallisation of ferrous sulphate heptahydrate: experiments and modelling - Shaikh, Latif; Pandit, Aniruddha; Ranade, Vivek (Canadian Journal of Chemical Engineering, 2013)
Crystallisation is an industrially important unit operation for purifying and separating chemical mixtures. A generic crystallisation modelling framework has been implemented in the general process modelling system (gPROMS) software (of PSE, UK). This framework can be used to model the batch cooling crystallisation of ferrous sulphate heptahydrate (FSH). The parameter estimation and sensitivity of the predicted results with various numerical parameters was studied for batch crystalliser. An Excel front-end to the gPROMS model was developed to facilitate the interactive use of the model. (c) 2011 Canadian Society for Chemical Engineering
Keywords: batch crystallisation; ferrous sulphate heptahydrate; gPROMS; MSExcel-linking; parameter estimation

Crystallization: key thermodynamic, kinetic and hydrodynamic aspects - Vedantam, Sreepriya; Ranade, Vivek V. (Sadhana-Academy Proceedings in Engineering Sciences, 2013)
Crystallization is extensively used in different industrial applications, including the production of a wide range of materials such as fertilizers, detergents, food and pharmaceutical products, as well as in the mineral processing industries and treatment of waste effluents. In spite of the wide-spread use of crystallization, a clear understanding of the thermodynamic, kinetic and hydrodynamic aspects of the design methodologies are not yet well established. More often than not crystallization is still considered an art especially in fine-chemicals, pharmaceuticals and life-sciences sector. It is essential to understand and relate key thermodynamic, kinetic and hydrodynamic aspects to crystallizer performance, not just in terms of yield but also in terms of product quality (characterized by particle size distribution, morphology, polymorphism and the amount of strain as well as the uptake of solvent or impurities in the crystal lattice). This paper attempts to do that by critically reviewing published experimental and modelling studies on establishing and enhancing state-of-the-art thermodynamic, kinetic and hydrodynamic aspects of crystallization. Efforts are made to discuss and raise points for emerging modelling tools needed for a flexible design and operation of crystallizers and crystallization processes that are needed to meet the ever increasing demand on precise product specifications. Focus is on bringing out the trends which can be used as perspectives for future studies in this field.
Keywords: CFD; Crystallization; growth; Nucleation; polymorphism; supersaturation

CuCN-Mediated cascade cyclization of 4-(2-bromophenyl)-2-butenoates: a high-yield synthesis of substituted naphthalene amino esters - Reddy, R. Santhosh; Prasad, Pragati K.; Ahuja, Brij Bhushan; Sudalai, Arumugam (Journal of Organic Chemistry, 2013)
A new method of CuCN-mediated one-pot cyclization of 4-(2-bromophenyl)-2-butenoates leading to efficient synthesis of substituted naphthalene amino esters including phenanthrene aromatic structural units is described. Deuterium labeling studies establish that this one-pot cascade cyclization proceeds through isomerization of olefin, intramolecular C-C bond cyclization, and aromatization as the key intermediates, all occurring in a single step.

Design and performance aspects of a custom-built ambient pressure photoelectron spectrometer toward bridging the pressure gap: oxidation of Cu, Ag, and Au surfaces at 1 mbar O-2 pressure - Roy, Kanak; Vinod, C. P.; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2013)
The critical features of a custom-built laboratory version ambient pressure photoelectron spectrometer (Lab-APPES) are presented. A double front cone differential pumping arrangement and an aperture free design employed in the electrostatic lens regime improve the data collection and data quality. In contrast to the conventional X-ray photoelectron spectrometers (XPS) operating at ultrahigh vacuum (UHV), it is possible to explore the electronic structure of solid surfaces under working conditions or closer to working conditions with Lab-APPES. Especially surface-dependent phenomena can be explored up to 1 mbar pressure and up to 873 K by conventional heating methods and at least up to 1273 K by a laser heating method. Simultaneous XPS and reaction kinetic measurements on solid surfaces make the Lab-APPES an important tool to measure the dynamic electronic structure changes on material surfaces under reaction conditions. The interaction of O-2 with polycrystalline foils of Cu, Ag, and Au from UHV to 1 mbar and up to 773 K has been studied.

Design of decanter in heterogeneous azeotropic distillation column by minimizing Gibbs free energy - Rahman, Imran; Ubaidullah, S.; Das, Anwesh Kr. (Asia-Pacific Journal of Chemical Engineering, 2013)
In this paper, liquid-liquid equilibrium in decanter of heterogeneous azeotropic distillation is solved by minimizing Gibbs free energy, by using global optimization technique. The azeotropic distillation column is modeled by solving material balance, equilibrium and summation equations, and repulsive particle swarm optimization (RPSO), a stochastic global optimization formalism, is employed to predict stable steady state solution in decanter. To verify the performance of the RPSO algorithm, it is compared with equation solving method for liquid-liquid equilibria by considering two azeotropic systems, namely (1) benzene-ethanol-water and (2) furfural-water. The proposed methodology shows feasibility of the RPSO algorithm in predicting liquid-liquid equilibrium in decanter of heterogeneous azeotropic distillation. (c) 2013 Curtin University of Technology and John Wiley & Sons, Ltd.
Keywords: decanter; Gibbs free energy; heterogeneous azeotropic distillation; liquid-liquid equilibrium; Optimization; repulsive particle swarm optimization method

Design, synthesis, structural characterization by IR, 1H, 13C, 15N, 2D-NMR, X-ray diffraction and evaluation of a new class of phenylaminoacetic acid benzylidene hydrazines as pfENR inhibitors - Samal, Ramanuj P.; Khedkar, Vijay M.; Pissurlenkar, Raghuvir R. S.; Bwalya, Angela Gono; Tasdemir, Deniz; Joshi, Ramesh A.; Rajamohanan, P. R.; Puranik, Vedavati G.; Coutinho, Evans C. (Chemical Biology & Drug Design, 2013)
Recent studies have revealed that plasmodial enoyl-ACP reductase (pfENR, FabI), one of the crucial enzymes in the plasmodial type II fatty acid synthesis II (FAS II) pathway, is a promising target for liver stage malaria infections. Hence, pfENR inhibitors have the potential to be used as causal malarial prophylactic agents. In this study, we report the design, synthesis, structural characterization and evaluation of a new class of pfENR inhibitors. The search for inhibitors began with a virtual screen of the iResearch database by molecular docking. Hits obtained from the virtual screen were ranked according to their Glide score. One hit was selected as a lead and modified to improve its binding to pfENR; from this, a series of phenylamino acetic acid benzylidene hydrazides were designed and synthesized. These molecules were thoroughly characterized by IR, 1H, 13C, 15N, 2D-NMR (COSY, NOESY, 1H-13C, 1H-15N HSQC and HMBC), and X-ray diffraction. NMR studies revealed the existence of conformational/configurational isomers around the amide and imine functionalities. The major species in DMSO solution is the E, E form, which is in dynamic equilibrium with the Z, E isomer. In the solid state, the molecule has a completely extended conformation and forms helical structures that are stabilized by strong hydrogen bond interactions, forming a helical structure stabilized by N-H...O interactions, a feature unique to this class of compounds. Furthermore, detailed investigation of the NMR spectra indicated the presence of a minor impurity in most compounds. The structure of this impurity was deduced as an imidazoline-4-one derivative based on 1H-13C and 1H-15H HMBC spectra and was confirmed from the NOESY spectra. The molecules were screened for in vitro activity against recombinant pfENR enzyme by a spectrophotometric assay. Four molecules, viz. 17, 7, 10, and 12 were found to be active at 7, 8, 10, and 12m concentration, respectively, showing promising pfENR inhibitory potential. A classification model was derived based on a binary QSAR approach termed recursive partitioning (RP) to highlight structural characteristics that could be tuned to improve activity.
Keywords: ADMET; docking; enoyl-ACP reductase; FabI; hydrogen bonding; NMR; phenylaminoacetic acid benzylidene hydrazine; Plasmodium falciparum; Plasmodium falciparum enoyl-ACP reductase; QSAR; recursive partitioning; X-ray diffraction

Designing a thiol specific fluorescent probe for possible use as a reagent for intracellular detection and estimation in blood serum: kinetic analysis to probe the role of intramolecular hydrogen bonding - Das, Priyadip; Mandal, Amal Kumar; Reddy, Upendar G.; Baidya, Mithu; Ghosh, Sudip K.; Das, Amitava (Organic & Biomolecular Chemistry, 2013)
A new and simple chemodosimetric probe L-1 is utilized for the selective detection of biothiols in the presence of other relevant amino acids under physiological conditions (pH = 7.4). This eventually led to a turn-off luminescence response due to an effective photoinduced electron transfer based signaling mechanism. A comparison of the results of the fluorescence kinetic analysis and H-1 NMR studies of the reaction between thiol and L-1 or the analogous compound L-2 revealed the role of intramolecular hydrogen bonding in activating the imine functionality towards nucleophilic addition. Such an example is not common in contemporary literature. Conventional MTT assay studies revealed that this probe (L-1) has low cytotoxicity. Results of the cell imaging studies revealed that this probe was cell membrane permeable and could detect the intracellular distribution of biothiols within living HeLa cells. Furthermore, our studies with human blood plasma demonstrated the possibility of using this reagent for the quantitative optical detection of total biothiols in biological fluid. Such an example for the detection of biothiols in real biological samples is rare in the contemporary literature. These results clearly demonstrate the possibility of using this reagent in medicinal biology and diagnostic applications.

Direct contact heat transfer via injecting volatile liquid in a hot liquid pool: generation and motion of bubbles - Kulkarni, Amol A.; Ranade, Vivek V. (Chemical Engineering Science, 2013)
Direct contact heat transfer via injection of volatile liquid is an effective strategy for removing heat from a viscous liquid pool. The rapid evaporation effectively removes heat and the generated bubbles move quickly to the top surface. In this paper, we present an experimental and phenomenological analysis of the evaporation of a drop in a slightly miscible liquid. The phenomenon was visualized using a two-dimensional transparent experimental set-up with a single inlet at the bottom. The videos were used to estimate bubble dimensions, its rise velocity, distance from the detachment point, and fraction of vapor and the liquid phases in the evaporating drop. The initial drop size, temperature difference between the hot fluid and the low boiling solvent and the nucleation rate governed the rate of change of the drobble (combined entity of drop and bubble) diameter and its rise velocity. A phenomenological model describing transient behavior of drobble (motion and heat transfer) is developed. The transient variation in the interfacial areas for heat transfer and the projected area were found to have effect on the predictions. The model and results will also provide useful basis for extending the work towards better understanding of direct contact heat transfer in viscous systems like polymerization reactors. (C) 2013 Elsevier Ltd. All rights reserved.
11th International Conference on Gas-Liquid and Gas-Liquid-Solid Reactor Engineering (GLS) Held in Conjunction with 9th World Congress on Chemical Engineering (WCCE) / Asian Pacific Conference on Chemical Engineering (APCChE), Seoul, SOUTH KOREA, AUG 19-22, 2013
Keywords: Bubble; Direct contact HT; Drobble; Drop; Evaporation; Slightly miscible liquids

Diverted total syntheses of potent cell adhesion inhibitor peribysin E analogues - Handore, Kishor L.; Reddy, D. Srinivasa (Organic Letters, 2013)
Preliminary results from a program aimed at the creation of a focused library of analogues around the natural product peribysin E, a potent biologically active and structurally fascinating molecule, are reported. The total synthesis of (+/-)-peribysin E was accomplished using a short route. Eight new analogues of the natural compound have been accomplished by means of ``diverted total synthesis'' in less than 10 steps. The present effort highlights protecting-group-free total syntheses and the shortest route to access these functionally embellished hydrindanes.

Effect of carbon dioxide pressure on 4-t-butylphenol hydrogenation activity of supported rhodium catalyst - Hiyoshi, Norihito; Sato, Osamu; Yamaguchi, Aritomo; Rode, Chandrashekhar V.; Shirai, Masayuki (Journal of the Japan Petroleum Institute, 2013)
Hydrogenation of 4-t-butylphenol over an activated carbon-supported rhodium catalyst in carbon dioxide solvent was analyzed based on phase observation with a view cell and calculations of the solubility of 4-t-butylphenol using the Peng-Robinson equation of state as a function of carbon dioxide pressure. The reaction experiments showed that the initial reaction rate of 4-t-butylphenol at 313 K under 2 MPa of hydrogen pressure was increased by the addition of carbon dioxide, especially above a total pressure of 11 MPa. Direct visual observation showed that the solubility of 4-t-butylphenol increased with higher carbon dioxide pressure. The calculations based on the Peng-Robinson equation of state also showed that the solubility of 4-t-butylphenol in the 4-t-butylphenol carbon dioxide hydrogen (2 MPa) system at 313 K significantly increased by addition of carbon dioxide above a total pressure of 11 MPa. We concluded that the increase in the hydrogenation rates was caused by the increased concentration of 4-t-butylphenol substrate in the carbon dioxide solvent.
Keywords: 4-t-Butylphenol hydrogenation; Carbon dioxide solvent; Peng-Robinson equation; Rhodium catalyst; Supercritical fluid

Efficient and stereoselective nitration of mono- and disubstituted olefins with AgNO2 and TEMPO - Maity, Soham; Manna, Srimanta; Rana, Sujoy; Naveen, Togati; Mallick, Arijit; Maiti, Debabrata (Journal of the American Chemical Society, 2013)
Nitroolefin is a common and versatile reagent. Its synthesis from olefin is generally limited by the formation of mixture of cis and trans compounds. Here we report that silver nitrite (AgNO2) along with TEMPO can promote the regio- and stereoselective nitration of a broad range of olefins. This work discloses a new and efficient approach wherein starting from olefin, nitroalkane radical formation and subsequent transformations lead to the desired nitroolefin in a stereoselective manner.

Enantiodivergent routes to (+) and (-)-novioses from (-)-pantolactone - Rajesh, B. M.; Shinde, Madhuri V.; Kannan, M.; Srinivas, Gujjary; Iqbal, Javed; Reddy, D. Srinivasa (RSC Advances, 2013)
Noviose, a rare sugar moiety present in many biologically interesting molecules such as novobiocin and tiacumicin was obtained through formal synthesis in (+)- and (-)-forms starting from commercially available (-)-pantolactone in an enantiodivergent manner.

Engaging isatins in solvent-free, sterically congested passerini reaction - Kaicharla, Trinadh; Yetra, Santhivardhana Reddy; Roy, Tony; Biju, Akkattu T. (Green Chemistry, 2013)
A facile, atom-economic and environmentally-benign protocol for the synthesis of biologically important oxindole derivatives in high yields has been demonstrated by employing isatins as carbonyl compound surrogates in a Passerini reaction carried out under solvent-free conditions. Moreover, electron-deficient phenols can also be used as the acid component in this reaction. In addition, the synthetic utility of the present methodology was examined by the one-pot synthesis of oxindoles with a free -OH group at the benzylic position.

Ester vs. amide on folding: a case study with a 2-residue synthetic peptide - Vijayadas, Kuruppanthara N.; Nair, Roshna V.; Gawade, Rupesh L.; Kotmale, Amol S.; Prabhakaran, Panchami; Gonnade, Rajesh G.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Organic & Biomolecular Chemistry, 2013)
Although known for their inferiority as hydrogen-bonding acceptors when compared to amides, esters are often found at the C-terminus of peptides and synthetic oligomers (foldamers), presumably due to the synthetic readiness with which they are obtained using protected peptide coupling, deploying amino acid esters at the C-terminus. When the H-bonding interactions deviate from regularity at the termini, peptide chains tend to ``fray apart''. However, the individual contributions of C-terminal esters in causing peptide chain end-fraying goes often unnoticed, particularly due to diverse competing effects emanating from large peptide chains. Herein, we describe a striking case of a comparison of the individual contributions of C-terminal ester vs. amide carbonyl as a H-bonding acceptor in the folding of a peptide. A simple two-residue peptide fold has been used as a testing case to demonstrate that amide carbonyl is far superior to ester carbonyl in promoting peptide folding, alienating end-fraying. This finding would have a bearing on the fundamental understanding of the individual contributions of stabilizing/destabilizing non-covalent interactions in peptide folding.

Evaluation of viability of halogen•••O2N interactions: insight form crystal packing in a series of isomeric halo and nitro substituted triaryl compounds with modular positioning of halogen and NO2 groups - Ramana, Chepuri V.; Goriya, Yogesh; Durugkar, Kulbhushan A.; Chatterjee, Soumitra; Krishnaswamy, Shobhana; Gonnade, Rajesh G. (CrystEngComm, 2013)
A series of isomeric triaryl compounds with a modular positioning of the halogen and NO2 groups have been synthesized by the azide–alkyne “click reaction” and have been characterized by single crystal X-ray structure analysis. This isomeric series has provided an opportunity for understanding the efficiency of the bifurcated halogen⋯NO2 synthon in the organization of the molecules in the crystalline lattice. The changes in molecular conformation, crystal packing and supramolecular aggregation due to the change in the relative positioning of the complementary groups, halogen atom and the NO2 group on ring A and ring C respectively, have been discussed. All the isomers synthesized are crystalline and establish the triazole as a reliable linker for crystal engineering oriented molecular synthesis. The 2-NO2 derivatives display in general, a helical architecture and 3-NO2 derivatives exhibit a centrosymmetric dimeric assembly via the complementary C–H⋯O interactions leading to either a helical or a 2-dimensional sheet pattern. The molecular organization in 4-NO2 derivatives revealed in general a 2D sheet pattern.

Evidence and characterization of dynamic heterogeneity in binary mixtures of phosphoric acid and benzimidazole - Pahari, Swagata; Roy, Sudip (Journal of Chemical Physics, 2013)
We report here anomalous diffusions of components in mixtures of monomer of polybenzimidazole, i.e., 2-phenyl-1H, 1'H-5,5'-bibenzo[d] imidazole (BI) and phosphoric acid (PA) from molecular dynamics simulations. We have observed initial drop and further increase in self-diffusion constant for both monomer molecule (BI) and PA with gradual increase in PA concentration. The origin of such anomalous diffusion is identified in this work, which happens to be the presence of dynamic heterogeneity in each component of the binary mixture. We characterized microscopic picture of dynamical heterogeneity by finding correlation between dynamical heterogeneity and structural arrangement among the components of the binary system. Different types of H-bonding arrangements in the BI-PA systems at different concentration of PA are observed. The stability of the H-bonded network consisting of different types of H-bonds between BI and PA in the system has been studied by calculating the lifetime of various H-bonds. The results indicate that there are fast and slow moving PA molecules in the mixtures because of coexistence of different types of hydrogen bonds among the components of the mixture. (C) 2013 AIP Publishing LLC.

Extra- and intracellular gold nanoparticles synthesis using live peanut callus cells - Raju, D.; Mehta, Urmil J.; Ahmad, Absar (Current Nanoscience, 2013)
An important challenge of considerable topical significance in nanotechnology is the development of eco-friendly experimental processes for the synthesis of nanomaterials in large quantities with variable sizes, shapes and chemical compositions. Green synthesis routes for the production of inorganic metal nanoparticles using whole cell of microorganisms and plant extracts are gaining tremendous popularity as these are non-toxic, cheap and occur at ambient conditions. The present work emphasizes on gold nanoparticles synthesis protocol using live plant callus cells. Peanut callus cells when incubated with HAuCl4 solution in ambient conditions reduced the precursor and lead to formation of well dispersed, water soluble extracellular and intracellular gold nanoparticles within 24 hours. The biosynthesis of gold nanoparticles was monitored by UV-visible spectroscopy (UV-Vis) and further characterized by X-ray diffraction analysis (XRD), Energy Dispersive Spectroscopy (EDS) and Selected Area Electron Diffraction (SAED). The particle size distribution shows that the average particle size is 50 nm for extra-and 31 nm for intracellular gold nanoparticles. The nanoparticles may be stabilized by proteins secreted by callus cells. The reduction process is believed to occur enzymatically, thus creating the possibility of a rational, plant cell-based method for the synthesis of nanoparticles over a wide range of chemical compositions.
Keywords: Biosynthesis; callus; gold nanoparticles; live cells; Peanut; TEM

First total synthesis of hunanamycin A - Shingare, Rahul D.; Velayudham, R.; Gawade, Jalindar R.; Reddy, D. Srinivasa (Organic Letters, 2013)
The first total synthesis of hunanamycin A, an antibiotic natural product with a pyrido[1,2,3-de]quinoxaline-2,3-dione core from a marine-derived Bacillus hunanensis, is disclosed. The present effort provides access to sufficient amounts of scarce hunanamycin A for further biological evaluation and confirmation of the assigned absolute configuration. In addition, four new analogues of the natural product are reported.

Flow and heat transfer in serpentine channels - Karale, Chaitanya M.; Bhagwat, Sunil S.; Ranade, Vivek V. (Aiche Journal, 2013)
Serpentine channels are often used in microchannel reactors and heat exchangers. These channels offer better mixing, higher heat and mass-transfer coefficients than straight channels. In the present work, flow and heat transfer experiments were carried out with a serpentine channel plate comprising of 10 units (single unit dimensions: 1 x 1.5 mm(2) in cross section, length 46.28 mm, D-h 1.2 mm) in series. Pressure drop and heat-transfer coefficients were experimentally measured. Flow and heat transfer in the experimental set-up were simulated using computational fluid dynamics (CFD) models to understand the mechanisms responsible for performance enhancement. The CFD methodology, thus, developed was applied to understand the effect of various geometrical parameters on heat transfer enhancement. A criterion was defined for evaluation of heat transfer performance (heat transfer per unit pumping power), thus, ensuring due considerations to required pumping power. The effect of geometrical parameters and the corresponding mechanisms contributing for enhancement are discussed briefly. Based on the results, a design map comprising different serpentine channels showing heat transfer enhancement with pumping power was developed for Reynolds number of 200 which will be useful for further work on flow and heat transfer in serpentine channels. (C) 2012 American Institute of Chemical Engineers AIChE J, 59: 1814-1827, 2013
Keywords: computational fluid dynamics; heat transfer; pressure drop; serpentine

Functional and disordered meso-macroporous gamma-Al2-xMxO3 +/- y (M = Cu and/or Ce) - Gnanakumar, Edwin S.; John, Jino C.; Raja, Thirumalaiswamy; Gopinath, Chinnakonda S. (Journal of Nanoscience and Nanotechnology, 2013)
Disordered meso-macro porous Cu-Ce-Al2O3 nanocomposite (gamma-Al2-xMxO3 +/- y, M = Cu and or Ce) with different compositions has been synthesized. In situ templated sol-gel method has been adopted with simple EDTA ethylenediamine tetra aceticacid and ethylenediamine molecules to prepare gamma-Al2-xMxO3 +/- y, (M = Cu and or Ce). Above meso-macro porous materials were characterized by structural, spectroscopy, microscopy and textural techniques. Detailed characterization indicates that Cu2+ ions are introduced into the ceria and alumina lattice positions. Nano composite nature of the gamma-Al2-xMxO3 +/- y has been confirmed by detailed microscopy investigations. Catalytic activity of the above nanocomposite materials have been screened for environmentally important CO oxidation reaction. 30% Ce-60% Al and 10% Cu containing material shows the best activity among other meso-nnacroporous material with (50%) 100% CO oxidation at (107 degrees C) 145 degrees C.
Keywords: Alumina; CO oxidation; heterogeneous catalysis; Meso-Macroporous Material; Nanocomposite; Sol-gel synthesis

Functional characterization, homology modeling and docking studies of beta-glucosidase responsible for bioactivation of cyanogenic hydroxynitrile glucosides from Leucaena leucocephala (subabul) - Shaik, Noor M.; Misra, Anurag; Singh, Somesh; Fatangare, Amol B.; Ramakumar, Suryanarayanarao; Rawal, Shuban K.; Khan, Bashir Mohammad (Molecular Biology Reports, 2013)
Glycosyl hydrolase family 1 beta-glucosidases are important enzymes that serve many diverse functions in plants including defense, whereby hydrolyzing the defensive compounds such as hydroxynitrile glucosides. A hydroxynitrile glucoside cleaving beta-glucosidase gene (Llbglu1) was isolated from Leucaena leucocephala, cloned into pET-28a (+) and expressed in E. coli BL21 (DE3) cells. The recombinant enzyme was purified by Ni-NTA affinity chromatography. The optimal temperature and pH for this beta-glucosidase were found to be 45 A degrees C and 4.8, respectively. The purified Llbglu1 enzyme hydrolyzed the synthetic glycosides, pNPGlucoside (pNPGlc) and pNPGalactoside (pNPGal). Also, the enzyme hydrolyzed amygdalin, a hydroxynitrile glycoside and a few of the tested flavonoid and isoflavonoid glucosides. The kinetic parameters K (m) and V (max) were found to be 38.59 mu M and 0.8237 mu M/mg/min for pNPGlc, whereas for pNPGal the values were observed as 1845 mu M and 0.1037 mu M/mg/min. In the present study, a three dimensional (3D) model of the Llbglu1 was built by MODELLER software to find out the substrate binding sites and the quality of the model was examined using the program PROCHEK. Docking studies indicated that conserved active site residues are Glu 199, Glu 413, His 153, Asn 198, Val 270, Asn 340, and Trp 462. Docking of rhodiocyanoside A with the modeled Llbglu1 resulted in a binding with free energy change (Delta G) of -5.52 kcal/mol on which basis rhodiocyanoside A could be considered as a potential substrate.
Keywords: Glycosyl hydrolase family 1; homology modeling; Leucaena leucocephala; Molecular docking

Functional characterization of a flavonoid glycosyltransferase gene from withania somnifera (Ashwagandha) - Singh, Somesh; Vishwakarma, Rishi. K.; Kumar, R. J. Santosh; Sonawane, Prashant D.; Ruby; Khan, Bashir Mohammad (Applied Biochemistry and Biotechnology, 2013)
Glycosylation of flavonoids is mediated by family 1 uridine diphosphate (UDP)-dependent glycosyltransferases (UGTs). Until date, there are few reports on functionally characterized flavonoid glycosyltransferases from Withania somnifera. In this study, we cloned the glycosyltransferase gene from W. somnifera (UGT73A16) showing 85-92 % homology with UGTs from other plants. UGT73A16 was expressed as a His(6)-tagged fusion protein in Escherichia coli. Several compounds, including flavonoids, were screened as potential substrates for UGT73A16. HPLC analysis and hypsochromic shift indicated that UGT73A16 transfers a glucose molecule to several different flavonoids. Based on kinetic parameters, UGT73A16 shows more catalytic efficiency towards naringenin. Here, we explored UGT73A16 of W. somnifera as whole cell catalyst in E. coli. We used flavonoids (genistein, apigenin, kaempferol, naringenin, biochanin A, and daidzein) as substrates for this study. More than 95 % of the glucoside products were released into the medium, facilitating their isolation. Glycosylation of substrates occurred on the 7- and 3-hydroxyl group of the aglycone. UGT73A16 also displayed regiospecific glucosyl transfer activity towards 3-hydroxy flavone compound, which is the backbone of all flavonols and also for a chemically synthesized compound, not found naturally. The present study generates essential knowledge and molecular as well as biochemical tools that allow the verification of UGT73A16 in glycosylation.
Keywords: Flavonoid; glycosylation; Glycosyltransferase; Hypsochromic shift; Plant secondary product glycosyltransferase (PSPG); Withania somnifera

Functional characterization of a glucosyltransferase specific to flavonoid 7-O-glucosides from withania somnifera - Kumar, R. J. Santosh; Ruby; Singh, Somesh; Sonawane, Prashant D.; Vishwakarma, R. K.; Khan, Bashir Mohammad (Plant Molecular Biology Reporter, 2013)
Flavonoids are a large class of phenylpropanoid-derived secondary metabolites, which are usually glycosylated by UDP-glycosyltransferases with one or more sugar groups. Here, we report the cloning and biochemical characterization of a flavonoid glycosyltransferase gene from Withania somnifera (WsGT), which is an important medicinal plant used in Ayurvedic formulations. Using PCR primers, designed for a highly conserved region of previously reported glycosyltransferases, we were able to isolate the corresponding fragment of the WsGT gene. Rapid amplification of cDNA ends (RACE) was then employed to isolate full-length cDNA, which had an open reading frame of 1,371 bp that encode for 456 amino acids. Phylogenetic analysis indicated that WsGT was similar to that of family 1 GT-B glycosyltransferase. Biochemical analysis revealed that WsGT interacts with UDP-glucose and was capable of regiospecifically glycosylating flavonoid-7-ols, such as apigenin, naringenin, luteolin, diadzein and genistein. Expression profiling studies showed that WsGT was highly expressed in young and mature leaves of W. somnifera. Furthermore, exposure to salicylic acid enhanced the expression of WsGT in the leaves and heat shock treatment resulted in decreased expression of WsGT after an initial increase. This may suggest the role of WsGT in response to abiotic/biotic stresses.
Keywords: Diadzein; Flavonoids; Glycosyltransferase; Withania somnifera

Genome-wide identification and characterization of microRNA genes and their targets in flax (Linum usitatissimum) - Barvkar, Vitthal T.; Pardeshi, Varsha C.; Kale, Sandip M.; Qiu, Shuqing; Rollins, Meaghen; Datla, Raju; Gupta, Vidya S.; Kadoo, Narendra Y. (Planta, 2013)
MicroRNAs (miRNAs) are small (20-24 nucleotide long) endogenous regulatory RNAs that play important roles in plant growth and development. They regulate gene expression at the post-transcriptional level by translational repression or target degradation and gene silencing. In this study, we identified 116 conserved miRNAs belonging to 23 families from the flax (Linum usitatissimum L.) genome using a computational approach. The precursor miRNAs varied in length; while most of the mature miRNAs were 21 nucleotide long, intergenic and showed conserved signatures of RNA polymerase II transcripts in their upstream regions. Promoter region analysis of the flax miRNA genes indicated prevalence of MYB transcription factor binding sites. Four miRNA gene clusters containing members of three phylogenetic groups were identified. Further, 142 target genes were predicted for these miRNAs and most of these represent transcriptional regulators. The miRNA encoding genes were expressed in diverse tissues as determined by digital expression analysis as well as real-time PCR. The expression of fourteen miRNAs and nine target genes was independently validated using the quantitative reverse transcription PCR (qRT-PCR). This study suggests that a large number of conserved plant miRNAs are also found in flax and these may play important roles in growth and development of flax.
Keywords: Digital expression analysis; Gene cluster; Linseed; miRNA; MiRNA target transcript; Promoter analysis

GIAO/DFT studies on 1,2,4-triazole-5-thiones and their propargyl derivatives - Phalgune, Usha D.; Vanka, Kumar; Rajamohanan, P. R. (Magnetic Resonance in Chemistry, 2013)
Density functional theory (DFT)/Becke-Lee-Yang-Parr (B3LYP) and gauge-including atomic orbital (GIAO) calculations were performed on a number of 1,2,4-triazole derivatives, and the optimized structural parameters were employed to ascertain the nature of their predominant tautomers. C-13 and N-15 NMR chemical shifts of 3-substituted 1,2,4-triazole-5-thiones and their propargylated derivatives were calculated via GIAO/DFT approach at the B3LYP level of theory with geometry optimization using a 6-311++G** basis set. A good agreement between theoretical and experimental C-13 and N-15 NMR chemical shifts could be found for the systems investigated. The data generated were useful in predicting N-15 chemical shifts of all the nitrogen atoms of the triazole ring, some of which could not be obtained in solution state N-15 HMBC/HSQC NMR measurements. The energy profile computed for the dipropargylated derivatives was found to follow the product distribution profile of regioisomers formed during propargylation of 1,2,4-triazole thiones. Copyright (c) 2013 John Wiley & Sons, Ltd.
Keywords: 1; 2; 4-triazole-5-thiones; C-13; DFT; GIAO; N-15; NMR; Regioisomers; tautomers

Heat transfer calculations for decomposition of structure i methane hydrates by molecular dynamics simulation - Baghel, Vikesh Singh; Kumar, Rajnish; Roy, Sudip (Journal of Physical Chemistry C, 2013)
Microcanonical ensemble molecular dynamics simulations of structure I methane hydrate is presented in this work to study the endothermic decomposition process. The mechanism of decomposition of methane hydrate as a function of time was explained at the molecular level. The initial temperature and pressure of the simulation were chosen so as to depict the natural gas hydrate in conditions of oceanic sediments. A more realistic strategy was developed to perform the microcanonical ensemble simulation of solid liquid interface of hydrate and amorphous water. Two water models, SPC/E and TIP4P, were used for the simulations, and the results of the simulations were compared. Heat transfer calculations were performed on the adiabatic system, and an attempt has been made to fit the MD simulation results to the heat balance equations derived from the heat transfer calculations. Estimates of the properties at the macroscopic scale, like the equilibrium temperature of methane hydrate and rate of supply of hot water for sustained release of methane from solid hydrate phase, were determined. The equilibrium temperature obtained by the above method was found to be in agreement with the experimentally observed value. Both the SPC/E and TIP4P water models gave similar results.

Heterogeneous Co3O4 catalyst for selective oxidation of aqueous veratryl alcohol using molecular oxygen - Mate, Vivek R.; Shirai, Masayuki; Rode, Chandrashekhar V. (Catalysis Communications, 2013)
Nano-structured, spinel Co3O4 catalyst was developed for the aqueous phase oxidation of veratryl alcohol, which showed the highest conversion of 85% with 96% selectivity to veratryl aldehyde. The co-existence of Co3+ and Co2+ species in the octahedral and tetrahedral positions respectively, was confirmed by XPS, cyclic voltammogram, TPR and TPO characterization. The rod-like morphology of Co3O4 catalyst was confirmed by HRTEM. The effects of various reaction parameters namely, catalyst concentration, temperature and partial oxygen pressure on conversion and selectivity patterns were also studied for the oxidation of veratryl alcohol. This catalyst also showed an excellent stability as evidenced by successful reusability for three times. (C) 2012 Published by Elsevier B.V.
Keywords: Co3O4; Cyclic voltammogram; Liquid phase oxidation; Molecular oxygen; Veratryl alcohol; XPS

Heterovalent cation substitutional doping for quantum dot homojunctions - Stavrinadis, Alexandros; Rath, Arup Kumar; Pelayo Garcia de Arquer, F.; Diedenhofen, Silke L.; Magen, Cesar; Martinez, Luis; So, David; Konstantatos, Gerasimos (Nature Communications, 2013)
Colloidal quantum dots have emerged as a material platform for low-cost high-performance optoelectronics. At the heart of optoelectronic devices lies the formation of a junction, which requires the intimate contact of n-type and p-type semiconductors. Doping in bulk semiconductors has been largely deployed for many decades, yet electronically active doping in quantum dots has remained a challenge and the demonstration of robust functional optoelectronic devices had thus far been elusive. Here we report an optoelectronic device, a quantum dot homojunction solar cell, based on heterovalent cation substitution. We used PbS quantum dots as a reference material, which is a p-type semiconductor, and we employed Bi-doping to transform it into an n-type semiconductor. We then combined the two layers into a homojunction device operating as a solar cell robustly under ambient air conditions with power conversion efficiency of 2.7%.

Highly efficient povidone-phosphotungstic acid catalyst for the tandem acetalization of aldehydes to bis- and tris(indolyl)methanes - Kamble, Sumit B.; Swami, Rameshwar K.; Sakate, Sachin S.; Rode, Chandrashekhar V. (ChemPlusChem, 2013)
A novel, nonleachable hybrid of heteropoly acid and polyvinylpyrrolidone (or povidone) catalyzes the acetalization of aldehydes in methanol at room temperature followed by reaction with indole to give bis(indolyl)methanes (BIMs) and tris(indolyl)methanes (TIMs) in quantitative yields (90-97%). The catalyst was shown by pyridine FTIR spectroscopy to possess BrOnsted acidity, and the hybrid formation was confirmed by XRD and (PNMR)-P-31 studies. Friedel-Crafts alkylation of indole as well as the tandem synthesis of BIMs and TIMs were established with several types of carbonyl and indole substrates to give the corresponding products quantitatively. The catalyst was recycled efficiently for three successive runs without losing its original activity.
Keywords: acetals; Acidity; aldehydes; heterogeneous catalysis; heteropoly acids

Highly selective liquid-phase aerobic oxidation of vanillyl alcohol to vanillin on cobalt oxide (Co3O4) nanoparticles - Jha, Ajay; Rode, Chandrashekhar V. (New Journal of Chemistry, 2013)
Spinel Co3O4 nanoparticles prepared by solution phase method having particle size in the range of 12-20 nm exhibited excellent activity for the liquid-phase aerobic oxidation of vanillyl alcohol with 80% conversion and 98% selectivity to vanillin. Our catalyst could be reused three times without appreciable loss in activity. The catalytic activity of the Co3O4 nanoparticles was found to be similar to its homogenous precursor (cobalt acetate) and greater than the commercial Co3O4 oxide. The detailed characterization results of morphology, size and structure of the prepared Co3O4 nanoparticles obtained by XRD, FT-IR, H-2-TPR, HR-TEM and cyclic voltammetry technique were used to understand the roles of various Co species in directing the selectivity towards vanillin.

High-resolution outgoing longwave radiation dataset from Kalpana-1 satellite during 2004-2012 - Mahakur, M.; Prabhu, A.; Sharma, A. K.; Rao, V. R.; Senroy, S.; Singh, Randhir; Goswami, B. N. (Current Science, 2013)
Long record of high-resolution quality-controlled outgoing longwave radiation (OLR) from geostationary platforms like Kalpana-1 has the potential not only to provide detailed information of cloud types contributing to the measure of rain, but also helps unravel convective cloud organization in the tropics from small scale to meso- and synoptic scales. A research quality product of three hourly OLR for the period May 2004 June 2012 is produced from Kalpana-1 very high resolution radiometer (VHRR) radiances over the Indian region (40 degrees S-40 degrees N, 25-125 degrees E) in a regular grid of 0.25 x 0.25 degrees. The quality and usefulness of the dataset is demonstrated here using some illustrative examples. Although these data are available for a relatively short-period, it is shown that they will be potentially more useful than the widely used OLR from NOAA satellites in representing the annual cycles, particularly over the desert and humid oceans, due to their frequent sampling and quality. The active-break periods in the Indian summer monsoon picked up by both the OLR match well. This three hourly OLR estimated from Kalpana-1 VHRR is able to describe the fine-scale structure of the diurnal variation over the region.
Keywords: Active break periods; diurnal variation; geostationary platforms; outgoing longwave radiation

Imprinted electrodes for enhanced light trapping in solution processed solar cells - Mihi, Agustin; Beck, Fiona J.; Lasanta, Tania; Rath, Arup Kumar; Konstantatos, Gerasimos (Advanced Materials, 2013)

Interesting thermal variations owing to cationic ring structural features in protic ionic liquids - Rai, Gitanjali; Kumar, Anil (Physical Chemistry Chemical Physics, 2013)
The present communication divulges interesting thermal behavior of different protic ionic liquids arising due to the hydrophobicity modifications in their parent cationic ring structures. This work assists us in differentiating between protic ionic liquids, their aprotic counterparts and common electrolytes in water. The thermal signatures produced by protic ionic liquids, aprotic ionic liquids and electrolytes emerge as individual fingerprints for them.

Isolation, purification and characterization of vinblastine and vincristine from endophytic fungus fusarium oxysporum isolated from catharanthus roseus - Kumar, Ashutosh; Patil, Deepak; Rajamohanan, Pattuparambil Ramanpillai; Ahmad, Absar (Plos One, 2013)
Endophytic fungi reside in a symbiotic fashion inside their host plants, mimic their chemistry and interestingly, produce the same natural products as their hosts and are thus being screened for the production of valuable compounds like taxol, camptothecin, podophyllotoxin, etc. Vinblastine and vincristine are excellent anti-cancer drugs but their current production using plants is non-abundant and expensive. In order to make these drugs readily available to the patients at affordable prices, we isolated the endophytic fungi from Catharanthus roseus plant and found a fungus AA-CRL-6 which produces vinblastine and vincristine in appreciable amounts. These drugs were purified by TLC and HPLC and characterized using UV-Vis spectroscopy, ESI-MS, MS/MS and H-1 NMR. One liter of culture filtrate yielded 76 mu g and 67 mu g of vinblastine and vincristine respectively. This endophytic fungal strain was identified as Fusarium oxysporum based upon its cultural and morphological characteristics and internal transcribed spacer (ITS) sequence analysis.

Is it possible to change wettability of hydrophilic surface by changing its roughness? - Pandey, Prithvi Raj; Roy, Sudip (Journal of Physical Chemistry Letters, 2013)
Wetting behavior of model rough surfaces made of hydrophilic square pillars is investigated. The hydrophilic pillars are equally spaced on hydrophilic surface. The surface roughnesses are altered by varying the pillar width and interpillar spacing. Wetting to dewetting transition is observed for these surfaces. This is one of the first accounts of observation from molecular simulations where hydrophilic surface converts into hydrophobic by changing its roughness. The extent of hydrophilicities are also changed to gain more insightful observations. Energies of the wetting to dewetting transitions are analyzed by calculating the contribution from water water and water surface energy components. A correlation between energy and the wetting to dewetting transition has been established, which rationally explains the observed water repellent nature of hydrophilic surface as a function of roughness.

Low-pressure synthesis and characterization of hydrogen-filled ice ic - Kumar, Rajnish; Klug, Dennis D.; Ratcliffe, Christopher I.; Tulk, Christopher A.; Ripmeester, John A. (Angewandte Chemie-International Edition, 2013)
Keywords: Clathrates; cubic ice; hydrates; Hydrogen

Magnetically separable single-site Ti-Fe3O4@MCM-41 catalyst for selective epoxidation of olefins - Jha, Ajay; Patil, Chetana R.; Garade, Ajit C.; Rode, Chandrashekhar V. (Industrial & Engineering Chemistry Research, 2013)
Magnetically separable Ti-Fe3O4@MCM-41 (Ti-MS) catalysts were prepared by postgrafting Ti with varying loading on mesoporous silica containing dispersed magnetite. The hexagonal structure of Ti-MS catalysts with a periodicity in the pores and a highly ordered hexagonal matrix was established by X-ray diffraction and transmission electron microscopy, while diffuse reflectance UV showed the isolated tetrahedral Ti species coordinated with O2-. From the Fourier transform infrared studies, the extent of Ti-O-Si linkage was found to increase with increase in Ti-loading from 1 to 5 wt %beyond which (10%), the intensity of Ti-O-Si band decreased due to the polymerization of the Ti on the silica surface. Silanol groups on the surface of silica interact with the precursor Ti((OPr)-Pr-i)(4) to give site isolated tetrahedral Ti-species responsible for complete selectivity to the epoxide in the epoxidation of cyclooctene. The magnetic property facilitated easy recovery of the catalyst for its successful eight recycles showing its stability under reaction conditions.

Mechanistic insights into the inhibition of endo-beta 1,4 xyloglucan hydrolase by a classical aspartic protease inhibitor - Menon, Vishnu; Rao, Mala (Journal of Fluorescence, 2013)
This is the first report of inactivation of xyloglucanase from Thermomonospora sp by pepstatin A, a specific inhibitor towards aspartic proteases. The steady state kinetics revealed a reversible, competitive, two-step inhibition mechanism with IC (50) and K (i) values of 3.5 +/- 0.5 mu M and 1.25 +/- 0.5 mu M respectively. The rate constants determined for the isomerization of EI to EI* and the dissociation of EI* were 14.5 +/- 1.5 x 10(-5) s(-1) and 2.85 +/- 1.2 x 10(-8) s(-1) respectively, whereas the overall inhibition constant K (i) (*) was 27 +/- 1 nM. The conformational changes induced upon inhibitor binding to xyloglucanase were monitored by fluorescence analysis and the rate constants derived were in agreement with the kinetic data. The abolished isoindole fluorescence of o-phthalaldehyde (OPTA)-labeled xyloglucanase and far UV analysis suggested that pepstatin binds to the active site of the enzyme. Our results revealed that the inactivation of xyloglucanase is due to the interference in the electronic microenvironment and disruption of the hydrogen-bonding network between the essential histidine and other residues involved in catalysis.
Keywords: 4 xyloglucan hydrolase; Endo-beta 1; Enzyme kinetics; Inactivation mechanism; Pepstatin; Slow-tight binding

Metal cation-exchanged montmorillonite clay as catalysts for hydroxyalkylation reaction - Jha, Ajay; Garade, Ajit C.; Shirai, M.; Rode, C. V. (Applied Clay Science, 2013)
Several solid acid catalysts were prepared by exchanging metal cations such as Zn2+, Fe3+ and Al3+ with montmorillonite clay. Among these, Al-montmorillonite showed the highest acidity determined by the pyridine-IR as well as NH3-TPD methods. A systematic comparison of the performance of these catalysts along with parent montmorillonite was carried out for the hydroxyalkylation of p-cresol with formaldehyde to give 2, 2'-methylenebis (4-methyl phenol) (DAM). It was found that the activity of these catalysts was in accordance with the increase in acidity of parent montmorillonite after the exchange of cations in the order of Zn2+, Fe3+ and Al3+. The selectivity pattern was also influenced by the exchanged cations. Since Al-montmorillonite showed the highest conversion of 51% with 98% selectivity to DAM, the effects of various reaction parameters, namely, mole ratio, catalyst concentration, temperature, reaction time on conversion and selectivity pattern were also studied using the same catalyst This catalyst also showed an excellent stability as evidenced by its eight times reuse. (C) 2012 Published by Elsevier B.V.
Keywords: Cations-exchanged clay; Montmorillonite; NH3-TPD; Pyridine-IR

Metal-mediated alkynediol cycloisomerization: first and second generation formal total syntheses of didemniserinolipid B - Das, Shyamsundar; Induvadana, Boddeti; Ramana, C. V. (Tetrahedron, 2013)
A formal total synthesis of didemniserinolipid B was developed by employing a regioselective metal-mediated 6-endo-dig alkynol-cycloisomerization reaction. Two routes for the synthesis of key Burke's intermediate have been developed. Our initial approach involved the introduction of a C-17-allcynol followed by Pd-mediated cycloisomerization and then coupling with the serinol unit prior to the introduction of an alpha,beta-unsaturated ester unit through selective oxidation of 1 degrees-OH followed by a two-carbon Wittig homologation. Alternatively, the second generation strategy featuring the serinol coupling with the C-17-alkynol followed by alkyne addition to the epoxide and subsequent Au-mediated cycloisomerization of an acetonide protected alkynediol unit has been executed. This approach has avoided several late stage protection-deprotection events. (C) 2012 Elsevier Ltd. All rights reserved.
Keywords: Alkynol-cycloisomerization; Bicyclic ketal; Gold catalysis; Palladium catalysis; Zipper reaction

MgCl2 center dot 6CH(3)OH: a simple molecular adduct and its influence as a porous support for olefin polymerization - Gnanakumar, Edwin S.; Gowda, Ravikumar R.; Kunjir, Shrikant; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Chakraborty, Debashis; Gopinath, Chinnakonda S. (ACS Catalysis, 2013)
A single phase molecular adduct, MgCl2 center dot 6CH(3)OH has been synthesized using MgCl2 and the simplest alcohol, methanol. Structural, spectroscopic, and morphological studies have been carried out for a better understanding of the single phase MgCl2 center dot 6CH(3)OH adduct. C-13 CPMAS solid state NMR studies show all six methanol molecules are magnetically equivalent and present in a single environment around the Mg2+ center. Raman spectral analysis of the characteristic peak at 708 cm(-1) substantiates octahedral coordination of six CH3OH molecules around Mg2+. Solid state C-13 NMR measurements, made after heat treatment at different temperatures, have been utilized to understand the variations in CH3OH stoichiometry and coordination around Mg2+ with temperature. A titanated active catalyst, TiCl4 on MgCl2 center dot 6CH(3)OH, has also been synthesized and subjected to detailed characterizations. The active catalyst shows high surface area (102 m(2)/g) and mesoporosity. The titanated catalyst has been screened for ethylene polymerization reactions using different cocatalysts (R3Al; R= -CH3, -CH2CH3, and -CH2CH(CH3)(2)). A total of 7.25 kg of polyethylene per gram of catalyst has been obtained with Me3Al cocatalyst, which is six times higher in activity compared with commercial Me3Al/TiCl4/MgCl2 center dot 6EtOH-supported orted catalystAlthough porosity influences the catalytic activity, other factors also seem to contribute to the total catalytic activity.
Keywords: heterogeneous catalysis; MgCl2; Molecular adduct; olefin polymerization; Ziegler-Natta catalyst

Mixed Co-Mn oxide-catalysed selective aerobic oxidation of vanillyl alcohol to vanillin in base-free conditions - Jha, Ajay; Patil, Kashinath R.; Rode, Chandrashekhar V. (Chempluschem, 2013)
Manganese-doped cobalt mixed oxide (MnCo-MO) catalyst was prepared by a solvothermal method. The as-prepared catalyst was characterised by X-ray photoelectron spectroscopy, H-2 temperature-programmed reduction, O-2 temperature-programmed oxidation and XRD. This catalyst gave 62% conversion with 83% selectivity to vanillin in 2hours for the liquid-phase air oxidation of vanillyl alcohol without using base. Three different types of metal oxides were observed in the prepared catalyst, which could be identified as Co3O4, Mn3O4 and CoMn2O4. Among these, the tetragonal phase of CoMn2O4 was found to be more active and selective for vanillyl alcohol oxidation than Co3O4 and Mn3O4. High-resolution TEM characterisation revealed the morphology of MnCo-MO nanorods with a particle size of 10nm. Successful recycling of the catalyst was also established in this oxidation reaction.
Keywords: aerobic oxidation; cobalt; heterogeneous catalysis; manganese; spinel phases

Modular total synthesis of (+/-)-trigonoliimine C - Reddy, B. Narendraprasad; Ramana, Chepuri V. (Chemical Communications, 2013)
A convergent total synthesis of trigonoliimine C has been executed by employing three catalytic transformations in sequence. The key reactions that have been developed in this context include the [Au]-catalyzed addition of protected tryptamine to isatogens and the reduction of N-OH to NH with hydrazine monohydrate.

Molecular characterization and differential expression studies of an oxidosqualene cyclase (OSC) gene of Brahmi (Bacopa monniera) - Vishwakarma, Rishi K.; Sonawane, Prashant; Singh, Somesh; Kumari, Uma; Ruby; Khan, Bashir Mohammad (Physiology and Molecular Biology of Plants, 2013)
Triterpenoid saponins are the class of secondary metabolites, synthesized via isoprenoid pathway. Oxidosqualene cyclases (OSCs) catalyzes the cyclization of 2, 3-oxidosqualene to various triterpene skeletons, the first committed step in triterpenoid biosynthesis. A full-length oxidosqualene cyclase cDNA from Bacopa monniera (BmOSC) was isolated and characterized. The open reading frame (ORF) of BmOSC consists of 2,292 bp, encoding 764 amino acid residues with an apparent molecular mass of 87.62 kDa and theoretical pI 6.21. It contained four QxxxxxW motifs, one Asp-Cys-Thr-Ala-Glu (DCTAE) motif which is highly conserved among the triterpene synthases and another MWCYCR motif involved in the formation of triterpenoid skeletons. The deduced amino acid sequence of BmOSC shares 80.5 % & 71.8 % identity and 89.7 % & 83.5 % similarity with Olea europaea mixed amyrin synthase and Panax notoginseng dammarenediol synthase respectively. Phylogenetic analysis revealed that BmOSC is closely related with other plant OSCs. Quantitative real-time PCR (qRT-PCR) data showed that BmOSC is expressed in all tissues examined with higher expression in stem and leaves as compared to roots and floral parts.

Molecular cloning, biochemical characterization, and differential expression of an acetyl-CoA C-acetyltransferase gene (AACT) of brahmi (Bacopa monniera) - Vishwakarma, Rishi K.; Ruby; Singh, Somesh; Sonawane, Prashant D.; Srivastava, Sameer; Kumari, Uma; Kumar, R. J. Santosh; Khan, Bashir Mohammad (Plant Molecular Biology Reporter, 2013)
Bacopa monniera (Brahmi) is an important Indian medicinal herb found in wet damp and marshy places. It produces medicinally important compounds known as bacosides along with alkaloids like brahmine and herpestine. Bacosides are triterpenoid saponins and their biosynthesis takes place via the isoprenoid pathway starting with acetyl-CoA. Acetyl-CoA C-acetyltransferase (AACT; EC 2.3.1.9), also known as acetoacetyl-CoA thiolase (Thiolase II), catalyzes the condensation of two acetyl-CoA to form 4-C compound acetoacetyl-CoA. Acetoacetyl-CoA is an important starting molecule for biosynthesis of various metabolites. Here, we report the cDNA cloning and characterization of acetyl-CoA C-acetyltransferase gene from B. monniera. The full-length gene was isolated using a RACE PCR protocol. The cDNA encoding AACT was designated as BmAACT (FJ947159) revealed an ORF of 1,218 bp and 405 amino acids, and shares 80 % similarity with other plant AACTs. Phylogenetic analysis showed that BmAACT is related closely to other dicot plants AACTs. The BmAACT gene was over-expressed in Escherichia coli as a 6X His-tag fusion protein and purified to homogeneity by Ni-NTA and gel filtration chromatography. Activity of recombinant protein was confirmed by thiolytic cleavage of acetoacetyl-CoA in the presence of 5 mM Mg2+, showing K (m) and V (max) of 20.67 mu M and 96.21 mu mol/min, respectively, with high catalytic efficiency (k (cat) = 2.30 x 10(5) min(-1)). Quantitative real-time PCR analysis showed that the expression of BmAACT is tissue-specific, and accumulation of transcripts is greater in roots and petals, followed by sepals, stem, leaf and pedicel.
Keywords: Acetyl-CoA C-acetyltransferase; Bacopa monniera; Isoprenoid pathway; Triterpenoid saponin

Molecular mapping of leaf rust resistance gene Lr15 in hexaploid wheat - Dholakia, Bhushan B.; Rajwade, A. V.; Hosmani, P.; Khan, R. R.; Chavan, S.; Reddy, D. M. R.; Lagu, Meena D.; Bansal, Urmil K.; Saini, R. G.; Gupta, V. S. (Molecular Breeding, 2013)
Leaf rust is a widespread and commonly occurring rust disease of wheat. Genetic resistance is the most economical method of reducing losses due to leaf rust. Lr15 has been shown to be present on wheat chromosome 2D and is reported to be a seedling resistance gene. However, tightly linked markers associated with Lr15 have not been reported to date. To identify molecular markers linked to Lr15, an F-2 mapping population of Thatcher x Thatcher-Lr15 was generated. Available wheat simple sequence repeat markers were utilized in parental screening and polymorphic markers were used to analyze the entire population of 221 plants. Phenotypic evaluations of the F-2-derived F-3 progenies with Puccinia triticina Eriks. pathotype 162A (93R15) confirmed the monogenic inheritance of Lr15. The linkage group representing chromosome 2DS was constructed at LOD 4.0 which revealed the closest flanking markers Xgwm4562 and Xgwm102 at a distance of 3.1 and 9.3 cM, respectively. Furthermore, utilization of these flanking markers in combination has successfully identified wheat lines with or without Lr15. These markers could potentially be useful in gene pyramiding with other genes to enhance rust resistance in wheat.
Keywords: Disease resistance; Leaf rust; Marker-assisted selection; Simple sequence repeat; Wheat

Morphology and dynamics of carbon nanotube in polycarbonate carbon nanotube composite from dissipative particle dynamics simulation - Chakraborty, Souvik; Choudhury, Chandan Kumar; Roy, Sudip (Macromolecules, 2013)
Morphology and dynamics of carbon nanotube (CNT) in polycarbonate matrix with different mixing ratios are studied in mesoscale by using dissipative particle dynamics (DPD). We have used atomistic simulation to derive necessary interaction parameter for mesoscale DPD simulation for polycarbonate nanotube composite using Flory-Huggins theory. The diffusion and morphology of nanotubes in different concentrations (2%, 5%, 10%) are investigated. Diffusivity of nano tubes in polymer matrices is explored at different temporal regimes of simulation. Diffusion of nanotubes becomes significantly slow when bundling of nanotubes takes place. The bundle formation of nanotubes is observed in all of three mixtures with varying degrees of assembling and alignment Bundle size analysis is performed to study the extent of bundling affinity of CNTs in different filler concentrations. Size of the bundles of nanotubes is more in higher nanotube concentrations. In the 10% mixture percolation network is found to be formed by bundles of nanotubes.

Multiphase flows with phase change foreword - Ranade, Vivek V. (Sadhana-Academy Proceedings in Engineering Sciences, 2013)

New receptor with a FRET based fluorescence response for selective recognition of fumaric and maleic acids in aqueous medium - Reddy, Upendar G.; Lo, Rabindranath; Roy, Sovan; Banerjee, Tanmay; Ganguly, Bishwajit; Das, Amitava (Chemical Communications, 2013)
Preferential binding of a new reagent to fumaric acid could be utilized for its estimation in aqueous medium and in commercial fruit juice.

N-Heterocyclic carbene catalyzed oxidative stannylation of aldehydes: a facile entry to organotin(IV) carboxylates - Reddi, Rambabu N.; Malekar, Pushpa V.; Sudalai, Arumugam (Tetrahedron Letters, 2013)
A simple protocol is described for the oxidative transformation of aldehydes to the corresponding organotin(IV) carboxylates in high yields (up to 90%) that utilizes atmospheric O-2 as the sole oxidant, N-heterocyclic carbene as catalyst (at 10 mol %), and tributyl tin chloride as stannylating agent. The uniqueness of the reaction lies in the direct conversion of aldehydes to the corresponding organotin(IV) carboxylates via stannylation of carboxylic acids, generated from the reaction of a Breslow intermediate with O-2. (c) 2013 Elsevier Ltd. All rights reserved.
Keywords: Carboxylic acid stannanes; N-Heterocyclic carbene; Oxidative stannylation; oxygen; Tributyltin chloride

N-Heterocyclic carbene catalyzed regioselective oxo-acyloxylation of alkenes with aromatic aldehydes: a high yield synthesis of alpha-acyloxy ketones and esters - Reddi, Rambabu N.; Malekar, Pushpa V.; Sudalai, Arumugam (Organic & Biomolecular Chemistry, 2013)
An N-heterocyclic carbene (NHC)-catalyzed reaction of alkenes with aromatic aldehydes providing for a high yield synthesis of alpha-acyloxy ketones and esters has been described. This unprecedented regioselective oxidative process employs NBS and Et3N in stoichiometric amounts and O-2 (1 atm) as an oxidant under ambient conditions in DMSO as a solvent.

Novel vanadium n-propylamino phosphate catalyst: synthesis, characterization and applications - Anumula, Rajini; Nookaraju, Muralasetti; Selvaraj, Kaliaperumal; Reddy, Ingala Ajit Kumar; Narayanan, Venkatathri (Materials Research-Ibero-American Journal of Materials, 2013)
A novel, lamellar type Vanadium n-propylamino phosphate catalyst is synthesized and characterized by using various physicochemical techniques such as Powder X-ray diffraction, Scanning electron microscopy/Energy dispersive X-ray analysis, Thermogravimetry/Differential thermal analysis, Fourier transform Infrared analysis, Electron spin resonance spectroscopy, Ultraviolet - Visible Diffuse reflectance spectroscopy, X-ray Photoelectron spectroscopy, P-31 Magic angle spinning Nuclear Magnetic Resonance spectroscopy and Catalytic applications toward Octahydroquinazolinone synthesis. It is found that the n-propylamine is present as sandwich between Vanadyl phosphate layers. Most of the Vanadium is present as V4+ ions in tetrahedral co-ordination. Vanadium n-propylamino phosphate catalyses Octahydroquinazolinone synthesis more effeciently and the optimum conditions required for Octahydroquinazolinone synthesis are, Benzaldehyde (2 mmol), Dimedone (2 mmol), Urea (4 mmol), Methanol + Water (1:1, 5 mL) and Catalyst (0.05 g). A plausible mechanism is also proposed.
Keywords: n-propylamino phosphate; octahydroquinazolinones; synthesis; Vanadium

One-pot process for the conversion of aroyl chlorides to acyl thioureas - Ramana, Chepuri V.; Senthilkumar, B. (WO2014087431A1, WO2014087431A8, 2013)
The present invention disclose an improved one pot process for synthesis of acyl thioureas of formula (I), with yield greater than 80%, from aroyl chlorides of formula (I) wherein, R′ is an aryl or a heteroarylene group substituted with one or more groups selected from hydrogen, alkyl, alkylene, alkynyl, alkoxy, alkenyloxy, halo, hydroxyl, nitro, amino, carboxyl, ester, halogenated hydrocarbon or an aryl or heteroaryl; R″ and R′″ are selected independently from hydrogen, alkyl, alkylene, alkynyl, alkoxy, alkenyloxy, halo, hydroxyl, nitro, amino or halogenated hydrocarbon.

Optimization of the production of a maltooligosaccharides producing amylase from the alkalophilic streptomyces lonarensis strain NCL 716 using SVR modeling - Sharma, Trupti K.; Bhadane, Vaibhav A.; Kumar, Lalitha S.; Rele, Meenakshi V.; Bhawar, Gajanan; Rahman, Imran (Starch-Starke, 2013)
The Streptomyces lonarensis strain NCL 716 hydrolyses starch to produce a mixture of maltotriose (G3) and maltotetraose (G4) along with maltose (G2). The objective of the present work was to determine an optimum cost effective media composition for the production of a-amylase from this strain. The most influential factor was found to be starch while the least influential factor found was peptone by PlackettBurman method. Peptone amount was kept constant throughout the fermentation. Peptone, which is one of the expensive media components was used at a concentration of 1?g/L, which made the optimum media composition cost effective. A support vector regression-based process model was developed for approximating the non-linear relationship between the fermentation operating variables and the a-amylase yield. Multicanonical Jump Walk Annealing, a stochastic optimization technique is used to obtain optimal operating variables to maximize amylase yield. The maximum amylase activity thus obtained was in good agreement with the experimental values at the optimized levels. The optimum media composition obtained by this method was: yeast extract: 4.53?g/L, starch: 20.246?g/L, K2HPO4: 0.0827%, MgSO4: 0.15%, peptone: 1?g/L. A maximum enzyme activity of 297?U/mL, which was achieved using the above approaches compares well with the activity of reported amylases producing maltooligosaccharides.
Keywords: Alkaline a-amylase; Optimization; Streptomyces; Support vector regression analysis

Orthanilic acid-promoted reverse turn formation in peptides - Kale, Sangram S.; Priya, Gowri; Kotmale, Amol S.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, P. R.; Sanjayan, Gangadhar J. (Chemical Communications, 2013)
Orthanilic acid (2-aminobenzenesulfonic acid, (S)Ant), an aromatic beta-amino acid, has been shown to be highly useful in inducing a folded conformation in peptides. When incorporated into peptide sequences (Xaa-(S)Ant-Yaa), this rigid aromatic beta-amino acid strongly imparts a reverse-turn conformation to the peptide backbone, featuring robust 11-membered-ring hydrogen-bonding.

Oxidative dehydrogenation of ethyl benzene to styrene over hydrotalcite derived cerium containing mixed metal oxides - Venugopal, Ashok Kumar; Venugopalan, Aswathy Thareparambil; Kaliyappan, Periyasamy; Raja, Thirumalaiswamy (Green Chemistry, 2013)
Cerium containing mixed oxides derived from hydrotalcites was prepared and its catalytic activity was studied for oxidative dehydrogenation of ethyl benzene to styrene. Structural, spectroscopic and morphological features of the catalyst have been thoroughly examined with various physico-chemical characterization methods. Raman spectroscopy studies show evidence for oxygen vacancies in lower loadings of cerium which enhanced the oxygen migration. The transmission electron microscopy image showed good dispersion of ceria clusters on the mixed metal oxide. The catalytic activity results suggested that the conversion of ethyl benzene and styrene yield is stable for at least 12 hours without any significant catalyst deactivation. The styrene selectivity and ethyl benzene conversion were higher in a catalyst containing 0.03 mole percentage of cerium. Structural features of the spent catalysts have also been examined to demonstrate the stability of the catalyst during the reaction.

PEEK/SiO2 composites with high thermal stability for electronic applications - Goyal, R. K.; Rokade, K. A.; Kapadia, A. S.; Selukar, B. S.; Garnaik, Baijayantimala (Electronic Materials Letters, 2013)
Thermal and mechanical properties of new high performance polymer matrix composites based on poly(etheretherketone) (PEEK) as matrix and crystalline-silica (SiO2) as reinforcement were discussed for application in electronic packaging substrates or printed circuit boards. The content of SiO2 was varied between 0 and 50 wt. %. Scanning electron microscopy showed uniform dispersion of SiO2 particles in the matrix. Thermogravimetry analysis showed significant increase in thermal stability and char yield with increase in SiO2 content in the matrix. Differential scanning calorimetry showed that SiO2 had a heterogeneous nucleating effect on PEEK, leading to an increase in peak temperature of crystallization and onset crystallization temperature of the composites compared to a pure matrix. The microhardness increased approximately 42%. A modified rule of mixtures with a strengthening efficiency factor equal to 0.06 fit the data nicely. The results show that the prepared PEEK/SiO2 composites may have potential applications in electronics.
Keywords: hardness; PEEK; polymer matrix composites; Thermal properties

Photopolymerization of bis-aromatic and alicyclic based solid urethane acrylate macromonomer in the presence of large excess of reactive diluent Kinetics and modeling - Harikrishna, Reghunathan; Ponrathnam, S.; Rajan, C. R.; Tambe, S. S. (Journal of Thermal Analysis and Calorimetry, 2013)
A solid urethane acrylate macromonomer with bis-aromatic as well as alicyclic moieties was synthesized and the kinetics of photopolymerization reactions were studied in the presence of varying concentration of photoinitiator and large excess of reactive diluent using photo DSC. The studies show that the rate of maximum polymerization was found to increase with increase in concentration of photoinitiator while a decrease was observed by an increase in temperature. The final conversion showed a decrease at highest isothermal condition due to vitrification. Estimation of kinetic parameters including applicability of autocatalytic and modified autocatalytic models were investigated by nonlinear regression. It was observed that the modified models gave a better fit with the experimental data and kinetic parameters showed a decrease with increase in temperature and an increase with increase in concentration of photoinitiator.
Keywords: Autocatalytic model; kinetics; Levenberg-Marquardt method; Photopolymerization

Phytosynthesis of silver nanoparticles by semecarpus anacardium L. leaf extract - Raju, D.; Hazra, Sulekha; Mehta, Urmil J. (Materials Letters, 2013)
Green synthesis of silver nanoparticles (AgNPs) using Semecmpus anacardium L leaf extract was studied. The reduction of silver (Ag+) ions was characterized by using UV-vis spectrophotometer showing formation of AgNPs within 15-20 mm. A time dependent reaction showed the increase in the nanoparticles (NPs) with time. Transmission electron microscopy (TEM) analysis showed that the synthesized AgNPs varied from 10 to 25 nm and has spherical shape. The Fourier transform infrared (FTIR) analysis showed that phenols and protein were responsible for the formation of the AgNPs. The energy dispersive spectroscopy (EDAX) analysis confirms the formed NPs were of silver. The quantification of AgNPs was studied by inductive coupled plasma spectrometry (ICP-AES). The important outcome of this work can be value addition to the medicinal plants in synthesis of NPs for biomedical applications. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: FTIR; Leaf extract; Nanoparticles; Semecarpus anacardium; synthesis; TEM

Polyproline fold-In imparting kinetic stability to an alkaline serine endopeptidase - Rohamare, Sonali B.; Dixit, Vaishali; Nareddy, Pavan Kumar; Sivaramakrishna, D.; Swamy, Musti J.; Gaikwad, Sushama M. (Biochimica Et Biophysica Acta-Proteins and Proteomics, 2013)
Polyproline II (PPII) fold, an unusual structural element was detected in the serine protease from Nocardiopsis sp. NCIM 5124 (NprotI) based on far UV circular dichroism spectrum, structural transitions of the enzyme in presence of GdnHCl and a distinct isodichroic point in chemical and thermal denaturation. The functional activity and conformational transitions of the enzyme were studied under various denaturing conditions. Enzymatic activity of NprotI was stable in the vicinity of GdnHCl upto 6.0 M concentration, organic solvents viz, methanol, ethanol, propanol (all 90% v/v), acetonitrile (75% v/v) and proteases such as trypsin, chymottypsin and proteinase K (NprotI:protease 10:1). NprotI seems to be a kinetically stable protease with a high energy barrier between folded and unfolded states. Also, an enhancement in the activity of the enzyme was observed in 1 M GdnHCl upto 8 h, in organic solvents (75% v/v) for 72 h and in presence of proteolytic enzymes. The polyproline fold remained unaltered or became more prominent under the above mentioned conditions. However, it diminished gradually during thermal denaturation above 60 degrees C. Thermal transition studies by differential scanning calorimetry (DSC) showed scan rate dependence as well as irreversibility of denaturation, the properties characteristic of kinetically stable proteins. This is the first report of PPII helix being the global conformation of a non structural protein, an alkaline serine protease, from a microbial source, imparting kinetic stability to the protein. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Conformation; differential scanning calorimetry; Kinetic stability; Nocardiopsis sp.; Polyproline fold; Serine protease

Proline catalyzed sequential alpha-aminooxylation or -amination/reductive cyclization of o-nitrohydrocinnamaldehydes: a high yield synthesis of chiral 3-substituted tetrahydroquinolines - Rawat, Varun; Kumar, B. Senthil; Sudalai, Arumugam (Organic & Biomolecular Chemistry, 2013)
A new sequential organocatalytic method for the synthesis of chiral 3-substituted (X = OH, NH2) tetrahydroquinoline derivatives (THQs) [ee up to 99%, yield up to 87%] based on alpha-aminooxylation or -amination followed by reductive cyclization of o-nitrohydrocinnamaldehydes has been described. This methodology has been efficiently demonstrated in the synthesis of two important bioactive molecules namely (-)-sumanirole (96% ee) and 1-[(S)-3-(dimethylamino)-3,4-dihydro-6,7-dimethoxy-quinolin-1(2H)-yl]- propanone (92% ee).

Rationally designed CuFe2O4-mesoporous Al2O3 composite towards stable performance of high temperature water-gas shift reaction - Subramanian, Vijayanand; Gnanakumar, Edwin S.; Jeong, Dae-Woon; Han, Won-Bi; Gopinath, Chinnakonda S.; Roh, Hyun-Seog (Chemical Communications, 2013)
High temperature water-gas shift reaction was demonstrated for the first time on a CuFe2O4-mesoporous alumina nanocomposite between 350 and 550 degrees C with 70-80% CO-conversion using simulated waste derived syngas under realistic conditions. Despite high Al-content, the catalyst exhibited stable activity, which was attributed to the nano-architectured robust porous nature of alumina integrated with surrounding CuFe2O4.

Reactivity of thiophenes, oligothiophenes and benzothiophenes - Rajappa, Srinivasachari; Gumaste, Vikas K. (Advances in Heterocyclic Chemistry, 2013)
This article surveys the literature on the reactivity of thiophenes and benzothiophenes published since the appearance of the third edition of Comprehensive Heterocyclic Chemistry. Two areas that have received maximum attention are: (1) homo- and cross-coupling reactions leading to C C bond formation with high site selectivity and under mild reaction conditions, as well as the regioselective introduction of heteroatom substituents and (2) dithienylethenes and their symmetry-allowed photocyclized isomers, with special reference to the use of this photochromic system as photoswitching units.
Keywords: Benzothiophenes and oligothiophenes; Newer results on the reactivity of thiophenes; Pericyclic reactions; Transition metal-catalyzed bond formation

Response to the comments on `Investigations on Ru doped ZnO: strain calculations and gas sensing study' - Navale, Shalaka C.; Ravi, V.; Mulla, Imtiaz S. (Sensors and Actuators B-Chemical, 2013)

Rhenium(I) tricarbonyl complex of 5,20-bis(p-tolyl)-10,15-bis(p-methoxyphenyl)-21-selenaporphyrin: first X-ray structural characterization of metal complex of 21-selenaporphyrin - Ghosh, Avijit; Gonnade, Rajesh G.; Ravikanth, Mangalampalli (Dalton Transactions, 2013)
Synthesis and first structural characterization of hexa coordinated rhenium(I)tricarbonyl complex of 5,20-bis( p-tolyl)-10,15-bis(p-methoxyphenyl)-21-selenaporphyrin 3 are described. The Re(I)complex of 21-selenaporphyrin 3 was synthesized by treating free base 21-selenaporphyrin in 1,2-dichlorobenzene with Re(CO)(5)Cl at reflux for 7 h and analyzed using mass, NMR, FT-IR, UV-vis and electrochemical techniques. The first structure of metal complex of 21-selenaporphyrin was determined by X-ray single crystal analysis. The crystal structure revealed that the Re(CO)(3) coordinates to two of the three inner nitrogens and one selenium to produce compound 3. The selenophene ring bent towards the Re(I)ion and the selenium is displaced by 0.41 angstrom from the mean plane of 24-atoms to coordinate with Re(I)ion in eta(1)-fashion. The 21-selenaporphyrin is distorted in compound 3 compared to free base 21-selenaporphyrin. H-1 and C-13 NMR studies indicated that compound 3 exhibits fluxional behaviour in coordination mode of binding in solution. The compound 3 is highly stable and does not undergo decomplexation under acidic conditions. The absorption spectra showed three broad Q-bands and splitted Soret band and electrochemical studies indicated that compound 3 is stable under redox conditions.

Sensing behavior of atomically thin-layered MoS2 transistors - Late, Dattatray J.; Huang, Yi-Kai; Liu, Bin; Acharya, Jagaran; Shirodkar, Sharmila N.; Luo, Jiajun; Yan, Aiming; Charles, Daniel; Waghmare, Umesh V.; Dravid, Vinayak P.; Rao, C. N. R. (ACS Nano, 2013)
Most of recent research on layered chalcogenides is understandably focused on single atomic layers. However, it is unclear if single-layer units are the most ideal structures for enhanced gas solid interactions. To probe this issue further, we have prepared large-area MoS2 sheets ranging from single to multiple layers on 300 nm SiO2/Si substrates using the micromechanical exfoliation method. The thickness and layering of the sheets were identified by optical microscope, invoking recently reported specific optical color contrast, and further confirmed by AFM and Raman spectroscopy. The MoS2 transistors with different thicknesses were assessed for gas-sensing performances with exposure to NO2, NH3, and humidity in different conditions such as gate bias and light Irradiation. The results show that, compared to the single-layer counterpart, transistors of few MoS2 layers exhibit excellent sensitivity, recovery, and ability to be manipulated by gate bias and green light. Further, our ab initio DFT calculations on single-layer and bilayer MoS2 show that the charge transfer is the reason for the decrease in resistance in the presence of applied field.

Single pot conversion of furfuryl alcohol to levulinic esters and gamma-valerolactone in the presence of sulfonic acid functionalized ILs and metal catalysts - Hengne, Amol M.; Kamble, Sumit B.; Rode, Chandrashekhar V. (Green Chemistry, 2013)
Ionic liquids functionalized with acidic anions, HSO4, ClSO3H, PTSA, TFA (MIm), HSO4 and TFA (NMP) were found to efficiently (99% conversion) catalyze the alcoholysis of furfuryl alcohol (FAL) in the presence of methanol, ethanol, n-butanol and isopropyl alcohol (IPA) to the corresponding levulinic acid esters under mild temperature (90-130 degrees C) conditions. The extended alkyl chain length of [MIm] using 1,4-butane sultone enhanced the Bronsted acidity of [BMIm-SH][HSO4] catalyst resulting into the highest selectivity of >95% to Me-LA. An increase in both temperature and catalyst concentration increased the furfuryl alcohol conversion and selectivity to levulinate esters. In contrast, an increase in the substrate concentration from 5 to 15% caused a decrease in Me-LA selectivity due to accumulation of intermediate ethers of furfuryl alcohol. Using a combination of [BMIm-SH][HSO4] and 5% Ru/C catalyst, direct conversion of FAL to gamma-valerolactone (GVL) is shown for the first time. A complete conversion of FAL with the highest selectivity of 68% to GVL could be achieved under optimum conditions while higher Ru loading enhanced the GVL selectivity to 94% in the hydrogenation step of this tandem approach. Our catalyst system could be efficiently recycled five times retaining the original activity and selectivity levels.

Structural and catalytic properties of a novel vanadium containing solid core mesoporous silica shell catalysts for gas phase oxidation reaction - Venkatathri, N.; Pillai, Vijayamohanan K.; Rajini, A.; Raju, M. Nooka; Reddy, I. A. K. (Journal of Chemical Sciences, 2013)
A novel vanadium containing solid core mesoporous silica shell catalyst was synthesized with different Si/V ratios by sol-gel method under neutral conditions. The synthesized materials were characterized by various techniques and gas phase diphenyl methane oxidation reaction. The mesoporosity combined with microporosity are formed by incorporation of octadecyltrichloro silane and triethylamine in the catalyst and it was found out from E-DAX and BET-surface area analysis. The material was found to be nanocrystalline. Vanadium is present as V4 + species in as-synthesized samples and convert to V5 + on calcination. Most of the vanadium is present in tetrahedral or square pyramidal environment. Incorporation of vanadium in silica framework was confirmed by Si-29 MAS NMR analysis. Among the various vanadium containing solid core mesoporous silica shell catalysts, the Si/V = 100 ratio exhibited maximum efficiency towards diphenyl methane to benzophenone gas phase reaction. The optimum condition required for maximum conversion and selectivity was found out from the catalytic studies.
Keywords: diphenylmethane; Gas phase oxidation; vanadium containing solid core mesoporous silica shell

Structural and dynamical properties of polyethylenimine in explicit water at different protonation states: a molecular dynamics study - Choudhury, Chandan Kumar; Roy, Sudip (Soft Matter, 2013)
PEI is a pH sensitive polymer which acts as a proton sponge in acidic conditions. Despite many experimental and theoretical efforts, a fundamental understanding of the structure and dynamics of linear PEI chains on the atomistic level at different protonation states in dilute solutions remains a topic of discussion. This report analyses the structural properties of PEI at different protonation states, which are representative of different pH, using all atomistic molecular dynamic simulations. The structural properties revealed that the polymer at high pH (basic medium) is highly coiled, while at low pH (strong acidic conditions) the chains are elongated. We studied the dynamics and ordering of water molecules that are part of the solvation shells of the PEI chains at different protonation states. We observe that the water molecules are ordered along the polymer backbone for a completely protonated PEI chain (i.e. in the case of acidic pH) and hop to the neighbouring solvation shell. The residence time and the self-diffusion of water molecules in the solvation shells and their activation barriers were also calculated and analysed further. We concluded the study by correlating the solvation shell water dynamics and the structure of the PEI chain at different protonation states.

Structural modelling of substrate binding and inhibition in penicillin V acylase from pectobacterium atrosepticum - Avinash, Vellore Sunder; Panigrahi, Priyabrata; Suresh, C. G.; Pundle, Archana V.; Ramasamy, Sureshkumar (Biochemical and Biophysical Research Communications, 2013)
Penicillin V acylases (PVAs) and bile salt hydrolases (BSHs) have considerable sequence and structural similarity; however, they vary significantly in their substrate specificity. We have identified a PVA from a Gram-negative organism, Pectobacterium atrosepticum (PaPVA) that turned out to be a remote homolog of the PVAs and BSHs reported earlier. Even though the active site residues were conserved in PaPVA it showed high specificity towards penV and interestingly the penV acylase activity was inhibited by bile salts. Comparative modelling and docking studies were carried out to understand the structural differences of the binding site that confer this characteristic property. We show that PaPVA exhibits significant differences in structure, which are in contrast to those of known PVAs and such enzymes from Gram-negative bacteria require further investigation. (C) 2013 Elsevier Inc. All rights reserved.
Keywords: Bile salt hydrolase; docking; Homology modelling; Inhibition; Pectobacterium; Penicillin acylase

Structure-property relationship of different types of polyester industrial yarns - Samui, Barun Kumar; Prakasan, Manikanda Priya; Ramesh, C.; Chakrabarty, Debabrata; Mukhopadhyay, R. (Journal of the Textile Institute, 2013)
Four major types of polyester industrial yarns (1000 Denier) which are used commercially were studied for their key structural parameters. An attempt has been made to establish a relationship between morphology and properties of these yarns. High tenacity (HT) polyester yarn has the highest birefringence, amorphous orientation, and long period but is relatively less crystalline. High shrinkage characteristic of HT polyester yarn can be accounted for its higher amorphous orientation. High modulus low shrinkage (HMLS) polyester yarn has higher crystallinity and crystal size compared to HT yarn. Fraction of tie molecules of these yarns has been calculated and found that low shrinkage (LS) and super low shrinkage (SLS) yarns have lesser tie molecules. These LS and SLS yarns are tailor-made to achieve lower shrinkage and at the same time maintaining a good level of tenacity. This is achieved with lower amorphous orientation in the final drawn yarn structure. Amorphous orientation was found to have stronger influence than any other structural parameter on the key yarn properties like modulus, tenacity, elongation, and shrinkage.
Keywords: modulus; orientation; polyester; shrinkage; structure

Studies on fabrication, characterization, and metal extraction using metal chelating nonwoven nanofiber mats of poly(vinyl alcohol) and sodium alginate blends - Rathna, G. V. N.; Birajdar, Mallinath S.; Bhagwani, Manish; Paul, V. L. (Polymer Engineering and Science, 2013)
Poly(vinyl alcohol) and sodium alginate blends with and without the metal chelate, bis(2,4,4-trimethylpentyl)phosphinic acid were prepared in various compositions and fabricated to stable nanofibers and films to evaluate their efficacy for metals adsorption and desorption. Surface morphology of the nanofibers was characterized by scanning electron microscopy. The solution properties and variation in content of sodium alginate in the feed mixture have influenced morphology of nanofibers. However, influence of bis(2,4,4-trimethylpentyl)phosphinic acid was insignificant. The films and nanofibers were characterized using Fourier transform infrared spectroscopy, differential scanning calorimetry, thermo gravimetric analysis, and X-ray diffraction to understand compatibility between polymers, thermal stability, decomposition temperature, and variations in crystallinity. Metal adsorption studies for nanofiber mats comprising bis(2,4,4-trimethylpentyl)phosphinic acid were demonstrated using copper (II), cobalt(II), and nickel(II) salts. The nanofibers adsorbed more copper (363 mg/g) when compared with films (105 mg/g). Nanofiber mats immobilized with bis(2,4,4-trimethylpentyl)phosphinic acid adsorbed copper in greater magnitude (497 mg/g) than nanofiber mats without bis(2,4,4-trimethylpentyl)phosphinic acid (363 mg/g). However, adsorption of cobalt and nickel was very low to be detected. The metal adsorption and desorption studies were also confirmed by energy dispersive X-ray spectroscopy. POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers

Superior field emission properties of layered WS2-RGO nanocomposites - Rout, Chandra Sekhar; Joshi, Padmashree D.; Kashid, Ranjit V.; Joag, Dilip S.; More, Mahendra A.; Simbeck, Adam J.; Washington, Morris; Nayak, Saroj K.; Late, Dattatray J. (Scientific Reports, 2013)
We report here the field emission studies of a layered WS2-RGO composite at the base pressure of similar to 1 x 10(-8) mbar. The turn on field required to draw a field emission current density of 1 mu A/cm(2) is found to be 3.5, 2.3 and 2 V/mu m for WS2, RGO and the WS2-RGO composite respectively. The enhanced field emission behavior observed for the WS2-RGO nanocomposite is attributed to a high field enhancement factor of 2978, which is associated with the surface protrusions of the single-to-few layer thick sheets of the nanocomposite. The highest current density of similar to 800 mu A/cm(2) is drawn at an applied field of 4.1 V/mu m from a few layers of the WS2-RGO nanocomposite. Furthermore, first-principles density functional calculations suggest that the enhanced field emission may also be due to an overalp of the electronic structures of WS2 and RGO, where graphene-like states are dumped in the region of the WS2 fundamental gap.

Supramolecular nanoparticles that target phosphoinositide-3-kinase overcome insulin resistance and exert pronounced antitumor efficacy - Kulkarni, Ashish A.; Roy, Bhaskar; Rao, Poornima S.; Wyant, Gregory A.; Mahmoud, Ayaat; Ramachandran, Madhumitha; Sengupta, Poulomi; Goldman, Aaron; Kotamraju, Venkata Ramana; Basu, Sudipta; Mashelkar, Raghunath Anant; Ruoslahti, Erkki; et al. (Cancer Research, 2013)
The centrality of phosphoinositide-3-kinase (PI3K) in cancer etiology is well established, but clinical translation of PI3K inhibitors has been limited by feedback signaling, suboptimal intratumoral concentration, and an insulin resistance ``class effect.'' This study was designed to explore the use of supramolecular nanochemistry for targeting PI3K to enhance antitumor efficacy and potentially overcome these limitations. PI3K inhibitor structures were rationally modified using a cholesterol-based derivative, facilitating supramolecular nanoassembly with L-alpha-phosphatidylcholine and DSPE-PEG [1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polythylen e glycol)]. The supramolecular nanoparticles (SNP) that were assembled were physicochemically characterized and functionally evaluated in vitro. Antitumor efficacy was quantified in vivo using 4T1 breast cancer and K-Ras(LSL/+)/Pten(fl/fl) ovarian cancer models, with effects on glucose homeostasis evaluated using an insulin sensitivity test. The use of PI103 and PI828 as surrogate molecules to engineer the SNPs highlighted the need to keep design principles in perspective; specifically, potency of the active molecule and the linker chemistry were critical principles for efficacy, similar to antibody-drug conjugates. We found that the SNPs exerted a temporally sustained inhibition of phosphorylation of Akt, mTOR, S6K, and 4EBP in vivo. These effects were associated with increased antitumor efficacy and survival as compared with PI103 and PI828. Efficacy was further increased by decorating the nanoparticle surface with tumor-homing peptides. Notably, the use of SNPs abrogated the insulin resistance that has been associated widely with other PI3K inhibitors. This study provides a preclinical foundation for the use of supramolecular nanochemistry to overcome current challenges associated with PI3K inhibitors, offering a paradigm for extension to other molecularly targeted therapeutics being explored for cancer treatment. (C)2013 AACR.

Switching the H-bonding network of a foldamer by modulating the backbone chirality and constitutional ratio of amino acids - Ramesh, Veera V. E.; Vijayadas, Kuruppanthara N.; Dhokale, Snehal A.; Gonnade, Rajesh G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Organic & Biomolecular Chemistry, 2013)
This communication describes the folding propensity of a hetero-foldamer motif featuring proline (Pro) and anthranilic acid (Ant) residues in a 1:2:1 (alpha: beta: alpha) constitutional ratio. Structural investigations unequivocally suggest that the hydrogen-bonding network of this foldamer motif can be switched between 9-membered and 6-membered by modulating the backbone chirality and constitutional ratio of the amino acid residues.

Synergetic effect of combination of AOP's (hydrodynamic cavitation and H2O2) on the degradation of neonicotinoid class of insecticide - Raut-Jadhav, Sunita; Saharan, Virendra Kumar; Pinjari, Dipak; Sonawane, Shirish; Saini, Daulat; Pandit, Aniruddha (Journal of Hazardous Materials, 2013)
In the present work, degradation of imidacloprid (neonicotinoid class of insecticide) in aqueous solution has been systematically investigated using hydrodynamic cavitation and combination of hydrodynamic cavitation (HC) and H2O2. Initially, effect of different operating parameters such as inlet pressure to the cavitating device (5-20 bar) and operating pH (2-7.5) has been investigated. Optimization of process parameters was followed by the study of effect of combination of HC and H2O2 process on the rate of degradation of imidacloprid. Significant enhancement in the rate of degradation of imidacloprid has been observed using HC+H2O2 process which lead to a complete degradation of imidacloprid in 45 min of operation using optimal molar ratio of imidacloprid:H2O2 as 1:40. Substantial synergetic effect has been observed using HC+H2O2 process which confer the synergetic coefficient of 22.79. An attempt has been made to investigate and compare the energy efficiency and extent of mineralization of individual and combined processes applied in the present work. Identification of the byproducts formed during degradation of imidacloprid has also been done using LC-MS analysis. The present work has established a fact that hydrodynamic cavitation in combination with H2O2 can be effectively used for degradation of imidacloprid. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Advanced oxidation processes; Hydrodynamic cavitation; Imidacloprid; Synergetic coefficient; Venturi

Synergistic mechanical response of Nylon 6/Trogamid (R) T blends - Ridhore, Amol; Jog, Jyoti Prakash (Journal of Applied Polymer Science, 2013)
Blends of semicrystalline Nylon 6 with a varying ratios of amorphous Nylon are studied for their morphological, thermal, dielectric, and mechanical behavior. Thermal analysis indicated a compositional dependant decrease in the melting and crystallization temperatures of Nylon 6. The blends exhibited a single compositional dependant glass transition temperature in dynamic mechanical thermal analysis and dielectrical relaxation spectroscopy over entire mixing ratio indicating miscibility between the blend components. The values of flexural modulus and tensile modulus of the blends are found to increase without significant loss in the impact properties. The water absorption of the blends is also lower than the values calculated by rule of mixtures. The observed synergistic behavior of the mechanical properties of the blends is indicative of presence of strong interactions in the blends components. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Keywords: blends; dielectric properties; mechanical properties; polyamides; Thermal properties

Syntheses and determination of absolute configurations and biological activities of the enantiomers of the longtailed mealybug pheromone - Ramesh, Remya; Swaroop, Pandrangi Siva; Gonnade, Rajesh G.; Thirupath, Choppari; Waterworth, Rebeccah A.; Millar, Jocelyn G.; Reddy, D. Srinivasa (Journal of Organic Chemistry, 2013)
Preparation and assignment of absolute configurations to both enantiomers of the sex pheromone of the longtailed mealybug, an irregular monoterpenoid with extraordinary biological activity, has been completed. Comparison of the biological activities of both enantiomers and the racemate in field trials showed that the (S)-(+)-enantiomer was highly attractive to male mealybugs, strongly suggesting that female longtailed mealybugs produce this enantiomer. The (R)-(-)-enantiomer was benign, being neither attractive nor inhibitory.

Synthesis of 3,5-Bis(acrylaldehyde) boron-dipyrromethene and application in detection of cysteine and homocysteine in living cells - Madhu, Sheri; Gonnade, Rajesh G.; Ravikanth, Mangalampalli (Journal Of Organic Chemistry, 2013)
Synthesis, characterization, and spectral and electrochemical properties of 3,5-bis(acrylaldehyde) BODIPY are described. The compound exhibited higher selectivity toward cysteine/homocysteine than toward other amino acids and thiol-containing compounds as shown by absorption and emission titration experiments and by experiments in living cells.

Synthesis of a sex pheromone of the longtailed mealybug, pseudococcus longispinus - Kurhade, Suresh E.; Siddaiah, V.; Bhuniya, Debnath; Reddy, D. Srinivasa (Synthesis-Stuttgart, 2013)
The synthesis of a recently identified and highly active sex pheromone of the longtailed mealybug, Pseudococcus longispinus is reported. A concise synthetic route, use of the under explored Meyer-Schuster rearrangement, Claisen rearrangement, and ring-closing metathesis are the highlights of this work.
Keywords: Acylation; Metathesis; pheromones; rearrangement; Total synthesis

Synthesis of Ag-glyconanoparticles using C-glycosides, their lectin binding studies and antibacterial activity - Ramtenki, Vilas; Raju, D.; Mehta, Urmil J.; Ramana, C. V.; Bhagavatula L. V. Prasad (New Journal of Chemistry, 2013)
Two 12-C-glycosyl dodecanoic acids, namely, 1-(alpha-D-mannopyranosyl)-12-dodecanoic acid and 1-(alpha-D-glucopyranosyl)-12-dodecanoic acid were synthesized. Their ability to act as reducing and capping agents for the synthesis of water re-dispersible silver nanoparticles is displayed. These Ag C-glycosyl nanoparticles were later utilized to investigate the carbohydrate-lectin interactions. Furthermore, the specificity of mannoside binding to the surface of the Gram negative bacterium Escherichia coli has been utilized to demonstrate the enhanced antibacterial activity of Ag-C-mannosyl nanoparticles towards this bacterium as compared to Ag-C-glycosyl nanoparticles.

Synthesis of C(27)–C(38) fragment of aflastatin A - Narute, Sachin B.; Ramana, C.V. (Tetrahedron, 2013)
Efforts at finding out a strategy for the synthesis of the densely hydroxylated C(27)–C(48) fragment of aflastatin A have been described. The initial studies dealing with alkyne–epoxide coupling using a linear polyol epoxide resulted in a debenzylative cycloetherification leading to a C-arabinoside derivative. This problem has been addressed by applying an epoxide pendant on a furanosyl unit. With the model alkyne, the epoxide–alkyne coupling proceeded smoothly. Subsequently, following a sequence of [Pd]-mediated alkynone cycloisomerization/stereoselective hydroboration–oxidation, the synthesis of the central C(27)–C(38) fragment has been executed. When employed, the original C(33)–C(48) alkyne, the coupling and the cycloisomerizations are facile. However, the resulting glycals are unstable, thus warranting a revision in our approach.
Keywords: Aflastatin; Epoxide–alkyne coupling; ω-Alkynone cycloisomerization; Palladium catalysis; Hydroboration

Synthesis of C-disaccharides through a one-pot alkynol cycloisomerization-reductive deoxygenation - Narute, Sachin B.; Rout, Jeetendra Kumar; Ramana, Chepuri V. (Chemistry-A European Journal, 2013)
Keywords: C-disaccharides; carbohydrates; Epoxide-alkyne coupling; Gold catalysis; Reductive deoxygenation

Synthesis of low coercive BaFe12O19 hexaferrite for microwave applications in low-temperature cofired ceramic - Rane, Vivek A.; Meena, Sher Singh; Gokhale, Suresh P.; Yusuf, S. M.; Phatak, Girish J.; Date, Sadgopal K. (Journal of Electronic Materials, 2013)
Polycrystalline M-type barium hexaferrite (BaFe12O19) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe12O19 were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mossbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe12O19, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mossbauer spectra illustrate the existence of Fe3+ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800A degrees C to 1200A degrees C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (> 10(9) Omega-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed.
Keywords: Barium hexaferrite; coercivity; LTCC; Mossbauer spectroscopy; Raman spectroscopy

Synthesis of palmyrolide A and its cis-isomer and mechanistic insight into trans-cis isomerisation of the enamide macrocycle - Philkhana, Satish Chandra; Seetharamsingh, B.; Dangat, Yuvraj B.; Vanka, Kumar; Reddy, D. Srinivasa (Chemical Communications, 2013)
Concise and protecting-group free synthesis of ent-palmyrolide A and (-)-cis-palmyrolide A were achieved starting from commercially available (S)-citronellal. The key fragment of palmyrolide A, ``(5S,7S)-7-hydroxy-5,8,8-trimethylnonanamide'', which makes up the most challenging part of the target molecule, was prepared in just three steps. A plausible mechanism for the trans-cis isomerization of the double bond in the macrocycle has been investigated.

Synthesis of pseudo-indoxyl derivatives via sequential Cu-catalyzed SNAr and Smalley cyclization - Goriya, Yogesh; Ramana, Chepuri V. (Chemical Communications, 2013)
ortho-Bromophenyl sec-alkyl/sec-alkenyl ketones, on reaction with sodium azide in the presence of copper salts, undergo sequential SNAr followed by Smalley cyclization to provide pseudo-indoxyl derivatives. Some of these pseudo-indoxyl derivatives exhibit interesting fluorescent properties and broad Stokes shifts.

Synthetic zipper peptide motif orchestrated via co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality - Nair, Roshna V.; Kheria, Sanjeev; Rayavarapu, Suresh; Kotmale, Amol S.; Jagadeesh, Bharatam; Gonnade, Rajesh G.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Journal of the American Chemical Society, 2013)
Here, we report on a new class of synthetic zipper peptide which assumes its three-dimensional zipper-like structure via a co-operative interplay of hydrogen bonding, aromatic stacking, and backbone chirality. Structural studies carried out in both solid- and solution-state confirmed the zipper-like structural architecture assumed by the synthetic peptide which makes use of unusually remote inter-residual hydrogen-bonding and aromatic stacking interactions to attain its shape. The effect of chirality modulation and the extent of noncovalent forces in the structure stabilization have also been comprehensively explored via single-crystal X-ray diffraction and solution-state NMR studies. The results highlight the utility of noncovalent forces in engineering complex synthetic molecules with intriguing structural architectures.

Target cum flexibility: simple access to benzofuran conjugated sugar and nucleoside derivatives - Kommagalla, Yadagiri; Srinivas, Kolluru; Ramana, C. V. (Tetrahedron Letters, 2013)
The [Pd]-catalyzed domino process comprising of the coupling of alkynes and o-iodophenol and the subsequent cyclization leading to benzofurans has been successfully applied on the sugar and nucleoside derived alkynes. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: Benzofuran; carbohydrates; cyclization; Nucleoside; Palladium

Tetrazine templated method for the synthesis of ternary conjugates - Rao, Boddu Venkateswara; Dhokale, Snehal A.; Rajamohanan, Pattuparambil R.; Hotha, Srinivas (Chemical Communications, 2013)
Conjugation is an important reaction that enables coupling of molecules. Many protocols exist for the synthesis of binary conjugates from two different molecules or for the polyvalent display of a singlemolecule. There aren'tmanymethods for the synthesis of ternary conjugates. However, methods for ternary conjugation are important for understanding the interplay of interactions between three biomolecules (or any three molecules per se). A strategy for ternary bioconjugation using inverse electron demand Diels-Alder reaction with tetrazine is studied. Ternary conjugation was demonstrated by the reaction of a model glyco-peptide binary conjugate with a fluorescent tagged olefin.

Transition-metal-free multicomponent reactions involving arynes, N-heterocycles, and isatins - Bhunia, Anup; Roy, Tony; Pachfule, Pradip; Rajamohanan, Pattuparambil R.; Biju, Akkattu T. (Angewandte Chemie-International Edition, 2013)
Mix and match: With isoquinoline as the nucleophilic trigger, multicomponent reactions afforded spirooxazino isoquinoline derivatives, proceeding through 1,4-dipolar intermediates. The use of pyridine as a nucleophile furnished indolin-2-one derivatives, with the reaction likely proceeding through a pyridylidene intermediate.

Triazole-linked anthracenyl-appended calix[4]arene conjugate as receptor for Co(II): synthesis, spectroscopy, microscopy, and computational studies - Mummidivarapu, V. V. Sreenivasu; Hinge, Vijaya Kumar; Tabbasum, Khatija; Gonnade, Rajesh G.; Rao, Chebrolu P. (Journal of Organic Chemistry, 2013)
A new triazole-linked anthracenyl-appended calix[4]arene-1,3-diconjugate (L) has been synthesized and characterized, and its single crystal XRD structure has been established. Binding properties of L toward different biologically relevant metal ions have been studied by fluorescence and absorption spectroscopy in ethanol. L exhibits selective recognition of Co2+ and can detect down to a concentration of 55 ppb (0.92 mu M). The roles of the calix[4]arene platform as well as the preorganized binding core in L's selective recognition have been demonstrated by studying appropriate control molecules. The mode of binding of L with Co2+ has been modeled both by DFT and MD computational calculations. L and its Co2+ complex could be differentiated on the basis of the nanostructural features observed in AFM and TEM.

Two-phase flow boiling in small channels: a brief review - Sardeshpande, Madhavi V.; Ranade, Vivek V. (Sadhana-Academy Proceedings in Engineering Sciences, 2013)
Boiling flows are encountered in a wide range of industrial applications such as boilers, core and steam generators in nuclear reactors, petroleum transportation, electronic cooling and various types of chemical reactors. Many of these applications involve boiling flows in conventional channels (channel size >= 3 mm). The key design issues in two phase flow boiling are variation in flow regimes, occurrence of dry out condition, flow instabilities, and understanding of heat transfer coefficient and vapor quality. This paper briefly reviews published experimental and modeling work in these areas. An attempt is made to provide a perspective and to present available information on boiling in small channels in terms of channel size, flow regimes, heat transfer correlations, pressure drop, critical heat flux and film thickness. An attempt is also made to identify strengths and weaknesses of published approaches and computational models of boiling in small channels. The presented discussion and results will provide an update on the state-of-the-art and will be useful to identify and plan further research in this important area.
Keywords: Boiling; dry-out; heat transfer; instabilities; small channel; two-phase flow

1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU): a highly efficient catalyst in glycerol carbonate synthesis - Munshi, Mudassir K.; Gade, Swapna M.; Mane, Manoj V.; Mishra, Deepti; Pal, Sourav; Vanka, Kumar; Rane, Vilas H.; Kelkar, Ashutosh A. (Journal of Molecular Catalysis A-Chemical, 2014)
Transesterification of dimethyl carbonate (DMC) with glycerol (GLY) was investigated using various amines as catalysts. Amidines like 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) were found to be the best catalysts for this reaction. Best results: 98% conversion of GLY with 96% selectivity to GC (TON: 9408), were obtained with DBU as a catalyst. Effect of various reaction conditions on activity and selectivity were investigated using DBU as catalyst. The mechanism of the reaction was investigated with the help of H-1, C-13 and N-15 NMR analysis and OFT calculations. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: DBU; Glycerol; Glycerol carbonate; transesterification

2-Aroylindoles from o-bromochalcones via Cu(I)-catalyzed SNAr with an azide and intramolecular nitrene C-H insertion - Goriya, Yogesh; Ramana, Chepuri V. (Chemical Communications, 2014)
A simple procedure for the synthesis of 2-aroylindole derivatives comprising a one-pot CuI-catalyzed SNAr reaction of o-bromochalconeswith sodium azide and subsequent intramolecular cyclization through nitrene C-H insertion has been developed. This protocol is also applicablewith the 2'-bromocinnamates giving the indole-2-carboxylates.

3D flow reactors: flow, hydrodynamics, and performance - Sharma, Mrityunjay; Reddy, Venkateswara S.; Kulkarni, Amol A. (Industrial & Engineering Chemistry Research, 2014)
A device comprised of a sequence of converging or diverging units aligned either in an axisymmetric or nonaxisymmetric manner can be used as a continuous flow reactor. Here we report the analysis of flow and hydrodynamics (pressure drop, residence time distribution, and mass transfer) for an axisymmetric geometry of a 3D flow reactor for single phase and two-phase flows. CFD simulations of the single phase flow have been used for identification of the precise geometrical configuration. The sequence of converging units as a flow reactor has been found to always be better than the sequence of diverging units. The residence time distribution analysis also favored the choice of converging flow as a better option. The performance of the device was verified by successfully carrying out a highly exothermic two-phase aromatic nitration of benzaldehyde (Delta H-r approximate to -172 kg/mol) with fuming nitric acid.

9-Fluorenemethanol: an internal electron donor to fine tune olefin polymerization activity - Gnanakumar, Edwin S.; Chokkapu, Eswara Rao; Kunjir, Shrikant; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Chakraborty, Debashis; Gopinath, Chinnakonda S. (Dalton Transactions, 2014)
A new MgCl2 based molecular adduct has been synthesized with 9-fluorenemethanol (9FM) as a novel internal electron donor (IED), along with ethanol (EtOH) (MgCl2 center dot n9FM center dot xEtOH). The above molecular adduct has been subjected to a variety of structural, spectroscopic and morphological characterization techniques. The results of the solid state C-13 CPMAS NMR technique suggests the coordination of 9FM to MgCl2. Observation of a low angle diffraction peak at 2 theta = 5.7 degrees (d = 15.5 angstrom) underscores the coordination of 9FM along the z-axis, and ethanol in the molecular adduct. Active Ziegler-Natta catalysts were prepared by two different synthesis methods; the conventional method to obtain a high surface area active catalyst, and other one with 9FM as an integral part of the active catalyst in order to study the influence of 9FM as an IED over the active sites. The active catalysts were also characterized thoroughly with different analytical tools. The XRD results show (003) facets of delta-MgCl2 (alpha-MgCl2) for the conventional (non-conventional) titanated catalyst. Results of the ethylene polymerization activity study reveals that the conventionally prepared highly porous active catalyst shows 1.7-2.5 times higher activity than the non-conventional prepared catalyst; however, the latter shows a low molecular weight distribution and confirms the role of the Lewis base as an IED.

Access to harmonine, a chemical weapon of ladybird beetles - Philkhana, Satish Chandra; Dhasaiyan, Prabhu; Bhagavatula L. V. Prasad; Reddy, D. Srinivasa (RSC Advances, 2014)
The synthesis of harmonine, a defense alkaloid from the harlequin ladybird is reported by three different routes. The preparation of several new analogs with the same molecular weight and the decoration of gold nanoparticles with harmonines are also part of the present communication.

Allostery mapping in enterococcus faecalis Bile Salt Hydrolase (BSH) - Yadav, Yashpal; Ramasamy, Sureshkumar (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Allostery; Bile salt hydrolase; MD Simulation

Asymmetric vinylogous mannich reaction of silyloxy furans with N-tert-butanesulfinyl ketimines - Rao, V. U. Bhaskara; Jadhav, Amol P.; Garad, Dnyaneshwar N.; Singh, Ravi P. (Organic Letter, 2014)
A highly regio- and diastereoselective TMSOTf promoted vinylogous Mannich reaction for the synthesis of chiral quaternary 3-aminooxindole butenolides from 2-silyloxy furans and chiral ketimines is described. The method is found to be very efficient and also provides a facile access to sterically challenging 3-aminooxindole butenolides bearing two quaternary centers in continuation. Further, the versatility of the method is demonstrated by the 1,4-addition of nucleophiles on the sterically congested butenolide substructure..

Bacillus enclensis sp nov., isolated from sediment sample - Dastager, Syed Gulam; Mawlankar, Rahul R.; Tang, Shan-Kun; Srinivasan, Krishnamurthi; Ramana, V. Venkata; Shouche, Yogesh S. (Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2014)
A novel bacterial strain, designated SGD-1123(T) was isolated from Chorao Island, in Goa Province, India. The strain was found to be able to grow at 15-42 A degrees C, pH 5-12 and 0-12 % (w/v) NaCl. The whole cell hydrolysates were found to contain meso-diaminopimelic acid, galactose and arabinose. The major fatty acids were identified as iso-C-15:0 and anteiso-C-15:0, MK-7 was identified as the predominant menaquinone and the predominant polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and an unidentified aminolipid. The genomic DNA G+C content was determined to be 44.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences placed the isolate within the genus Bacillus and further revealed that strain SGD-1123(T) had highest sequence similarity with Bacillus aquimaris, and forms a separate clade with its closest relatives i.e. B. aquimaris, Bacillus vietnamensis and Bacillus marisflavi, with which it shares 94.5, 94.1 and 94.1 % similarity respectively. The phylogenetic, chemotaxonomic and phenotypic analyses indicated that strain SGD-1123(T) represents a novel species within the genus Bacillus, for which the name Bacillus enclensis is proposed. The type strain is SGD-1123(T) (NCIM 5450(T)=CCTCC AB 2011125(T)).
Keywords: Bacillus sp; Marine sediment; Polyphasic

Biological synthesis of cationic gold nanoparticles and binding of plasmid DNA - Raju, D.; Vishwakarma, Rishi K.; Khan, Bashir Mohammad; Mehta, Urmil J.; Ahmad, Absar (Materials Letters, 2014)
Nanobiotechnology is the development of eco-friendly experimental processes for the synthesis of nanomaterials. The present work focuses on synthesis of cationic gold nanoparticles (C-GNPs) for biological applications, especially in gene and drug delivery studies. A biosynthesis methodology has been developed for the functionalization of gold nanoparticles to cationic nature. The synthesis of C-GNPs was done by using peanut leaf extract in the presence of cysteamine. The formed C-GNPs were characterized by using UV-visible spectroscopy (UV-vis), the particles sizes and shapes were confirmed by a Transmission electron microscope (TEM) and crystallinity of C-GNPs was characterized by diffraction. The binding of plasmid DNA on the C-GNPs was confirmed by agarose gel electrophoresis. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Biomaterials; Cationic; Nanoparticles; Plasmid DNA; synthesis; TEM

Calorimetric elucidation of ionic interactions in room temperature ionic liquid solutions - Rai, Gitanjali; Kumar, Anil (Clean Technologies and Environmental Policy, 2014)
Knowledge of thermal properties of room temperature ionic liquid (RTIL) solutions is essential in chemical process designing in addition to their application in understanding ionic interactions at molecular level. RTILs are considered to be substitutes for volatile organic compounds. While some experimental thermal data on these systems are available in a random manner, the modeling efforts to correlate enthalpy-concentration profiles of RTIL solutions are very scanty. In this review, an effort has been made to compare and discuss the experimental data of these RTIL solutions available in the literature. The readers are also made aware of the disappointing situation regarding the availability of any type of correlative models for the enthalpy-concentration data of the RTIL systems. An accurate knowledge of activity coefficients at infinite dilutions, Iyen (i) (a) acquired from thermal data will serve as inputs for the newer less polluting process designing and thus open opportunity for a cleaner environment.
Keywords: Calorimeters; Correlative models; Excess partial molar enthalpy; Room temperature ionic liquids

Chemically doped perylene diimide lamellae based field effect transistor with low operating voltage and high charge carrier mobility - Arulkashmir, Arulraj; Jain, Bhanprakash; John, Jino C.; Roy, Kanak; Krishnamoorthy, Kothandam (Chemical Communications, 2014)
Chemical doping of an electron transporter results in the formation of a radical anion containing semiconductor which showed high electron mobility (13 cm(2) V-1 s(-1)) at low operating voltage (1 V).

Chickpea Kunitz Inhibitor: a mechanistic basis for trypsin inhibition - Bendre, Ameya Dipak; Ramasamy, Sureshkumar; Suresh, C. G. (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Chickpea; Kunitz Inhibitor; Protease

Chitosan and chitosan-co-poly(epsilon-caprolactone) grafted multiwalled carbon nanotube transducers for vapor sensing - Rana, Vijay Kumar; Akhtar, Shamim; Chatterjee, Sudipta; Mishra, Satyendra; Singh, Raj Pal; Ha, Chang-Sik (Journal of Nanoscience and Nanotechnology, 2014)
Vapor sensitive transducer films consisting of chitosan grafted (CNT-CS) and chitosan-co-polycaprolactone grafted (CNT-CS-PCL) multiwalled carbon nanotubes were prepared using a spray layer-by-layer technique. The synthesized materials (CNT-CS and CNT-CS-PCL) were characterized by Fourier transform infrared spectroscopy, C-13 CP/MAS solid state nuclear magnetic resonance spectroscopy and thermogravimetric analysis. Both CNT-CS and CNT-CS-PCL transducers were analyzed for the response of volatile organic compounds and toluene vapors. The ranking of the relative resistance (A(r)) for both chitosan based transducers were as follows: toluene < chloroform < ethanol < methanol. The CNT transducer (CNT-CS) was correlated selectively with an exponential law to the inverse of Flory-Huggins interaction parameters, chi(12). Dosing the films on the interdigitated electrodes with methanol, ethanol, chloroform and toluene vapors increased the film resistance of CNT-CS but decreased the resistance of CNT-CS-PCL compared to that of the reported transducers.
Keywords: Biocompatibility; Chitosan; MWCNTs; Poly(epsilon-caprolactone); Vapour Sensing

Comparison of sodium zirconium phosphate and calcium zirconium phosphate structures for the retention of fluoride - Dey, Ambarish; Das Gupta, Amit; Basu, Debrata; Ambashta, Ritu D.; Wattal, P. K.; Kumar, Sanjiv; Body, Monique; Rajamohanan, P. R. (Journal of Radioanalytical and Nuclear Chemistry, 2014)
Fluoride anion interaction has been explored for the first time to investigate how the structure of sodium zirconium phosphate (NZP) and calcium zirconium phosphate (CZP) can be altered in its presence. Different compositions were made by adding NaF and CaF2 in CZP and NZP matrices respectively. Fluoride interaction differs with NZP and CZP structure as suggested by F-NMR data. The addition of fluoride to the NZP or CZP structure enables to stabilize the structure at a low temperature of 600-700 A degrees C under microwave conditions.
Keywords: F-NMR; Fluoride characterization; Microwave; NZP; PIGE

Confined space synthesis of fully alloyed and sinter-resistant AuPd nanoparticles encapsulated in porous silica - Samanta, Anupam; Rajesh, Thattarathody; Devi, R. Nandini (Journal of Materials Chemistry A, 2014)
Facile synthesis of highly sinter-resistant silica encapsulated Au-Pd alloy nanocatalysts with average particle size stabilized at similar to 4.5 nm even after calcination at 750 degrees C temperature is reported. The synthesis was achieved by utilizing thiol protected ultra small clusters of Au and Pd as precursors for silica encapsulation. The presence of intimate mixtures of the clusters within silica encapsulation ensures the formation of fully alloyed nanoparticles at high temperatures, at the same time controlling further growth and sintering. At optimum alloy compositions, these catalysts showed high catalytic activity for CO oxidation displaying low light-off temperatures.

Conformational modulation of peptide secondary structures using beta-aminobenzenesulfonic acid - Kale, Sangram S.; Kunjir, Shrikant M.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, P. R.; Sanjayan, Gangadhar J. (Chemical Communications, 2014)
This communication describes the influence of beta-aminobenzenesulfonic acid ((S)Ant) on the conformational preferences of hetero foldamers. The designed (Aib-(S)Ant-Aib)(n) and (Aib-(S)Ant-Pro)(n) oligomers display a well-defined folded conformation featuring intramolecular mixed hydrogen bonding (7/11) and intra-residual (6/5) H-bonding interactions, respectively.

Controlled release of antimicrobial Cephalexin drug from silica microparticles - Rao, B. V. Bhaskara; Mukherji, Ruchira; Shitre, G.; Alam, F.; Prabhune, Asmita; Kale, Sangeeta N. (Materials Science & Engineering C-Materials for Biological Applications, 2014)
Release of antimicrobial drugs in a controlled fashion for extended duration of time has been investigated for long. Such controlled-drug-releasing materials show promising applications in medicinal bandages. Along with antimicrobial agents, one could also incorporate other therapeutic drugs, to make such bandages more versatile. In this context, silica micro particles were synthesized using direct reduction method, in which the synthesis was done in the presence of Cephalexin. Cephalexin was chosen as an antimicrobial candidate. The morphological characterization shows formation of monodispersed, silica microparticles of similar to 200 nm in size. The FTIR spectroscopy shows weak interaction of the drug molecule at its hydroxide (OH) site with oxygen ions on the silica surface. Upon conjugation, the UV-vis spectroscopy shows persistence of the Cephalexin signature, especially its R group, confirming its antimicrobial activity even after conjugation. Loading studies reveal 12% Cephalexin loading on silica. The antimicrobial studies were done on three micro-organisms, namely, Staphylococcus aureus, Bacillus subtilis and Escherichia coli. Using zone-of-inhibition studies, it was found that E. coli, did not respond to the delivery of Cephalexin either directly or via microparticles. However, for both S. aureus and B. subtilis, the particles showed controlled release of Cephalexin for the duration of 48 h and continued maintenance and even increase in the zone of inhibition. This work demonstrates an effective protocol to prepare antimicrobial patches for controlled drug delivery. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Antimicrobial; Medicinal bandage; Silica microparticles; sustained drug release

Crystal shape evolution using polyhedral population balance - Shaikh, Latif J.; Ranade, Vivek V.; Pandit, Aniruddha B. (Industrial & Engineering Chemistry Research, 2014)
Research on crystal morphology covers shape evolution of single crystal and evolution of the size and shape distribution of populations of crystals. The population balance models have been used for the single or multiple dimensions for predicting the evolution of crystal size distributions (CSDs). More often than not these models do not consider the change in solute concentration due to disappearance/appearance of the crystal faces and therefore compromise rigorous mass balance. The present work focuses on the methodology for the morphological evolution of crystal shape using a polyhedral population balance model. This methodology is based on the morphodrome which illustrates the shapes of crystals at various operating conditions. gPROMS software (PSE, UK) along with Microsoft Excel is used to devise the framework for predicting the crystal shape evolution. The developed approach and models can be implemented for various crystallization systems and will be useful for simulating crystal shape evolutions.

Crystal structure of AtGet3 Delta L, a chloroplast Get3 from Arabidopsis thaliana - Manu, M. S.; Ramasamy, Sureshkumar (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Arabidopsis thaliana; Get3; protein targeting

Cu(II) conjugation along the transformation of a vitamin K-3 derivative to a dinaphthoquinone methide radical - Badave, Kirti D.; Patil, Shalaka S.; Khan, Ayesha A.; Srinivas, Darbha; Butcher, Raymond J.; Gonnade, Rajesh G.; Puranik, Vedavati G.; Pinjari, Rahul V.; Gejji, Shridhar P.; Rane, Sandhya Y. (New Journal of Chemistry, 2014)
1,1'-Methide-bi-vitamin K-3 (B) has been isolated as a dinaphthoquinone methide radical (DNQM) by the transformation of 1-imino(acetylhydrazino)-vitamin K-3 (A). The transformation follows a biomimetic activation pathway mediated via Cu(II) ion catalyzed oxidative coupling. Single crystal X-ray and electron spin resonance (ESR) experiments combined with density functional calculations elucidate the ``resonance structure'' of the DNQM radical (B). Fluorescence investigations reveal that DNQM facilitates interaction with the cysteine residue. As compared to the parent substrate, B shows a depletion in the level of GSH, triggering apoptosis in HeLa cells.

Culturable bacterial phylogeny from a shallow water hydrothermal vent of espalamaca (Faial, Azores) reveals a variety of novel taxa - Rajasabapathy, Raju; Mohandass, Chellandi; Colaco, Ana; Dastager, Syed Gulam; Santos, Ricardo Serrao; Meena, Ram Murti (Current Science, 2014)
Phylogenetic diversity of the 16S rRNA gene associated with the domain bacteria was examined at the level of operational taxonomic units (OTUs) using the rarefaction analysis from a newly identified shallow water hydrothermal vent, Espalamaca in the Azorean Island Faial (Horta), North Atlantic Ocean. Diluted sea water nutrient agar amended with metals manganese, lead, iron and element sulphur, could help in retrieving highest OTUs (95) from the vent and 39 OTUs from nonvent. Molecular tools implemented on bacterial census indicated the occupancy of gamma-Proteobacteria by 55.78%, alpha-Proteobacteria by 21.05% and 12.63% of Bacteroidetes in the total population. Occurrence of novel species maximized with alpha-Proteobacteria (11/20) followed by Bacteroidetes (5/12) signified the necessity of studying these groups to strengthen the biodiversity database. Shannon index (H') and the Chao I richness estimator illustrated a strong bacterial community in the venting area. The current study confers many bacterial genera which were not reported earlier in any of the shallow water vents and adds 33 new taxa to the database.
Keywords: Bacterial phylogeny; metals; novel taxa; rarefaction analysis; shallow vent

Design and engineering of organic molecules for customizable terahertz tags - Ray, Shaumik; Dash, Jyotirmayee; Nallappan, Kathirvel; Kaware, Vaibhav; Basutkar, Nitin; Ambade, Ashootosh; Joshi, Kavita; Pesala, Bala (Terahertz, RF, Millimeter, and Submillimeter-Wave Technology and Applications VII, 2014)
Terahertz (THz) frequency band lies between the microwave and infrared region of the electromagnetic spectrum. Molecules having strong resonances in this frequency range are ideal for realizing "Terahertz tags" which can be easily incorporated into various materials. THz spectroscopy of molecules, especially at frequencies below 10 THz, provides valuable information on the low frequency vibrational modes, viz. intermolecular vibrational modes, hydrogen bond stretching, torsional vibrations in several chemical and biological compounds. So far there have been very few attempts to engineer molecules which can demonstrate customizable resonances in the THz frequency region. In this paper, Diamidopyridine (DAP) based molecules are used as a model system to demonstrate engineering of THz resonances (< 10 THz) by fine-tuning the molecular mass and bond strengths. Density Functional Theory (DFT) simulations have been carried out to explain the origin of THz resonances and factors contributing to the shift in resonances due to the addition of various functional groups. The design approach presented here can be easily extended to engineer various organic molecules suitable for THz tags application.

Determination of carrier lifetime and mobility in colloidal quantum dot films via impedance spectroscopy - Rath, Arup Kumar; Lasanta, Tania; Bernechea, Maria; Diedenhofen, Silke L.; Konstantatos, Gerasimos (Applied Physics Letters, 2014)
Impedance Spectroscopy (IS) proves to be a powerful tool for the determination of carrier lifetime and majority carrier mobility in colloidal quantum dot films. We employ IS to determine the carrier lifetime in PbS quantum dot Schottky solar cells with Al and we verify the validity of the technique via transient photovoltage. We also present a simple approach based on an RC model that allows the determination of carrier mobility in PbS quantum dot films and we corroborate the results via comparison with space charge limited measurements. In summary, we demonstrate the potential of IS to characterize key-to-photovoltaics optoelectronic properties, carrier lifetime, and mobility, in a facile way. (C) 2014 AIP Publishing LLC.

Development of bioconjugate from streptomyces tyrosinase and gold nanoparticles for rapid detection of phenol constituents - Zainab, Mazhari Bi Bi; Madhusudhan, D. N.; Raghavendra, H.; Dastager, Syed Gulam; Dayanand, Agsar (Indian Journal of Experimental Biology, 2014)
Most of the phenol compounds are toxic and have been considered as hazardous pollutants. Several physicochemical and biological methods are available to detect and monitor the phenol pollutants in water and soil. In the present study, phenol constituents of winery, paper and plastic industrial effluents were successfully detected employing tyrosinase-gold nanoparticles bioconjugate. The synthesis of extracellular tyrosinase and gold nanoparticles was achieved by a single isolate of Streptomyces sp. DBZ-39. Enhanced production (369.41 IU) of tyrosinase was produced in submerged bioprocess employing response surface method with central composite design. Extracellular gold nanoparticles synthesized (12-18 nm) by Streptomyces sp. DBZ-39 were characterized with TEM, EDAX and FTIR analysis. A rapid detection (within 10 min) of phenol constituents from winery effluents was achieved by bioconjugate, when compared to tyrosinases and gold nanoparticles independently. Streptomyces tyrosinase could exhibit relatively a better performance than commercially available mushroom tyrosinase in the detection of phenol constituents. Winery effluent has shown much higher content (0.98 O.D) of phenol constituents than paper and plastic effluents based on the intensity of color and U.V absorption spectra.
Keywords: Bioconjugate; gold nanoparticles; Phenol detection; Streptomyces; Tyrosinase

Differential transcriptional activity of SAD, FAD2 and FAD3 desaturase genes in developing seeds of linseed contributes to varietal variation in alpha-linolenic acid content - Rajwade, Ashwini V.; Kadoo, Narendra Y.; Borikar, Sanjay P.; Harsulkar, Abhay M.; Ghorpade, Prakash B.; Gupta, Vidya S. (Phytochemistry, 2014)
Linseed or flax (Linum usitatissimum L.) varieties differ markedly in their seed a-linolenic acid (ALA) levels. Fatty acid desaturases play a key role in accumulating ALA in seed. We performed fatty acid (FA) profiling of various seed developmental stages of ten Indian linseed varieties including one mutant variety. Depending on their ALA contents, these varieties were grouped under high ALA and low ALA groups. Transcript profiling of six microsomal desaturase genes (SAD1, SAD2, FAD2, FAD2-2, FAD3A and FAD3B), which act sequentially in the fatty acid desaturation pathway, was performed using real-time PCR. We observed gene specific as well as temporal expression pattern for all the desaturases and their differential expression profiles corresponded well with the variation in FA accumulation in the two groups. Our study points to efficient conversion of intermediate FAs [stearic (SA), oleic (OA) and linoleic acids (LA)] to the final product, ALA, due to efficient action of all the desaturases in high ALA group. While in the low ALA group, even though the initial conversion up to OA was efficient, later conversions up to ALA seemed to be inefficient, leading to higher accumulation of OA and LA instead of ALA. We sequenced the six desaturase genes from the ten varieties and observed that variation in the amino acid (AA) sequences of desaturases was not responsible for differential ALA accumulation, except in the mutant variety TL23 with very low (<2%) ALA content. In TL23, a point mutation in the FAD3A gene resulted into a premature stop codon generating a truncated protein with 291 AA. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: ALA; Fatty acid desaturases; Fatty acids; Flax; Gene expression; Linseed

Dimorphism and hydrocarbon metabolism in Yarrowia lipolytica var. indica - Palande, A. S.; Kulkarni, S. V.; Leon-Ramirez, C.; Campos-Gongora, E.; Ruiz-Herrera, J.; Deshpande, Mukund V. (Archives of Microbiology, 2014)
Yarrowia lipolytica is able to metabolize high Mr hydrophobic natural compounds such as fatty acids and hydrocarbons. Characteristically, strains of Y. lipolytica can grow as populations with variable proportions of yeast and filamentous forms. In the present study, we describe the dimorphic characteristics of a variant designated as Y. lipolytica var. indica isolated from petroleum contaminated sea water and the effect of cell morphology on hydrocarbon metabolism. The variant behaved as a yeast monomorphic strain, under conditions at which terrestrial Y. lipolytica strain W29 and its derived strains, grow as almost uniform populations of mycelial cells. Using organic nitrogen sources and N-acetylglucosamine as carbon source, var. indica was able to form mycelial cells, the proportion of which increased when incubated under semi-anaerobic conditions. The cell surface characteristics of var. indica and W29 were found to be different with respect to contact angle and percent hydrophobicity. For instance, percent hydrophobicity of var. indica was 89.93 +/- A 1.95 while that of W29 was 70.78 +/- A 1.1. Furthermore, while all tested strains metabolize hydrocarbons, only var. indica was able to use it as a carbon source. Yeast cells of var. indica metabolized hexadecane with higher efficiency than the mycelial form, whereas the mycelial form of the terrestrial strain metabolized the hydrocarbon more efficiently, as occurred with the mycelial monomorphic mutant AC11, compared to the yeast monomorphic mutant AC1.
Keywords: Hexadecane metabolism; Yarrowia lipolytica; Yeast-mycelium transition

Disordered mesoporous TiO2-xNx+Nano-Au: an electronically integrated nanocomposite for solar H-2 generation - Sivaranjani, Kumarsrinivasan; Rajaambal, Sivaraman; Das, Tanmay; Roy, Kanak; Bhattacharyya, Somnath; Gopinath, Chinnakonda S. (ChemCatChem, 2014)
We report on H-2 generation by photocatalysis driven by simulated white light by electronically integrated Au nanoparticles with multifunctional, disordered mesoporous TiO2-xNx (Au-NT) nanocomposites. Solar H-2 generation (1.5 mmolh(-1)g(-1)) from aqueous methanol has been demonstrated with Au-NT nanocomposites. The water splitting activity of Au-NT is attributed to the 21.1 ps lifetime of charge carriers observed from fluorescence lifetime measurements, which indicates a high electron-injection efficiency from nano-Au to the conduction band of TiO2, and hence charge separation as well as utilization. This is directly supported by the observation of a high photoluminescence emission intensity with Au-NT that highlights the energy transfer from nano-Au to TiO2. The p-n heterojunction observed between the Au (001) and TiO2 (101) facets helps to-wards the higher charge separation and their utilization. A low mesochannel depth (< 10 nm) associated with disordered mesoporous TiO2-xNx helps the charge carriers to move towards the surface for redox reactions and hence charge utilization. Visible-light absorption, as a result of the surface plasmon resonance of nano-Au, is observed in a broad range between 500 and 750 nm, which helps in harvesting visible-light photons. Finally, electronically integrated nano-Au with TiO2-xNx in Au-NT is evident from Raman and X-ray photoelectron spectroscopy measurements. All of these factors help to achieve a high rate of H-2 production. It is likely that a higher rate of H-2 production than that reported here is feasible by strategically locating Au clusters in porous TiO2 to generate hot spots through electronic integration.
Keywords: heterogeneous catalysis; Hydrogen; mesoporous materials; photochemistry; water splitting

Effect of composition and pretreatment parameters on activity and stability of Cu-Al catalysts for water-gas shift reaction - Mane, Rasika B.; Jeong, Dae-Woon; Malawadkar, Atul V.; Roh, Hyun-Seog; Rode, Chandrashekhar V. (ChemCatChem, 2014)
We investigated various Cu species responsible for highly efficient Cu-Al oxide catalyst for the water-gas shift reaction (WGSR). The formation of various Cu species was achieved by systematically varying the Cu-Al composition in the coprecipitated mixed Cu-Al oxides. The Cu-Al composition of 70:30 (Cu-Al-7) was the best for WGSR using the reformate gas composition. In addition, the Cu-Al-7 catalyst reduced under 100% H-2, was relatively stable with time on stream of 100 h, at higher gas hourly space velocity of 36201 h(-1). The structural investigation of our coprecipitated catalysts with varying Cu-Al compositions revealed the formation of nonzero oxidation state copper and metallic Cu to be essential for the observed WGSR activity. In addition, the highest activity and stability of Cu-Al-7 catalysts reduced under 100% H-2 at lower temperature was attributed to particle-size stabilization and a lower extent of Cu aggregation by Cu2O and boehmite phases, respectively, along with the formation of various Cu species during the activation protocol for 12 h. Complete CO2 selectivity without methanation was observed for all the Cu-Al compositions irrespective of their pretreatment conditions.
Keywords: aluminum; Copper; fuel cells; Hydrogen; reduction

Effect of gold nanoparticle on structure and fluidity of lipid membrane - Mhashal, Anil R.; Roy, Sudip (Plos One, 2014)
This paper deals with the effect of different size gold nanoparticles on the fluidity of lipid membrane at different regions of the bilayer. To investigate this, we have considered significantly large bilayer leaflets and incorporated only one nanoparticle each time, which was subjected to all atomistic molecular dynamics simulations. We have observed that, lipid molecules located near to the gold nanoparticle interact directly with it, which results in deformation of lipid structure and slower dynamics of lipid molecules. However, lipid molecules far away from the interaction site of the nanoparticle get perturbed, which gives rise to increase in local ordering of the lipid domains and decrease in fluidity. The bilayer thickness and area per head group in this region also get altered. Similar trend, but with different magnitude is also observed when different size nanoparticle interact with the bilayer.

Effect of preparation parameters on characterization and activity of Co3O4 catalyst in liquid phase oxidation of lignin model substrates - Mate, Vivek R.; Jha, Ajay; Joshi, U. D.; Patil, K. R.; Shirai, M.; Rode, C. V. (Applied Catalysis A-General, 2014)
The nano structured spinel cobalt oxide (Co3O4) was prepared via simple co-precipitation method and its catalytic activity was evaluated for the liquid phase aerobic oxidation of lignin sub structure compounds such as veratryl alcohol. Catalyst preparation parameters influenced its morphology eventually affecting its oxidation activity. Thus, nano rod shaped CO3O4 catalyst showed 75% and 38% conversion of veratryl alcohol with complete selectivity to veratryl aldehyde in toluene and water, respectively, under base free condition. The influence of reaction conditions, such as temperature, oxygen pressure and catalyst loading was studied to obtain the optimum product yield and selectivity to the desired product. Furthermore, oxidation of various sub-structures of lignin model compounds was also studied over the same catalyst which was found to be in the following order: secondary alcohol >di-substituted > tri-substituted > monosubstituted > non-substitution. The stability of the catalyst was confirmed by its successful recycle for three times. (c) 2014 Elsevier B.V. All rights reserved.
Keywords: Coniferyl alcohol; Nano Co3O4; Sinapyl alcohol; TPR; Veratryl alcohol

Effect of pt incorporation in LaBO3 (B = Mn, Fe, Co) perovskites on water gas shift activity - Rajesh, Thattarathody; Upadhyay, Anuj; Sinha, Anil K.; Deb, Sudip K.; Devi, R. Nandini (Journal of Molecular Catalysis A-Chemical, 2014)
Pt incorporated perovskites LaBO3 (B = Mn, Co, Fe) were synthesised and characterised to understand the charge state of Pt in these materials. At the temperature range used in this study, Pt could be stabilised in ionic form in Co and Fe perovskites but not in LaMnO3. Consequent to incorporation of Pt in +2 and +4 oxidation states, reduction in B site ion charge state occurred, enhancing oxygen vacancies. Pt doped Co and Fe perovskites showed high activity for CO conversion under water gas shift conditions but the activity characteristics were found to be different for the two catalysts; LaCo1-xPtxO3-delta showed methanation whereas the Fe counterpart was active in water gas shift reaction. It was also observed that methanation could be decreased and water gas shift enhanced in case of Pt doped Co perovskite when compared to Pt impregnated perovskite or mixed oxides. (C) 2014 Elsevier B.V. All rights reserved.
Keywords: Methanation; Perovskites; Pt doping; Water gas shift reaction; XANES

Effect of SnO2/Al2O3 ratio of Si-based MFI on its acidity and hydrophobicity: application in selective hydroxyalkylation of p-cresol - Garade, Ajit C.; Malwadkar, A. V.; Niphadkar, P. S.; Jha, Ratnesh Kumar; Joshi, P. N.; Rode, C. V. (Catalysis Communications, 2014)
Silica based MR type molecular sieves with various SnO2/Al2O3 ratios were synthesized from gels having molar compositions SiO2:xSnO(2):yAl(2)O(3):0.23(TPA)(2)O:35H(2)O where 0 <= x <= 0.02 and 0 <= y <= 0.01. Recyclable, Al-free Sn-MFI catalyst showed 31% conversion of formaldehyde with 100% selectivity to 2,2'-methylenebis(4-methylphenol) in hydroxyalkylation of p-cresol with formaldehyde on account of moderate acidity and higher hydrophobicity. (C) 2013 Elsevier B.A. All rights reserved.
Keywords: Al-27 MAS NMR; Hydroxyalkylation; Molecular sieves; p-Cresol; Stannosilicate

Efficient synthesis of glycerol carbonate/glycidol using 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU) based ionic liquids as catalyst - Munshi, Mudassir K.; Biradar, Pradeep S.; Gade, Swapna M.; Rane, Vilas H.; Kelkar, Ashutosh A. (RSC Advances, 2014)
Transesterification of dimethyl carbonate with glycerol to glycerol carbonate has been catalyzed efficiently using basic ionic liquids as catalysts. Activity of all the ILs tested is very high and the best result (96% conversion with 82% selectivity to glycerol carbonate and 18% selectivity to glycidol) was obtained using IL1 as catalyst. The effect of catalyst loading has significant influence on the selectivity pattern. The higher activity of the ionic liquid is explained with a plausible mechanism based on the co-operative effect of both cation and anion.

Efforts towards the synthesis of microsporin B: ready access to both the enantiomers of the key amino acid fragment - Swaroop, Pandrangi Siva; Tripathy, Sibanarayan; Jachak, Gorakhnath R.; Reddy, D. Srinivasa (Tetrahedron Letters, 2014)
Both the isomers methyl-(2S,8R)-2-((tert-butoxycarbonyl)amino)-8-hydroxydecanoate and methyl-(2S,8S)-2-((tert-butoxycarbonyl)amino)-8-hydroxydecanoate of an unusual amino acid residue and the key fragment of microsporin B are prepared. The key steps include cross metathesis and enzymatic kinetic resolution. In addition, a linear tetrapeptide with desired components towards total synthesis is also reported. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Cross metathesis; Enzymatic resolution; HDAC inhibitor; Microsporin; Tetrapeptide

Electrochemical preparation of vertically aligned, hollow CdSe nanotubes and their p-n junction hybrids with electrodeposited Cu2O - Debgupta, Joyashish; Devarapalli, Rami Reddy; Rahman, Shakeelur; Shelke, Manjusha V.; Pillai, Vijayamohanan K. (Nanoscale, 2014)
Vertically aligned, hollow nanotubes of CdSe are grown on fluorine doped tin oxide (FTO) coated glass substrates by ZnO nanowire template-assisted electrodeposition technique, followed by selective removal of the ZnO core using NH4OH. A detailed mechanism of nucleation and anisotropic growth kinetics of nanotubes have been studied by a combination of characterization tools such as chronoamperometry, SEM and TEM. Interestingly, ``as grown'' CdSe nanotubes (CdSe NTs) on FTO coated glass plates behave as n-type semiconductors exhibiting an excellent photo-response (with a generated photocurrent density value of similar to 470 mu A cm(-2)) white in contact with p-type Cu2O (p-type semiconductor, grown separately on FTO plates) because of the formation of a n-p heterojunction (type II). The observed photoresponse is 3 times higher than that of a similar device prepared with electrodeposited CdSe films (not nanotubes) and Cu2P on FTO. This has been attributed to the hollow 1-D nature of CdSe NTs, which provides enhanced inner and outer surface areas for better absorption of light and also assists faster transport of photogenerated charge carriers.

Electronic structure-sunlight driven water splitting activity correlation of (Zn1-yGay)(O1-zNz) - Rajaambal, Sivaraman; Yadav, A. K.; Jha, Shambhu Nath; Bhattacharyya, Dibyendu; Gopinath, Chinnakonda S. (Physical Chemistry Chemical Physics, 2014)
(Zn1-yGay)(O1-zNz) (y <= 0.10; z <= 0.15) solid solutions have been investigated for their electronic structure and visible light photocatalytic activity, and a correlation was found between them. (Zn1-yGay)(O1-zNz) with ZnO as the major component have been synthesized by a solution combustion method in 10 minutes using simple raw materials. The local structures of Zn K edge and Ga K edge, and changes in the chemical environment with the incorporation of Ga and N in ZnO were determined by EXAFS study. EXAFS and XRD results suggested the dissolution of GaN in the ZnO lattice. The homogeneity of the solid solution was demonstrated from HRTEM studies. Photoluminescence studies revealed the creation of a new band at the top of the ZnO valence band (VB), and thus the broadening of the VB of (Zn1-yGay)(O1-zNz) or a decrease in the band gap was attributed to the origin of visible light absorption. UV-Vis spectral studies showed light absorption up to 550 nm, which directly supports the VB broadening. Predominant oxygen vacancies and high photocorrosion observed for ZnO were fully suppressed for (Zn1-yGay)(O1-zNz) , indicating the minimization of defects, and thus more sustainability under irradiation conditions. The bare solid solution exhibited reasonable and promising activity for solar hydrogen evolution and photoelectrochemical current generation at 0 V. The present work explained factors such as the preparation method, single phase structure with the stabilization of integral parts, homogeneity in the structure, compensation of oxygen vacancies, and suppression of the density of recombination centres that play a pivotal role in realizing solar energy harvesting.

Elucidation of ionic interactions in the protic ionic liquid solutions by isothermal titration calorimetry - Rai, Gitanjali; Kumar, Anil (Journal of Physical Chemistry B, 2014)
The strong hydrogen-bonded network noted in protic ionic liquids (PILs) may lead to stronger interactions of the ionic entities of PILs with solvents (water, methanol, ethylene glycol, climethylsulfoxide (DMSO), N,N'-dimethylformamide (DMF)) as compared with those of aprotic ionic liquids (APILs). The PILs used in this work are 1-methylimidazolium tetrafluoroborate, 2-methylpyridinium tetrafluoroborate, and N-methylpyrrolodinium tetrafluoroborate in comparison to 1-butyl-3-methylimidazolium tetrafluoroborate, which is classified as an APIL. In this work, the excess partial molar enthalpy, H-IL(E) obtained from isothermal calorimetric titrations at 298.15 K is used to probe the nature of interactions of the PIL cations with solvent molecules against those present in APIL solvent systems. This work also reports interesting flip-flopping in the thermal behavior of these PIL-solvent systems depending upon the structure of the cationic ring of a PIL. In some cases, these flip-flops are the specific fingerprints for specific PILs in a common solvent environment. The excess partial molar enthalpy at infinite dilution, H-IL(E,infinity), of these PILs bears a critical dependence on the solvent properties. An analysis of relative apparent molar enthalpies, phi(L), of the PIL solutions by the ion interaction model of Pitzer yields important information on ionic interactions of these systems.

Engineering of the tat pathway and chaperons - Ghosh, Deepanjan; Ramasamy, Sureshkumar (Acta Crystallographica A‐Foundation and Advances, 2014)
Keywords: Protein transport; Signal sequence; Tat Pathway

Engineering reactors for catalytic reactions - Ranade, Vivek V. (Journal of Chemical Sciences, 2014)
Catalytic reactions are ubiquitous in chemical and allied industries. A homogeneous or heterogeneous catalyst which provides an alternative route of reaction with lower activation energy and better control on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies and recent advances in process intensification/ multifunctional reactors are discussed to illustrate the approach.
21st National Symposium on Catalysis (CATSYMP), CSIR Indian Inst Chem Technol, Hyderabad, INDIA, FEB 11-13, 2013
Keywords: Catalyst; effectiveness; engineering; hydrodynamics; reactors

Enhanced field emission properties of doped graphene nanosheets with layered SnS2 - Rout, Chandra Sekhar; Joshi, Padmashree D.; Kashid, Ranjit V.; Joag, Dilip S.; More, Mahendra A.; Simbeck, Adam J.; Washington, Morris; Nayak, Saroj K.; Late, Dattatray J. (Applied Physics Letters, 2014)
We report here our experimental investigations on p-doped graphene using tin sulfide (SnS2), which shows enhanced field emission properties. The turn on field required to draw an emission current density of 1 mu A/cm(2) is significantly low (almost half the value) for the SnS2/reduced graphene oxide (RGO) nanocomposite (2.65 V/mu m) compared to pristine SnS2 (4.8 V/mu m) nanosheets. The field enhancement factor beta (similar to 3200 for the SnS2 and similar to 3700 for SnS2/RGO composite) was calculated from Fowler-Nordheim (F-N) plots, which indicates that the emission is from the nanometric geometry of the emitter. The field emission current versus time plot shows overall good emission stability for the SnS2/RGO emitter. The magnitude of work function of SnS2 and a SnS2/graphene composite has been calculated from first principles density functional theory (DFT) and is found to be 6.89 eV and 5.42 eV, respectively. The DFT calculations clearly reveal that the enhanced field emission properties of SnS2/RGO are due to a substantial lowering of the work function of SnS2 when supported by graphene, which is in response to p-type doping of graphene. (C) 2014 AIP Publishing LLC.

Enhancing cubosome functionality by coating with a single layer of poly-epsilon-lysine - Deshpande, Sonal; Venugopal, Edakkal; Ramagiri, Shobha; Bellare, Jayesh R.; Kumaraswamy, Guruswamy; Singh, Neetu (ACS Applied Materials & Interfaces, 2014)
We report the preparation and characterization of monoolein cubosomes that can be easily surface modified through adsorption of a single layer of cationic poly-epsilon-lysine. Poly-epsilon-lysine coated cubosomes show remarkable stability in serum solution, are nontoxic and, are readily internalized by HeLa cells. The poly-epsilon-lysine coating provides chemical handles for further bioconjugation of the cubosome surface. We also demonstrate that the initial release rate of a hydrophilic drug, Naproxen sodium, from the cubosomes is retarded with just a single layer of polymer. Interestingly, cubosomes loaded with Naproxen sodium, recently shown to have anticancer properties, cause more apoptosis in HeLa cells when compared to free unencapsulated drug.
Keywords: bioconjugation; cubosomes; drug delivery vehicle; dual loading; theranostics

Extracellular synthesis of silver nanoparticles using living peanut seedling - Raju, D.; Paneliya, Nikita; Mehta, Urmil J. (Applied Nanoscience, 2014)
Synthesis of nanoparticles by environment friendly method is an important aspect of nanotechnology. In the present study, extracellular reduction of silver ions to silver nanoparticles was carried out using living peanut plant. The electron microscopic analysis shows that the formed nanoparticles were of different shapes and sizes. The formed nanoparticles were polydispersed. The shapes of the nanoparticles were spherical, square, triangle, hexagonal and rod. Most of the particles were spherical and 56 nm in size. EDS analysis confirmed the formed nanoparticles were of silver. The crystalline nature of nanoparticles was confirmed by diffraction. This method opens up an exciting possibility of plant-based synthesis of other inorganic nanomaterials. This study confirms the synthesis of extracellular silver nanoparticles by living plant.
Keywords: Nanoparticles; Shapes; Silver; synthesis; TEM

Facile single-step synthesis of nitrogen-doped reduced graphene oxide-Mn3O4 hybrid functional material for the electrocatalytic reduction of oxygen - Bag, Sourav; Roy, Kanak; Gopinath, Chinnakonda S.; Raj, C. Retna (ACS Applied Materials & Interfaces, 2014)
Development of efficient electrocatalyst based on non-precious metal that favors the four-electron pathway for the reduction of oxygen in alkaline fuel cell is a challenging task. Herein, we demonstrate a new facile route for the synthesis of hybrid functional electrocatalyst based on nitrogen-doped reduced graphene oxide (N-rGO) and Mn3O4 with pronounced electrocatalytic activity towards oxygen reduction reaction (ORR) in alkaline solution. The synthesis involves one-step in situ reduction of both graphene oxide (GO) and Mn(VII), growth of Mn3O4 nanocrystals and nitrogen doping onto the carbon framework using a single reducing agent, hydrazine. The X-ray photoelectron (XPS), Raman and FTIR spectral, and X-ray diffraction measurements confirm the reduction of GO and growth of nanosized Mn3O4. The XPS profile reveals that N-rGO has pyridinic (40%), pyrrolic (53%), and pyridine N oxide (7%) types of nitrogen. The Mn3O4 nanoparticles are single crystalline and randomly distributed over the wrinkled N-rGO sheets. The hybrid material has excellent ORR activity and it favors the 4-electron pathway for the reduction of oxygen. The electrocatalytic performance of the hybrid catalyst is superior to the N-rGO, free Mn3O4 and their physical mixture. The hybrid material shows an onset potential of -0.075 V, which is 60-225 mV less negative than that of the other catalyst tested. It has excellent methanol tolerance and high durability. The catalytic current density achieved with the hybrid material at 0.1 mg cm(-2) is almost equivalent to that of the commercial Pt/C (10%). The synergistic effect of N-rGO and Mn3O4 enhances the overall performance of the hybrid catalyst. The nitrogen in N-rGO is considered to be at the interface to bridge the rGO framework and Mn3O4 nanoparticles and facilitates the electron transfer.
Keywords: electrocatalysis; hybrid material; Mn3O4; nitrogen-doped graphene; oxygen reduction; synergistic effect

Factors influence on growth, don and niv production by two species of fusarium isolated from finger millets [eleusine coracana l.] - Vankudoth, Koteswara Rao; Penugonda, Shilpa; Sivadevuni, Girisham; Reddy, S. M. (International Journal of Pharmacy and Pharmaceutical Sciences, 2014)
ABSTRACT Objective: The present investigations (In vitro) on an influence of different synthetic and food based [flour] media, pH, temperature and microbial nutrients on growth, Deoxynivalenol [DON] and Nivalenol [NIV] production by Fusarium aethiopicum and F. culmorum was carried out. Methods: Fusarium species associated with the finger millets were isolated and identified phenotypically and further confirmed by molecular methods by Polymerase Chain Reaction [PCR]. Monosporic seven day old F. aethiopicum and F. culmorum were grown in CYA broth and incubated at 27±2°C on rotary shaker for 21 days at 120 rpm. At the end of 21 day incubation period, cultures were harvested for determination of fungal biomass. The resultant culture filtrates were extracted twice with ethyl acetate and concentrated to get and final concentration of 1 ml in methanol and employed for RP-HPLC analysis for detection of DON and NIV production. Results: Finger millets flour medium induced the highest amount of mycelial growth, DON and NIV production by F. aethiopicum. However, F. culmorum achieved highest amount of hyphal growth, DON and NIV production under the influence of yeast extract sucrose [YES] medium. Maize flour medium, rice flour medium and sorghum flour medium was next preffered substrates. Optimum pH of 5.5-6.5 and temperature of 20-35°C for growth, DON and NIV production was observed. Both the species of Fusarium failed to grow and produce toxins at pH 2.5-3.5 and temperature of 40°C. Yeast extract was most favorable for maximum DON and NIV production, which increased with an increase in its concentration. On the other hand, malt extract and beef extract induced good growth and mycotoxin production at comparatively higher concentration in both the species of Fusarium under study. Conclusion: Comparatively food based media were the better substrates than synthetic media for both growth and DOIN and NIV production by two species of Fusarium under investigation. A positive correlation coefficient [r] on growth [0.458], DON [0.744] and NIV [0.882] was recorded among the media and both the species of Fusarium. Keywords: Finger millets, F. aethiopicum, F. culmorum, Synthetic media, pH, Temperature, Microbial nutrients, DON, NIV, HPLC

Ferromagnetism at room temperature in activated graphene oxide - Raj, K. Govind; Joy, Pattayil Alias (Chemical Physics Letters, 2014)
High room temperature ferromagnetic moment with high Curie temperature (>700 K) for graphene oxide (GO) is obtained by a simple chemical activation using phosphoric acid followed by heat treatment at 800 degrees C. The field and temperature variations of the magnetization data indicate ferromagnetic, paramagnetic and diamagnetic contributions in the acid/heat treated sample. IR spectroscopic studies suggest hydrogenation (reduction) of GO after the acid and heat treatments. The results point to the role of defects, extent of hydrogenation, changes in the bonding characteristics and the nature of the functional groups in determining the different magnetic contributions. (C) 2014 Elsevier B.V. All rights reserved.

Fictibacillus enclensis sp nov., isolated from marine sediment - Dastager, Syed Gulam; Mawlankar, Rahul R.; Srinivasan, Krishnamurthi; Tang, Shan-Kun; Lee, Jae-Chan; Ramana, V. Venkata; Shouche, Yogesh S. (Antonie Van Leeuwenhoek International Journal of General and Molecular Microbiology, 2014)
A novel Gram-positive strain, designated NIO-1003(T), was isolated from a marine sediment sample collected from the Chorao Island, Goa Provence, India. Strain NIO-1003(T) was found to be strictly aerobic, motile, endospore-forming rods. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NIO-1003(T) belongs to the genus Fictibacillus and to be most closely related to Fictibacillus rigui KCTC 13278(T), Fictibacillus solisalsi KCTC 13181(T) and Fictibacillus barbaricus DSM 14730(T) with 98.2, 98.0 and 97.2 % similarity and 25, 28, 39 nucleotide differences respectively. Strain NIO-1003(T) was characterized by having cell-wall peptidoglycan based on meso-diaminopimelic acid and MK-7 as the predominant menaquinone. The polar lipid profile exhibited the major compounds diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. In addition, minor amounts of an aminophospholipid were detected. The major fatty acids were identified as ai-C-15:0, iso-C-15:0, ai-C-17:0 and C-16:0, supporting the grouping of strain NIO-1003(T) into the family Bacillaceae. The DNA G+C content of strain NIO-1003(T) was determined to be 42.6 mol%. On the basis of phenotypic properties, phylogeny and DNA-DNA hybridisation analysis, strain NIO-1003(T) is considered to represent a novel species of the genus Fictibacillus for which the name Fictibacillus enclensis sp. nov. is proposed. The type strain is NIO-1003(T) (= NCIM 5458(T) = DSM 25142(T)).
Keywords: Chorao Island; Fictibacillus sp.; Polyphasic taxonomy

Field emission properties of ZnO nanosheet arrays - Naik, Kusha Kumar; Khare, Ruchita T.; Chakravarty, Disha; More, Mahendra A.; Thapa, Ranjit; Late, Dattatray J.; Rout, Chandra Sekhar (Applied Physics Letters, 2014)
{Electron emission properties of electrodeposited ZnO nanosheet arrays grown on Indium tin oxide coated glass substrates have been studied. Influence of oxygen vacancies on electronic structures and field emission properties of ZnO nanosheets are investigated using density functional theory. The oxygen vacancies produce unshared d electrons which form an impurity energy state; this causes shifting of Fermi level towards the vacuum, and so the barrier energy for electron extraction reduces. The ZnO nanosheet arrays exhibit a low turn-on field of 2.4 V/mu m at 0.1 mu A/cm(2) and current density of 50.1 mu A/cm(2) at an applied field of 6.4 V/mu m with field enhancement factor

Flexible, polymer-supported synthesis of sphingosine derivatives provides ceramides with enhanced biological activity - El-Dahshan, Adeeb; Al-Gharabli, Samer I.; Radetzki, Silke; Al-Tel, Taleb H.; Kumar, Pradeep; Rademann, Joerg (Bioorganic & Medicinal Chemistry, 2014)
A polymer-supported route for the synthesis of sphingosine derivatives is presented based on the C-acylation of polymeric phosphoranylidene acetates with an Fmoc-protected amino acid. The approach enables the flexible variation of the sphingosine tail through a deprotection-decarboxylation sequence followed by E-selective Wittig olefination cleavage. D-Erythro-sphingosine analogs have been synthesized by diastereoselective reduction of the keto group employing LiAlH(O-tBu)(3) as reducing agent. The effect of ceramides and keto-ceramides on the proliferation of three cancer cell lines HEP G-2, PC-12 and HL-60 was investigated and a ceramide containing an aromatic sphingosine tail was identified as being most active. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords: Apoptosis; Ceramide; Lipid rafts; Lipids; Sphingosine

Formation of a pseudo-beta-hairpin motif utilizing the Ant-Pro reverse turn: consequences of stereochemical reordering - Nair, Roshna V.; Kotmale, Amol S.; Dhokale, Snehal A.; Gawade, Rupesh L.; Puranik, Vedavati G.; Rajamohanan, Pattuparambil R.; Sanjayan, Gangadhar J. (Organic & Biomolecular Chemistry, 2014)
Herein, we report a special case of pseudo-beta-hairpin formation by tetrapetide sequences featuring a two-membered Ant Pro dipeptide motif (Ant = anthranilic acid and Pro = proline) at the loop region. These folded structures uniquely feature the presence of C9- and C17-H-bonding patterns at reverse turn and interstrand regions, respectively. Their hairpin nucleation and folding propensities have been expounded using solution and solid state studies of distinct stereochemically altered sequences.

Functional isoDNA aptamers: modified thrombin binding aptamers with a 2'-5'-linked sugarphosphate backbone (isoTBA) - Gunjal, Anita D.; Fernandes, Moneesha; Erande, Namrata D.; Rajamohanan, P. R.; Kumar, Vaijayanti A. (Chemical Communications, 2014)
The regioisomeric 3'-deoxy-2'-5'-linked thrombin binding DNA aptamers (isoTBAs) were chemically synthesized and their ability to form unimolecular anti-parallel G-quadruplexes in the presence of K+ ions was evaluated. These modified sequences retain the function of the native thrombin binding aptamer (TBA), exhibit better stability against exonuclease and are capable of slowing down the process of blood clotting.

General approach to N-heterocyclic carbenes with a fused tetracyclic core: ligands for suzuki-miyaura cross-coupling reaction - Sutar, Revannath L.; Kumar, Vinod; Shingare, Rahul D.; Thorat, Shridhar; Gonnade, Rajesh G.; Reddy, D. Srinivasa (European Journal of Organic Chemistry, 2014)
The synthesis of an N-heterocyclic carbene (NHC) based on a tetracyclic scaffold by using simple, general, and scalable chemistry is disclosed. The developed route is suitable for introducing multiple substitutions on the tetracyclic scaffold. The utility of the present NHC as a ligand in the Suzuki-Miyaura cross-coupling reaction is demonstrated with a low catalyst loading.
Keywords: C-C coupling; carbenes; Homogeneous catalysis; N ligands; synthetic methods

Genome-wide identification and tissue-specific expression analysis of UDP-glycosyltransferases genes confirm their abundance in cicer arietinum (chickpea) genome - Sharma, Ranu; Rawat, Vimal; Suresh, C. G. (Plos One, 2014)
UDP-glycosyltransferases (EC 2.4.1.x; UGTs) are enzymes coded by an important gene family of higher plants. They are involved in the modification of secondary metabolites, phytohormones, and xenobiotics by transfer of sugar moieties from an activated nucleotide molecule to a wide range of acceptors. This modification regulates various functions like detoxification of xenobiotics, hormone homeostasis, and biosynthesis of secondary metabolites. Here, we describe the identification of 96 UGT genes in Cicer arietinum (CaUGT) and report their tissue-specific differential expression based on publically available RNA-seq and expressed sequence tag data. This analysis has established medium to high expression of 84 CaUGTs and low expression of 12 CaUGTs. We identified several closely related orthologs of CaUGTs in other genomes and compared their exon-intron arrangement. An attempt was made to assign functional specificity to chickpea UGTs by comparing substrate binding sites with experimentally determined specificity. These findings will assist in precise selection of candidate genes for various applications and understanding functional genomics of chickpea.

Gold(I)-catalysed [1,3] O -> C rearrangement of allenyl ethers - Kona, Chandrababu Naidu; Ramana, Chepuri V. (Chemical Communications, 2014)
A simple and rapid access to the alpha-substituted acryl aldehydes has been provided by developing a gold-catalysed [1,3] rearrangement of the allenyl ethers importantly with a record turnover frequency of 4600 h(-1) (at 0.05 mol% of the catalyst concentration) in homogeneous gold(I) catalysis.

Green chemistry approach to styrene from ethylbenzene and air on MnxTi1-xO2 catalyst - Negi, Sanjay Singh; Venugopalan, Aswathy Thareparambil; Raja, Thirumalaiswamy; Singh, Anand Pal; Gopinath, Chinnakonda S. (RSC Advances, 2014)
Styrene (ST) is an industrially important commodity chemical, and design of a suitable catalyst, which provides high ethyl benzene (EB) conversion and styrene selectivity at Lower temperature with sustainable activity, is one of the major challenges in the field of heterogeneous catalysis. Manganese incorporated in titania (MnxT1-xO2) anatase Lattice, prepared via the solution combustion method, was evaluated for oxidative dehydrogenation (ODH) of EB with O-2 or air. MnxTi1-xO2 catalysts were characterized by different physiochemical methods. Up to 15% Mn could be introduced into the TiO2 Lattice. TEM and XRD indicate disordered mesoporosity, further confirmed by adsorption isotherm analysis. MnxTi1-xO2 catalysts were evaluated for ST synthesis from EB using air or oxygen as oxidant between 440 and 570 degrees C. Reaction conditions have been varied systematically, such as catalyst composition, and EB/air/O-2 flow. MnxTi1-xO2 shows sustainable 55% styrene yield for 45 h without deactivation under optimum conditions. A thorough analysis of spent catalysts demonstrates the conversion of initial anatase phase MnxTi1-xO2 to Mn3O4 supported on the rutile (R) phase of TiO2. The above change occurs in the first few hours of reaction and the Mn3O4 on R-TiO2 phase is the active phase of the catalyst and responsible for sustainable activity for Longer duration.

Green synthesis of polysaccharide stabilized gold nanoparticles: chemo catalytic and room temperature operable vapor sensing application - Tagad, Chandrakant K.; Rajdeo, Kishor S.; Kulkarni, Atul; More, Pooja; Aiyer, Rohini C.; Sabharwal, Sushma G. (RSC Advances, 2014)
A facile, one pot, completely green, and cheap route for the synthesis of gold nanoparticles (AuNPs) has been developed by using locust bean gum (LBG), both as a reducing and a stabilizing agent. Synthesized AuNPs were characterized by UV-vis spectroscopy, TEM, XRD, dynamic light scattering analysis (DLS) and EDAX. A characteristic surface plasmon peak at 537 nm confirmed the formation of AuNPs. Synthesized AuNPs were found to be an efficient catalyst for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). The reaction follows pseudo-first order kinetics with a rate constant of 14.46 X 10(-2) min(-1). Furthermore, the catalytic efficiency of AuNPs for ethanol vapor sensing was investigated by doping AuNPs in a tin oxide (SnO2) matrix synthesized by a single step thermal decomposition method. The AuNPs doped SnO2 sensor showed a fast response (similar to 5 seconds) and excellent ethanol sensing behavior in the range of 10 to 120 ppm at room temperature. A two fold increase in ethanol vapor sensing response was observed with AuNPs doped SnO2 as compared with the pure SnO2 sensor.

Heterogeneous foldamers from aliphatic-aromatic amino acid building blocks: current trends and future prospects - Nair, Roshna V.; Vijayadas, Kuruppanthara N.; Roy, Arup; Sanjayan, Gangadhar J. (European Journal of Organic Chemistry, 2014)
Chemists' constant pursuit of understanding of the underlying principles of nature's most intricate phenomenon such as protein folding has led to the development of the field of foldamers. The emergence of diverse classes of unnatural amino acid building blocks has unleashed countless opportunities to design, develop and explore the structural and functional aspects of synthetic peptides. One current trend in foldamer chemistry is the heterofoldamer approach, which involves systematic stoichiometric variation of various natural/unnatural amino acid residues, leading to conformational ordering with intriguing structural architectures. In this regard, the incorporation of aromatic amino acids provides efficient structural rigidification and tunability to the molecular scaffolds, which can exhibit a range of secondary structural features. Recent times have witnessed an upsurge of foldamers featuring aliphatic-aromatic residues with diverse structural propensities. This review is an effort to cover this rapidly developing field of foldamer science and also to envisage its future perspectives.
Keywords: Amino acids; Conformation analysis; Foldamers; hydrogen bonding; Peptides; Stacking interactions

Hybrid diphosphorus ligands in rhodium catalysed asymmetric hydroformylation - Chikkali, Samir H.; van der Vlugt, Jarl Ivar; Reek, Joost N. H. (Coordination Chemistry Reviews, 2014)
This review aims to illustrate recent advances in the application of hybrid diphosphorus ligands for the Rh catalysed hydroformylation of alkenes, discussing the most prevalent classes of hybrid systems, i.e. phosphine-phosphinite, phosphine-phosphonite, phosphine-phosphite, phosphite-phosphoramidite and phosphite-phosphoramidite and comparing their performance with relevant C-2 symmetric counterparts. In order to introduce the field and put the results in context, a short overview on Rh hydroformylation is provided. Available spectroscopic (in situ) data on the coordination modes of hybrid phosphorus ligands and the catalytic performance of these systems in asymmetric hydroformylation of vinyl arenes are reported. Potential avenues for future research are shortly discussed. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Asymmetric hydroformylation; Catalyst resting state; Hybrid ligand design; In situ spectroscopy; Rhodium

I-2-catalyzed regioselective Oxo- and hydroxy-acyloxylation of alkenes and enol ethers: a facile access to alpha-acyloxyketones, esters, and diol derivatives - Reddi, Rambabu N.; Prasad, Pragati K.; Sudalai, Arumugam (Organic Letters, 2014)
I-2-catalyzed oxo-acyloxylation of alkenes and enol ethers with carboxylic acids providing for the high yield synthesis of a-acyloxyketones and esters is described. This unprecedented regioselective oxidative process employs TBHP and Et3N in stoichiometric amounts under metal-free conditions in DMSO as solvent. Additionally, I-2-catalysis allows the direct hydroxy-acyloxylation of alkenes with the sequential addition of BH3 center dot SMe2 leading to monoprotected diol derivatives in excellent yields.

IFN-gamma signaling maintains skin pigmentation homeostasis through regulation of melanosome maturation - Natarajan, Vivek T.; Ganju, Parul; Singh, Archana; Vijayan, Vinaya; Kirty, Kritika; Yadav, Shalini; Puntambekar, Shraddha; Bajaj, Sonali; Dani, Prachi P.; Kar, Hemanta K.; Gadgil, Chetan J.; Natarajan, Krishnamurthy; et al. (Proceedings of the National Academy of Sciences of the United States of America, 2014)
Cellular homeostasis is an outcome of complex interacting processes with nonlinear feedbacks that can span distinct spatial and temporal dimensions. Skin tanning is one such dynamic response that maintains genome integrity of epidermal cells. Although pathways underlying hyperpigmentation cascade are recognized, negative feedback regulatory loops that can dampen the activated melanogenesis process are not completely understood. In this study, we delineate a regulatory role of IFN-gamma in skin pigmentation biology. We show that IFN-gamma signaling impedes maturation of the key organelle melanosome by concerted regulation of several pigmentation genes. Withdrawal of IFN-gamma signal spontaneously restores normal cellular programming. This effect in melanocytes is mediated by IFN regulatory factor-1 and is not dependent on the central regulator microphthalmia-associated transcription factor. Chronic IFN-gamma signaling shows a clear hypopigmentation phenotype in both mouse and human skin. Interestingly, IFN-gamma KO mice display a delayed recovery response to restore basal state of epidermal pigmentation after UV-induced tanning. Together, our studies delineate a new spatiotemporal role of the IFN-gamma signaling network in skin pigmentation homeostasis, which could have implications in various cutaneous depigmentary and malignant disorders.
Keywords: detanning; gene regulation; interferon; melanin

Immobilization of bile salt hydrolase enzyme on mesoporous SBA-15 for co-precipitation of cholesterol - Bhange, Pallavi; Sridevi, N.; Bhange, Deu S.; Prabhune, Asmita; Ramaswamy, Veda (International Journal of Biological Macromolecules, 2014)
We describe herein a simple and effective strategy for immobilization of bile salt hydrolase enzyme by grafting glutaraldehyde groups inside channels of APTES functionalized SBA-15. The increase in glutaraldehyde concentration prevents leakage of enzyme but showed a steep decrease in enzyme activity in the immobilized matrix. So the degree of cross-linking should be the minimum possible to ensure sufficient stability without loss of activity. Cross-linking carried out with 0.1% glutaraldehyde concentration showed the highest activity, so this was used in all further experiments. Physico-chemical characterizations of the immobilized enzyme were carried out by XRD, N-2 adsorption, TEM, FUR and Si-29 CP-MAS NMR techniques. Immobilized BSH exhibits enhanced stability over a wide pH (3-11) and temperature range (40-80 degrees C) and retains an activity even after recycling experiments and six months of storage. From our in vivo research experiment toward co-precipitation of cholesterol, we have shown that immobilized BSH enzyme may be the promising catalyst for the reduction of serum cholesterol levels in our preliminary investigation. Enhancement in pH stability at the extreme side of pH may favor the use of immobilized BSH enzyme for drug delivery purpose to with stand extreme pH conditions in the gastrointestinal conditions. (C) 2013 Elsevier B.V. All rights reserved.
Keywords: Bile salt hydrolase; Co-precipitation of cholesterol; SBA-15

Improved method for specificity annotation shows a distinct evolutionary divergence among the microbial enzymes of the cholylglycine hydrolase family - Panigrahi, Priyabrata; Sule, Manas; Sharma, Ranu; Ramasamy, Sureshkumar; Suresh, C. G. (Microbiology-SGM, 2014)
Bile salt hydrolases (BSHs) are gut microbial enzymes that play a significant role in the bile acid modification pathway. Penicillin V acylases (PVAs) are enzymes produced by environmental microbes, having a possible role in pathogenesis or scavenging of phenolic compounds in their microbial habitats. The correct annotation of such physiologically and industrially important enzymes is thus vital. The current methods relying solely on sequence homology do not always provide accurate annotations for these two members of the cholylglycine hydrolase (CGH) family as BSH/PVA enzymes. Here, we present an improved method [binding site similarity (BSS)-based scoring system] for the correct annotation of the CGH family members as BSH/PVA enzymes, which along with the phylogenetic information incorporates the substrate specificity as well as the binding site information. The BSS scoring system was developed through the analysis of the binding sites and binding modes of the available BSH/PVA structures with substrates glycocholic acid and penicillin V. The 198 sequences in the dataset were then annotated accurately using BSS scores as BSH/PVA enzymes. The dataset presented contained sequences from Gram-positive bacteria, Gram-negative bacteria and archaea. The clustering obtained for the dataset using the method described above showed a clear distinction in annotation of Gram-positive bacteria and Gram-negative bacteria Based on this clustering and a detailed analysis of the sequences of the CGH family in the dataset, we could infer that the CGH genes might have evolved in accordance with the hypothesis stating the evolution of diderms and archaea from the monoderms.

In the sense of transcription regulation by G-quadruplexes: asymmetric effects in sense and antisense strands - Agarwal, Tani; Roy, Saumya; Kumar, Santosh; Chakraborty, Tushar Kanti; Maiti, Souvik (Biochemistry, 2014)
G-Quadruplexes occupy important regulatory regions in the genome. DNA G-quadruplexes in the promoter regions and RNA quadruplexes in the UTRs (untranslated regions) have been individually studied and variously implicated at different regulatory levels of gene expression. However, the formation of G-quadruplexes in the sense and antisense strands and their corresponding roles in gene regulation have not been studied in much detail. In the present study, we have elucidated the effect of strand asymmetry in this context. Using biophysical methods, we have demonstrated the formation of stable G-quadruplex structure in vitro using CD and UV melting. Additionally, ITC was employed to demonstrate that a previously reported selective G-quadruplex ligand was able to bind and stabilize the G-quadruplex in the present sequence. Further, we have shown using reporter constructs that although the DNA G-quadruplex in either strand can reduce translation efficiency, transcriptional regulation differs when G-quadruplex is present in the sense or antisense strand. We demonstrate that the G-quadruplex motif in the antisense strand substantially inhibits transcription, while when in the sense strand, it does not affect transcription, although it does ultimately reduce translation. Further, it is also shown that the G-quadruplex stabilizing ligand can enhance this asymmetric transcription regulation as a result of the increased stabilization of the G-quadruplex.

In1-XGaXN@ZnO: a rationally designed and quantum dot integrated material for water splitting and solar harvesting applications - Rajaambal, Sivaraman; Mapa, Maitri; Gopinath, Chinnakonda S. (Dalton Transactions, 2014)
The highly desirable combination of the visible light absorption properties of In1-xGaxN Quantum dots (QD) along with the multifunctionality of ZnO into a single integrated material was prepared for solar harvesting. This is the first report on InGaN QD integrated with ZnO (InGaN@ZnO), synthesized by a highly reproducible, simple combustion method in 15 min. Structural, microstructural and electronic integration of the nitride and oxide components of InGaN@ZnO was demonstrated by appropriate characterization methods. Self-assembly of InGaN QD is induced in growing nascent zinc oxo nanoclusters taking advantage of the common wurtzite structure and nitrogen incorporation at the expense of oxygen vacancies. Direct integration brings about a single phase structure exhibiting extensive visible tight absorption and high photostability. InGaN@ZnO suggests synergistic operation of tight harvesting and charge conducting components for solar H-2 generation without using any co-catalyst or sacrificial agent, and a promising photocurrent generation at 0 V under visible light illumination. The present study suggests a direct integration of QD with the host matrix and is a potential method to realize the advantages of QDs.

Influence of method of preparation on the activity of La-Ni-Ce mixed oxide catalysts for dry reforming of methane - Sagar, T. V.; Sreelatha, N.; Hanmant, G.; Surendar, M.; Lingaiah, N.; Rao, K. S. Rama; Satyanarayana, C. V. V.; Reddy, I. A. K.; Prasad, P. S. Sai (RSC Advances, 2014)
La-Ni-x-Ce1-x mixed oxide catalysts were prepared by a sol-gel method varying the Ni composition (0 <= x <= 1). The catalysts were characterized by X-ray diffraction (XRD), inductively coupled plasma optical emission spectroscopy (ICP-OES), BET surface area, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), H-2 chemisorption and Fourier transform infrared spectroscopy (FT-IR) techniques. CO2 reforming of methane was carried out at atmospheric pressure and 800 degrees C, maintaining a reactant CO2/CH4/N-2 ratio of 80/80/80 (total flow rate = 240 ml min(-1), GHSV of 28 800 h(-1)). The catalysts offered higher activity even at lower Ni compositions. LaNi0.4Ce0.6O3. showed the highest conversion of CH4 and CO2. The H-2/CO ratio in the syngas was stable at 0.85 +/- 0.02. The performance of the sol-gel catalysts was compared with that of the hydrothermally prepared catalysts, reported earlier. High surface area and better Ni dispersion were found to be the reasons for superior activity of the sol-gel catalysts.

Interactions of a low molecular weight inhibitor from streptomyces sp. MBR04 with human cathepsin D: implications in mechanism of inactivation - Menon, Vishnu; Rao, Mala (Applied Biochemistry and Biotechnology, 2014)
Cathepsin D, a lysosomal aspartic protease, is of potential interest as a target for drug design due to its implication in breast and ovarian cancer. The article reports a low molecular weight cathepsin D inhibitor from Streptomyces sp. MBR04. The M-r of the inhibitor was 1,078 Da as determined by MALDI-TOF, and the amino acid analysis showed the presence of Asp, Asp, Gly, Ala, Lys, Leu, Tyr, Trp residues. The steady-state kinetic interactions revealed reversible, competitive, slow-tight-binding nature of the inhibitor with an IC50 and K (i) values of 3.2 and 2.5 nM, respectively. The binding of the inhibitor with the enzyme and the subsequent conformational changes were monitored by exploiting the intrinsic fluorescence of the surface exposed Trp-54 residue. Based on the fluorescence and circular dichroism studies, we demonstrate that the inhibitor binds to the active site of cathepsin D and causes inactivation. All these kinetic, thermodynamic, and quenching studies suggest that the newly isolated peptidic inhibitor could be a potential scaffold to study and can be used to develop new potent therapeutic lead molecule for the development of drugs. The inhibitor will be significant as a potential lead molecule to target cathepsin D.
Keywords: Cancer treatment; Cathepsin D inhibitor; Inactivation mechanism; Slow-tight-binding inhibition; Streptomyces sp MBR04

Investigations into variations in local cationic environment in layered oxide series InGaO3(ZnO)(m) (m=1-4) - Narendranath, Soumya B.; Yadav, Ashok Kumar; Ajithkumar, Thalasseril G.; Bhattacharyya, Dibyendu; Jha, Shambhu Nath; Dey, Krishna K.; Raja, Thirumalaiswamy; Devi, R. Nandini (Dalton Transactions, 2014)
Layered oxides of the series InGaO3(ZnO)(m) (m = 1-4) are interesting due to their structural anisotropy. Here, we report a comprehensive study of their structural details, focusing on the local cationic environment in bulk powder samples by MASNMR and EXAFS, which is hitherto not attempted. It is found that the Ga geometry varies gradually from pure pentacoordinated to a mixture of penta and tetracoordinated with increasing amounts of tetracoordination as we move across the series, contrary to previous reports suggesting exclusively trigonal bipyramidal coordination in all the compounds. A similar observation is also made in the case of Zn and structural evolution involving the dissolution of Ga in a ZnO4 tetrahedral network in a sandwich layer can be discerned, as the insulating ZnO layer size increases.

Isohexide-diacetal based polymers and a process thereof - Chikkali, Samir H.; Rajput, Bhausaheb S. (WO/2014/181358, 2014)
The present invention discloses isohexide based compounds and their polymers which are derived from renewable resources and are potentially degradable. Also disclosed herein is the synthesis of isohexide based monomers and their polymers from renewable resources which are potentially degradable. Further, the present invention disclose a process for the synthesis of isohexide based copolymers via copolymerization of isohexide based monomers and long chain diols, which are degradable. (FR)Cette invention concerne des composés à base d'isohexide et leurs polymères qui sont dérivés de ressources renouvelables et sont potentiellement dégradables. Cette invention concerne également la synthèse de monomères à base d'isohexide et leurs polymères à partir de ressources renouvelables qui sont potentiellement dégradables. Un procédé de synthèse de copolymères à base d'isohexide par copolymérisation desdits monomères à base d'isohexide et de diols à chaîne longue, qui sont dégradables, est en outre décrit.

Isolation, characterization and antihyperlipidemic activity of secoisolariciresinol diglucoside in poloxamer-407-induced experimental hyperlipidemia - Zanwar, Anand A.; Hegde, Mahabaleshwar V.; Rojatkar, Supada R.; Sonawane, Kiran B.; Rajamohanan, P. R.; Bodhankar, Subhash L. (Pharmaceutical Biology, 2014)
Context: Linum usitatissimum L. (Linaceae), commonly known as flaxseed, is a good source of dietary fiber and lignans. Earlier we reported cardioprotective, antihyperlipidemic, and in vitro antioxidant activity of flax lignan concentrate (FLC) obtained from flaxseed. Objectives: To isolate secoisolariciresinol diglucoside (SDG) from FLC and to evaluate the antihyperlipidemic activity of SDG in poloxamer-407 (P-407)-induced hyperlipidaemic mice. Material and methods: FLC was subjected to column chromatography and further subjected to preparative HPTLC to isolate SDG. The chemical structure of the isolated compound was elucidated by UV, IR, H-1 NMR, C-13 NMR, DEPT, COSY, HSQC, HMBC, ROESY, MS, and specific optical rotation was recorded. Further, we have investigated the antihyperlipidaemic effect of SDG (20 mg/kg) in P-407-induced hyperlipidaemic rats. Hyperlipidaemia was induced by intraperitoneal administration of P-407 (30% w/v). Serum lipid parameters such as total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C) levels were measured. Results and discussion: The structure and stereochemistry of the isolated compound were confirmed on the basis of 1D and 2D spectral data and characterized as SDG. Finally, isolated pure SDG was screened using a P-407-induced mice model for its antihyperlipidemic action using serum lipid parameters. The isolated SDG (20 mg/kg) significantly reduced serum cholesterol, triglyceride (p<0.001), very low-density lipoprotein (p<0.05), and non-significantly increased HDL-C. Conclusion: Finally, it was concluded unequivocally that SDG showed antihyperlipidaemic effects in P-407-induced hyperlipidaemic mice. Isolated pure SDG confirms that SDG is beneficial in the prevention of experimental hyperlipidemia in laboratory animals.
Keywords: column chromatography; flaxseed; Linum usitatissimum

Living plant-mediated synthesis of different shaped gold nanoparticles - Raju, D.; Paneliya, Nikita; Mehta, Urmil J. (Nanoscience and Nanotechnology Letters, 2014)
We demonstrate extracellular green synthesis of gold nanoparticles with different shapes and sizes by using live Prosopis juliflora L. seedling. The conversion of ionic to metallic gold nanoparticles by P. juliflora seedling was carried out in short period. The formed nanoparticles were characterized by UV, TEM, Diffraction and EDS. TEM shows well dispersed particles of different shapes and sizes. The percentage of different shapes of nanoparticles was calculated, most of the particles were spherical in shape (75%). The triangle nanoparticles were 10%, followed by squares (8%), hexagonal (5%) and rods (2%). The diffraction shows the formed nanoparticles are crystalline in nature and EDS confirms the formed nanoparticles are of gold. This shows P. juliflora seedling can synthesis different shapes of well dispersed nanoparticles.
Keywords: Gold; Nanoparticles; Prosopis juliflora; Shapes; synthesis; TEM

Magnetism in disordered carbon as a function of the extent of graphitization - Raj, K. Govind; Joy, Pattayil Alias (Solid State Communications, 2014)
Magnetic properties of disordered carbon have been investigated as a function of the extent of graphitization. It is found that the magnetization of the disordered carbon decreases with increasing degree of graphitization. Treatment with acid modifies the magnetic characteristics considerably and the original magnetic characteristics are retained upon further heat treatment. The results show that the intrinsic magnetic behavior of the disordered carbon depends on the microstructure and that the edge states play a critical role in deciding the magnetic interactions in the amorphous carbon system. (C) 2013 Elsevier Ltd. All rights reserved.
Keywords: Amorphous carbon; disordered carbon; Graphitization; magnetic properties

Mechanochemical synthesis of amide functionalized porous organic polymers - Rajput, Lalit; Banerjee, Rahul (Crystal Growth & Design, 2014)
Two porous organic polymers decorated with the amide functionality were synthesized mechanochemically and their properties were compared with the ones prepared by conventional solution mediated method. All the POPs were subjected to gas and water vapor sorption studies. The mechanochemically synthesized POPs have less surface area and show moderate adsorption properties compared to the solution mediated POPs. The amide based POPs show remarkable stability in water and concentrated acids.

Metallic few-layer flowerlike VS2 nanosheets as field emitters - Rout, Chandra Sekhar; Khare, Ruchita T.; Kashid, Ranjit V.; Joag, Dilip S.; More, Mahendra A.; Lanzillo, Nicholas A.; Washington, Morris; Nayak, Saroj K.; Late, Dattatray J. (European Journal of Inorganic Chemistry, 2014)
We report first-principles DFT calculations of the single-layer VS2 work function, the experimental synthesis of flower-like few-layer-thick VS2 nanosheets by a simple one-step hydrothermal method, and the investigation of their field emission properties. The turn-on field required to draw emission current densities of 1 and 10 mu A/cm(2) were 4 and 5.01 V/mu m, respectively. The observed turn-on field values are attributed to the high field enhancement factor (ca. 2500), which is due to presence of sharp protrusions in the VS2 nanosheets. Furthermore, the field-emission current stability of the VS2 emitter shows stable behavior over a period of 12 h. Further, DFT calculations show that the work function (f) of the single-layer VS2 emitter is 6.01 eV.
Keywords: Density functional calculations; field emission; Layered compounds; Nanostructures; Sulfur; Vanadium

Methane reforming with carbon dioxide over La-Ni-x-Ce1-x mixed oxide catalysts - Sagar, T. V.; Sreelatha, N.; Hanmant, G.; Upendar, K.; Lingaiah, N.; Rao, Kamaraju Seetha Rama; Satyanarayana, C. V. V.; Reddy, I. A. K.; Prasad, P. S. Sai (Indian Journal of Chemistry Section A-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry, 2014)
La-Ni-x-Ce1-x mixed oxide (0 <= x <= 1) catalysts have been hydrothermally prepared, characterized by physico-chemical techniques and evaluated for CO2 reforming of methane. High conversions are achieved for both methane and carbon dioxide over the LaNi0.6Ce0.4O3 catalyst tested under the conditions of CO2/CH4/N-2 ratio of 80/80/80. (total flow rate = 240 mL/min), space velocity of 28,800 h(-1) and at a temperature of 800 degrees C. The H-2/CO ratio in the syngas is stable at 0.93 +/- 0.02. Exchanging Ni with Ce, rather than with La as reported in the literature, appears to be a better option for the improved performance of the catalysts.
Keywords: Carbon dioxide reforming; Catalysts; Cerium; Dry reforming; Hydrothermal synthesis; Lanthanum; Methane reforming; Mixed oxides; Nickel

MicroRNA156: a potential graft-transmissible microrna that modulates plant architecture and tuberization in solanum tuberosum ssp andigena - Bhogale, Sneha; Mahajan, Ameya S.; Natarajan, Bhavani; Rajabhoj, Mohit; Thulasiram, Hirekodathakallu V.; Banerjee, Anjan K. (Plant Physiology, 2014)
MicroRNA156 (miR156) functions in maintaining the juvenile phase in plants. However, the mobility of this microRNA has not been demonstrated. So far, only three microRNAs, miR399, miR395, and miR172, have been shown to be mobile. We demonstrate here that miR156 is a potential graft-transmissible signal that affects plant architecture and tuberization in potato (Solanum tuberosum). Under tuber-noninductive (long-day) conditions, miR156 shows higher abundance in leaves and stems, whereas an increase in abundance of miR156 has been observed in stolons under tuber-inductive (short-day) conditions, indicative of a photoperiodic control. Detection of miR156 in phloem cells of wild-type plants and mobility assays in heterografts suggest that miR156 is a graft-transmissible signal. This movement was correlated with changes in leaf morphology and longer trichomes in leaves. Overexpression of miR156 in potato caused a drastic phenotype resulting in altered plant architecture and reduced tuber yield. miR156 overexpression plants also exhibited altered levels of cytokinin and strigolactone along with increased levels of LONELY GUY1 and StCyclin D3.1 transcripts as compared with wild-type plants. RNA ligase-mediated rapid amplification of complementary DNA ends analysis validated SQUAMOSA PROMOTER BINDING-LIKE3 (StSPL3), StSPL6, StSPL9, StSPL13, and StLIGULELESS1 as targets of miR156. Gel-shift assays indicate the regulation of miR172 by miR156 through StSPL9. miR156-resistant SPL9 overexpression lines exhibited increased miR172 levels under a short-day photoperiod, supporting miR172 regulation via the miR156-SPL9 module. Overall, our results strongly suggest that miR156 is a phloem-mobile signal regulating potato development.

Model atomistic protrusions favouring the ordering and retention of water - Pandey, Prithvi Raj; Roy, Sudip (Physical Chemistry Chemical Physics, 2014)
The ordering of water molecules near model linear atomistic protrusions is studied using classical molecular dynamics simulations. The protrusions are made up of Lennard-Jones particles of hydrophobic and hydrophilic blocks. Simulations are performed at a range of temperatures and pressures, keeping the position of the protrusions fixed. At different temperatures and pressures, the ordering and residence time of water molecules is enhanced on the surface of the hydrophilic block. Detailed analysis of the systems shows that the surface region is potentially the most energetically favorable for water molecules, which is consistent with the tetrahedral ordering of water molecules. A competition between energetics and structuring is observed from residence time calculations.

Molecular cloning and characterization of genistein 4'-O-glucoside specific glycosyltransferase from Bacopa monniera - Ruby; Kumar, R. J. Santosh; Vishwakarma, Rishi K.; Singh, Somesh; Khan, Bashir Mohammad (Molecular Biology Reports, 2014)
Health related benefits of isoflavones such as genistein are well known. Glycosylation of genistein yields different glycosides like genistein 7-O-glycoside (genistin) and genistein 4'-O-glycoside (sophoricoside). This is the first report on isolation, cloning and functional characterization of a glycosyltransferase specific for genistein 4'-O-glucoside from Bacopa monniera, an important Indian medicinal herb. The glycosyltransferase from B. monniera (UGT74W1) showed 49 % identity at amino acid level with the glycosyltransferases from Lycium barbarum. The UGT74W1 sequence contained all the conserved motifs present in plant glycosyltransferases. UGT74W1 was cloned in pET-30b (+) expression vector and transformed into E. coli. The molecular mass of over expressed protein was found to be around 52 kDa. Functional characterization of the enzyme was performed using different substrates. Product analysis was done using LC-MS and HPLC, which confirmed its specificity for genistein 4'-O-glucoside. Immuno-localization studies of the UGT74W1 showed its localization in the vascular bundle. Spatio-temporal expression studies under normal and stressed conditions were also performed. The control B. monniera plant showed maximum expression of UGT74W1 in leaves followed by roots and stem. Salicylic acid treatment causes almost tenfold increase in UGT74W1 expression in roots, while leaves and stem showed decrease in expression. Since salicylic acid is generated at the time of injury or wound caused by pathogens, this increase in UGT74W1 expression under salicylic acid stress might point towards its role in defense mechanism.
Keywords: Bacopa monniera; Expression analysis; Glycosyltransferase; Immuno-localization; Plant secondary product glycosyltransferase motif

Morphological effects of G-quadruplex stabilization using a small molecule in zebrafish - Agarwal, Tani; Lalwani, Mukesh Kumar; Kumar, Santosh; Roy, Saumya; Chakraborty, Tushar Kanti; Sivasubbu, Sridhar; Maiti, Souvik (Biochemistry, 2014)
Zebrafish (Danio rerio) embryos are transparent and advantageous for studying early developmental changes due to ex utero development, making them an appropriate model for studying gene expression changes as a result of molecular targeting. Zebrafish embryos were injected with a previously reported G-quadruplex selective ligand, and the phenotypic changes were recorded. We report marked discrepancies in the development of intersegmental vessels. In silico analysis determined that the putative G-quadruplex motif occur in the upstream promoter region of the Cdh5 (N-cadherin) gene. A real-time polymerase chain reaction-based investigation indicated that in zebrafish, CDH-2 (ZN-cad) was significantly downregulated in the ligand-treated embryos. Biophysical characterization of the interaction of the ligand with the G-quadruplex motif found in this promoter yielded strong binding and stabilization of the G-quadruplex with this ligand. Hence, we report for the first time the phenotypic impact of G-quadruplex targeting with a ligand in a vertebrate organism. This study has unveiled not only G-quadruplex targeting in non-human animal species but also the potential that G-quadruplexes can provide a ready tool for understanding the phenotypic effects of targeting certain important genes involved in differentiation and developmental processes in a living eukaryotic organism.