Effect of halogen addition to monolayer protected gold nanoparticles - Singh, Sanjay; Pasricha, Renu; Bhatta, Umananda M.; Satyam, P. V.; Sastry, Murali; Bhagavatula L. V. Prasad (Journal of Materials Chemistry, 2007)
The effects of N-halosuccinimide and halogen addition to monolayer protected gold nanoparticles (Au NPs) dispersed in organic media are described. Contrary to the expectation that nanoparticles dispersed in organic media are stable against aggregation, N-iodosuccinimide addition induced aggregation of octadecylamine capped gold nanoparticles in chloroform or toluene. It was observed that even KI and CuI addition could bring about the aggregation though they are very sparingly soluble in organic solvents. It was also found that even molecular iodine could bring about the above mentioned aggregation. Interestingly, when CuI is used the aggregated structures readily convert to very thin flat nanostructures upon exposure to an electron beam or UV irradiation. In fact when the aggregation is induced by the addition of KI or N-iodosuccinamide we do not see the flattening of the aggregated structures exemplifying the important role of Cu ions in making these flat structures.

Effect of surface chemistry of Fe-Ni nanoparticles on mechanistic pathways of azo dye degradation - Bokare, Alok D.; Chikate, Rajeev C.; Rode, Chandrashekhar V.; Paknikar, Kishore M. (Environmental Science & Technology, 2007)
The degradation of Orange G a monoazo dye, in aqueous solutions was investigated using as-synthesized and stored Fe-Ni bimetallic nanoparticles. Batch experiments with a nanocatalyst loading of 3 g/L showed complete. dye degradation (150 mg/L) after 10 min of reactiontime. HPLC-MS analysis of the degradation products showed that assynthesized nanoparticles reductively cleaved the azo linkage to produce aniline as the major degradation product. However, 1-year-stored nanoparticles showed an oxidative degradation of Orange G through a hydroxyl-radical induced coupling of parent and/or product molecules. XPS analysis in corroboration with HPLC-MS data showed that the surface chemistry between Fe and Ni in assynthesized and stored nanoparticles play a crucial role. in directing the mode of degradation. Reductive dye degradation using as-synthesized nanoparticles proceeded through hydride transfer from nickel, whereas formation of a Fe (2+) -Ni(0) galvanic cell in stored nanoparticles generated hydroxyl radicals from water in a nonFenton type reaction. The latter were responsible for the generation of radical centers on the dye molecule, which led to a coupling-mediated oxidative degradation of Orange G. The generation of hydroxyl radicals is further substantiated with radical quenching experiments using ascorbic acid indicating that stored nanoparticles degrade Orange G through a predominantly oxidative mechanism. HPLC-MS and XPS analysis of dye degradation using as-synthesized nanoparticles exposed to air and water confirmed that the reductive or oxidative degradation capability of Fe-Ni nanoparticles is decided by the time and type of catalyst aging process.

Efficient higher-order cycloaddition reactions of 8,8-dicyanoheptafulvenes with dienes - Nair, Vijay; Gopalakrishnan Abhilash, K.; Biju, Akkattu T.; Eringathodi, Suresh (Synthesis-Stuttgart, 2007)
The cycloaddition reactions of 8,8-dicyanoheptafulvene with electron-rich dienes afforded the higher order cycloaddition products in excellent yields. With cyclic dienes as well as dimethoxybutadiene the [8+2] adducts were obtained exclusively. With methyl- and dimethylbutadienes the [6+4] adducts were the only products isolated.
Keywords: cycloadditions - bicyclic compounds - polycycles - dicyanoheptafulvene - tetrahydroazulenes

Efficient N-arylation of amines catalyzed by Cu-Fe-hydrotalcite - Jadhav, Vinod H.; Dumbre, Deepa K.; Phapale, Vilas B.; Borate, Hanumant B.; Wakharkar, Radhika D. (Catalysis Communications, 2007)
An efficient N-arylation of amines with aryl halides in presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been developed. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: amines; Aryl halides; Cu-Fe-hydrotalcite; heterogeneous catalyst; N-arylation

Efficient one-pot synthesis of alpha-amino phosphonates catalyzed by bismuth nitrate pentahydrate - Bhattacharya, Asish K.; Kaur, Tanpreet (Synlett, 2007)
A simple, efficient, and environmentally benign method has been developed for the synthesis of alpha-amino phosphonates through a one-pot reaction of aldehydes with amines and diethyl phosphite in the presence of bismuth nitrate pentahydrate as a catalyst. Some of the major advantages of this protocol are: good yields, the involvement of a less-expensive and non-toxic catalyst, mild and solvent-free reaction conditions and also tolerance towards other functional groups present in the substrates. Eighteen examples are described, highlighting the substrate scope of the reaction.
Keywords: aldehydes; alkyl phosphite; alpha-amino phosphonates; amines; bismuth nitrate pentahydrate; synthetic methods

Enantiomeric separation of novel anticancer agent 5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en- 1-one - Shinde, Popat D.; Jadhav, Vinod H.; Borate, Hanumant B.; Bhide, Sunil R.; Sonawane, Kiran B.; Wakharkar, Radhika D. (Journal of Chromatography A, 2007)
The enantiomers of 5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2-en- 1-one, a novel anticancer agent, were separated by derivatisation with caronaldehyde, separation of the resulting diastereoisomers of the corresponding esters by silica gel column chromatography and regeneration of alcohols (S)-5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2 -en-1-one and (R)5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2- en- 1-one under aqueous conditions. The absolute configuration of the enantiomers was determined by H-1 NMR studies of the corresponding Mosher esters. Alternatively, the enantiomers were separated by preparative HPLC to collect the (S)- and (R)-5-hydroxy-3-(4-methoxyphenyl)-2-(3,4,5-trimethoxyphenyl)-cyclopent-2 -en-1-ones with high purity which was comparable with that obtained by the chemical method. The details of these methods have been presented herein. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: Anticancer; column chromatography; diaryl cyclopentenone; diastereoisomers; enantioseparation; HPLC; Resolution

Enantioselective syntheses of (-)-pinellic acid, alpha- and beta-dimorphecolic acid - Baruah, Pranjal K.; Gonnade, Rajesh G.; Sanjayan, Gangadhar J. (Tetrahedron, 2007)
An efficient enantioselective convergent approach for the synthesis of (-)-pinellic acid 1, alpha- and beta- dimorphecolic acid (2 and 3) from 1,9-nonane diol is described. The synthetic strategy features Sharpless asymmetric hydroxylation, Sonogashira coupling and Birch reduction. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: asymmetric dihydroxylation; influenza; Sonogashira coupling

Encapsulation of endoglucanase using a biopolymer Gum arabic for its controlled release - Ramakrishnan, Anish; Pandit, Nilesh; Badgujar, Mahesh; Bhaskar, C.; Rao, Mala (Bioresource Technology, 2007)
{Gum Arabic, a biodegradable natural polymer was used as a matrix to encapsulate endoglucanase from Thermomonospora sp. The modified enzyme retained complete biocatalytic activity and exhibited a shift in the optimum temperature [
Keywords: Enzyme catalysis; OPTA; Thermomonospora sp.; Xylanase

Enforcing periodic secondary structures in hybrid peptides: a novel hybrid foldamer containing periodic gamma-turn motifs - Baruah, Pranjal K.; Sreedevi, N. K.; Gonnade, Rajesh G.; Ravindranathan, Sapna; Damodaran, Krishnan; Hofmann, Hans-Joerg; Sanjayan, Gangadhar J. (Journal of Organic Chemistry, 2007)
{This note describes the design, synthesis, and conformational studies of a novel hybrid foldamer that adopts a definite compact, three-dimensional structure determined by a combined effect of the special conformational properties of the foldamer constituents. The striking feature of this de novo designed foldamer is its ability to display periodic gamma-turn conformations stabilized by intramolecular hydrogen bonds. Conformational investigations by single-crystal X-ray studies, solution-state NMR, and ab initio MO theory at the HF/6-31G*
Keywords: ammonia-TPD; benzylation reaction; Ce-Al-MCM-41; Friedel-Crafts alkylation; pyridine-FrIR

Estimation of gross calorific value of coals using artificial neural networks - Patel, Shagufta U.; Kumar, B. Jeevan; Badhe, Yogesh P.; Sharma, B. K.; Saha, Sujan; Biswas, Subhasish; Chaudhury, Asim; Tambe, Sanjeev S.; Kulkarni, Bhaskar D. (Fuel, 2007)
The gross calorific value (GCV) is an important property defining the energy content and thereby efficiency of fuels, such as coals. There exist a number of correlations for estimating the GCV of a coal sample based upon its proximate and/or ultimate analyses. These correlations are mainly linear in character although there are indications that the relationship between the GCV and a few constituents of the proximate and ultimate analyses could be nonlinear. Accordingly, in this paper a total of seven nonlinear models have been developed using the artificial neural networks (ANN) methodology for the estimation of GCV with a special focus on Indian coals. The comprehensive ANN model developed here uses all the major constituents of the proximate and ultimate analyses as inputs while the remaining six sub-models use different combinations of the constituents of the stated analyses. It has been found that the GCV prediction accuracy of all the models is excellent with the comprehensive model being the most accurate GCV predictor. Also, the performance of the ANN models has been found to be consistently better than that of their linear counterparts. Additionally, a sensitivity analysis of the comprehensive ANN model has been performed to identify the important model inputs, which significantly affect the GCV. The ANN-based modeling approach illustrated in this paper is sufficiently general and thus can be gainfully extended for estimating the GCV of a wide spectrum of solid, liquid and gaseous fuels. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: Artificial neural network; gross calorific value (GCV); proximate and ultimate analyses

Facile chemo-, regio-, and diastereoselective approach to cis-3,5-disubstituted gamma-butyrolactones and fused gamma-butyrolactones - Baag, Md. Merajuddin; Puranik, Vedavati G.; N. P. Argade (Journal of Organic Chemistry, 2007)
Chemoselective S(N)2' condensation of primary enolates of alkyl methyl ketones 2a-e with dimethyl bromomethylfumarate ( 1) followed by highly diastereoselective NaBH4 reduction of the ketone function in the formed ketodiesters 3a-e and the regioselective in situ lactonization of the unisolable intermediates 4a-e exclusively furnished the cis-3,5-disubstituted gamma-butyrolactones (+/-)-5a-e in very good yields. Similarly, the face-selective coupling reaction of cyclohexanone enolate with 1 to form a mixture of diastereomers in an 8: 2 ratio followed by a highly selective reductive cyclization of 9 plus 10 exclusively provided the cis-octahydrobenzofuran (+/-)- 12 in 70% overall yield.

Ferromagnetic resonance in nanomagnetic metal core and noble metal shell systems - Bala, Tanushree; Enoki, Toshiaki; Bhagavatula L. V. Prasad (Journal of Nanoscience and Nanotechnology, 2007)
The change in the line widths in the ferromagnetic resonance (FMR) spectra of Co and Ni nanoparticles upon shell formation with noble metals like gold or silver are described. The NicoreAgshell, CocoreAgshell, and CocoreAushell nanoparticles were prepared by a simple transmetallation reaction between the Co and Ni nanoparticles and the Ag+ or AuCl−4 ions. It is revealed that the FMR line width decreases upon Ag shell formation whereas it increases upon core–shell composite formation with Au. Several probable explanations such as the differences in size distributions before and after the reaction or the changes occurring in shape anisotropy of the particles due to the shell formation or the different extents of electronic interaction between the core and shell materials have been offered for this observation.
Keywords: Fmr Study; Line Width Comparison; Magnetic Core-Noble Metal Shell Nanoparticles

Field emission investigations of RuO2-doped SnO2 wires - Bhise, Ashok B.; Late, Dattatray J.; Ramgir, Niranjan S.; More, Mahendra A.; Mulla, Imtiaz S.; Pillai, Vijayamohanan K.; Joag, Dilip S. (Applied Surface Science, 2007)
Field emission studies of a bunch and a single isolated RuO2:SnO2 wire have been performed. A current density of 5.73 x 10(4) A/cm(2) is drawn from the single wire emitter at an applied field of 8.46 x 10(4) V/mu m. Nonlinearity in the Fowler-Nordheim (F-N) plot has been observed and explained on the basis of electron emission from both the conduction and the valence bands of the semiconductor. The current stability recorded at the preset value of 1.5 LA is observed to be good. Overall the high emission current density, good stability and mechanically robust nature of the RuO2:SnO2 wires offer advantages as field emitters for many potential applications. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: doped semiconductor; field emission; field enhancement factor; RuO2; SnO2

Gas sorption and transport in polyarylates: effect of substituent symmetry and polarity - Karadkar, Prasad B.; Kharul, Ulhas K.; Bhole, Yogesh S.; Badhe, Yogesh P.; Tambe, Sanjeev S.; Kulkarni, Bhaskar D. (Journal of Membrane Science, 2007)
The gas sorption properties of polyarylates based on bisphenol-A possessing symmetric/asymmetric substitution by nonpolar -CH3 group and symmetrically linked terephthalic acid were examined. The effects of substitution of polar bromine on terephalic acid moiety of polyarylate based on asymmetrically substituted bisphenol were also studied for physical, sorption and transport properties. The estimation of dual mode sorption parameters, solubility and diffusion coefficient revealed that nature of the substituent and substitution type plays a crucial role in depicting permeation properties. An asymmetric substitution by -CH3 group increased solubility coefficient of pure gases (N-2, O-2, CH4 and CO2) up to 27% and symmetric substitution increased the same up to 106%. This was coupled with 7-35% increase in solubility selectivity in both cases of substitution, which ascertained the usefulness of methyl group substitution in polyarylates based on terephalic acid. The pressure dependency of solubility coefficients and solubility selectivity was also investigated for these polyarylates. The sorption and transport properties of these polyarylates correlated well with physical properties of polyarylates and gases studied. The sorption/desorption kinetics of symmetrically substituted TMBisA-T was performed in order to deduce time dependent sorption behavior and to evaluate diffusivity coefficient. The apparent diffusion coefficients from sorption kinetics, desorption kinetics and from steady-states permeation-sorption were compared. The diffusion coefficients of CH4 and N-2 deduced by these methods correlated well with each other. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: Diffusion; kinetics; permeation; polyarylates; Sorption

Grafting reactions of living macroanions with multi-walled carbon nanotubes - Baskaran, Durairaj; Sakellariou, Georgios; Mays, Jimmy W.; Bratcher, Matthew S. (Journal of Nanoscience and Nanotechnology, 2007)
Grafting reactions of living polystyryllithium (PSLi) with acid chloride containing multi-walled carbon nanotubes (MWNTs-COCl) were performed under vacuum in benzene at room temperature. Covalent grafting of polystyrene (PS) was characterized using spectroscopic, microscopic, and thermogravimetric analyses. Grafting at different ratios of macroanion to acylchloride of the carbon nanotubes showed that the grafting efficiency was not dependent on the concentration of the macroanions. The mole percent of PS present in the MWNTs-g-PS samples was inversely proportional to the precursor molecular weight of PSLi. Direct reactions of PSLi, polybutadienyllithium and n-butyllithium with pristine MWNTs without any functional groups were also performed in the presence and in the absence of tetrahydrofuran in benzene. The grafting reactions of living macroanions either with MWNTs-COCl or with pristine MWNTs indicated a partial grafting of polymer on the carbon nanotubes in benzene at room temperature.
Keywords: Anionic polymerization; covalent functionalization; grafting; multi-walled carbon nanotubes

Group 11 metal complexes of mesocyclic thioether-aminophosphonites, (-OC10H6) - Punji, Benudhar; Mague, Joel T.; Balakrishna, Maravanji S. (European Journal of Inorganic Chemistry, 2007)
Group 11 metal complexes of the mesocyclic thioether aminophosphonites [-OC10H6(μ-S)C10H6O-]PNC4H8E {2a: E = O; 2b: E = NMe; IUPAC names: 4-(dinaphtho[2,1-d:1′,2′-g][1,3,6,2]dioxathiaphosphocin-4-yl)morpholine (2a), 1-(dinaphtho[2,1-d:1′,2′-g][1,3,6,2]dioxathiaphosphocin-4-yl)-4-methylpiperazine (2b)} are reported. Thioether aminophosphonites 2a and 2b react with CuX (X = Cl, Br, and I) in a 1:1 molar ratio to give the tricoordinate, dimeric complexes [{[{-OC10H6(μ-S)C10H6O-}PNC4H8E-κP]Cu(μ-X)}2] (4a: E = O, X = Cl; 4b: E = NMe, X = Cl; 5a: E = O, X = Br; 5b: E = NMe, X = Br; 6a: E = O, X = I; 6b: E = NMe, X = I), whereas with 2:1 molar ratios monomeric complexes of the type[{[-OC10H6(μ-S)C10H6O-]PNC4H8O-κP}2CuX] (7a: E = O, X = Cl; 7b: E = NMe, X = Cl; 8a: E = O, X = Br; 8b: E = NMe, X = Br; 9a: E = O, X = I; 9b: E = NMe, X = I) are obtained in excellent yield. The P,S-chelated cationic complexes[{[-OC10H6(μ-S)C10H6O-]PNC4H8E-κP,κS}2Cu]BF4 (10a: E = O; 10b: E = NMe) are obtained when 2a and 2b are treated with half an equivalent of [(MeCN)4Cu]BF4. Similarly, thesilver complexes [{[{-OC10H6(μ-S)C10H6O-}PNC4H8E-κP,κS]AgCF3SO3}2] (11a: E = O: 11b: E = NMe) and [{[-OC10H6(μ-S)C10H6O-]PNC4H8E-κP,κS}Ag(PPh3)]CF3SO3 (12a: E = O; 12b: E = NMe) are synthesized by the treatment of thioether aminophosphonites 2a and 2b with AgOTf and [Ag(PPh3)][OTf], respectively. Reactions of 2a and 2b with [AuCl(SMe2)] produce the simple monomeric gold(I) complexes [{[-OC10H6(μ-S)C10H6O-]PNC4H8E-κP}AuCl] (13a: E = O; 13b: E = NMe). The iodo derivatives [{[-OC10H6(μ-S)C10H6O-]PNC4H8E-κP}AuI] (14a: E = O; 14b: E = NMe) are obtained by the halide-exchange reaction of 13a and 13b with CuI at room temperature. The structures of complexes 5a, 7a, 8a, 13a, 13b, and 14a are confirmed by single-crystal X-ray diffraction studies. In all of these complexes, the sulfur atom in the mesocyclic ring shows coordinative interaction towards the phosphorus atom, and in 5a, 7a, 8a, and 14a towards the metal center as well. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Highly air-stable anionic mononuclear and neutral binuclear palladium(ii) complexes for C−C and C−N bond-forming reactions - Punji, Benudhar; Mague, Joel T.; Balakrishna, Maravanji S. (Inorganic Chemistry, 2007)
The short-bite aminobis(phosphonite), PhN{P(−OC10H6(μ-S)C10H6O−)}2 (2), containing a mesocyclic thioether backbone is synthesized by either treating PhN(PCl2)2 with 2 equiv of thiobis(2,2‘-naphthol) or reacting chlorophosphite (−OC10H6(μ-S)C10H6O−)PCl (1) with aniline in the presence of a base. Treatment of 2 with an equimolar amount of Pd(COD)Cl2 in the presence of H2O affords a P−N−P-bridged and P,S-metalated binuclear complex, [PhN(P(−OC10H6(μ-S)C10H6O−)-κP)2Pd2Cl2{P(−OC10H6(μ-S)C10H6O−)(O)-κP,κS}2] (3), whereas the same reaction with 2 equiv of Pd(COD)Cl2 in the presence of H2O and Et3N produces the mononuclear anionic complex [{(−OC10H6(μ-S)C10H6O−)P(O)-κP,κS}PdCl2](Et3NH) (5). By contrast, reaction of 2 with 2 equiv of Pd(COD)Cl2 and H2O in the absence of Et3N gives the hydrogen phosphonate coordinated complex [{(−OC10H6(μ-S)C10H6O−)P(OH)}PdCl2] (4) which converts to the anionic complex in solution or in the presence of a base. Compound 2 on treatment with Pt(COD)X2 (X = Cl or I) afforded P-coordinated four-membered chelate complexes [PhN(P(−OC10H6(μ-S)C10H6O−)-κP)2PtX2] (6 X = Cl, 7 X = I). The crystal structures of compounds 2, 3, 5, and 7 are reported. Compound 3 is the first example of a crystallographically characterized binuclear palladium complex containing a bidentate bridging ligand and its hydrolyzed fragments forming metallacycles containing a palladium−phosphorus σ bond. All palladium complexes proved to be very good catalysts for the Suzuki−Miyaura and Mizoroki−Heck cross-coupling and amination reactions with excellent turnover numbers (TON up to 1.46 × 105 in the case of the Suzuki−Miyaura reaction).

Impact of orientational distribution of adsorbing objects on dynamics of Random Sequential Ballistic Adsorption (RSBA) dynamics - Shelke, Pradip B.; Banpurkar, Arun G.; Ogale, Satishchandra B.; Limaye, A. V. (Surface Science, 2007)
Recently, by proposing a new variant of Random Sequential Adsorption (RSA) namely Random Sequential Ballistic Adsorption (RSBA) model [Pradip B. Shelke, A.G. Banpurkar, S.B. Ogale, A.V. Limaye, Surf. Sci. 601 (2007) 274], we addressed the issue of adsorption dynamics of extended objects where the objects, upon adsorption, protrude outside the substrate. This study brought out the role of the arriving trajectory in the adsorption dynamics. In the present work the possible role of the orientational distribution of the arriving objects in the RSBA dynamics is investigated. The dynamics of RSBA of needles (line segments) is studied analytically and by computer simulation for different types of theta distributions of arriving needles, theta being the angle made by the arriving needle with normal to the substrate. Three types of theta distributions, namely a uniform distribution over the range (0, pi/2), a Gaussian distribution and a distribution uniform over the solid angle, are considered. Analytical treatment establishes that in all the three cases, the number n(t) of adsorbed objects at a late time t follows a power law n(t) similar to t(alpha), and the exponent a depends on the specifics of the theta distribution. In general, for distribution f(theta) proportional to theta(beta), for theta -> 0, alpha is found to be 2/(beta + 3). The simulation results are in excellent agreement with the analytical findings and together they reveal that the orientational distribution of arriving objects has significant consequences for the Random Sequential Ballistic Adsorption (RSBA) process. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: Adsorption; adsorption kinetics; Monte Carlo simulations; random sequential adsorption (RSA)

Improve polyethylene process control and product quality - using artificial intelligence-based sensors can improve costs - Badhe, Yogesh P.; Lonari, J.; Tambe, S. S.; Kulkarni, B. D.; Valecha, N. K.; Deshmukh, S. V.; Ravichandran, S. (Hydrocarbon Processing, 2007)

Interaction of different metal ions with carboxylic acid group: a quantitative study - Bala, Tanushree; Bhagavatula L. V. Prasad; Sastry, Murali; Kahaly, Mousumi Upadhyay; Waghmare, Umesh V. (Journal of Physical Chemistry A, 2007)
The binding strength of the carboxylic acid group (-COOH) with different divalent metal ions displays considerable variation in arachidic acid (AA) thin films. It is considered that in AA thin films the metal ions straddle the hydrophilic regions of the stacked bilayers of AA molecules via formation of carboxylates. In this study first the uptake of different divalent cations in films of AA is estimated by atomic absorption spectroscopy (AAS). Through the amount of cation uptake, it is found that the strength of binding of different cations varies as Ca2+ > Co2+ > Pb2+ > Cd2+. Variation in the binding strength of different ions is also manifested in experiments where AA thin films are exposed to metal ion mixtures. The higher binding strength of AA with certain metal ions when exposed individually, as well as the preference over the other metal ions when exposed to mixtures, reveal some interesting deviation from the expected behavior based on considerations of ionic radii. For example, Pb2+ is always found to bind to AA much more strongly than Cd2+ even though the latter has smaller ionic radius, indicating that other factors also play an important role in governing the binding strength trends apart from the effects of ionic radii. Then, to get a more meaningful knowledge regarding the binding capability, first-principles calculations based on density functional theory have been applied to study the interaction of different cations with the simplest carboxylic acid, acetic acid, that can result in formation of metal diacetates. Their electronic and molecular structures, cohesive energies, and stiffness of the local potential energy well at the cation (M) site are determined and attempts are made to understand the diversity in geometry and the properties of binding of different metal ions with -COOH group. We find that the calculated M−O bond energies depend sensitively on the chemistry of M atom and follow the experimentally observed trends quite accurately. The trends in M−O bond energies and hence the total M−acetate binding energy trends can actually be related to their molecular structures that fall into different categories:  Ca and Cd have tetrahedral coordination; Fe, Ni, and Co exhibit planar 4-fold coordination; and Pb is off-centered from the planar structure (forming pyramidal structure) due to its stereochemically active lone pair of electrons.

Interface and defect structures in YBa(2)Cu(3)O(7-delta) and Nb : SrTiO(3) heterojunction - Fu, Lian-feng; Browning, Nigel D.; Ramadan, W.; Ogale, Satishchandra B.; Kundaliya, D. C.; Venkatesan, T. (Journal of Physics D-Applied Physics, 2007)
YBa(2)Cu(3)O(7-delta) thin films grown on a Nb-doped SrTiO(3) substrate by a pulsed laser deposition method have been fully characterized by scanning transmission electron microscopy Z- contrast imaging and electron energy loss spectroscopy techniques. The Nb distribution was found to be uniform and unchanged across the interface, ensuring a high quality p - n junction heterointerface. We first observed the coexistence of 124 and 125 YBCO defect structure phases, appearing as planar defects in a YBCO thin film. Dispersive Y(2)O(3) nanoparticles have also been observed in the thin film. The interaction of these defect structures and Y(2)O(3) nanoparticles is thought to be beneficial for pinning flux through the entire film thickness.

Investigating organization of molecules that facilitates intermolecular acyl transfer in crystals: reactivity and x-ray structures of O-benzoyl-myo-inositol 1,3,5-orthoesters - Murali, Chebrolu; Shashidhar, Mysore S.; Gonnade, Rajesh G.; Bhadbhade, Mohan M. (European Journal of Organic Chemsitry, 2007)
{Crystal structure analysis of racemic 2,6-di-O-benzoyl-myo-inositol 1,3,5-orthobenzoate reveals helical organization of the molecules, remarkably similar to that observed earlier in crystals of racemic 2,6-di-O-benzoyl-myo-inositol 1,3,5-orthoformate. Both these dibenzoates are isostructural despite the bulkier phenyl substituent in place of hydrogen. The latter compound shows highly facile intermolecular benzoyl transfer reactivity in its crystals and as anticipated from the crystal structure, the orthobenzoate indeed exhibits facile benzoyl transfer reactivity in its crystals. 2-O-Benzoyl-myo-inositol 1,3,5-orthoformate and the corresponding orthobenzoate also undergo transesterification in their crystals, but the specificity of acyl transfer is very low, and the reaction yields a mixture of products. The parameters of helical molecular assembly that facilitates acyl transfer in crystals have been investigated. A comparison of the molecular assemblies and lattice interactions in crystals of all the four compounds with the observed reactivity patterns show that facile acyl transfer reaction is brought about by a modular ``reaction tunnel''
Keywords: AOT; CdS-Ag2S; core-shell; Nanoparticles; w/o microemulsion; XPS

Large bite bisphosphite, 2,6-C5H3N{CH2OP(-OC10H6) - Punji, Benudhar; Balakrishna, Maravanji S. (Journal of Organometallic Chemistry, 2007)
<div class="abstract svAbstract " data-etype="ab" style="border: 0px; font-size: 16px; margin: 0px; padding: 0px; vertical-align: baseline; font-family: Arial, Helvetica, 'Lucida Sans Unicode', 'Microsoft Sans Serif', 'Segoe UI Symbol', STIXGeneral, 'Cambria Math', 'Arial Unicode MS', sans-serif; color: rgb(46, 46, 46); line-height: 23.68px;"> Large bite bisphosphite ligand, 2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2 (2), is obtained by reacting chlorophosphite, {-OC10H6(μ-S)C10H6O-}PCl (1) with 2,6-pyridinedimethanol in presence of triethylamine.Treatment of 2 with aqueous solution of H2O2 or elemental sulfur resulted in the formation of bis(oxide) or bis(sulfide) derivatives, 2,6-C5H3N{CH2OP(E)(–OC10H6)(μ-S)(C10H6O–)}2 (3, E = O; 4, E = S) in quantitative yield.The 10-membered cationic chelate complex, [RuCl(η6-C10H14)η2-2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2-κP,κP]Cl (5) is produced in the reaction between [Ru(p-cymene)(μ-Cl)(Cl)]2 and bisphosphite 2, whereas the neutral chelate complex, cis-[Rh(CO)Cl{2,6-C5H3N{CH2OP(–OC10H6(μ-S)C10H6O–)}2}-κP,κP] (6) is isolated in the reaction of 2 with 0.5 equiv.of [Rh(CO)2Cl]2.Compound 2 on treatment with M(COD)Cl2 (M = Pd, Pt) produce the chelate complexes, [MCl2{η2-2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2}-κP,κP] (7, M = Pd;10, M = Pt).Similarly the reaction of bisphosphite 2 with Pd(COD)MeCl affords cis-[PdMe(Cl)η2-2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2-κP,κP] (8).Treatment of 2 with [Pd(η3- C3H5)Cl]2 in the presence of AgClO4 furnish the cationic complex, [Pd(η3-C3H5)η2-2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2-κP,κP]ClO4 (9). The binuclear complex, [Au2Cl2{2,6-C5H3N{CH2OP(–OC10H6)(μ-S)(C10H6O–)}2}-κP,κP] (11) is obtained in the reaction of compound 2 with two equiv. of AuCl(SMe2), where the ligand exhibits bridged bidentate mode of coordination. All the complexes are characterized by the 1H NMR, 31P NMR, elemental analysis and mass spectroscopy data. The cationic ruthenium complex 5 is proved to be an active catalyst for the hydrogenation of styrene and α-methyl styrene.

Low temperature synthesis of magnetite and maghemite nanoparticles - Bhagwat, Shrikant; Singh, Hema; Athawale, Anjali; Hannoyer, Beatrice; Jouen, Samuel; Lefez, Benoit; Kundaliya, Darshan; Pasricha, Renu; Kulkarni, Shailaja; Ogale, Satishchandra B. (Journal of Nanoscience and Nanotechnology, 2007)
We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammoniurn sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe-2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.
Keywords: low temperature synthesis; maghemite; magnetite; Nanoparticles

Macroporous beads for lipase immobilization: kinetic resolution of a racemic drug intermediate - Bhushan, Indu; Parshad, Rajinder; Qazi, G. N.; Ingavle, Ganesh C.; Jamalpure, Trupti M.; Rajan, C. R.; Ponrathnam, Surendra; Gupta, V. K. (Journal of Bioactive and Compatible Polymers, 2007)
{Lipase isolated from Arthrobacter sp. (RRLJ-1, MTCC No. 5125, named ABL), is effective in resolving a wide range of racemic drug intermediates. In this study, ABL was immobilized on a series of synthetic macroporous epoxy copolymers beads with varying pore sizes, surface area and hydrophobicity. Poly(glycidyl methacrylate-co-ethylene dimethacrylate) beads, with 75% crosslink density and 10% of epoxy groups modified with dibutyl amine [
Keywords: auxin pulse; coco-peat; grape; micropropagation; plantlet survival

Metal complexes of crosslinked chitosans. part II. an investigation of their hydrolysis to chitooligosaccharides using chitosanase - Trimukhe, K. D.; Bachate, S.; Gokhale, D. V.; Varma, Anjanikumar (International Journal of Biological Macromolecules, 2007)
This paper investigates the behavior of crosslinked chitosans and metal-complexed crosslinked chitosans under similar hydrolytic conditions. Crosslinked chitosans with trimellitic anhydride, diisocyanatohexane, and dibromodecane as crosslinking agents under heterogenous reaction conditions were used as metal complexing agents by equilibrating them with metal salts such as ZnCl2, MnSO4, CuSO4, CdSO4, Pb(NO3)(2), and HgCl2. Crosslinked chitosan without metal complexation had the same hydrolytic behavior as uncrosslinked chitosan. However, when the crosslinked chitosans were complexed with metals, their rates of hydrolysis and extent of hydrolysis were significantly reduced. Thus, while for chitosan about 840 mu g/ml reducing sugar was produced in 4 h time, and 780 mu g/ml was produced for diisocyanatohexane crosslinked chitosan, only 400 mu g/ml and 320 [mu g/ml reducing sugars were produced for cadmium sulfate with crosslinked chitosan and diisocyanatohexane crosslinked chitosan, respectively. Similar results are obtained for other crosslinking agents. Studies on preincubation of the metal with the enzyme show that of the metals studied, Mn has no effect on preincubatioin with the enzyme, Hg, Cd, Pb, and Cu completely deactivates the enzyme, while Zn reduces the enzyme activity by about 43.3%. Preincubation of the metal salts with the chitosan shows that Hg and Cu completely deactivate the molecule from enzyme hydrolysis, Cd and Zn inactivate it to the extent of 56.8% and 43.3%, respectively, while Mn has no effect. Availability of the amino functions seems to be a key feature for the chitosanase to hydrolyze the chitosan polymer. This was also proved by the significant increase in the extent of hydrolysis for chitosan samples with 88% (final value 1120 mu g/ml reducing sugar) and 85% deacetylation (final value 840 mu g/ml reducing sugar). HPIC studies of the products show that a variety of oligomers are produced in the chitosanase enzyme hydrolytic reaction. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: chitooligosaccharides; Chitosan; chitosanase hydrolysis; Crosslinked chitosan; metal-complexed crosslinked chitosan

NCL-7, a novel all silica analog of polymorph B rich member of BEA family: synthesis and characterization - Kadgaonkar, Mahesh D.; Kasture, Mahesh W.; Bhange, Deu S.; Joshi, Praphulla N.; Ramaswamy, Veda; Kumar, Rajiv (Microporous and Mesoporous Materials, 2007)
{Polymorph B-rich BEA type structure, NCL-7, was synthesized using hydrothermal method in fluoride medium using perchloric acid as promoter. The samples were characterized using XRD, low temperature N-2-adsorption and Si-29 MASNMR. As the structure of beta is highly disordered Rietveld refinement of powder XRD patterns is precluded. Phase composition is derived using the simulated patterns for the random intergrowths of polymorph A and B by DIFFaX. The stacking direction c' is perpendicular to the a'b' plane of the layer. The composition of polymorph B is found to be ca. 60-65%. Two other structures namely NCL-5 and NCL-6 with varying degree of polymorph B enrichment were also synthesized. Synthesis parameters such as effect of H2O/SiO2, TEAOH/SiO2, HClO4/SiO2 and crystallization temperature were studied thoroughly. The present article explains for the first time the synthesis and characterization of NCL-7, an analog of BEA type family with enrichment of polymorph B and its comparison with normal beta (*
International Symposium on Zeolite and Microporous Crystals (ZMPC 2006), Yonago, JAPAN, JUL 30-AUG 02, 2006
Keywords: B-polymorph; DIFFaX; Promoter; Reitveld refinement; synthesis; zeolite beta

Nitration and amination of polyphenylene oxide: synthesis, gas sorption and permeation analysis - Bhole, Yogesh S.; Karadkar, Prasad B.; Kharul, Ulhas K. (European Polymer Journal, 2007)
A high degree of nitration of polyphenylene oxide (PPO) was successfully achieved by carefully optimizing synthetic protocol. The reduction of nitro group to amino could be done quantitatively. The physical properties of formed polymers were investigated and correlated with gas sorption and permeation properties. The formed polymers were amorphous in nature as revealed by wide angle X-ray diffraction spectra. An increase in the packing density in comparison to unsubstituted PPO as a result of induced polarity was indicated by lowering of fractional free volume and d-spacing. The substitution by either nitro or amino group increased the chain stiffness as revealed by the dynamic mechanical analysis. Though both, nitro and amino group substitution on PPO led to a decrease in pure gas permeability, the selectivity of various gas pairs was increased by these substitutions. The gas sorption analysis revealed that both, solubility selectivity and diffusivity selectivity were increased by these polar group substitutions. The nitro group substitution was more effective in improving solubility selectivity, while amino group substitution was more effective in improving diffusivity selectivity. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: Amination; nitration; permeation; polyphenylene oxide; Sorption

Novel reaction of the “huisgen zwitterion” with chalcones and dienones: an efficient strategy for the synthesis of pyrazoline and pyrazolopyridazine derivatives - Nair, Vijay; Biju, Akkattu T.; Mathew, Smitha C.; Eringathodi, Suresh (Angewandte Chemie-International Edition, 2007)
Two unexpected transformations: The reaction of the Huisgen zwitterion derived from triphenylphosphane and diisopropyl azodicarboxylate (DIAD) with chalcones affords functionalized pyrazolines. In contrast, the reaction with dienones affords pyrazolopyridazines, presumably by Diels–Alder reaction of the initially formed pyrazoline with excess DIAD (see scheme).
Keywords: chalcones; nitrogen heterocycles; pyrazolines; synthetic methods; zwitterions

O-2-Naphthyl diphenylthiophosphinate - Mague, Joel T.; Punji, Benudhar; Ganesamoorthy, Chelladurai; Balakrishna, Maravanji S. (Acta Crystallographica Section E-Crystallographic Communications, 2007)
The molecule of the title compound, C10H7OP(S)(C6H5)2 or C22H17OPS, exhibits distorted tetrahedral geometry about the P atom. The P=S bond of 1.9355 (4) Å is shorter than that found in Ph3P=S [1.950 (3) Å] because the replacement of one carbon on phosphorus by oxygen increases the effective electronegativity of the P atom, thereby enhancing pπ–dπ back-donation from a lone-pair orbital of the S atom.

One-step preparation of alpha-chlorostyrenes - Borate, Hanumant B.; Galkwad, Abaji G.; Maujan, Suleman R.; Sawargave, Sangmeshwer P.; Kalal, Kamalakar M. (Tetrahedron Letters, 2007)
alpha-Chlorostyrenes were prepared via a one-step method involving Friedel-Crafts reaction of various aromatic substrates with acid chlorides in the presence of a heterogeneous Si-Fe catalyst. (c) 2007 Elsevier Ltd. All rights reserved.

One-step synthesis of SBA-15 containing tungsten oxide nanoclusters: a chemoselective catalyst for oxidation of sulfides to sulfoxides under ambient conditions - Bordoloi, Ankur; Vinu, Ajayan; Halligudi, Shivaraj B. (Chemical Communications, 2007)
Tungsten oxide nanoclusters supported highly ordered mesoporous SBA-15 material has been successfully synthesized in a single step using a non-ionic surfactant as a template and used for the selective oxidation of sulfur compounds, giving excellent yields at room temperature with exceptional catalyst recyclability.

Organotin-oxometalate coordination polymer catalyzed oxyfunctionalization of monoterpenes - Bordoloi, Ankur; Lefebvre, F.; Halligudi, Shivaraj B. (Journal of Molecular Catalysis A-Chemical, 2007)
Keywords: Heck reaction; kinetics; Palladacycle

Oxidation of benzylic alcohols and sulfides over LaCoO3 and TBHP - Patil, Mahesh L.; Maujan, Suleman R.; Borate, Hanumant B.; Uphade, Balu S. (Arkivoc, 2007)
A simple and efficient methodology has been described for the selective oxidation of secondary benzylic alcohols to the corresponding ketones. In contrast, primary benzylic alcohols afforded dimethyl acetals.
Keywords: acetals; benzylic alcohols; Oxidation; perovskite LaCoO3

Oxyfunctionalisation of adamantane using inorganic-organic hybrid materials based on isopoly and heteropoly anions: kinetics and mechanistic studies - Bordoloi, Ankur; Vinu, Ajayan; Halligudi, Shivaraj B. (Applied Catalysis A-General, 2007)
{Oxyfunctionalisation of adamantane with 30% aq.H2O2 in butyronitrile solvent was efficiently catalyzed by inorganic-organic hybrid materials synthesized by the immobilisation of isopoly (WOx = sodium tungstate
Keywords: adamantane; inorganic-organic hybrid materials; oxyfunctionalisation; vanadium (V) superoxo intermediate

Phosphotungstic acid as an efficient solid catalyst for intramolecular rearrangement of benzyl phenyl ether to 2-benzyl phenol - Bhure, Mahesh H.; Rode, Chandrashekhar V.; Chikate, Rajeev C.; Patwardhan, Neeraj; Patil, Shraddha (Catalysis Communications, 2007)
An heteropoly acid (phosphotungstic acid, PTA) was found to be a promising solid acid catalyst as an alternative to the conventional stoichiometric reagents for the rearrangement of benzyl phenyl ether giving 2-benzyl phenol as a major product and 4-benzyl phenol and dibenzylated phenols as side products. Catalyst was recovered from the reaction mixture and reused again without loss of activity. Based on the observed product distribution for various substrates a plausible catalytic reaction pathway has also been proposed. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: benzyl phenyl ether; Intramolecular rearrangement; Phosphotungstic acid

Preparation and evaluation of cellulose acetate butyrate and poly(ethylene oxide) blend microspheres for gastroretentive floating delivery of repaglinide - Rokhade, Ajit P.; Patil, Sangamesh A.; Belhekar, Anagha A.; Halligudi, Shivaraj B.; Aminabhavi, Tejraj M. (Journal of Applied Polymer Science, 2007)
In this study, hollow microspheres of cellulose acetate butyrate (CAB) and poly(ethylene oxide) (PEO) were prepared by emulsion-solvent evaporation method. Repaglinide was successfully encapsulated into floating microspheres. Various formulations were prepared by varying the ratio of CAB and PEO, drug loading and concentration of poly(vinyl alcohol) (PVA) solution. Encapsulation of the drug up to 95% was achieved. The microspheres tend to float over the simulated gastric media for more than 10 h. The micromeritic properties of microspheres reveal the excellent flow and good packing properties. The % buoyancy of microspheres was found to be up to 87. SEM showed that microspheres have many pores on their surfaces. Particle size ranges from 159 to 601 mu m. DSC and X-RD revealed the amorphous dispersion in the polymer matrix. In vitro release experiments were performed in simulated gastric fluid. In vitro release studies indicated the dependence of release rate on the extent of drug loading and the amount of PEO in the microspheres; slow release was extended up to 12 h. The release data were fitted to an empirical equation to compute the diffusional exponent (n), which indicated that the release mechanism followed the non-Fickian trend. (C) 2007 Wiley Periodicals, Inc.
Keywords: cellulose acetate butyrate; Controlled release; floating drug delivery; microspheres; repaglinide

Reaction of huisgen zwitterion with diaryl-1,2-diones and ketones: an efficient protocol for carbon-nitrogen bond formation - Nair, Vijay; Biju, Akkattu T.; Mathew, Smitha C. (Synthesis-Stuttgart, 2007)
The reaction of Huisgen zwitterion, derived from triphenylphosphine and dialkyl azodicarboxylate, with diaryl-1,2-diones afforded N,N-dicarboalkoxy monohydrazones via a mechanistically novel rearrangement. Cyclic and acyclic ketones furnished vinyl hydrazinedicarboxylates under similar conditions.
Keywords: betaines - diazo compounds - hydrazones - ketones - rearrangements

Reaction of tpp-azodicarboxylate zwitterions and aldehydes: unprecedented synthesis of acyl carbamates - Nair, Vijay; Mathew, Smitha C.; Biju, Akkattu T.; Eringathodi, Suresh (Tetrahedron Letters, 2007)
An efficient synthesis of acyl carbamates from aryl aldehydes by the reaction of triphenylphosphine and dialkyl azoesters is described.

Reactions of o-aminothiophenol and o-aminophenyl disulfide with itaconic anhydride and (-)-dimenthyl itaconate: access to enantiomerically pure 1,5-benzothiazepines and benzothiazolyl-2-methylacrylic acid - Baag, Md. Merajuddin; Sahoo, Manoj Kumar; Puranik, Vedavati G.; N. P. Argade (Synthesis-Stuttgart, 2007)
{A facile chemo- and regioselective reactions of o-aminothiophenol (o-ATP) with itaconic anhydride is described. 1,5-Benzothiazepinyl-3-acetic acid is obtained in 81% yield via the exclusive Michael type addition of the thiol unit from o-ATP to the carbon-carbon double bond in itaconic anhydride followed by an intramolecular anhydride ring opening with an amine unit. The moderately stereoselective Michael type addition of the thiol unit from o-ATP to (-)-dimenthyl itaconate to obtain a mixture of diastereomers in a 7:3 ratio in 82% yield has been demonstrated. The reductive sulfur-sulfur bond cleavage in the dicarboxylic acid, 2({2-[2-(3-carboxybut-3-enoylamino)phenyidisulfanyl]phenylcarbamoyl\
Keywords: Magnetic nanoparticles; magnetic properties; spin glasses

Reduction of oxygen by hydroxylammonium salt or hydroxylamine over supported Au nanoparticles for in situ generation of hydrogen peroxide in aqueous or non-aqueous medium - Choudhary, Vasant R.; Jana, Prabhas; Bhargava, Suresh Kumar (Catalysis Communications, 2007)
Reaction of O-2 with hydroxylamine or its salts over a number of supported gold catalysts containing An nanoparticles (at 10-70 degrees C) has been studied at atmospheric pressure for the in situ generation of H2O2 (required for organic oxidation reactions in the synthesis of fine/specialty chemicals) in aqueous (water) or non-aqueous medium. Hydrogen peroxide in high yields with harmless by-products (viz. water and nitrogen) can be generated in situ by the reduction Of O-2 by hydroxylammonium sulfate (or chloride) or hydroxylamine using the supported gold catalysts particularly Au/Gd2O3, Au/La2O3 and Au/MgO, in aqueous (water) or non-aqueous (viz. methanol) medium at close to ambient conditions. The reduction of O-2 by hydroxylammonium salt to H2O2, however, requires preneutralization of the salt by alkali; in the absence of the neutralization, only water is formed in the reaction. (c) 2006 Elsevier B.V. All rights reserved.
Keywords: Au Nanoparticles; Au/Gd2O3; Au/La2O3; Au/MgO; Hydrogen peroxide; hydroxylamine; hydroxylammonium salts; in situ H2O2 generation

Role of ionic diffusion in polymer gel mediated growth (PMG) technique for the synthesis of nanoparticulate fillers - Sonawane, Pradip S.; Biradar, Santoshkumar S.; Radhakrishnan, S.; Kulkarni, B. D. (Materials Chemistry and Physics, 2007)
Polymer mediated growth (PMG), which forms an important method for synthesis of nanoparticles, has one of the ions bound by polymer matrix while the other is allowed to diffuse and react to form desired compound. The exact role of ionic diffusion in the formation of nanoparticles has been investigated by taking specific case studies. Typically calcium carbonate, calcium phosphate and calcium sulfate have been formed in nano-size by PMG route using polyacrylamide gel. The extent of cross-linking of the polymer matrix in the formation of gel, affects the diffusivity of ions into polymer matrix and the size of particles formed. The rates of diffusion for different extents of cross-linking of polymer are estimated during the synthesis of nanoparticles using Fick's law. The inter-correlation between the particle size formation and the diffusion length has been clearly brought out in these studies. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: ionic diffusion; nanoparticulate fillers; polymeric gels

Selective oxidation of anthracene using inorganic-organic hybrid materials based on molybdovanadophosphoric acids - Bordoloi, Ankur; Lefebvre, F.; Halligudi, Shivaraj B. (Journal of Catalysis, 2007)
{Inorganic-organic hybrid materials were synthesized by immobilization of molybdovanadophosphoric acids onto mesoporous silicas, such as MCM-41, MCM-48, and SBA-15, through an organic linker. 12-Molybdovanadophosphoric acids of the general formula H3+xPMO12-xVxO40 (x = 0-3).nH(2)O, such as H-4[
Keywords: EPDM; Photostabilization; polymeric HALS

Semi-synthesis of deoxyartemisinin - Bhattacharya, Asish K.; Pathak, Ashish K.; Sharma, Ram P. (Mendeleev Communications, 2007)
The reaction of artemisinin with aluminium-nickel chloride hexahydrate in THF or nickel boride in MeOH furnishes deoxyartemisinin in an excellent yield.

Simple and efficient synthesis of thysanone methyl ether - Bulbule, Vivek J.; Koranne, Priti S.; Deshpande, Vishnu H.; Borate, Hanumant B. (Tetrahedron, 2007)
The synthesis of thysanone methyl ether is achieved by employing semivioxanthin methyl ether, which in turn is prepared by the tandem Michael addition of an anion of orsellinate to a substituted dihydropyrone. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: human pathogen; Michael addition; orsellinate derivative; semivioxanthin

Stereoselective synthesis of 3,4-trans-disubstituted γ-lactams by cerium(iv) ammonium nitrate mediated radical cyclization of cinnamamides - Nair, Vijay; Mohanan, Kishor; Suja, Tachapully D.; Biju, Akkattu T. (Synthesis-Stuttgart, 2007)
A facile synthesis of 3,4-trans-disubstituted γ-lactams was developed, consisting of the radical cyclization of cinnamamides mediated by cerium(IV) ammonium nitrate. The single-electron-transfer (SET) reaction of the methoxystyrenyl moiety mediated by cerium(IV) ammonium nitrate gives rise to a cation radical, whose cyclization followed by reaction with oxygen and methanol generates 3,4-trans-disubstituted γ-lactams.
Keywords: cerium(IV) ammonium nitrate - intramolecular cyclization - cinnamamides - single electron transfer - γ-lactams

Strain improvement of penicillium janthinellum ncim 1171 for increased cellulase production - Adsul, Mukund G.; Bastawade, Kulbhushan B.; Varma, Anjanikumar; Gokhale, D. V. (Bioresource Technology, 2007)
The strain of Penicilhuinjanthinellunt NOM 1171 was subjected to mutation involving treatment of Ethyl Methyl Sulfonate (EMS) for 24 h followed by UV-irradiation for 3 min. Successive mutants showed enhanced cellulase production (EMS-UV-8), clearance zone on Avicel containing plate (SM2) and rapid growth on Walseth cellulose agar plates containing 0.2% 2-deoxy-D-glucose (SM3). These mutants were transferred to Walseth cellulose plates containing higher concentration (1.5%) of 2-deoxy-D-glucose (SM4) in which only five mutants showed clearance zone on SM4. All these mutants showed approximately two-fold increase in activity of both FPase and CMCase in shake flask culture when grown on basal medium containing CP-123 (1%) and wheat bran (2.5%). The enzyme preparations from these mutants were used to hydrolyze Avicel. Higher hydrolysis yields of Avicel were obtained with enzyme preparations of EU1. This is the first report on the isolation and selection of mutants based on hydrolysis of Avicel, which is the most crystalline substrate. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: 2-deoxy-D-glucose resistant mutants; cellulase activity; EMS and ultraviolet mutation; Penicillium janthinellum

Swelling and mechanical behavior of modified poly(vinyl alcohol)/laponite nanocomposite membranes - Nair, Shubhangi H.; Pawar, Kiran C.; Jog, Jyoti Prakash; Badiger, Manohar V. (Journal of Applied Polymer Science, 2007)
Nanocomposite (NC) membranes based on hydrophobically modified PVA and laponite were synthesized with varying laponite content in the feed. The incorporation of laponite in NC membranes was investigated by FTIR spectroscopy and thermogravimetric analysis. The swelling ratio of membranes was determined as a function of temperature and laponite content. Swelling studies of NC membranes exhibited the decrease in swelling with an increase in laponite content in the NC membranes. The swelling ratio of NC membrane with 20% laponite slightly increased with an increase in temperature. Dynamic mechanical analysis showed the systematic increase in storage modulus with laponite content, which indicates the enhancement of mechanical property upon laponite addition. There was also a decrease in the tan 6 peak values of NC membranes with an increase in laponite content in NCs. The permeabilities through NC membranes as a function of solute size and laponite content were studied and the results showed molecular screening based on size. The permeability of solute reduced due to the presence of well-dispersed laponite in the NC. (c) 2006 Wiley Periodicals, Inc.
Keywords: Dynamic mechanical analysis; laponite; membranes; nanocomposite hydrogel; poly(vinyl alcohol)

Synergistic effect of CPPU and benzyladenine on embryo rescue in six. stenospermocarpic cultivars of grapevine - Nookaraju, A.; Barreto, M. S.; Karibasappa, G. S.; Agrawal, Dinesh C. (Vitis, 2007)
In ovulo/embryo culture technique has been used to recover hybrids from seedless grapevines. The present investigation was carried out to study the influence of pre-bloom sprays of N-(2-chloro-4-pyridyl)-N'-phenylurea (CPPU) - a synthetic cytokinin, and N-6-benzyladenine (BA) supplemented in culture media on embryo recovery in six stenospermocarpic grapevine cultivars. The results showed synergistic effect of CPPU and BA on embryo recovery. Though a CPPU spray alone increased embryo recovery in four out of six cultivars tested, the efficiency was enhanced several fold on culture of excised ovules on media supplemented with BA. The percentage of embryo recovery also depended on BA concentration and varied among six cultivars indicating a genotypic influence as well. Germination percentage of rescued embryos varied among the six cultivars and mostly corresponded with embryo recovery. Germinated embryos developed into normal plantlets. Present study demonstrates that spraying of panicles with CPPU and incorporation of BA in the ovule culture medium can enhance the embryo recovery in stenospermocarpic cultivars of grapevine.
Keywords: benzyladenine; CPPU; embryo rescue; seedless grapes

Synthesis and characterization of NCL-5, NCL-6 and NCL-7: new zeolites enriched with polymorph B of the BEA family - Kadgaonkar, Mahesh D.; Kasture, Mahesh W.; Bhange, Deu S.; Joshi, Praphulla N.; Ramaswamy, Veda; Gupta, Narendra M.; Kumar, Rajiv (Microporous and Mesoporous Materials, 2007)
The synthesis of all-silica analogs of polymorph B-enriched zeolites of the BEA family denoted as NCL-5, NCL-6 and NCL-7 was realized hydrothermally at lower water content in fluoride medium using perchloric acid as promoter and terraethylammonium hydroxide as template. The present article explains the effect of different synthesis parameters on NCL-5, NCL-6 and NCL-7. The samples were characterized using XRD, low temperature N-2-adsorption, Si-29 MAS NMR and FTIR spectroscopy. The phase composition of the structures was derived using simulated patterns for the random intergrowths of polymorphs A and B using DIFFaX Code. The stacking direction c' is perpendicular to the a'b' plane of the layer. The phase composition of polymorph B derived using DIFFaX code was found to be 90-95%. 70-75% and 60-65% in NCL-5, NCL-6 and NCL-7, respectively. The gradual decrease of polymorph B concentration in these samples showed a correlation with the decrease in water/SiO2 molar ratio in gel. The framework FTIR spectral analysis of NCL-5 and all-silica-beta supported the postulation that significant enrichment of polymorph B in NCL-5 compared to that in all-silica-beta, as indicated by the relative intensities of pair of bands at 1097 and 1018 cm(-1) and 460 and 423 cm(-1) vibrations, leads to more tortuous channel structure associated with polymorph B. (C) 2007 Elsevier Inc. All riahts reserved.
Keywords: BEA family; NCL-5; NCL-6; NCL-7; polymorph B enrichment; synthesis; zeolites

Synthesis and characterization of value added catalysts zeolite beta using environmentally detrimental flyash - Kasture, M. W.; Bokade, Vijay V.; Joshi, P. N.; Kumar, R. (From Zeolites to Porous Mof Materials: the 40th Anniversary of International Zeolite Conference, Proceedings of the 15th International Zeolite Conference, 2007)
Fly ash is a major byproduct of Thermal power plant, which makes a lot of pollution to the environment due to its fineness. When a large amount of fly ash is dumped in the places near to power plants, it mixes in all segment of environment like water, air as well as soil. Though it can be utilized for different useful purposes, due to the lack of technical knowledge about how and proper motivation, no progress has been made in its utilization. It has been demonstrated that the fly ash can be used for making a value added catalyst zeolite beta by using simple and low cost process. In the present paper it is demonstrated that the fly ash can be used as a source of silica and alumina in the synthesis of value added catalyst zeolite beta. Moreover, the influence of different silica sources such as tetraethylortho silicate, silica sol and fumed silica on the physiochemical characteristics of well crystallized zeolite beta was also studied. The detailed characterization was carried out by using powder XRD, (27)Al and (29)Si MAS NMR, chemical analysis and low temperature nitrogen adsorption. Based on the data obtained from various systems containing different silica source, fumed silica is found to be most efficient source materials and showed superiority in the uniformity of aluminum distribution and possesses higher surface area.
15th International Zeolite Conference, Beijing, PEOPLES R CHINA, AUG 12-17, 2007

Synthesis and evaluation of 4/5-hydroxy-2,3-diaryl(substituted)-cyclopent-2-en-1-ones as cis-restricted analogues of combretastatin A-4 as novel anticancer agents - Gurjar, Mukund K.; Wakharkar, Radhika D.; Singh, Anu T.; Jaggi, Manu; Borate, Hanumant B.; Shinde, Popat D.; Verma, Ritu; Rajendran, Praveen; Dutt, Sarjana; Singh, Gurvinder; Sanna, Vinod K.; Singh, Manoj K.; et al. (Journal of Medicinal Chemistry, 2007)
A new series of 2,3-diaryl-4/5-hydroxy-cyclopent-2-en-1-one analogues replacing the cis double bond of combretastatin A-4 (CA-4) by 4/5-hydroxy cyclopentenone moieties was designed and synthesized. The analogues displayed potent cytotoxic activity (IC50 < 1 mu g/mL) against a panel of human cancer cell lines and endothelial cells. The most potent analogues 11 and 42 belonging to the 5-hydroxy cyclopentenone class were further evaluated for their mechanism of action. Both of the analogues led to cell cycle arrest at G2/M phase and induced apoptosis in endothelial cells. Antitubulin property of 42 was superior to 11 and comparable to CA-4. The compound 42 had better aqueous solubility, metabolic stability, and pharmacokinetic profile than CA-4 and also demonstrated significant tumor regression in the human colon xenograft model. Our data suggests that cis-restricted analogues of CA-4 are a new class of molecules that have the potential to be developed as novel agents for the treatment of cancer.

Synthesis and evaluation of antifungal properties of a series of the novel 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and its analogues - Gholap, Atul R.; Toti, Kiran S.; Shirazi, Fazal; Kumari, Ratna; Bhat, Manoj Kumar; Deshpande, Mukund V.; Srinivasan, Kumar V. (Bioorganic & Medicinal Chemistry, 2007)
A series of 2-amino-5-oxo-4-phenyl-5,6,7,8-tetrahydroquinoline-3-carbonitrile and various analogues have been synthesized in excellent isolated yields starting from various arylidenemalononitrile and 3-amino-2-cyclohexen-1-one in 1-propanol as solvent at reflux temperature in the absence of any added catalyst. All the synthesized compounds were evaluated for their antifungal activity. The relationship between functional group variation and biological activity of the evaluated compounds is discussed in the article. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: Antifungal activity; antiproliferative activity; arylidenemalononitriles; arylquinoline carbonitrile; Michael addition

Synthesis of Bio-diesel and Bio-lubricant by transesterification of vegetable oil with lower and higher alcohols over heteropolyacids supported by clay (K-10) - Bokade, Vijay V.; Yadav, G. D. (Process Safety and Environmental Protection, 2007)
{The use of different lower and higher alcohols viz; methanol, ethanol, n-propanol and n-octanol, for the synthesis of methyl, ethyl, propyl and octyl fatty acid esters by transesterification of vegetable oil (triglycerides) with respective alcohols also known as `Bio-diesel' and `Biolubricants' was studied in detail. The reactions were carried out in a batch process. The activity with different supports like clay (K-10), activated carbon, ZSM-5, H-beta and TS-1 were compared. The superacids (heteropolyacids, HPA) viz; Dodeca-Tungstophosphoric acid [
Theoretical Chemistry Symposium 2006 (TCS 2006), Bharathidasan Univ, Trichy, INDIA, DEC 11-13, 2006
Keywords: coprecipitation; lithium aluminate; Microemulsion; Nanoparticles; sol-gel; Surfactants

Synthesis of pharmaceutical intermediates by toluene benzylation over heteropoly acids on different support - Bokade, Vijay V.; Yadav, G. D. (Journal of Natural Gas Chemistry, 2007)
{Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, plane MFI structured titanosilicate (TS-1) and heteropoly acids [
International Conference on Nano Science and Technology (ICONSAT 2006), New Delhi, INDIA, MAR 16-18, 2006
Keywords: heteroassembly; nanoplates; polyfunctional capping agents; shape selective synthesis of gold-silver nanostructures; surface confinement

Synthesis, structure, and reactivity of diazoketiminato complexes of platinum(II) and palladium(II): cytotoxic properties of a platinum complex - Pratihar, Jahar Lal; Shee, Biswaranjan; Pattanayak, Poulami; Patra, Debprasad; Bhattacharyya, Arindam; Puranik, Vedavati G.; Hung, C. H.; Chattopadhyay, Surajit (European Journal of Inorganic Chemistry, 2007)
{Reaction of the 2-(arylazo)anilines Ar-N = N-C6H4NH2 [
19th International Symposium on Chemical Reaction Engineering (ISCRE 19), Pottsdam, GERMANY, SEP, 2006
Keywords: CFD; hydro processing; scale-down; scale-up; trickle bed

Template-assisted synthesis of ruthenium oxide nanoneedles: electrical and electrochemical properties - Subhramannia, Mahima; Balan, Beena K.; Sathe, Bhaskar R.; Mulla, Imtiaz S.; Pillai, Vijayamohanan K. (Journal of Physical Chemistry C, 2007)
We here demonstrate the formation of bundles of RuO2 nanoneedles (ca. 100 nm diameter) by a templateassisted electrodeposition from aqueous RuCl3 solution under potentiostatic conditions at room temperature. Cyclic voltammetric measurements in 0.5 M H2SO4 show significantly higher redox-related charging behavior for the RuO2 nanoneedles compared to that of the commercial sample, which is also supported by the electrochemical impedance data. A comparison of the specific capacitance reveals a higher value for nanoneedles (3 F/g instead of 0.4 F/g for the bulk), which has been explained on the basis of enhanced reactivity. More interestingly, electrical transport measurements reveal a transition from metallic to semiconducting behavior especially at low-temperature caused by an impurity scattering mechanism. We anticipate that the present simple route for the fabrication of RuO2 nanostructures will be useful to exploit their potentials in various fields such as electrocatalysis, nanoelectronics, and more importantly for designing supercapacitors.

Thermal stability of the Mobil Five type metallosilicate molecular sieves - an in situ high, temperature X-ray diffraction study - Bhange, Deu S.; Ramaswamy, Veda (Materials Research Bulletin, 2007)
We have carried out in situ high temperature X-ray diffraction (HTXRD) studies of silicalite-1 (S-1) and metallosilicate molecular sieves containing iron, titanium and zirconium having Mobil Five (MFI) structure (iron silicalite-1 (FeS-1), titanium silicalite-1 (TS-1) and zirconium silicalite-1 (ZrS-1), respectively) in order to study the thermal stability of these materials. Isomorphous substitution of Si4+ by metal atoms is confirmed by the expansion of unit cell volume by X-ray diffraction (XRD) and the presence of Si-O-M stretching band at similar to 960 cm(-1) by Fourier transform infrared (FTIR) spectroscopy. Appearance of cristobalite phase is seen at 1023 and 1173 K in S-1 and FeS-1 samples. While the samples S-1 and FeS-1 decompose completely to cristobalite at 1173 and 1323 K, respectively, the other two samples are thermally stable upto 1623 K. This transformation is irreversible. Although all materials show a negative lattice thermal expansion, their lattice thermal expansion coefficients vary. The thermal expansion behavior in all samples is anisotropic with relative strength of contraction along `a' axes is more than along `b' and V axes in S- 1, TS-1, ZrS-1 and vice versa in FeS-1. Lattice thermal expansion coefficients (alpha(v)) in the temperature range 298-1023 K were -6.75 x 10(-6) K-1 for S-1, -12.91 x 10(-6) K-1 for FeS-1, -16.02 x 10(-6) K-1 for TS-1 and -17.92 x 10(-6) K-1 for ZrS-1. The highest lattice thermal expansion coefficients (alpha(v)) obtained were -11.53 x 10(-6) K-1 for FeS-1 in temperature range 298-1173 K, -20.86 x 10(-6) K-1 for TS-1 and -25.54 x 10(-6) K-1 for ZrS-1, respectively, in the temperature range 298-1623 K. Tetravalent cation substitution for Si4+ in the lattice leads to a high thermal stability as compared to substitution by trivalent cations. (c) 2006 Elsevier Ltd. All rights reserved.
Keywords: microporous materials; Thermal expansion; X-ray diffraction

Thioether-functionalized ferrocenyl-bis(phosphonite), Fe(C5H4)P(−OC10H6(μ-S)C10H6O−)2: synthesis, coordination behavior, and application in suzuki-miyaura cross-coupling reactions - Punji, Benudhar; Mague, Joel T.; Balakrishna, Maravanji S. (Inorganic Chemistry, 2007)
The thioether-functionalized metalloligand ferrocenyl-bis(phosphonite), Fe(C5H4PR)2 (4, R = −OC10H6(μ-S)C10H6O−) is synthesized in three steps starting from ferrocene, and its coordination behavior toward various transition-metal derivatives is described. The reactions of 4 with [Rh(CO)2Cl]2 or M(COD)Cl2 afforded the chelate complexes, cis-[Rh(CO)Cl{Fe(C5H4PR)2-κP,κP}] (5) or cis-[MCl2{Fe(C5H4PR)2-κP,κP}] (6, M = PdII; 7, M = PtII), respectively. However, treatment of 4 with CuX (X = Cl, Br, and I) produces binuclear complexes, [Cu2(μ-X)2(MeCN){Fe(C5H4PR)2-κP,κP}] (8, X = Cl; 9, X = Br; 10, X = I) where the sulfur atom on one side of the ligand is involved in a weak interaction with the copper center. Reaction of 4 with 1 equiv of Ag(PPh3)OTf gives the mononuclear chelate complex [Ag(OTf)PPh3{Fe(C5H4PR)2-κP,κP}] (11), whereas treatment with 2 equiv of AuCl(SMe2) produces the dinuclear gold complex [Au(Cl){Fe(C5H4PR)2-κP,κP}Au(Cl)] (12). The crystal structures of 10 and 12 are reported, where a strong metallophilic interaction is observed between the closed-shell metal centers. The palladium complex 6 catalyzes the Suzuki cross-coupling reactions of aryl bromides with phenylboronic acid with excellent turnover numbers (TON up to 1.36 × 105).

Toluene alkylation with methanol to p-xylene over heteropoly acids supported by clay - Bokade, Vijay V.; Deshpande, Suvarna S.; Patil, R.; Jain, S.; Yadav, G. D. (Journal of Natural Gas Chemistry, 2007)
{The alkylation of toluene with methanol for the selective formation of p-xylene was systematically studied. Very few studies have been reported on the use of superacids such as heteropolyacids on cheap supports, such as clay. This article deals with the use of different heteropoly acids (HPAs), viz, Dodeca-Tungstophosphoric acid [
Keywords: co-crystalline; p-xylene; toluene alkylation; ZSM-12; ZSM-5

Total syntheses of schulzeines B and C - Gurjar, Mukund K.; Pramanik, Chinmoy; Bhattasali, Debabrata; Ramana, Chepuri V.; Mohapatra, Debendra K. (Journal of Organic Chemistry, 2007)
Schulzeines B (2) and C (3) were synthesized by a convergent strategy using epimeric tricyclic lactam building blocks, 4 and 5, and the C28 fatty acid side chain 6. Syntheses of tricyclic lactams (4/5) were achieved by Bischler-Napieralski reaction. Sharpless asymmetric dihy-droxylation and BINAL-H-mediated asymmetric reduction of an enone was employed to prepare the key fatty acid side chain 6. The spectral as well as analytical data of 2 and 3 were in good agreement with the reported data for the natural products, thus confirming their assigned structures.
Keywords: Alpha-Glucosidase Inhibitors; Asymmetric Dihydroxylation; Adjuvant Activity; Pinellic Acid; Ketones; Reduction; Reagents; Configuration; Imbricatine; Alkaloids

Transesterification of alpha-haloesters and beta-ketoesters over Mg-Al-hydrotalcites (HT)-like anionic clays - Bulbule, Vivek J.; Borate, Hanumant B.; Munot, Yogesh S.; Deshpande, Vishnu H.; Sawargave, Sangmeshwer P.; Gaikwad, Abaji G. (Journal of Molecular Catalysis A-Chemical, 2007)
Transesterification of alpha-haloesters was achieved by reaction of alcohols in the presence of Mg-Al-HT-like anionic clays. beta-Ketoesters were also transesterified under similar conditions on reaction with alcohols with a wide variety of functional groups. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: alpha-haloesters; beta-ketoesters; heterogeneous catalyst; Hydrotalcites; transesterification

Zirconia enrichment in zircon sand by selective fungus-mediated bioleaching of silica - Bansal, Vipul; Syed, Asad; Bhargava, Suresh Kumar; Ahmad, Absar; Sastry, Murali (Langmuir, 2007)
One of the important routes for the production of zirconia is by chemical treatment and removal of silica from zircon sand (ZrSixOy). We present here a completely green chemistry approach toward enrichment of zirconia in zircon sand; this is based on the reaction of the fungus Fusarium oxysporum with zircon sand by a process of selective extracellular bioleaching of silica nanoparticles. Since this reaction does not result in zirconia being simultaneously leached out from the sand, there is a consequent enrichment of the zirconia component in zircon sand. We believe that fungal enzymes specifically hydrolyze the silicates present in the sand to form silicic acid, which on condensation by certain other fungal enzymes results in room-temperature synthesis of silica nanoparticles. This fungus-mediated twofold approach might have vast commercial implications in low-cost, ecofriendly, room-temperature syntheses of technologically important oxide nanomaterials from potentially cheap naturally available raw materials like zircon sand.

Albumin competitively inhibits glycation of less abundant proteins - Bhonsle, Hemangi S.; Singh, Sameer Kumar; Srivastava, Ghanshyam; Boppana, Ramanamurthy; Kulkarni, Mahesh J. (Protein and Peptide Letters, 2008)
Glycation, a non-enzymatic reaction between glucose and protein is the primary cause of diabetic complications. Albumin, the most abundant plasma protein undergoes glycation both in vivo and in vitro. The influence of albumin on glycation of less abundant proteins has not been addressed. For the first time, we show that albumin competitively inhibits the glycation of less abundant proteins. This study suggests that at least in the initial stages of diabetes, albumin may protect other proteins from glycation.
Keywords: Diabetes; glucose; insulin; MALDI-TOF-MS; vascular complication

Amberlite-IR 120 catalyzed three-component synthesis of alpha-amino phosphonates in one-pot - Bhattacharya, Asish K.; Rana, Kalpeshkumar C. (Tetrahedron Letters, 2008)
A simple, efficient, and environmentally benign method for a three-component reaction of an amine, an aldehyde or a ketone, and diethyl phosphite catalyzed by Amberlite-IR 120 resin has been developed to afford alpha-amino phosphonates in high yields and short reaction times under solvent-free reaction conditions. The major advantages of the present method are good yields, inexpensive, ecofriendly and reusable catalyst, mild and solvent-free reaction conditions and tolerance towards various functionalities present in the substrates. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: aldehydes; alkyl phosphite; alpha-amino phosphonates; amines; ion-exchange resin; multi-component reaction

Analysis of reactive oxygen species and antioxidant defenses in complex I deficient patients revealed a specific increase in superoxide dismutase activity - Wani, Aijaz A.; Rangrez, Ashraf Y.; Kumar, Himanshu; Bapat, Sharmila A.; Suresh, C. G.; Barnabas, Shama; Patole, Milind S.; Shouche, Yogesh (Free Radical Research, 2008)
The mechanism of free radical production by complex I deficiency is ill-defined, although it is of significant contemporary interest. This study studied the ROS production and antioxidant defenses in children with mitochondrial NADH dehydrogenase deficiency. ROS production has remained significantly elevated in patients compared to controls. The expression of all antioxidant enzymes significantly increased at mRNA level. However, the enzyme activities did not correlate with high mRNA or protein expression. Only the activity of superoxide dismutase (SOD) was found to correlate with higher mRNA expression in patient derived cell lines. The activities of the enzymes such as glutathione peroxidase (GPx), Catalase (CAT) and glutathione-S-transferase (GST) were significantly reduced in patients (p < 0.05 or p < 0.01). Glutathione reductase (GR) activity and intracellular glutathione (GSH) levels were not changed. Decreased enzyme activities could be due to post-translational or oxidative modification of ROS scavenging enzymes. The information on the status of ROS and marking the alteration of ROS scavenging enzymes in peripheral lymphocytes or lymphoblast cell lines will provide a better way to design antioxidant therapies for such disorders.
Keywords: antioxidant enzymes; mitochondrial complex I; mitochondrial myopathies; Reactive Oxygen Species (ROS)

Bacterial synthesis of silicon/silica nanocomposites - Singh, Sanjay; Bhatta, Umananda M.; Satyam, P. V.; Dhawan, Alok; Sastry, Murali; Bhagavatula L. V. Prasad (Journal of Materials Chemistry, 2008)
The synthesis of silicon/silica nanoparticle composites by the bacterium Actinobacter sp. is demonstrated. More specifically, the formation of silicon/silica nanocomposite is shown to occur when the bacterium is exposed to K(2)SiF(6) precursor under ambient conditions. Based on the earlier reports where this bacterium has been shown to synthesize iron oxide and iron sulfide nanoparticles, it is hypothesized that this bacterium secretes reductases and oxidising enzymes, which lead to the Si/SiO(2) nanocomposite synthesis. The particles obtained by bacterial synthesis were thoroughly characterized. The cytotoxicity studies revealed that the particles do not display any cytotoxicity to human skin cells. The synthesis of silica nanoparticles by bacteria in the present study demonstrates the versatility of the organism, and the formation of elemental silicon by this environmentally friendly process expands further the scope of microorganism based nanomaterial synthesis.

Bacteria-mediated precursor-dependent biosynthesis of superparamagnetic iron oxide and iron sulfide nanoparticles - Bharde, Atul A.; Parikh, Rasesh Y.; Baidakova, Marina; Jouen, Samuel; Hannoyer, Beatrice; Enoki, Toshiaki; Bhagavatula L. V. Prasad; Shouche, Yogesh S.; Ogale, Satishchandra B.; Sastry, Murali (Langmuir, 2008)
The bacterium Actinobacter sp. has been shown to be capable of extracellularly synthesizing iron based magnetic nanoparticles, namely maghemite (gamma-Fe2O3) and greigite (Fe3S4) Under ambient conditions depending on the nature of precursors used. More precisely, the bacterium synthesized maghemite when reacted with ferric chloride and iron sulfide when exposed to the aqueous solution of ferric chloride-ferrous sulfate. Challenging the bacterium with different metal ions resulted in induction of different proteins, which bring about the specific biochemical transformations in each case leading to the observed products. Maghemite and iron sulfide nanoparticles show superparamagnetic characteristics as expected. Compared to the earlier reports of magnetite and greigite synthesis by magnetotactic bacteria and iron reducing bacteria, which take place strictly under anaerobic conditions, the present procedure offers significant advancement since the reaction occurs under aerobic condition. Moreover, reaction end products can be tuned by the choice of precursors used.

Calculation of vibrational energy of molecule using coupled cluster linear response theory in bosonic representation: convergence studies - Banik, Subrata; Pal, Sourav; Prasad, M. Durga (Journal of Chemical Physics, 2008)
Vibrational excited state energies have been calculated using vibrational coupled cluster linear response theory (CCLRT). The method has been implemented on formaldehyde and water molecule. Convergence studies have been shown with varying the cluster operator from S(4) to S(6) as well as the excitation operator from four bosons to six bosons. A good agreement with full configuration interaction results has been observed with S(6) truncation at coupled-cluster method level and six bosonic excitations at CCLRT level. (C) 2008 American Institute of Physics.

Capsaicin: preclinical and clinical studies - Qureshi, Absar A.; Qureshi, Azfar A.; Omer, Shaista; Sanghai, Dhirendra B.; Setty, S. R.; Bhajipale, N. S. (Plant Archives, 2008)
Drugs obtained from plant sources occupy important position in different pharmacopoeias. Many of the life saving drugs in the present day allopathic system are obtained from plant origin only. Extensive scientific research on capsaicin, a natural compound, pungent principle, present in the fruits of plant Capsicum anum, has been performed. In preclinical studies capsaicin shows lipid lowering by stimulating its metabolism, gastroprotection against aspirin and ethanol induced ulcers. Capsaicin in rodents shows anticancer activity against NKK induced lung and liver cancer. It also exhibits antidiabetic, antimicrobial, anti-inflammatory and antioxidant properties in rodents. In clinical studies Capsaicin shows gastroprotection in healthy volunteers. In double blind studies capsaicin proved to be useful in skin disorders against prutitic psoriasis and prurigo nodularis with randomized double blind studies. It also exhibits good analgesic activity against post-therapeutic neuralgia, osteo-arthritis, rheumatoid arthritis and diabetic neuropathy. Capsaicin is fairly safe with oral dose 0.5-1.0 mg/kg.
Keywords: capsaicin; Capsicum anum; clinical studies; preclinical

Carbon-nitrogen bond-forming reactions of dialkyl azodicarboxylate: a promising synthetic strategy - Nair, Vijay; Biju, Akkattu T.; Mathew, Smitha C.; Pattoorpadi, Beneesh Babu (Chemistry an Asian Journal, 2008)
Azodicarboxylates have found applications in electrophilic amination reactions and in pericyclic reactions. The nucleophilic trigger in Mitsunobu reactions, that is, the zwitterion formed from triphenylphosphine and dialkyl azodicarboxylate, has been utilized recently in various heterocyclic constructions. This Focus Review summarizes the potential utility of azodicarboxylates in various carbon–nitrogen bond-forming reactions.
Keywords: amination reactions; azodicarboxylates; C[BOND]N bond formation; heterocycles; Huisgen zwitterion

Cellular polyamines influence maturation and germination of somatic embryos from pro-embryonal masses of two grapevine cultivars - Nookapaju, A.; Barreto, M. S.; Agrawal, Dinesh C. (Vitis, 2008)
Somatic embryos of grapevine multiply repeatedly and often fail to mature and germinate due to factors like dormancy and embryo teratology. The present investigation was carried out to improve the maturation and germination of somatic embryos from pro-embryonal masses (PEM) of 2A-Clone and `Crimson Seedless', two seedless grapevine cultivars. Also, the aim was to study a correlation between cellular and residual polyamine (PA) levels in PEM and culture media. The efficiency of maturation and germination of embryos from PEM varied significantly between the two cultivars and depended on incubation period and type of PAs in the medium. HPLC analysis showed that higher levels of cellular putrescine in PEM had correlation with maturation and germination percentages in both cultivars. The levels of three PAs depleted in the media rapidly indicating its uptake by PEM. Of the three PAs, putrescine (PUT) was the most effective and resulted in 100.0 or 92.0 % maturation at 14 d or 30 d in 2A-Clone or `Crimson Seedless', respectively. The maximum germination of somatic embryos was recorded with PUT at 14 d or 21 d in 2A-Clone or `Crimson Seedless', respectively.
Keywords: germination; Grapevine; maturation; polyamines; `2A-Clone'; `Crimson Seedless'

Chemical inhomogeneity and mixed-state ferromagnetism in diluted magnetic semiconductor Co : TiO2 - Ogale, Satishchandra B.; Kundaliya, Darshan; Mehraeen, Shareghe; Fu, Lian-feng; Zhang, Shixiong; Lussier, Alexandre; Dvorak, Joe; Browning, Nigel D.; Idzerda, Yves; Venkatesan, Thirumalai (Chemistry of Materials, 2008)
Diluted magnetic semiconductors (DMS) are among the most intensely investigated materials in recent times in view of their great application potential. Yet, they are also the most controversial because of the possibility of extrinsic effects attributable to dopant solubility and clustering, point defects, incorporation of unintentional impurities, etc. This has highlighted the central role of materials chemistry in rendering a specific microstate and property response. In this work, we provide a combined window of high-resolution scanning transmission electron microscopy and electron energy-loss spectrometry, X-ray absorption (XAS)/X-ray magnetic circular dichroism (XMCD), and magnetization measurements on epitaxial rutile CoxTi1-xO2 (x = 0-0.06) system (the first discovered oxide-DMS, which continues to be controversial) grown at low temperature (400 degrees C) under different ambient atmospheres. The study brings out a mixed-state scenario of ferromagnetism involving intrinsic DMS (uniform dopant distribution at low dopant concentration) and coupled cluster magnetism, involving cobalt associations within the matrix at higher concentrations. We also show that by matrix valence control during growth, it is possible to realize a uniform embedded cluster state and the related coupled cluster magnetism.

Co : CdS diluted magnetic semiconductor nanoparticles: radiation synthesis, dopant-defect complex formation, and unexpected magnetism - Bogle, Kashinath A.; Ghosh, Saurabh; Dhole, Sanjay D.; Bhoraskar, Vasant N.; Fu, Lian-feng; Chi, Miao-Fang; Browning, Nigel D.; Kundaliya, Darshan; Das, Gour P.; Ogale, Satishchandra B. (Chemistry of Materials, 2008)
Incorporating a dopant into a nanoparticle is a nontrivial proposition in view of the size dependent surface versus bulk energy considerations and the intrinsic proximity of the surface to the interior, which facilitates migration to the surface. If realized and controlled, however, it can open up new avenues to novel nanomaterials. Some previous studies have shown the dopability of nanosystems but only with specific surface functionalization. Here, we demonstrate the successful dopant incorporation via a new route of pulsed high energy electron induced synthesis. We choose a system Co:CdS (dilutely cobalt doped cadmium sulfide) in view of the well-known application-worthy properties of CdS and the potential possibility of its conversion to a diluted magnetic semiconductor of interest to spintronics. By using various techniques, we show that matrix incorporation and uniform distribution of cobalt are realized in US nanocrystals without the need for additional chemical or physical manipulation. Optical and photoluminescence properties also support dopant incorporation. Interestingly, although magnetism is realized, it is weak, and it decreases at higher cobalt concentration. First principle density functional calculations are performed to understand this counterintuitive behavior. These calculations suggest that the introduction of parent cation or anion vacancies lead to magnetic moment reduction, albeit marginally. However, with some Co impurity fraction in the octahedral interstitial site inside the wurtzite cage, the magnetic moment drops down drastically. This study reveals that defect states may have an interesting role in dopant stabilization in nanosystems, with interesting system dependent consequences for the properties.

Crystal-to-crystal transformation amongst dimorphs of racemic 2,6-di-O-(p-halobenzoyl)-myo-inositol 1,3,5-orthoformates that achieves halogen bonding contacts - Gonnade, Rajesh G.; Bhadbhade, Mohan M.; Shashidhar, Mysore S. (CrystEngComm, 2008)
{Racemic 2,6-di-O-(p-halobenzoyl)-myo-inositol 1,3,5-orthoformates (bromo (1) and chloro (2)) produced two polymorphs each, thin needle type crystals (Form I) were obtained from methanol, whereas larger rectangular crystals (Form II) were produced from ethyl acetate. Both forms could be produced concomitantly on crystallization (of 1 or 2) from ethyl acetate-light petroleum ether mixture; the yield of Form II crystal was always much more compared to Form I crystals. Although, a one-dimensional isostucturality linking molecules via O-H center dot center dot center dot O hydrogen bonding is seen in both forms, the difference arises in linking these chains. In larger Form II crystals (of 1 and 2), the adhesions are via halogen bonding (C-X center dot center dot center dot O=C

Development of nanofibrous morphology in LDPE/LLDPE/PP blends and its effect on mechanical properties of blend films - Sonawane, Pradip S.; Radhakrishnan, S.; Bhangale, J. A.; Gadhavi, A. L.; Khare, Anagha (Journal of Applied Polymer Science, 2008)
Nanofibrous morphology has been observed in ternary blends of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and isotactic polypropylene (PP) when these were melt-extruded via slit die followed by hot stretching. The morphology was dependent on the concentration of the component polymers in ternary blend LDPE/LLDPE/PP. The films were characterized by wide angle X-ray diffraction (XRD), scanning electron microscopy (SEM), and testing of mechanical properties. The XRD patterns reveal that the P phase of PP is obtained in the as-stretched nanofibrillar composites, whose concentration decreases with the increase of LLDPE concentration. The presence of PP nanofibrils shows significant nucleation ability for crystallization of LDPE/LLDPE blend. The SEM observations of etched samples show an isotropic blend of LDPE and LLDPE reinforced with more or less randomly distributed and well-defined nanofibrils of PP, which were generated in situ. The tensile modulus and strength of LDPE/LLDPE/PP blends were significantly enhanced in the machine direction than in the transverse direction with increasing LLDPE concentration. The ultimate elongation increased with increasing LLDPE concentration, and there was a critical LLDPE concentration above which it increased considerably. There was a dramatic increase in the falling dart impact strength for films obtained by blow extrusion of these blends. These impressive mechanical properties of extruded samples can be explained on the basis of the formation of PP nanofibrils with high aspect ratio (at least 10), which imparted reinforcement to the LDPE/LLDPE blend. (C) 2007 Wiley Periodicals, Inc.
Keywords: linear low density polyethylene; low density polyethylene; mechanical properties; melt-extruded films; nanofibrous morphology; polypropylene; ternary blends

Diastereoselective addition of planar N-heterocycles to vinyl sulfone-modified carbohydrates: a new route to isonucleosides - Sanki, Aditya K.; Bhattacharya, Rahul; Atta, Ananta Kumar; Suresh, Cheravakkattu G.; Pathak, Tanmaya (Tetrahedron, 2008)
Michael-type addition reactions of planar N-heterocycles at the C-2 positions of vinyl sulfone-modified carbohydrates provide an efficient and general route for the carbon-N-heterocycle bond formation. Therefore, the addition pattern of planar heterocycles, such as imidazole, triazole, thymine, and adenine to 3-C-phenyisulfonyl-hex-2-enopyranosides (1 alpha/1 beta) and 3-C-p-toluenesulfonyl-pent-2-enofuranosides (2 alpha/2 beta) was studied for developing a general methodology for the synthesis of new classes of isonucleosides possessing a carbon-N-heterocycle linkage at C-2 positions of furanosyl and pyranosyl sugars. To a great extent, the anomeric configurations of the starting vinyl sulfones play crucial roles in deciding the diastereoselectivity of addition of heterocycles. However, the trityl protected 3-C-p-toluenesulfonyl-hex-2-enopyranosides (33 alpha/33 beta) were judged to be More practical starting materials for desulfortylation and deprotection for the synthesis of a new class of thymine and adenine deoxyisonucleosides. (C) 2008 Elsevier Ltd. All rights reserved.

Digestive duet: midgut digestive proteinases of manduca sexta ingesting nicotiana attenuata with manipulated trypsin proteinase inhibitor expression - Zavala, Jorge A.; Giri, Ashok P.; Jongsma, Maarten A.; Baldwin, Ian T. (Plos One, 2008)
Background: The defensive effect of endogenous trypsin proteinase inhibitors (NaTPIs) on the herbivore Manduca sexta was demonstrated by genetically altering NaTPI production in M. sexta's host plant, Nicotiana attenuata. To understand how this defense works, we studied the effects of NaTPI on M. sexta gut proteinase activity levels in different larval instars of caterpillars feeding freely on untransformed and transformed plants. Methodology/Principal Findings: Second and third instars larvae that fed on NaTPI-producing (WT) genotypes were lighter and had less gut proteinase activity compared to those that fed on genotypes with either little or no NaTPI activity. Unexpectedly, NaTPI activity in vitro assays not only inhibited the trypsin sensitive fraction of gut proteinase activity but also halved the NaTPI-insensitive fraction in third-instar larvae. Unable to degrade NaTPI, larvae apparently lacked the means to adapt to NaTPI in their diet. However, caterpillars recovered at least part of their gut proteinase activity when they were transferred from NaTPI-producing host plants to NaTPI-free host plants. In addition extracts of basal leaves inhibited more gut proteinase activity than did extracts of middle stem leaves with the same protein content. Conclusions/Significance: Although larvae can minimize the effects of high NaTPI levels by feeding on leaves with high protein and low NaTPI activity, the host plant's endogenous NaTPIs remain an effective defense against M. sexta, inhibiting gut proteinase and affecting larval performance.

Direct H(2)-to-H(2)O(2) oxidation in aqueous acidic medium containing Br promoter over Pd/Al(2)O(3) and Pd/C catalysts thermally pretreated under different conditions - Choudhary, Vasant R.; Jana, Prabhas; Bhargava, Suresh Kumar (Catalysis Letters, 2008)
Influence of thermal pretreatments (under N(2), air or H(2) gas atmosphere at 500 degrees C or 700 degrees C) has been investigated for the Pd/Al(2)O(3) and Pd/Carbon catalysts in terms of its effect on their Pd particle size and performance in the H(2)-to-H(2)O(2) oxidation and H(2)O(2) destruction (by decomposition and/or hydrogenation) reactions in aqueous acidic medium containing Br promoter. The influence on the net H(2)O(2) formation is found to depend strongly upon the catalyst support due to support-Pd cluster interactions. For both the catalysts, the thermal treatments (except in air) caused a large increase in their Pd particle size. The increase in Pd particle size caused an increase in the H(2)O(2) formation activity of Pd/Al(2)O(3) but a decrease in the H(2)O(2) formation activity of Pd/C.
Keywords: Hydrogen peroxide; oxidation of H(2) to H(2)O(2); Pd/Al(2)O(3); Pd/C

Distributed chemical computing using chemstar: an open source java remote method invocation architecture applied to large scale molecular data from pubchem - Karthikeyan, Muthukumarasamy; Krishnan, S.; Pandey, Anil Kumar; Bender, Andreas; Tropsha, Alexander (Journal of Chemical Information and Modeling, 2008)
present the application of a Java remote method invocation (RMI) based open source architecture to distributed chemical computing. This architecture was previously employed for distributed data harvesting of chemical information from the Internet via the Google application programming interface (API; ChemXtreme). Due to its open source character and its flexibility, the underlying server/client framework can be quickly adopted to virtually every computational task that can be parallelized. Here, we present the server/client communication framework as well as an application to distributed computing of chemical properties on a large scale (currently the size of PubChem; about 18 million compounds), using both the Marvin toolkit as well as the open source JOELib package. As an application, for this set of compounds, the agreement of log P and TPSA between the packages was compared. Outliers were found to be mostly non-druglike compounds and differences could usually be explained by differences in the underlying algorithms. ChemStar is the first open source distributed chemical computing environment built on Java RMI, which is also easily adaptable to user demands due to its ``plug-in architecture''. The complete source codes as well as calculated properties along with links to PubChem resources are available on the Internet via a graphical user interface at http://moltable.nel.res.in/chemstar/.

Effect of gold dispersion on the photocatalytic activity of mesoporous titania for the vapor-phase oxidation of acetone - Awate, S. V.; Belhekar, Anagha A.; Bhagwat, S. V.; Kumar, R.; Gupta, N. M. (International Journal of Photoenergy, 2008)
Mesostructured titanium dioxide photocatalyst, having uniform crystallite size (6-12 nm) and average pore diameter of similar to 4.2 nm, was synthesized by using a low-temperature nonsurfactant hydrothermal route, employing tartaric acid as a templating agent. Gold additions from 0.5 to 2wt% were incorporated, either during the hydrothermal process or by postsynthesis wet impregnation. Compared to the impregnation-prepared samples, the samples synthesized hydrothermally contained smaller-size (<= 1 nm) gold clusters occluded in the pores of the host matrix. Whereas CO(2) and H(2)O were the main reaction products in UV-assisted vapor-phase oxidation of acetone using these catalysts, C(2)H(6) and HCO(2)CH(3) were also produced for higher acetone concentrations in air. The conversion of acetone was found to increase with decrease in the size of both TiO(2) and gold particles. In situ IR spectroscopy revealed that titania and gold particles serve as independent adsorption and reaction sites for acetone and oxygen molecules. Acetone molecules adsorb exclusively at TiO(2) surface, giving rise to a strongly adsorbed (condensed) state as well as to the formation of formate- and methyl formate- type surface species. Hydroxyl groups at titania surface participate directly in these adsorption steps. Nanosize gold particles, on the other hand, were primarily responsible for the adsorption and activation of oxygen molecules. Mechanistic aspects of the photochemical processes are discussed on the basis of these observations. Copyright (C) 2008.

Effect of sintering conditions and microstructure on the magnetostrictive properties of cobalt ferrite - Bhame, Shekhar D.; Joy, Pattayil Alias (Journal of the American Ceramic Society, 2008)
The effects of sintering temperature and dwell time on the magnetostrictive properties of polycrystalline cobalt ferrite synthesized by the conventional ceramic method have been investigated. The present study showed that the magnitude of magnetostriction strongly depends on the microstructure of the final sintered product. The presence of small and uniform grains with less porous structure in the sintered material leads to enhancement of the magnetostrictive strain. Higher magnetostriction is obtained for samples sintered at a relatively lower temperature of 1100 degrees C. These results are further corroborated by analyzing the effect of some additives during sintering on the microstructural and magnetostrictive properties.

Efficient method for the synthesis of acylals from aldehydes under solvent-free conditions catalyzed by antimony trichloride - Bhattacharya, Asish K.; Mujahid, Mohammad; Natu, Arvind A. (Synthetic Communications, 2008)
A mild and efficient method has been developed for the preparation of acylals from aldehydes catalyzed by antimony trichloride under solvent-free conditions in very good to excellent yields. The easy availability, low cost, and ease of handling of the catalyst make this procedure especially attractive for large-scale synthesis.
Keywords: acetic anhydride; Acylals; aldehydes; antimony trichloride; solvent-free conditions

Facile and highly selective deprotection of tert-butyldimethyl silyl ethers using sulfated SnO2 as a solid catalyst - Bhure, Mahesh H.; Kumar, Indresh; Natu, Arun D.; Rode, Chandrashekhar V. (Synthetic Communications, 2008)
Highly selective deprotection of tert-butyldimethylsilyl ethers at room temperature has been described using sulfated SnO2 as an efficient solid catalyst.
Keywords: deprotection; sulfated SnO2; TBDMS ethers

Facile synthesis and gas sensing properties of nanotriangular tin oxide - Deshmukh, Rupali G.; Badadhe, Satish S.; Vaishampayan, Mukta V.; Mulla, Imtiaz S. (Materials Letters, 2008)
In the present study we report a simple and convenient chemical route using pentaerythritol as a structure-directing agent for the synthesis of crystalline nanotriangular SnO2. We propose the scheme for the formation of nanotriangular structures wherein the preliminary spherical nanocrystallites are formed due to the low surface energy associated with them. These spherical nanocrystallites grow into the various linear intermediate shapes like Y, bi and tripods, which finally lead to the triangles, pyramids and bipyramids. Such variation in the structure occurs due to the structure directing pentaerythritol. These polycrystalline SnO2 nanomaterials with structural peculiarities were tested for the gas sensing characteristics. Their response towards ethanol vapor, H-2 and LPG were investigated. It was found to exhibit high response towards ethanol vapors at the operating temperature of 250 degrees C. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Nanomaterials; Oxides; Semiconductors; sensors

Ferrocene-linked thymine/uracil conjugates: base pairing directed self-assembly and supramolecular packing - Patwa, Amit N.; Gupta, Susmita; Gonnade, Rajesh G.; Kumar, Vaijayanti A.; Bhadbhade, Mohan M.; Ganesh, Krishna N. (Journal of Organic Chemistry, 2008)
Ferrocene-linked bis(nucleobase) (la-c) and chimeric nucleobase (1d) conjugates have been synthesized from mono- and bis(hydroxybutyl)ferrocene 6 via Mitsunobu reaction as the key step. X-ray crystallographic studies of ferrocene bis(nucleobase) conjugates reveal two-dimensional supramolecular organizations of backbones through self-assembled Watson-Crick and reverse Watson-Crick type pairs. Ferrocene-bis(thymine) conjugate self-assembles by reverse Watson-Crick pairing, while the corresponding bis(uracil) conjugate self-assembles by alternating WC and reverse WC type pairing. Such continuous assemblies are not seen in monosubstituted ferrocene nucleobase conjugates which form only planar sheets. The results are interesting from the point of understanding and engineering supramolecular assemblies through rational design of base pairing patterns.

First asymmetric total synthesis of penarolide sulfate A(1) - Mohapatra, Debendra K.; Bhattasali, Debabrata; Gujar, Mukund K.; Khan, Mohammad Islam; Shashidhara, K. S. (European Journal of Organic Chemistry, 2008)
Penarolide sulfate A(1), with three contiguous stereogenic centers on a macrocyclic skeleton, affords promise as an alpha-glucosidase inhibitor. Herein, we describe the first asymmetric total synthesis of this natural product. A stereoselective strategy for rapid assembly of the complete framework of the 30-membered macrocyclic core is delineated herein. Sequential amidation and intramolecular Sonogashira cross-coupling reactions were pivotal to the success of our efforts. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Keywords: Asymmetric synthesis; C-C coupling; Dihydroxylation; epoxidation; Macrocycles; Regioselectivity; Total synthesis

General model for analyzing data on the rate of reactive dissolution of poly-disperse particulate solids - Bhattacharya, Arijit (Chemical Engineering Journal, 2008)
A model has been presented which successfully simulates the experimentally observed integral batch reactive dissolution rate data while accounting for the poly-dispersity of the solid particulate charge. This allowed avoiding arbitrary assumptions about the particulate inventory and size independence of the mass transfer coefficient. There is also no need for a priori identification of the controlling regime, which can change from kinetic to mass transfer during the process, apart from the possibility of the shift with the specified process and operating conditions. The model was applied with equal ease to a simple isothermal reaction, an exothermic reaction with runaway potential and to a phase-transfer catalysis reaction with a complex mechanism. The model was shown to predict the time required for a specified extent of conversion of the particulate reactant or the rate of consumption of a key liquid reactant under a variety of process and operating conditions, like temperature, liquid reactant and the catalyst concentration, particle size, poly-dispersity of the charge and agitation speed. Such information is useful in reactor design and scale-up. Where dissolution is accompanied with a runaway reaction, the model can predict quantities of interest in hazard assessment and should aid safe reactor design. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: kinetic model; particle size distribution; poly-disperse solid reactant; reactive dissolution; reactive thermal hazard; solid-liquid PTC reaction

Heteropoly acid encapsulated SBA-15/TiO(2) nanocomposites and their unusual performance in acid-catalysed organic transformations - Sawant, Dhanashri P.; Justus, Josena; Balasubramanian, Veerappan V.; Ariga, Katsuhiko; Srinivasu, Pavuluri; Velmathi, Sivan; Halligudi, Shivappa B.; Vinu, Ajayan (Chemistry-A European Journal, 2008)
The preparation of SBA-15/TiO(2) nanocomposites with different loadings of Keggin-type 12-tungsto-phosphoric acid (TPA) nanocrystals in their mesochannels through a simple and effective vacuum impregnation method is reported for the first time. The catalysts have been characterised by various sophisticated techniques, including XRD, HRSEM, and TEM. It has been found that the acidity and the textural parameters of the nanocomposites can be controlled by simply changing the loadings of TPA and TiO(2) or the calcination temperature. TPA and TiO(2) loadings of 15 and 22.4 wt %, respectively, and a calcination temperature of 1123 K have proved to be optimal for obtaining mesoporous nanocomposite materials with the highest acidity. Moreover, the activities of these catalysts in promoting hydroamination as well as Mannich and Claisen rearrangement reactions have been extensively investigated. The results show that the amount of TPA has a great influence on the activity of the nanocomposites in all of the reactions studied. The effects of other reaction parameters, such as temperature and reaction time, on the conversion and product selectivity have also been studied in detail. A kinetic analysis of the formation of the products under various reaction conditions is presented. It has been found that the activity of the nanocomposite composed of 15 wt % TPA deposited on 22.4 wt of TiO(2) on SBA-15 in promoting the studied reaction is remarkably higher than the catalytic activities shown by pure TPA, TiO(2)-loaded SBA-15, or TPA-loaded SBA-15. The results obtained have indicated that the acidity and the structural control of the nanocomposite materials are highly critical for obtaining excellent catalytic activity, and the presented highly acidic nanocomposites are considered to show great potential for use as catalysts in promoting many acid-catalysed organic transformations.
Keywords: Bronsted acids; mesoporous materials; nanoreactors; nanotechnology; supported catalysts

Heteropoly acid-based supported ionic liquid-phase catalyst for the selective oxidation of alcohols - Bordoloi, Ankur; Sahoo, Suman; Lefebvre, F.; Halligudi, Shivaraj B. (Journal of Catalysis, 2008)
A supported ionic liquid strategy has been applied for the immobilization of a heteropolyacid, molybdovanadophosphoric acid, onto ionic liquid-modified mesoporous silica SBA-15. The immobilized catalyst demonstrated high activity in the aerobic oxidation of primary and secondary alcohols to aldehydes and ketones, respectively. No overoxidation of the primary alcohols to carboxylic acids was observed. Secondary alcohols were chemoselectively oxidized to ketones in the presence of primary alcohol, hetero atom, and allyl groups. This catalyst could be recycled five times without obvious loss of activity. (C) 2008 Elsevier Inc. All rights reserved.
Keywords: Air as an oxidant; Mesoporous silica SBA-15; Molybdovanadophosphoric acid; Selective oxidation; Supported ionic liquid

Heteropolyacid supported on acidic clay: a novel efficient catalyst for alkylation of ethylbenzene with dilute ethanol to diethylbenzene in presence of C-8 aromatics - Bokade, Vijay V.; Yadav, Ganapati D. (Journal of Molecular Catalysis A-Chemical, 2008)
Vapor phase alkylation of ethylbenzene with ethanol to diethylbenzene is industrially relevant. Diethylbenzene is an important raw material for the conversion of divinyl benzene monomer. Conventionally, it is prepared from diacetophenone by reduction. It is also prepared by vapor phase alkylation of ethylbenzene with ethylene using zeolitic catalysts. The efficacy of dodecatungsotphosphoric acid (DTPA) supported on acid treated clay has been evaluated in the current work in the alkylation of ethylbenzene with 80% (w/w) ethanol. 15% (w/w) DTPA/K-10 clay was found to be an efficient and robust catalyst. The use of aqueous ethanol and a mixed C-8 stream lowers the cost of production. A kinetic model is developed by studying the important process parameters with 15% (w/w) DTPA/K-10 as the catalyst. (c) 2008 Elsevier B.V. All rights reserved.
Keywords: Alkylation; diethylbenzene; Heteropolyacid; kinetics; Solid acids

High frequency occurrence of single cotyledonary embryo morphotype and repetitive somatic embryogenesis in `Thompson Seedless' crossed with seven grapevine male parents - Bharathy, P. V.; Agrawal, Dinesh C. (Vitis, 2008)
Direct somatic embryogenesis was observed in zygotic embryos rescued from intra- and inter-specific crosses between `Thompson Seedless' and seven male parents of grapevine when the embryos were cultured on Woody Plant Medium (WPM) supplemented with benzyladenine (1 mu M). Repetitive somatic embryogenesis occurred on the same medium, which also supported a high percentage of embryo maturation, germination and plantlet development. The cultures retained embryogenic potential for more than two years. We observed a high frequency occurrence of mono-cotyledonous embryo morphotype and other morphological variations in somatic embryos of all the crosses. The percentage of embryos having mono-, di-, tri-, multiple and abnormal cotyledons varied among the crosses. The overall percentage of monocot embryos was 35.50 %, as against 38.64 % of dicot embryos, while the germination rates for mono- and dicot- embryos were 24.44 % and 24.15 %, respectively. Shoot development was poor in tri- and multiple-cotyledonary embryos, while there was no shoot formation in abnormal embryos. We assume that the relatively high occurrence of single cotyledonary morphotype, may be due to the repetitive exposure of embryogenic tissues to a medium containing benzyladenine.
Keywords: cotyledon; Grapevine; somatic embryo; Vitis

Highly efficient and chemo selective catalyst system for the synthesis of blossom orange fragrance and flavoring compounds - Justus, Josena; Vinu, Ajayan; Devassy, Biju M.; Balasubramanian, Veerappan V.; Bohringer, Walter; Fletcher, Jack C. Q.; Halligudi, Shivaraj B. (Catalysis Communications, 2008)
{Acetal and acylal formation reactions of organic compounds are efficiently catalyzed by zirconia-supported mixed oxide systems under liquid-phase reaction conditions. 15WZ-750 (where
Keywords: Acetal; acylal; Silicotungstic acid; tungsten oxide; tungstophosphoric acid; Zirconia

Hydrated clay for catalyst removal in copper mediated atom transfer radical polymerization(a) - Munirasu, Selvaraj; Deshpande, Ashwini; Baskaran, Durairaj (Macromolecular Rapid Communications, 2008)
A simple method has been described to remove catalyst from the copper mediated atom transfer radical polymerization (ATRP) of benzyl methacrylate and methyl methacrylate in anisole at 25 degrees C using hydrated natural clay (sodium montmorillonite, Na-clay). The method consists of (1) addition of hydrated clay (CU(I/)clay approximate to 5 wt.-%) either during or after the polymerization, (2) oxidation of catalyst complex by exposing the terminated reaction mixture in air, and (3) filtration to obtain catalyst free polymer solution. A strong coordination of CuBr-ligand complex onto hydrated clay (10 wt.-%
Keywords: Atom transfer radical polymerization (ATRP); Catalysts; clay; selectivity; synthesis

Imaging the interaction between dengue 2 virus and human blood platelets using atomic force and electron microscopy - Ghosh, Kanjaksha; Gangodkar, Shobha; Jain, Preksha; Shetty, Shrimati; Ramjee, Sandhya; Poddar, Pankaj; Basu, Atanu (Journal of Electron Microscopy, 2008)
Thrombocytopenia is frequently associated with dengue virus infection. Host factors such as anti-platelet immunopathogenic processes have been implicated in the origin of dengue-associated thrombocytopenia but the role of dengue virus in directly interacting with platelets and altering their hemostatic property remains incompletely understood. In the present study, we examined the effect of dengue 2 virus on the morphology and physiological activation profile of normal human platelets using atomic force microscopy, electron microscopy and flowcytometry. Platelets obtained from healthy donors were exposed to a cell culture-adapted 10(4) LD(50) dengue 2 virus isolate in vitro and the subsequent effect on morphology and activation biology studied. Our results show that dengue 2 virus exposure at doses comparable to natural viremic states in human infections can activate platelets with an increase in P-selectin expression and fibrinogen-binding property. Atomic force, scanning and transmission electron microscopy also showed typical activation-related morphological changes such as altered platelet membrane architecture, degranulation, presence of filopodia and dilatation of the open canalicular system in the dengue 2 virus-exposed platelets but not in the controls. Importantly, Japanese encephalitis virus exposure at the same dose did not activate platelets or show any morphological changes. Our findings suggest that dengue 2 virus may directly interact with and activate platelets - an event that might be important in the origin of dengue-associated thrombocytopenia. Detailed molecular characterization of this effect might provide key knowledge toward better prophylaxis of the hemostatic complications of dengue disease.
Keywords: AFM; dengue virus; Electron microscopy; platelet

In vitro regeneration of `Green Sweet' apple via nucellus-raised callus - Joshi, Soumai Kant; Bisht, Vandana; Dhar, Uppeandra; Joshi, Meena; Bisht, Anil Kumar (Journal of Horticultural Science & Biotechnology, 2008)
For the first time, an in vitro regeneration system for `Green Sweet' apple has been developed from nucellus-raised callus. Callus induction (100%) occurred in nucellar explants excised from immature fruit when cultivated on Murashige and Skoog (MS) basal medium, free of plant growth regulators (PGR) and supplemented with 3.0% (w/v) sucrose and 0.8% (w/v) agar. When cultured on MS basal medium supplemented with 10.0 mu M benzyladenine (BA) and 1.0 mu M gibberellic acid (GA(3)), calli showed 88.9 +/- 5.6% shoot regeneration with 4.1 +/- 0.1. shoots per explant, and a mean shoot length of 3.5 +/- 0.2 cm. Elongated shoots produced roots (44.4 +/- 5.6%) when placed in half-strength MS basal medium supplemented with 1.0 mu M indole-3-butyric acid (IBA) and 1.0 mu M a-naphthaleneacetic acid (NAA). Maximum rooting percentage (55.6 +/- 5.6%) was obtained on 0.4% (w/v) agar, while the highest number of roots per shoot (2.8 +/- 0.4 roots) and root length (3.4 +/- 0.2 cm) were recorded on 0.6% (w/v) agar. Acclimatisation of in vitro-raised plantlets resulted in 39.1 % surviving plantlets. The findings of this study indicate that nucellus-raised callus of the apple cultivar `Green Sweet' can efficiently regenerate shoots that can be rooted and successfully acclimatised.

Influence of pretreatment of agriculture residues on phytase production by aspergillus niger NCIM 563 under submerged fermentation conditions - Bhavsar, Kavita P.; Shah, Parin; Soni, Sarvesh Kumar; Khire, Jayant Malhar (African Journal of Biotechnology, 2008)
The extracellular phytase production by Aspergillus niger NCIM 563 was evaluated in medium containing various agriculture residues under submerged fermentation conditions. Phytase production was affected by inorganic phosphate content of agriculture residues which ranged from 2.8 to 8 mg/g. The agriculture residues containing less than 4 mg/g inorganic phosphate supported phytase production with maximum activity of 68 IU/ml in medium containing 1% rice bran on 11(th) day of fermentation. Addition of glucose up to 5% in fermentation medium containing 1% rice bran, enhanced phytase production. Pretreatment of agriculture residues with water to remove excess inorganic phosphate has significantly enhanced the phytase activity in case of de-oiled rice bran, wheat bran, peanut cake (low and high oil) and coconut cake. Maximum increase of 20.3 times in phytase activity was observed in case of wheat bran as compared to de-oiled rice bran, coconut cake, peanut cake high and low oil in which the increase in phytase activity was 6.85, 6.1, 5.3 and 3.0 times, respectively. Maximum phytase activity of 68 IU/ml was produced on the 11(th) day of fermentation compared to earlier reported 41.47 IU/ml phytase activity on the 15(th) day of submerged fermentation using 5% dextrin and 2.5% glucose, thus increasing productivity.
Keywords: Agriculture residue; Aspergillus niger; Phytase; phytate degradation; Poultry feed supplement; Submerged fermentation

Inorganic-organic hybrid materials based on functionalized silica and carbon: a comprehensive understanding toward the structural property and catalytic activity difference over mesoporous silica and carbon supports - Bordoloi, Ankur; Mathew, Nevin T.; Lefebvre, F.; Halligudi, Shivaraj B. (Microporous and Mesoporous Materials, 2008)
Inorganic-organic hybrid materials based on functionalized silica and carbon were synthesized by anchoring molybdovanadophosphoric acid (H-5[PMo10V2O40]center dot 32.5H(2)O) onto amine-functionalized SBA-15, ethane-bridged SBA-15 and mesoporous carbon, respectively. Small angle X-ray diffraction, N-2 sorption analysis, HRTEM, SEM, IFT-IR, CP-MAS NMR were used to diagnose the mesoporous structure of inorganic-organic hybrid materials. The structural integrity of molybdovanadophosphoric acid has been found to be retained after immobilization over mesoporous materials. These inorganic-organic hybrid materials were tested in the environmentally friendly oxidation of 2-methylnaphthalene (2MN) with 30%, aqueous hydrogen peroxide. Molybdovanadophosphoric acid containing mesoporous organosilica hybrid material (ethane-bridged SBA-15) exhibited higher catalytic activities in the oxidation of 2MN to give a clean product 2-methy-1,4-naphthoquinone (menadione vitamin K3 precursor), because of the improved hydrophobicity of the material. The correlation between structural properties and catalytic activities of these hybrid materials has been well addressed in our present studies. (c) 2008 Elsevier Inc. All rights reserved.
Keywords: 2-Methylnaphthalene; inorganic-organic hybrid materials; mesoporous carbon; mesoporous organosilica; Oxidation

Insight into the micellization of dodecyldimethylethylammonium bromide (DDAB) in the presence of bovine serum albumin (BSA) - Mehta, S. K.; Bhawna; Bhasin, K. K.; Kumar, Anil (Journal of Colloid and Interface Science, 2008)
in this work, we report the effect of concentration of bovine serum albumin (BSA) on the micellization of a cationic surfactant, doclecyldimethylethylammonium bromide (DDAB). Several samples covering a wide range of concentrations of protein and surfactant have been investigated. The interactions between the moieties are investigated by measuring fluorescence quenching of BSA molecules. The aggregation number of DDAB micelles is found to be small in the presence of BSA. The formation of DDAB-BSA complex is confirmed by FTIR. Absorbance spectroscopy indicates that at higher concentration, the conformational stability of BSA in DDAB is higher. The viscosity data for protein-surfactant systems confirm conformational changes in protein chains induced by the surfactant. The cmc values for DDAB increase with increasing concentration of BSA. At higher temperatures the micellization-complexation becomes enthalpy-dominated. (c) 2008 Elsevier Inc. All rights reserved.
Keywords: Aggregation number; BSA; conductivity; conformational stability; DDAB; FFIR; fluorescence; UV-visible; viscosity

Intrinsic viscosity of aqueous solutions of carboxymethyl guar in the presence and in the absence of salt - Badiger, Manohar V.; Gupta, Nivika R.; Eckelt, John; Wolf, Bernhard A. (Macromolecular Chemistry and Physics, 2008)
Intrinsic viscosities were determined for solutions of CMG in pure water and 0.9 wt.-% aqueous NaCl. To avoid the 0/0-type extrapolation typical for Huggins plots, a new procedure was used. For CMG and pure water, this requires only two adjustable parameters: the specific hydrodynamic volume of the polymer in the limit of infinite dilution and a hydrodynamic interaction parameter. The intrinsic viscosity of CMG (no salt) at room temperature is 6 050 mL . g(-1); approximately half as large as that of Na-PSS of comparable molar mass. The ratio of the intrinsic viscosities with and without salt is approximate to 7 for CMG, as compared to >100 for Na-PSS. The reasons 1:5 5 for the different behaviors of the two types of polyelectrolytes are being discussed.
Keywords: Biopolymers; Carboxymethyl guar; intrinsic viscosity; polyelectrolyte; salt-free solutions

Invertase inhibition based electrochemical sensor for the detection of heavy metal ions in aqueous system: application of ultra-microlelectrode to enhance sucrose biosensor's sensitivity - Bagal-Kestwal, Dipali; Karve, Meena S.; Kakade, Bhalchandra A.; Pillai, Vijayamohanan K. (Biosensors & Bioelectronics, 2008)
We are reporting fabrication and characterization of electrochemical sucrose biosensor using ultra-microelectrode (UME) for the detection of heavy metal ions (Hg(II), Ag(I), Pb(II) and Cd(II)). The working UME, with 25 mu m diameter, was modified with invertase (INV, EC: 3.2.1.26) and glucose oxidase (GOD, EC: 1.1.3.4) entrapped in agarose-guar gum. The hydrophilic character of the agarose-guar gum composite matrix was checked by water contact angle measurement. The atomic force microscopy (AFM) images of the membranes showed proper confinement of both the enzymes during co-immobilization. The dynamic range for sucrose biosensor was achieved in the range of 1 x 10(-10) to 1 x 10(-7) M with lower detection limit 1 x 10(-10) M at pH 5.5 with 9 cycles of reuse. The spectrophotometric and electrochemical studies showed linear relationship between concentration of heavy metal ions and degree of inhibition of invertase. The toxicity sequence for invertase using both methods was observed as Hg(2+) > Pb(2+) > Ag(+) > Cd(2+). The dynamic linear range for mercury using electrochemical biosensor was observed in the range of 5 x 10(-10) to 12.5 x 10(-10) M for sucrose. The lower detection limit for the fabricated biosensor was found to be 5 x 10(-10) M. The reliability of the electrochemical biosensor was conformed by testing the spike samples and the results were comparable with the conventional photometric DNSA method. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Co-immobilization; Electrochemical biosensor; Heavy metal ions; Invertase (INV)-glucose oxidase (GOD); Mercury; Ultra-microelectrode (UME)

Iron-nickel bimetallic nanoparticles for reductive degradation of azo dye orange G in aqueous solution - Bokare, Alok D.; Chikate, Rajeev C.; Rode, Chandrashekhar V.; Paknikar, Kishore M. (Applied Catalysis B-Environmental, 2008)
The degradation of Orange G, a monoazo dye, in aqueous solutions was investigated using Fe-Ni bimetallic nanoparticles. Transmission electron microscopy (TEM) of as-synthesized nanoparticles showed the presence of spherical particles having a size of 20-40 nm. X-ray photoelectron spectroscopy (XPS) did not detect the presence of nickel on the nanoparticle surface, which suggested a uniform distribution of both metals inside the particle core. Batch experiments with a minimum nanocatalyst loading of 3 g/L showed complete dye degradation after 10 min of reaction time. The degradation efficiency was linearly dependent on the initial dye concentration, pH of the solution and total Fe-Ni catalyst concentration. The efficiency increased with increasing Fe-Ni concentration and decreasing pH of the solution, but decreased with an increase in the dye concentration. The degradation rate followed first order reaction kinetics with respect to the dye concentration. High performance liquid chromatography-mass spectrometry (HPLC-MS) analysis of the degradation products revealed that the degradation mechanism proceeds through a reductive cleavage of the azo linkage resulting in the formation of aniline and surface-adsorbed naphthol amine derivatives. The latter are subsequently hydroxylated through an oxidative process. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: Azo Dye; Degradation; iron; Nanoparticles; Nickel

Kinetic modeling of liquid phase autoxidation of cumene - Bhattacharya, Arijit (Chemical Engineering Journal, 2008)
A new kinetic model for the liquid phase autoxidation of cumene has been developed utilizing the existing knowledge about the traditional free-radical mechanism involving the initiation of the free-radicals, the chain propagation and transfer and the various modes of radical termination. Unlike previous work, in the re-organized reaction network an important cross-termination step replaces an often used but less likely one and a new derivation of the rate model has been provided. A base set of rate parameters for the elementary steps within this reaction network were chosen, many of them were same or very similar to those published in the literature, with a few critical ones re-estimated for correct match with directly observed kinetic data reported in the literature on cumene oxidation in bench scale reactors. Embedding this kinetic sub-model within a simple reaction engineering model for a single air-sparged continuous cumene oxidator, the liquid oxidate composition at the reactor exit could be predicted that compared closely with some limited published data from an industrial reactor. It is hoped that the kinetic model presented here would be a useful tool in the analysis and design of other autoxidation reactors as well with minor adaptations. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: air-sparged continuous oxidator; cumene oxidation; free-radical mechanism; kinetic model; liquid phase autoxidation

Lipase enzyme immobilization on synthetic beaded macroporous copolymers for kinetic resolution of chiral drugs intermediates - Bhushan, Indu; Parshad, Rajinder; Qazi, Gulam Nabi; Ingavle, Ganesh C.; Rajan, C. R.; Ponrathnam, Surendera; Gupta, Vijay Kumar (Process Biochemistry, 2008)
Lipase isolated from Arthrobacter sp. (bacterial strain, MTCC No. 5125) at RRL Jammu, being used for various process development. Arthrobacter sp. lipase (ABL) now has been immobilized on synthetic polymers and reused many a times. In this investigation number of various synthetic macroporous alkylated glycidyl epoxy copolymers with varying hydrophobicity, pore volume and surface area were prepared and used for this study. Among all the polymers prepared and used only two epoxy polymers GMA-EGDM 75-20(I) and GMA-EGDM 75-30(I) with particle size in the range of 150-450 nm, epoxy groups 80 and 70%, tertiary amino groups 20 and 30% was found suitable for immobilization of lipase (ABL). Dibutyl amine (DBA) incorporation created an internal pore radii 20-50 nm and hydrophobic microenvironment in both the polymers for binding the enzyme, which led to improvement in stability and enatioselectivity in racemic resolution process especially by binding to one of the isomers. The optimal ABL binding capacity of polymer GMA-EGDM 75-20(I) was 60 units, 34 mg protein and GMA-EGDM 75-30(l) was 36 units, 21 mg protein/g polymer. The immobilized lipase matrices displayed enhanced pH, thermal, organic solvent and long-term storage stability. Both the immobilized enzyme matrices were tested firstly for the hydrolysis of triglycerides using tributyrin as substrate. After testing, both the matrices were reused for racemic resolution of ethyl-3-hydroxy-3-phenyl propanoate (fluoxetine intermediate, an antidepressant drug) and racemic chiral auxiliary, acetyl-1-phenyl ethanol (intermediate of many chiral drugs) for 15 cycles. These immobilized lipase matrices have shown very high stability on recycling, high-enantioselectivity, high conversion and faster recovery of product compare to free enzyme, therefore these matrices may find use in kinetic resolution process developments. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: 1-phenyl ethanol and enantioselectivity; chiral resolution; enantiomeric excess (ee); ethyl-3-hydroxy-3-phenyl propanoate; Immobilization; Lipase

Local electronic structure and magnetic properties of LaMn(0.5)Co(0.5)O(3) studied by x-ray absorption and magnetic circular dichroism spectroscopy - Burnus, T.; Hu, Z.; Hsieh, H. H.; Joly, V. L. Joseph; Joy, Pattayil Alias; Haverkort, M. W.; Wu, Hua; Tanaka, A.; Lin, H. -J.; Chen, C. T.; Tjeng, L. H. (Physical Review B, 2008)
We have studied the local electronic structure of LaMn(0.5)Co(0.5)O(3) using soft-x-ray absorption spectroscopy at the Co-L(3,2) and Mn-L(3,2) edges. We found a high-spin Co(2+)-Mn(4+) valence state for samples with the optimal Curie temperature. We discovered that samples with lower Curie temperatures contain low-spin nonmagnetic Co(3+) ions. Using soft-x-ray magnetic circular dichroism, we established that the Co(2+) and Mn(4+) ions are ferromagnetically aligned. We also revealed that the Co(2+) ions have a large orbital moment: morb/mspin approximate to 0.47. Together with model calculations, this suggests the presence of a large magnetocrystalline anisotropy in the material and predicts a nontrivial temperature dependence for the magnetic susceptibility.

MCM-41-supported organometallic-derived nanopalladium as a selective hydrogenation catalyst - Maity, Niladri; Rajamohanan, Pattuparambil R.; Ganapathy, Subramanian; Gopinath, Chinnakonda S.; Bhaduri, Sumit; Lahiri, Goutam Kumar (Journal of Physical Chemistry C, 2008)
Palladium nanocatalysts have been prepared by anchoring (eta(3)-C(3)H(5))(2)Pd(2)Cl(2) onto dian-tine-functionalized MCM-41 supports followed by reaction with hydrogen under catalytic conditions. The catalyst precursor and used catalyst have been studied by solid-state NMR ((13)C, (29)Si), XPS, and TEM. The organometallic-derived catalyst exhibits the best performance (activity and selectivity) to date toward the selective hydrogenation of industrially relevant o- and m-chloronitrobenzene to the corresponding chloroaniline derivatives and is distinctly superior to 5% Pd/C. Grazing angle XPS studies reveal that conversion of the tethered molecular species to the nanoparticles of palladium produces a core-shell nanostructure.

MCM-41-supported ruthenium carbonyl cluster-derived catalysts for asymmetric hydrogenation reactions - Indra, Arindam; Basu, Susmit; Kulkarni, Dhanashree G.; Gopinath, Chinnakonda S.; Bhaduri, Sumit; Lahiri, Goutam Kumar (Applied Catalysis A-General, 2008)
{The anionic ruthenium carbonyl cluster [Ru-4(mu-H)(3)(CO)(12)](-) has been ion-paired with (3-chloropropyl)-trimethoxysilyl-cinchonidium or sparteinium groups chemically bound to the surfaces of MCM-41 [(MCM-41-)(-O)(3)SiCH2CH2CH2NR3+Cl-
Keywords: asymmetric catalysis; functionalized MCM-41; hydrogenation catalysts; nanocatalyst; ruthenium carbonyl cluster

Microwave studies on synthesis of biologically active chalcone derivatives - Katade, Sushama; Phalgune, Usha; Biswas, Sujata; Wakharkar, Radhika; Deshpande, Nirmala (Indian Journal of Chemistry Section B-Organic Chemistry Including Medicinal Chemistry, 2008)
Synthesis of pyrazole derivative using microwave energy has been carried out. The compound 1-[4-(2-hydroxy-ethoxy)-phenyl]-ethanone, is prepared from p-hydroxy-acetophenone and 2-chloro-ethanol. Chalcone derivative has been prepared by the condensation reaction of 1-[4-(2-hydroxy-ethoxy)-phenyl]- ethanone with 4-chlorobenzaldehyde. This chalcone. derivative cyclised with hydrazine hydrate and glacial acetic acid under microwave irradiation conditions give pyrazole derivative. These products have been characterized by detailed spectral analysis and have been screened for their antimicrobial activity, against Escherichia coli, Proteus vulgaris, and Salmonella typhimurium.
Keywords: Antimicrobial activity; chalcones; Pyrazole

Molecular association via halogen bonding and other weak interactions in the crystal structures of 11-bromo-12-oxo-5 beta-cholan derivatives - Salunke, Deepak B.; Hazra, Braja G.; Gonnade, Rajesh G.; Pore, Vandana S.; Bhadbhade, Mohan M. (Journal of Molecular Structure, 2008)
Methyl 3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 2, methyl 11 alpha-bromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 3, methyl 11 beta-bromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 4 and methyl 11,11-dibromo-3 alpha,7 alpha-diacetoxy-12-oxo-5 beta-cholan-24-oate 5 were synthesized. The crystal structures of these molecules were resolved to study the effect of bulky bromine atom in the steroid skeleton of cholic acid with different stereo-chemical orientations at C-11 on the two-dimensional arrangement of molecules and solid-state properties. All the molecules associate only via weak intermolecular interactions in their crystal structures, notable one being the Halogen Bonded assembly (C-Br center dot center dot center dot O) in 5. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: 11-Bromosteroids; Cholic acid; crystal structure; Halogen bonding

Mossbauer spectroscopic investigations of nanophase iron oxides synthesized by thermal plasma route - Nagar, Harshada; Kulkarni, Naveen V.; Karmakar, Soumen; Sahoo, B.; Banerjee, Indrani; Chaudhari, P. S.; Pasricha, R.; Das, A. K.; Bhoraskar, S. V.; Date, Sadgopal K.; Keune, W. (Materials Characterization, 2008)
Magnetic nanoparticles of iron oxide were synthesized by transferred arc plasma induced gas phase condensation method. Structural, morphological and magnetic studies of the as synthesized powder were carried out using X-ray diffraction, transmission electron microscopy and Mossbauer spectroscopy. These studies have revealed the simultaneous nucleation and condensation of different magnetic phases with a broad size distribution of the nanoparticles which is peaked at 30-50 nm and ranges from 10 nm to 80 nm. 57 Fe Mossbauer spectra recorded at various temperatures (5 K-300 K) in presence of external magnetic field (at 5 K) have suggested the presence of different phases of iron oxide with sizable amounts of gamma-Fe2O3 and alpha-Fe2O3 in addition to Fe3O4. The relative concentrations of these phases have been obtained by a self consistent spectral area analysis and were found to be 44:22:34 (%). (C) 2007 Elsevier Inc. All rights reserved.
Keywords: iron oxides; Mossbauer spectroscopy; phase analysis; plasma synthesis

Multipoint anchoring of the [2.2.2.2]metacyclophane motif to a gold surface via self-assembly: coordination chemistry of a cyclic tetraisocyanide revisited - Toriyama, Masaharu; Maher, Tiffany R.; Holovics, Thomas C.; Vanka, Kumar; Day, Victor W.; Berrie, Cindy L.; Thompson, Ward H.; Barybin, Mikhail V. (Inorganic Chemistry, 2008)
A one-pot transformation of bis(2-isocyano-3-methylphenyl)ethane affords gram quantities of 8,16,24,32-tetraisocyano[2.2.2.2]metacyclophane ( 3). The solid state structure of 3 is remarkably close to the lowest energy conformation found on the potential energy landscape for 3 by DFT. In solution, the structure of metacyclophane 3 is mobile but can be locked in a rectangular gauche- anti- gauche- anti conformation by coordination of the isocyanide substituents to the [W(CO) 5] units to give [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) ( 5). The tetranuclear [M] 4(mu 4-eta (1):eta (1):eta (1):eta (1)- 3) motif featured in crystallographically characterized 5 may be present in several insoluble complexes of 3 previously described as mononuclear eta (4) species. A self-assembled monolayer of metacyclophane 3 is formed upon exposing a solution of 3 to the gold(111) surface with no precautions to exclude air or light. The monolayer nature of the film was confirmed by optical ellipsometry. The isocyanide stretching band for 3 shifts from 2119 cm (-1) in solution to 2175 cm (-1) upon chemisorption to metallic gold. The FTIR spectrum of the film indicates interaction of 3 with the gold surface via all four of its isocyanide anchors. No gold-facilitated oxidation of the -NC junctions was detected under ambient conditions. The energy cost associated with accessing the conformations of 3 suitable for mu 4-eta (1):eta (1):eta (1):eta (1) interaction of the molecule with the Au(111) surface is under 8 kcal/mol, a value that can be easily offset by formation of a gold-isocyanide bond. Two different mu 4-eta (1):eta (1):eta (1):eta (1) coordination arrangements of 3 with respect to gold atoms on the (111) face of the fcc Au lattice are suggested.

Nanowires of metal-organic complex by photocrystallization: a system to achieve addressable electrically bistable devices and memory elements - Rath, Arup Kumar; Dhara, Koushik; Banerjee, Pradyot; Pal, Amlan J. (Langmuir, 2008)
A new method has been achieved to form a Cu:benzoquinone derivative (DDQ) charge-transfer complex by the photoexcitation of [Cu(DDQ)2(CH3COO)2] (1) that has been synthesized by the reaction of DDQ and hydrated cupric acetate in acetonitrile. Photoexcitation of coordinated complex 1 leads to the formation of charge-transfer complex Cu2+(DDQ•−)2 (2). The charge transfer complex 2, when spun on solid substrates, forms nanowires. Sandwich structures of 2 exhibit electrical bistability associated with memory phenomenon. Read-only and random-access memory phenomena are evidenced in nanowires of 2 providing a route to attend the issues pertaining to the addressibility of organic memory devices.

New microporous MOF material based on Zn(II)-polycarboxylate coordination polymer synthesized with the aid of 1,6-diaminohexane as template - Chandra, Debraj; Kasture, Mahesh W.; Bhaumik, Asim (Microporous and Mesoporous Materials, 2008)
A new microporous metal-organic framework (MOF) material ZBTEC-1 has been synthesized by designing infinite coordination polymer network formed between Zn(II) and 1,2,4,5-benzenetetracarboxylic acid (BTEC) under solvothermal conditions in the presence of 1,6-diaminohexane (DAH) as a single molecule template. Powder XRD data demonstrate that the ZBTEC-1 material has a new MOF structure. N-2 sorption studies indicated moderately good surface area (306 m(2) g(-1)) with large size micropores (average pore diameter ca. 0.7 nm) and very high pore volume (1.93 ccg(-1)). C-13 solid state MAS-NMR, FT-IR and UV-visible spectroscopic studies showed the presence of BTEC moieties in the framework. TEM and FE-SEM analysis indicated 30-60 nm diameter size microporous spherical particles for the ZBTEC-1 crystallites. This novel MOF material showed good hydrogen adsorption capacity at 77 K, indicating its potential application in hydrogen storage. (C) 2008 Elsevier Inc. All rights reserved.
Keywords: Coordination polymer; Metal-organic framework; Microporous material; porosity; Zinc complex

Non-isothermal kinetic studies of the template decomposition from silicalite-1 framework-high temperature X-ray diffraction and thermogravimetric analysis - Bhange, Deu S.; Pandya, N. A.; Jha, Ratnesh Kumar; Ramaswamy, Veda (Microporous and Mesoporous Materials, 2008)
Non-isothermal decomposition of the tetrapropylammonium cations (TPA(+)) intercalated in silicalite-1 framework has been carried out using thermogravimetric (TG) analysis and high temperature powder X-ray diffraction (HTXRD) techniques. Conversion factor for template decomposition is calculated using two methods viz., % weight loss from the thermogravimetric analysis and changes in the intensities of the Bragg reflections 101/011 and 200/020 in the HTXRD patterns scanned at different temperatures (range 298823 K). The calculated apparent activation energy for template decomposition in air was 129 and 125 kJ mol(-1), respectively, for the two techniques TG and HTXRD, calculated using the Kissinger method. By Flynn-Wall-Ozawa approach of isoconversion, apparent activation energy for template decomposition in air was 123 and 124 U mol-1, respectively, for TG and HTXRD data. The reaction order was determined using the method of Kennedy and Clark and it is similar to 2 by both the techniques. The second order of template decomposition can be attributed to the fact that TPA+ is positioned in two different orientations inside the silicalite-1 framework. Template removal occurs with a contraction in unit cell dimensions. There is a decrease in the lattice parameters of the as-synthesized silicalite-1 sample after removal of template from the framework. (C) 2007 Elsevier Inc. All rights reserved.
Keywords: HTXRD; non-isothermal kinetics; Silicalite-1

Novel three dimensional cubic Fm3m mesoporous aluminosilicates with tailored cage type pore structure and high aluminum content - Srinivasu, Pavuluri; Alam, Sher; Balasubramanian, Veerappan V.; Velmathi, Sivan; Sawant, Dhanashri P.; Boehlmann, Winfred; Mirajkar, Subhash P.; Ariga, Katsuhiko; Halligudi, Shivappa B.; Vinu, Ajayan (Advanced Functional Materials, 2008)
Novel three dimensional cubic Fm3m mesoporous aluminosilicates (AIKIT-5) with very high structural order and unprecedented loadings of Al in the silica framework have been successfully prepared for the first time by using non ionic surfactant as a template in a highly acidic medium. The obtained materials have been unambiguously characterized in detail by several sophisticated techniques such as XRD, N, adsorption, HRTEM, HRSEM, EDS, elemental mapping, Al-27 MAS NMR, and NH3-TPD. We also demonstrate that the nature, and the amount of Al incorporation in the silica framework can easily be controlled by simply varying the n(H2O)/n(HCl) and the n(Si)/n(Al), ratios, and the Al sources in the synthesis gel. Among the Al sources examined, the Al isopropoxide (AiPr) is superior over other Al sources. Al-27 MAS NMR results reveal that the amount of tetrahedral Al in the framework can be controlled by simply adjusting the nSi/nAl ratio in the synthesis gel, which increases with increasing the Al incorporation. One of the interesting findings in the work is the increase of the specific surface area, specific pore volume and the pore diameter of AIKIT-5 with increasing the Al incorporation in the silica framework (up to n(Si)/n(Al), ratio of 10) while retaining the well-ordered three dimensional cage type porous structure, and the mechanism for the unusual behavior has been discussed in detail. Finally, the acidity and the catalytic activity in the acetylation of veratrole of the AIKIT-5 catalysts have been studied and the results have been compared with the several zeolites catalysts. Among the catalysts examined, AIKIT-5(10) is found to be superior over the zeolites catalysts such as mordenite, zeolite H-Y, zeolite H-beta, and ZSM-5.

Phosphotungstic acid on silica with modified acid sites as a solid catalyst for selective cleavage of tert-butyldimethylsilyl ethers - Bhure, Mahesh H.; Kumar, Indresh; Natu, Arun D.; Chikate, Rajeev C.; Rode, Chandrashekhar V. (Catalysis Communications, 2008)
The strength and nature of acid sites of bulk phosphotungstic acid could be modified after dispersing it on silica support which was characterized by XRD, ammonia TPD and (31)P MAS NMR techniques. This solid acid catalyst was found to be highly selective for the cleavage of tert-butyldimethylsilyl ethers at room temperature. The catalyst was easily recovered by filtration and could be reused for several times without loss of any activity giving a TON of 9.5 x 10(5). (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Ammonia TPD; Catalytic cleavage; reaction pathway; solid acid; tert-butyldimethylsilyl ethers; XRD

Photocatalytic decomposition of methylene nanocrystalline titania prepared by different blue on methods - Ramaswamy, Veda; Jagtap, Neelam; Vijayanand, S.; Bhange, Deu S.; Awati, Preeti (Materials Research Bulletin, 2008)
Nanocrystalline particles of pure anatase titania were prepared by two different methods. One is the sol-gel method at ambient temperature using ultrasonication (TiO2-SG-US) and conventional stirring method (TiO2-SG-S) and the other by surfactant assisted hydrothermal synthesis (TiO2-HT). More uniform distribution/dispersion of the nanoparticles (SEM), marginally higher surface area, better thermal stability and phase purity are some of the advantages of preparation of nanocrystalline titania by sol gel ultrasonication method and hydrothermal synthesis method. The behavior of anatase titania in photocatalytic decomposition of methylene blue in aqueous medium was studied as a function of the method of preparation and the crystallite size. The nanoparticles prepared by ultrasonication method were more effective than both, the sample prepared by conventional stirring method and commercial Degussa P-25. The higher photocatalytic activity of TiO2-SG-US is attributed to the more uniform size of the particles as compared to TiO2-SG-S samples. Both TEM and XRD data on TiO2-HT samples reveal a uniform and nanocrystalline TiO2 particles, which showed photocatalytic activity in both UV and visible region although brookite phase was also present. (C) 2007 Elsevier Ltd. All rights reserved.
Keywords: Catalytic properties; Nanostructures; Sol-gel chemistry

Phytochemical constituents and pharmacological activities of calotropis procera - Qureshi, Absar A.; Qureshi, Azfar A.; Omer, Shaista; Sanghai, Dhirendra B.; Setty, S. R.; Bhajipale, N. S. (Plant Archives, 2008)
In spite of many synthetic compounds, the most efficient drugs have their origin directly or indirectly related with the plant kingdom. Many of the plant extracts have proven to posses important pharmacological actions depending upon the chemical constituents present. Calotropis procera, plant generally considered as a poisonous whereas widely used in the traditional medicinal system like Ayurveda and Unani. This plant has been reported to poses alkaloids, glycosides, flavonoids, triterpines etc in different parts and exhibit various pharmacological activities like anti-fertility, wound healing, antimalerial, antidiarrhoeal, anti-inflammatory etc. This review highlights some of the phytochemical and pharmacological aspects of Calotropis procera.
Keywords: calactin; calotoxin; Calotropis procera; pharmacological activities; phytochemical constituents; procesterol

Practical syntheses of 4-fluoroprolines - Chorghade, Mukund S.; Mohapatra, Debendra K.; Sahoo, Gokarneswar; Gurjar, Mukund K.; Mandlecha, Manish V.; Bhoite, Nitin; Moghe, Santosh; Raines, Ronald T. (Journal of Fluorine Chemistry, 2008)
4-Fluoroprolines are among the most useful nonnatural amino acids in chemical biology. Here, practical routes are reported for the synthesis of the 2S, 4R, 2S, 4S, and 2R,4S diastereomers of 4-fluoroproline. Each route starts with (2S,4R)-4-hydroxyproline, which is a prevalent component of collagen and hence readily available, and uses a fluoride salt to install the fluoro group. Hence, the routes provide process-scale access to these useful nonnatural amino acids. (c) 2008 Elsevier B.V. All rights reserved.
Keywords: 4-Fluoroproline; 4-Hydroxyproline; collagen; Nonnatural amino acid; Process-scale synthesis

Reaction of huisgen zwitterion with diaryl ketones leading to the facile synthesis of mono- and bis(alkoxycarbonyl)hydrazones - Nair, Vijay; Mathew, Smitha C.; Biju, Akkattu T.; Eringathodi, Suresh (Synthesis-Stuttgart, 2008)
The Huisgen zwitterion, generated from triphenylphosphine and dialkyl azodicarboxylates, afforded upon reaction with diaryl ketones both mono- and bis(alkoxycarbonyl)hydrazones, depending on the reaction conditions.

RuO(2) doped SnO(2) nanobipyramids on Si (100) as a field emitter - Bhise, Ashok B.; Late, Dattatray J.; Ramgir, Niranjan S.; More, Mahendra A.; Mulla, Imtiaz S.; Pillai, Vijayamohanan K.; Joag, Dilip S. (Thin Solid Films, 2008)
Thin films of RuO(2): SnO(2) nanobipyramids have been grown on silicon (100) flat substrates, and their field emission behavior has been investigated. The field emission experiments have been performed in parallel plate configuration. In this experiment, the onset field for 0. 1 gA/ cm 2 current density has been found to be 0.2 V/mu m. The Fowler-Nordheim plot shows non-linear nature typical that of a semiconductor. The field enhancement factor has been estimated to be 35,600 cm(-1), indicating that the field emission originates from the nanometric features of the emitter. The current stability recorded at a preset value of I tA is observed to be good. Our field emission results on RuO(2): SnO(2) nanobipyramids indicate that, RuO(2): SnO(2) nanobipyramids are a potential candidate for futuristic field emission based devices. (c) 2008 Elsevier B.V. All rights reserved.
Keywords: doped semiconductor; field emitter; field enhancement factor; ruthenium oxide; tin oxide

[Ru(salen)(NO)] complex encapsulated in mesoporous SBA-16 as catalyst for hydrogenation of ketones - Bordoloi, Ankur; Amrute, Amol P.; Halligudi, Shivaraj B. (Catalysis Communications, 2008)
SBA-16 mesoporous silica with cubic lm3m structure was synthesized using Pluronic F127 poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (EO106PO70EO106) and it blends with Pluronic P123 triblock copolymer (EO20PO70EO20) as supramolecular templates. The resulting material was used for encapsulating [Ru(salen)(NO)] complex and used in the hydrogenation of ketones to the corresponding alcohols. The pore entrance size of SBA-16 was precisely tailored by silylation with diphenyldichlorosilane to trap [Ru(salen)(NO)] complex in the cage of SBA-16. Small angle XRD, N-2 sorption measurements, UV-Vis and FT-IR analysis evidences the structural integrity of mesoporous silica as well as the complex. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Encapsulation; Hydrogenation; Ketones; SBA-16; [Ru(salen)(NO)] complex

SbCl(3) as a highly efficient catalyst for the acetylation of alcohols, phenols, and amines under solvent-free conditions - Bhattacharya, Asish K.; Diallo, Mamadou A.; Ganesh, Krishna N. (Synthetic Communications, 2008)
Antimony trichloride has been found to be an efficient and expedient catalyst for the acylation of alcohols, phenols, amines, and sugars with acetic anhydride in high yields and in a short reaction time under solvent-free conditions at room temperature. Also, racemization of chiral alcohols and epimerization of sugars were not observed in any of the substrates.
Keywords: acetic anhydride; acetylation; antimony trichloride; solvent-free conditions

Scanning tunneling microscopic and field emission microscopic studies of nanostructured molybdenum film synthesized by electron cyclotron resonance plasma - Purohit, Vishwas S.; Bhise, Ashok B.; Dey, Shirshendu; More, Mahendra A.; Dharmadhikari, C. V.; Joag, Dilip S.; Pasricha, Renu; Bhoraskar, S. V. (Vacuum, 2008)
Cathodic sputtering is demonstrated to be effective in synthesizing thin films of molybdenum nanoparticles. An electron cyclotron resonance plasma reactor has been used as the source. The particle size distribution is found to be controllable by proper choice of the cathodic bias potential. Sizes ranging between 20 and 30 nm deposited at the optimum bias potential are found to exhibit a self assembled structure as observed by scanning tunneling microscopy. Field emission microscopic studies on these films supported on W have exhibited very stable emission current over a period of 3 h. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: ECR plasma; Field emission microscopy; Hollow cathode chemical sputtering; Mo nanoparticles; Scanning tunneling microscopy

Selective cis-dihydroxylation of olefins using recyclable homogeneous molybdenum acetylide catalyst - Biradar, Ankush V.; Sathe, Bhaskar R.; Shubhangi B. Umbarkar; Dongare, Mohan K. (Journal of Molecular Catalysis A-Chemical, 2008)
Selective cis-dihydroxylation of various olefins has been carried out using molybdenum acetylide complex CpMO(CO)(3)(C CPh) (1) as catalyst and hydrogen peroxide as an efficient and environmentally benign oxidant. In case of cyclohexene, very high conversion (95%) and selectivity (86%) for cis-dihydroxylated product has been achieved using H2O2 as an oxidant and t-butanol as a solvent. cis-Dihydroxylation of other substrates like styrene, a-methyl styrene, limonene and cyclopentene has also been carried out with very high selectivity for diol. The catalyst and intermediate species have been characterized using FT-IR, UV-vis spectral analysis and XPS studies as well as cyclic voltametric studies. These studies suggest that molybdenum oxo-peroxo complex is the catalytically active species. The intermediate blue complex when characterized by ESI MS suggested the formation of dimeric molybdenum complex and XPS and cyclic voltametric studies confirm the presence of mixed valence Mo(V) and Mo(VI) in the reaction intermediate. Based on the characterization results possible mechanism for dihydroxylation is proposed. Interestingly, even though the catalyst is homogeneous; it could be recovered quantitatively by extraction in aqueous phase and recycled five times without any appreciable loss in cyclohexene conversion and selectivity for cis-1,2-cyclohexanediol. (c) 2008 Elsevier B.V. All rights reserved.
Keywords: acetylide complex; cis-dihydroxylation; Homogeneous catalysis; Hydrogen peroxide; recyclable

Selective N-oxidation of aromatic amines to nitroso derivatives using a molybdenum acetylide oxo-peroxo complex as catalyst - Biradar, Ankush V.; Kotbagi, Trupti V.; Dongare, Mohan K.; Shubhangi B. Umbarkar (Tetrahedron Letters, 2008)
The molybdenum acetylide oxo-peroxo complex obtained in situ by the treatment of the corresponding molybdenum acetylide carbonyl complex, CpMo(CO)(3)(C CPh); Cp = eta(5-)C(5)H(5) with H(2)O(2), has been used as an efficient catalyst for selective N-oxidation of primary amines to nitroso derivatives. Excellent amine conversion (up to 100%) and very high selectivity for nitroso compounds (99%) have been obtained using 30% hydrogen peroxide as an oxidant. The oxo peroxo, Mo(VI) complex has also been found to be very active for the oxidation of various substituted primary aromatic amines with electron donating as well as electron withdrawing substituents on the aromatic ring. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: aromatic amine; Homogenous catalyst; Hydrogen peroxide; Molybdenum complex; nitroso; Oxidation; Oxo-peroxo

Sheet-forming abiotic hetero foldamers - Baruah, Pranjal K.; Sreedevi, Naduthottiyil K.; Majumdar, Baisakhi; Pasricha, Renu; Poddar, Pankaj; Gonnade, Rajesh G.; Ravindranathan, Sapna; Sanjayan, Gangadhar J. (Chemical Communications, 2008)
Abiotic hetero oligomers, adopting a well-defined extended self-assembled sheet-like structure, derived from conformationally constrained aliphatic and aromatic amino acid residues repeating at regular intervals are reported.

Sol-gel synthesis of MoO(3)/SiO(2) composite for catalytic application in condensation of anisole with paraformaldehyde - Amrute, Amol P.; Bordoloi, Ankur; Lucas, Nishita; Palraj, K.; Halligudi, Shivaraj B. (Catalysis Letters, 2008)
MoO(3)/SiO(2) composite with varying amounts of MoO(3) loading (1-20 wt.%) were prepared by sol-gel method and calcined at 500 C. These catalysts were employed for the liquid phase condensation of anisole with paraformaldehyde. All the catalysts were characterized by N(2) sorption, XRD, and NH(3)-TPD. The activities of synthesized MoO(3)/SiO(2) catalysts were compared with p-toluene sulfonic acid (p-TSA), the most frequently used catalyst for the condensation reactions, and with a supported metal oxide (WO (x) /ZrO(2)). Under the similar reaction conditions, synthesized 10 wt.% MoO(3)/SiO(2) catalyst calcined at 500 C was found to be the most active in the condensation of anisole with paraformaldehyde.
Keywords: 4; 4'-Dimethoxydiphenylmethane; Condensation of anisole; MoO(3)/SiO(2) composites; Paraformaldehyde; Sol-gel synthesis

Studies in structural characterization and correlation with the catalytic activity of an efficient and stable WOx/SBA-15 nanocomposite catalyst - Bordoloi, Ankur; Halligudi, Shivaraj B. (Journal of Catalysis, 2008)
A new WOx/SBA-15 nanocomposite catalyst system was developed by hydrothermal synthesis. The material was characterized by X-ray diffraction, high-resolution transmission electron microscopy, sorption analysis, FT-IR, CP-MAS NMR, XPS, and energy-dispersive X-ray analysis. Various types of aromatic and aliphatic sulfides were selectively oxidized to sulfoxides in good to excellent yields without becoming overoxidized to the sulfones using 70% aq. tert-butyl hydrogen peroxide in the presence of nanocomposite catalyst at room temperature. The catalyst could be easily recovered and reused for at least eight reaction cycles under the reaction conditions described here with no significant loss of reactivity. (c) 2008 Elsevier Inc. All rights reserved.
Keywords: catalytic oxidation; mesoporous materials; Sulfides; Sulfoxides; tungsten oxide nanocluster

Study of a laboratory-scale froth flotation process using artificial neural networks - Kalyani, V. K.; Pallavika; Chaudhuri, Sanjay; Charan, T. Gouri; Haldar, D. D.; Kamal, K. P.; Badhe, Yogesh P.; Tambe, S. S.; Kulkarni, B. D. (Mineral Processing and Extractive Metallurgy Review, 2008)
A three-layer feed-forward artificial neural network (ANN) model, trained using the error back propagation algorithm, has been established to simulate the froth flotation process for the beneficiation of coal fines. The network model validates the experimentally observed qualitative and quantitative trends. The optimal model parameters in terms of network weights have been estimated and can be used to compute the parameters of the coal flotation process over wide-ranging experimental conditions.
Keywords: back propagation algorithm; froth flotation; laboratory-scale; neural network

Suzuki cross-coupling and intramolecular aza-michael addition reaction sequence towards the synthesis of 1,10b-epi-7-deoxypancratistatins and their cytotoxicity studies - Pandey, Ganesh; Balakrishnan, Madhesan; Swaroop, Pandrangi Siva (European Journal of Organic Chemistry, 2008)
The development of an efficient approach to the construction of a phenanthridone is described. The convergent strategy commences with the preparation of Suzuki cross-coupling reaction precursors, arylboronic acid 12 and a-iodo enone 14, from piperonylamine (9) and (-)-D-quinic acid (10), respectively. The coupling of 12 and 19 followed by a key intramolecular aza-Michael addition produced phenanthridone 21 featuring a cis-fused B-C ring junction. The syntheses of compounds 25 and 26, both of which are C-1 and C-10b epimers of the naturally occurring potent antitumor agent 7-deoxypancratistatin (2), from 21 are elaborated in detail in this paper. The cytotoxicities of 25 and 26 were evaluated against three different cancer cell lines. Compound 26 served as a moderate growth inhibitor of THP-1 monocytic cells (GI(50) = 14.5 mu g/mL). ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Keywords: antitumor agents; Chiral pool; Cross-coupling; Intramolecular aza-Michael addition; Pancratistatin

Suzuki cross-coupling/reductive debenzyloxycarbonylation sequence for the syntheses of [c]annulated isoquinolines: application for the syntheses of pancratistatin-like isoquinolines - Pandey, Ganesh; Balakrishnan, Madhesan (Journal of Organic Chemistry, 2008)
A two-step strategy involving Suzuki cross-coupling of boronic acids with a diverse array of alpha-iodoenones followed by hydrogenation is developed for the construction of [c]annulated isoquinolines. This mild and efficient procedure is also applied to the synthesis of highly oxygenated isoquinolines.

Synthesis and self-assembling properties of alpha,omega-hydroxy-poly(ethylene oxide) end-capped with 1-isocyanato-3-pentadecylcyclohexane - Kadam, Vijay S.; Badiger, Manohar V.; Wadgaonkar, Prakash P.; Ducouret, Guylaine; Hourdet, Dominique (Polymer, 2008)
A novel hydrophobic compound, 1-isocyanato-3-pentadecylcyclohexane (PDC) issued from a renewable resource material (Cashew Nut Shell Liquid), is used to end-cap poly(ethylene oxide) (PEO) of different molecular weights. The synthesis, characterization and self-assembling properties of these new associating polymers are reported. In aqueous solution, PDC modified PEOs self-associate into micellar structures which are characterized by neutron scattering. Using a star-polymer model with sticky hard sphere interactions, it is shown that the characteristics of the micelles mainly depend on the size of the PEO chain. In the case of PDC stickers, the aggregation number decreases from 25 to 17 with increasing molecular weight of PEO, from 10 to 20 kg/mol, respectively. The temperature directly impacts the interaction potential between the hydrophilic coronas of PEO which become less repulsive with increasing temperature. Rheological measurements, performed in dilute solution, clearly demonstrate that PEO micelles self-associate into open supramolecular structures. The correlation length of these loose clusters increases with polymer concentration and the hierarchical self-assembly follows the rules of the percolation theory. The sol/gel transition takes place at the overlap concentration of clusters. In semi-dilute solution, the viscoelastic properties of PDC end-capped PEOs are well described by the Maxwell model with a single relaxation mode. The characteristic time of the network follows an Arrhenius temperature dependence with an activation energy of 70 kJ/mol, in very good agreement with the size of PDC stickers. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Associating polymer; Hydrophobically end-capped; poly(ethylene oxide); Star micelles

Synthesis of amphiphilic poly(methyl methacrylate-b-ethylene oxide) copolymers from monohydroxy telechelic poly(methyl methacrylate) as macroinitiator - Dhara, Mahua Ganguly; Baskaran, Durairaj; Sivaram, Swaminathan (Journal of Polymer Science Part A-Polymer Chemistry, 2008)
The synthesis of well-defined poly(methyl methacrylate)-block-poly(ethylene oxide) (PMMA-b-PEO) dibock copolymer through anionic polymerization using monohydroxy telechelic PMMA as macroinitiator is described. Living anionic polymerization of methyl methacrylate was performed using initiators derived from the adduct of diphenylethylene and a suitable alkyllithium, either of which contains a hydroxyl group protected with tert-butyldimethylsilyl moiety in tetrahydrofuran (THF) at -78 degrees C in the presence of LiClO4. The synthesized telechelic PMMAs had good control of molecular weight with narrow molecular weight distribution (MWD). The H-1 NMR and MALDI-TOF MS analysis confirmed quantitative functionalization of chain-ends. Block copolymerization of ethylene oxide was carried out using the terminal hydroxyl group of PMMA as initiator in the presence of potassium counter ion in THF at 35 degrees C. The PMMA-b-PEO diblock copolymers had moderate control of molecular weight with narrow MWD. The H-1 NMR results confirm the absence of trans-esterification reaction of propagating PEO anions onto the ester pendants of PMMA. The micellation behavior of PMMA-b-PEO diblock copolymer was examined in water using H-1 NMR and dynamic light scattering. (C) 2008 Wiley Periodicals, Inc.
Keywords: Anionic polymerization; block copolymers; synthesis

Synthesis of biodiesel over zirconia-supported isopoly and heteropoly tungstate catalysts - Sunita, G.; Devassy, Biju M.; Vinu, Ajayan; Sawant, Dhanashri P.; Balasubramanian, Veerappan V.; Halligudi, Shivappa B. (Catalysis Communications, 2008)
The liquid-phase synthesis of biodiesel by transesterification of sunflower oil with methanol is carried out by using zirconia-supported isopoly and heteropoly tungstates (HPAs) as catalysts. The isopoly and heteropoly tungstate catalysts were prepared by suspending zirconium oxyhydroxide in water/methanol solution of ammonium metatungstate/silicotungstic acid, phosphotungstic acid (WO3/HPA loading, 15%,,) followed by drying and calcination at 750 degrees C. The catalysts were characterized by XRD, Raman spectroscopy, IR spectroscopy, NH3-TPD and FTIR pyridine adsorption spectroscopy. XRD results indicate that the presence of isopoly and heteropoly tungstates stabilizes ZrO2 in tetragonal phase. Raman and IR spectra of the catalysts show that tungstate species exist as zirconia-anchored octahedral mono-oxotungstate. The acidity measurements by NH3-TPD and FTIR pyridine adsorption spectroscopy show that zirconia-supported phosphotungstate has the highest total acidity and zirconia-supported isopoly tungstate has the highest Bronsted acidity. The zirconia-supported isopoly tungstate shows superior catalytic performance compared to zirconia-supported heteropoly tungstate catalysts. Under the reaction conditions of 200 degrees C and methanol/oil molar ratio 15, 15% WO3/ZrO2 calcined at 750 degrees C gave 97% conversion of oil. This catalyst also efficiently catalyzes methanolysis of other vegetable oils like mustard oil and sesame oil. The deactivated catalyst could be regenerated by calcination without appreciable loss in activity. (c) 2007 Elsevier B.V. All rights reserved.
Keywords: Biodiesel; phosphotungstic acids; Silicotungstic acid; transesterification; tungsten oxide; Zirconia

Synthesis of chimeric tetrapeptide-linked cholic acid derivatives: impending synergistic agents - Bavikar, Sudhir N.; Salunke, Deepak B.; Hazra, Braja G.; Pore, Vandana S.; Dodd, Robert H.; Thierry, Josiane; Shirazi, Fazal; Deshpande, Mukund V.; Kadreppa, Sreenath; Chattopadhyay, Samit (Bioorganic & Medicinal Chemistry Letters, 2008)
Tetrapeptides derived from glycine and beta-alanine were hooked at the C-3 beta position of the modified cholic acid to realize novel linear tetrapeptide-linked cholic acid derivatives. All the synthesized compounds were tested against a wide variety of microorganisms (Gram-negative bacteria, Gram-positive bacteria and fungi) and their cytotoxicity was evaluated against human embryonic kidney (HEK293) and human mammary adenocarcinoma (MCF-7) cell lines. While relatively inactive by themselves, these compounds interact synergistically with antibiotics such as fluconazole and erythromycin to inhibit growth of fungi and bacteria, respectively, at 1-24 mu g/mL. The synergistic effect shown by our novel compounds is due to their inherent amphiphilicity. The fractional inhibitory concentrations reported are comparable to those reported for Polymyxin B derivatives. (c) 2008 Elsevier Ltd. All rights reserved.
Keywords: Antimicrobial activity; Cholic acid; Cytotoxicity; Synergism; Tetrapeptide

Synthesis of gymnoascolide A - Baag, Md. Merajuddin; N. P. Argade (Synthesis-Stuttgart, 2008)
Recently isolated 4-benzyl-3-phenylfuran-2,5-dione and antifungal gymnoascolide A have been synthesized using the chemoselective S(N)2' coupling of phenylmagnesium bromide with dimethyl 2-(bromomethyl)fumarate, chemoselective allylic substitution of bromide in 3-(bromomethyl)-4-phenylfuran-2,5-dione with phenylmagnesium bromide and regioselective N-Selectride-induced reduction of 3-benzyl-4-phenylfuran-2,5-dione as the key reactions.
Keywords: dimethyl (bromomethyl)fumarate; functionalized maleic anhydrides; gymnoascolide A; regioselective reduction; S(N)2 ` Grignard coupling reaction

Synthesis of polyhydroxy piperidines and their analogues: a novel approach towards selective inhibitors of alpha-glucosidase - Pandey, Ganesh; Bharadwaj, Kishor Chandra; Khan, Mohammad Islam; Shashidhara, K. S.; Puranik, Vedavati G. (Organic & Biomolecular Chemistry, 2008)
Various polyhydroxy piperidine azasugars have been synthesized from precursors 18a and 18b, obtained in both enantiomeric forms from D-ribose. Out of these polyhydroxy piperidine azasugars, 22, 39 and 20 were found to be potent as well as selective inhibitors of a-glucosidase with K(i) values ranging as low as 1.07 mu M, 16.4 mu M, and 88.2 mu M, respectively. Replacement of the hydroxy methylene moiety of 19 (K(i) 33% at 1 mM) by an amino methylene moiety (32, K(i) 36.8 mu M) showed a remarkable increase in the activity (almost 30 times). Furthermore, increasing the lipophilicity of 33 by N-alkylation with a dodecyl group (36) showed a three-fold enhancement in the activity (K(i) 217 mu M to K(i) 72.3 mu M).

Synthesis of substituted styrenes and stilbenes mediated by palladium on zirconia - Borate, Hanumant B.; Dumbre, Deepa K.; Wakharkar, Radhika D.; Choudhary, Vasant R. (Journal of Chemical Research-S, 2008)
Palladium on zirconia has been found to be an effective catalyst for the synthesis of various substituted styrenes and stilbenes, including biologically active natural products, by reaction of aryl halides with olefins.
Keywords: heterogeneous catalyst; palladium on zirconia; stilbenes; styrenes

Ultrasound promoted asymmetric transfer hydrogenation of ketones using Ru(II)arene/amino alcohol catalyst system - Shingote, Savita K.; Kelkar, Ashutosh A.; Borole, Yogesh L.; Joshi, Pradip D.; Chaudhari, Raghunath V. (Ultrasonics Sonochemistry, 2008)
Asymmetric transfer hydrogenation of ketones using Ru(II)arene/amino alcohol catalyst system proceeds with significant rate enhancement by ultrasound promotion. Comparison of the silent reactions carried out at 25 degrees C with reactions under sonochemical activation at 25 degrees C clearly showed enhancement in catalytic activity by 5-10 times without significantly affecting the enantioselectivity. (C) 2007 Elsevier B.V. All rights reserved.
Keywords: asymmetric catalysis; transfer hydrogenation; Ultrasound

Variability among vitis vinifera cultivars to in vitro propagation - Barreto, M. S.; Nookaraju, A.; Joglekar, A. M.; Karibasappa, G. S.; Agrawal, Dinesh C. (Proceedings of the International Symposium on Grape Production and Processing, 2008)
Response of grapevines to tissue culture has been reported to be genotype dependent, hence it becomes imperative to optimize culture conditions for newly developed varieties or cultivars, needing a large scale planting but availability of sufficient planting stock is a constraint. In the present study, conditions for in vitro propagation of six popular table grape cultivars have been standardized. Single node stem segments of cultivars 2A-Clone of Thompson Seedless, Red Globe, Crimson Seedless, Thompson Seedless, Flame Seedless and Italia cultured on ten different basal media showed varied percentages of bud break and morphogenetic responses. The percentage of bud break varied among the six cultivars. Direct rooting at basal ends of single node segments was observed in all the cultivars except in Italia. Woody plant medium induced the highest response and Eriksson medium the least in all the cultivars tested. Rooted nodal segments with shoots in axils could be established into whole plants on potting. Six cultivars showed different optimum concentrations of growth regulators for induction of maximum number of multiple shoots in both primary as well as secondary nodal segments. Shoot proliferation could be enhanced by several fold in the majority of cultivars on culture of initial shoot clumps to glass bottles instead of culture tubes. Six cultivars showed significant differences in optimum requirement of nutrients and growth regulators for shoot elongation, in vitro and ex vitro rooting and survival rate. Tissue culture plants of all the six cultivars could establish successfully in a greenhouse.
International Symposium on Grape Production and Processing, Baramati, INDIA, FEB 06-11, 2006
Keywords: basal media; Grapevine; growth regulators; micropropagation; Tissue culture; Vitis

Vitamin K-3 family members - Part II: Single crystal X-ray structures, temperature-induced packing polymorphism, magneto-structural correlations and probable anti-oncogenic candidature - Rane, Sandhya; Ahmed, Khursheed; Salunke-Gawali, Sunita; Zaware, Santosh B.; Srinivas, D.; Gonnade, Rajesh G.; Bhadbhade, Mohan M. (Journal of Molecular Structure, 2008)
Temperature-induced packing polymorphism is observed for vitamin K-3 (menadione, 3-methyl-1,4-naphthoquinone, 1). Form la crystallizes at 300 K and 1b at 277 K both in the same space group P2(1)/c. Form 1b contains one molecule per asymmetric unit, performing anisotropy in g-factor viz. g(z) = 2.0082, g(y) = 2.0055 and g(x) = 2.0025, whereas form 1a contains two molecules in its asymmetric unit. Vitamin K-3 family members 2, [2-hydroxy vitamin K-3] and 3, [2-hydroxy-1-oximino vitamin K-3] also perform intrinsic neutral active naphthosemiquinone valence tautomers even in dark having spin concentrations due to hydrogen bonding and aromatic stacking interactions which are compared to vitamin K-3. The significant lateral C-H center dot center dot center dot O and O-H center dot center dot center dot pi bifurcated or pi-pi(center dot) interactions are discussed for molecular associations and radical formations. X-ray structure of 3 revealed pi-pi(center dot) stack dimers as radicals signatured in PR as triplet with five hyperfine splits [(A) over bar(N-14) = 11.9 G]. The centrosymmetric biradicals in 3 show diamagnetism at high temperature but below 10 K it shows paramagnetism with mu(eff) as 0.19 B.M. Vitamin K-3 and its family members inhibit biological activities of acid phosphatase (APase), which are proportional to their spin concentrations. This may relate to their probable anti-oncogenic candidature in future. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Anti-oncogenic candidature; H-bonding; Magneto-structural correlations; Naphthosemiquinones in vitamin K-3 family; Packing polymorphism; Spin concentrations

Acetalization of glycerol using mesoporous MoO3/SiO2 solid acid catalyst - Shubhangi B. Umbarkar; Kotbagi, Trupti V.; Biradar, Ankush V.; Pasricha, Renu; Chanale, Jyoti; Dongare, Mohan K.; Mamede, Anne-Sophie; Lancelot, Christine; Payen, Edmond (Journal of Molecular Catalysis A-Chemical, 2009)
Acetalization of glycerol with various aldehydes has been carried out using mesoporous MoO3/SiO2 as a solid acid catalyst. A series of MoO3/SiO2 catalysts with varying MoO3 loadings(1-20 mol%) were prepared by sol-gel technique using ethyl silicate-40 and ammonium heptamolybdate as silica and molybdenum source respectively. The sol-gel derived samples were calcined at 500 degrees C and characterized using various physicochemical characterization techniques. The XRD of the calcined samples showed the formation of amorphous phase up to 10 mol% MoO3 loading and at higher loading of crystalline alpha-MoO3 on amorphous silica support. TEM analyses of the materials showed the uniform distribution of MoO3 nanoparticles on amorphous silica support. Raman spectroscopy showed the formation of silicomolybdic acid at low Mo loading and a mixture of alpha-MoO3 and polymolybdate species at high Mo loadings. Moreover the Raman spectra of intermediate loading samples also suggest the presence of beta-MoO3. Acetalization of glycerol with benzaldehyde was carried out using series of MoO3/SiO2 catalysts with varying MoO3 loadings (1-20 mol%). Among the series, MoO3/SiO2 With 20 mol% MoO3 loadings was found to be the most active catalyst in acetalization under mild conditions. Maximum conversion of benzaldehyde (72%) was obtained in 8 h at 100 degrees C with 60% selectivity for the six-membered acetal using 20% MoO3/SiO2. Interestingly with substituted benzaldehydes under same reaction conditions the conversion of aldehydes decreased with increase in selectivity for six-membered acetals. These results indicate the potential of this catalyst for the acetalization of glycerol for an environmentally benign process. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Acetalization; Aldehyde; Glycerol; Silicomolybdic acid; solid acid

Acute and subacute toxicity studies of chitosan reduced gold nanoparticles: a novel carrier for therapeutic agents - Pokharkar, Varsha; Dhar, Sheetal; Bhumkar, Devika; Mali, Vishal; Bodhankar, Subhash L.; Bhagavatula L. V. Prasad (Journal of Biomedical Nanotechnology, 2009)
The objective of the present study was to evaluate the oral toxicity of chitosan reduced gold nanoparticles so as to demonstrate its applicability for drug delivery application. Acute oral toxicity studies in female rats documented no deaths or treatment related complications. The LD(50) value of gold nanoparticles was found to be greater than 2000 mg/kg. In case of sub-acute oral toxicity studies, gold nanoparticles were administered orally to male and female rats for a period of 28-days. At the end of study blood samples were collected for haematology and biochemical analysis. For histopathological analysis, organs of animals were weighed and processed for examination. All animals survived the duration of the study, with no significant changes in clinical signs, body weight, food consumption, hematological parameters, organ weights and histopathological findings. These studies establish that chitosan reduced gold nanoparticles produced no treatment related toxicity in rats following oral administration, thus can be exploited for potential therapeutic applications.
Keywords: Acute Toxicity; Chitosan; gold nanoparticles; Sub-Acute Toxicity; Wistar Rats

Application of a stability-indicating thin-layer chromatographic method to the determination of tenatoprazole in pharmaceutical dosage forms - Dhaneshwar, Sunil R.; Bhusari, Vidhya K.; Mahadik, Mahadeo V.; Santhakumari, B. (Journal of AOAC International, 2009)
A sensitive, selective, precise, and stability-indicating thin-layer chromatographic (TLC) method was developed and validated for the determination of tenatoprazole both as a bulk drug and in formulation. The method uses TLC aluminum plates precoated with Silica Gel 60(F-254) as the stationary phase and the solvent system toluene-ethyl acetate-methanol (6 + 4 + 1, v/v/v). This system gave compact spots for tenatoprazole (R(f) value of 0.34 +/- 0.02). Tenatoprazole was subjected to acid and alkali hydrolysis, oxidation, and photodegradation. The peaks of the degradation products were well-resolved from that of the pure drug and had significantly different Rf values. Densitometric analysis of tenatoprazole was performed in the absorbance mode at 306 nm. The linear regression analysis data for the calibration plots showed a good linear relationship over the concentration range of 100-1500 ng/spot. The mean values of the correlation coefficient, slope, and intercept were 0.9989 +/- 1.42, 10.27 +/- 0.965, and 4894.2 +/- 1.24, respectively. The method was validated for precision, robustness, and recovery. The limit of detection and limit of quantitation were 50 and 100 ng/spot, respectively. Statistical analysis showed that the method is repeatable and selective for estimation of tenatoprazole. Because the method can separate the drug from its degradation products, it can be used to monitor stability.

Applications of a high performance platinum nanocatalyst for the oxidation of alcohols in water - Maity, Prasenjit; Gopinath, Chinnakonda S.; Bhaduri, Sumit; Lahiri, Goutam Kumar (Green Chemistry, 2009)
Nanoparticles of platinum (NP-Pt), have been synthesized by supporting high nuclearity anionic carbonyl cluster (Chini cluster) on a water soluble anion exchanger, and the performance of this material, 1, as an oxidation catalyst for alcohols in water has been studied. The E-factor for the synthesis of NP-Pt by this method has been calculated and compared with that of other NP-Pt recently reported in the literature. With 1 as a catalyst, oxidations of a variety of primary and secondary alcohols by dioxygen are achieved and high turnover numbers and selectivities are obtained. The performances of 1 in the oxidation of benzyl alcohol and 1-phenylethanol are compared with those of three other platinum catalysts. These are platinum nanoparticles 2 prepared by the hydrogen reduction of [PtCl6](2-) supported on the same water soluble polymer, 5% Pt on carbon, and 5% Pt on alumina, designated as 3 and 4, respectively. 1 has been found to be considerably more active than 2- 4 and also other reported water soluble platinum nanocatalysts. After many turnovers (similar to 1000 and similar to 165 for benzyl alcohol and 1-phenyl ethanol, respectively) partial deactivation (similar to 40%) is observed, but the deactivated catalyst can be fully regenerated by treatment with dihydrogen. The TEM data of fresh, deactivated and regenerated 1 show a correlation between the particle size and activity. A mechanism consistent with this and other experimental observations including XPS data is proposed.

Biochemical characterization of two xylanases from yeast Pseudozyma hubeiensis producing only xylooligosaccharides - Adsul, Mukund G.; Bastawade, Kulbhushan B.; Gokhale, Digambar V. (Bioresource Technology, 2009)
Two distinct xylanases from Pseudozyma hubeiensis NCIM 3574 were purified to homogeneity. The molecular masses of two native xylanases were 33.3 kDa (PhX33) and 20.1 kDa (PhX20). PhX33 is predominant with alpha-helix and PhX20 contained predominantly beta-sheets. Xylanase, PhX33, possesses three tryptophan and one carboxyl residues at the active site. The active site of PhX20 comprises one residue each of tryptophan, carboxyl and histidine. Carboxyl residue is mainly involved in catalysis and tryptophane residues are solely involved in substrate binding. Histidine residue present at the active site of PhX20 appeared to have a role in substrate binding. Both the xylanases produced only xylooligosaccharides (XOS) with degree of polymerization (DP) 3-7 without formation of xylose and xylobiose. These XOS could be used in functional foods or as prebiotics. Lc ms-ms ion search of cryptic digestion of these xylanases revealed that there is no significant homology of peptides with known fungal xylanase sequences which indicate that these xylanases appear to be new. (c) 2009 Elsevier Ltd. All rights reserved.
Keywords: Cellulase-free xylanase; Pseudozyma hubeiensis; Xylooligosaccharides

Carbon nanofiber with selectively decorated pt both on inner and outer walls as an efficient electrocatalyst for fuel cell applications - Balan, Beena K.; Unni, SreeKuttan M.; Kurungot, Sreekumar (Journal of Physical Chemistry C, 2009)
A novel electrocatalyst, with excellent Pi dispersion oil the inner and outer wall of a carbon nanofiber (CNF) was prepared by a modified polyol process in which both surface tension and polarity characteristics of the medium were properly adjusted to favor solution entry into the tubular region by capillary filling and homogeneous wetting of the inner wall surface by the solvents. The pristine CNF, which possesses an inherently active inner wall surface and inactive outer Wall surface, led to selective Pt deposition along the inner wall, whereas activation of the outer wall with chemical functionalization resulted in excellent dispersion of Pt along both inner and outer walls. Structural and morphological characterizations using high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) revealed that when Pt could be dispersed along the inner as well as the Outer walls of CNF, the Pt particle size decreased to almost half as compared to the one With Pt decoration only along a single wall of the Substrate material. Further, electrochemical studies using cyclic voltammetry (CV) and rotating disk electrode (RDE) measurements revealed enhanced methanol oxidation and oxygen reduction properties, respectively. The electrochemical active area obtained for the catalyst with both inner and outer wall Pt decoration wits nearly two times higher than that corresponding to the one with only inner wall Pt decoration. Similarly, the rate constant for the oxygen reduction reaction displayed by this sample was four times higher in comparison with the sample prepared by Utilizing only one wall for Pt decoration.

Carboxylic-functionalized water soluble pi-conjugated polymer: highly selective and efficient chemosensor for mercury(II) ions - Balamurugan, A.; Reddy, M. L. P.; Jayakannan, M. (Journal of Polymer Science Part A-Polymer Chemistry, 2009)
Here, we report a new carboxylic-functionalized water soluble pi-conjugated polymer for selective detection of highly toxic Hg(2+) in neutral pH condition. carboxylic-functionalized thiophene containing oligophenylenevinylene was synthesized and polymerized under oxidative route to obtain water soluble polymer. Free carboxylic groups present in the pi-conjugated materials provide opportunity to use pH as external stimuli for studying secondary interaction such as hydrogen bonding and aromatic pi-stacking of the chromophores. The pH changes strongly influence on the molecular interactions in the monomer, whereas the long chain polymer was less disturbed. The polymer showed high selectivity for detecting Hg(2+) ions compared with any other transition metal ions in water. The detection efficiency of the polymer was found almost 40 times higher than that of its monomeric unit. Stern-Volmer constant for the Hg(2+) ion sensing was determined through concentration dependent studies as 6.4 x 10(5) M(-1). The carboxylic-functionalized polymer showed reversibility in the metal-ion detecting capabilities which was further investigated by NaCl complexation with Hg(2+) complex. Both funneling of excitation energy to the Hg(2+) center and also excitation energy migration through chain pi-conjugated backbone were correlated to the superior sensing characteristics of the polymer compared to its monomeric counterpart. (C) 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5144-5157, 2009
Keywords: conjugated polymer; pH sensitive; photophysical studies; sensing; synthesis; water soluble

Catalytic activity of cobalt containing MCM-41 and HMS in liquid phase oxidation of diphenylmethane - Bhoware, Shrikant S.; Kamble, K. R.; Singh, A. P. (Catalysis Letters, 2009)
Cobalt containing MCM-41 and HMS were synthesized by direct hydrothermal (DHT) and post synthesis methods (grafting and immobilization). The catalytic activity of these materials was investigated in the liquid phase oxidation of diphenylmethane at 80 A degrees C with TBHP (70 wt%) as oxidant. Comparative study of cobalt containing MCM-41 and HMS was carried out to reveal the catalytic performance of framework, extraframework and immobilized cobalt species. The role of the solvent in the performance of catalyst was examined with different polar and non polar solvents. Oxidation of diphenylmethane in solvent free media (under similar reaction conditions) shows formation of hydroxy derivatives of benzophenone in addition to main product (benzophenone). Hundred percent selectivity to benzophenone was obtained when the reaction was carried out in solvent.
Keywords: diphenylmethane; HMS; Immobilization; MCM-41; XRD

Challenges associated with metal chelation therapy in alzheimer's disease - Hegde, Muralidhar L.; Bharathi, P.; Suram, Anitha; Venugopal, Chitra; Jagannathan, Ramya; Poddar, Pankaj; Srinivas, Pullabhatla; Sambamurti, Kumar; Rao, Kosagisharaf Jagannatha; Scancar, Janez; Messori, Luigi; Zecca, Luigi; et al. (Journal of Alzheimers Disease, 2009)
A close association between brain metal dishomeostasis and the onset and/or progression of Alzheimer's disease ( AD) has been clearly established in a number of studies, although the underlying biochemical mechanisms remain obscure. This observation renders chelation therapy an attractive pharmacological option for the treatment of this disease. However, a number of requirements must be fulfilled in order to adapt chelation therapy to AD so that the term ``metal targeted strategies'' seems now more appropriate. Indeed, brain metal redistribution rather than brain metal scavenging and removal is the major goal of this type of intervention. The most recent developments in metal targeted strategies for AD will be discussed using, as useful examples, clioquinol, curcumin, and epigallocatechin, and the future perspectives will also be outlined.
Keywords: Alzheimer's disease; clioquinol; cuprizone; metal dishomeostasis; metal ions; nanomedicine; Parkinson's disease; polyphenols

On the change in bacterial size and magnetosome features for magnetospirillum magnetotacticum (MS-1) under high concentrations of zinc and nickel - Kundu, S.; Kale, A. A.; Banpurkar, Arun G.; Kulkarni, G. R.; Ogale, S. B. (Biomaterials, 2009)
The characteristic size, shape and specific alignment of magnetite crystals synthesized by magnetotactic bacteria is a highly coordinated process with precise control over magnetosome vesicle formation, uptake and transport of Fe, and magnetite biomineralization. Magnetosome membranes along with some specific membrane proteins regulate crystal nucleation and morphology of magnetite. Several previous works have indicated that the morphology of mature magnetite crystals is largely unaffected by environmental conditions, though some recent studies have shown the possibility of manipulation of the biomineralization process. In this study we have examined the effects of high concentrations of Zinc and Nickel on the growth of Magnetospirillum magnetotacticum (MS-1) and the corresponding magnetosome formation. Using various characterizations it is shown that the growth of the bacterial cells, as well as the size, shape and magnetosome chain alignment is significantly influenced in the presence of high concentrations of Zn or Ni. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Biomineralization; magnetite; Magnetosome; Magnetospirillum magnetotacticum; Nickel; zinc

Comparative study on liquid phase alkylation of 2-methylnaphthalene with long chain olefins using different solid acid catalysts - Lucas, Nishita; Bordoloi, Ankur; Amrute, Amol P.; Kasinathan, Palraj; Vinu, Ajayan; Bohringer, Walter; Fletcher, Jack C. Q.; Halligudi, Shivaraj B. (Applied Catalysis A-General, 2009)
A comparative study has been made over a variety of solid acid catalysts, which include isopoly and heteropoly ions supported on various supports such as zirconia, titania, a large variety of zeolites and a couple of mesoporous materials for liquid phasealkylation of 2-methylnaphthalene with 1-octene.All the catalyst systems were characterized by nitrogen sorption analysis, X-ray diffraction and NH(3)-TPD. Inspite of their high acid amounts zeolites gave poor catalytic performance due to their diffusional constraints; on the other hand mesoporous materials lacked diffusional constraints but due to their low acid amounts resulted in poor conversions. lsopoly and heteropoly ions supported on zirconia and titania were found to be catalytically active for the reaction due to total surface acidity. Among them, isopolytungstate supported on zirconia exhibited the best catalytic activity and was used for further optimization of reaction conditions. Excellent conversions of all olefins (>92%) with high selectivity of monoalkylmethylnaphthalene (>95%) was obtained under optimized reaction conditions. The catalyst could be recycled for several times without any obvious loss of its activity. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: 2-Methylnaphthalene; Alkylation; Long chain olefins; Zirconia

Comparing ultraviolet and chemical reduction techniques for enhancing photocatalytic activity of silver oxide/silver deposited nanocrystalline anatase titania - Priya, R.; Baiju, K. V.; Shukla, S.; Biju, S.; Reddy, M. L. P.; Patil, K.; Warrier, K. G. K. (Journal of Physical Chemistry C, 2009)
Silver oxide/silver have been deposited, with varying silver concentration (0.01-10 mol %), on the surface of sol-gel derived nanocrystal line anatase titania using two different techniques, namely the ultraviolet reduction and chemical reduction (using stannous ions). The pure and silver oxide/silver-deposited nanocrystalline anatase titania have been characterized for their morphology, average nanocrystal lite size, specific surface area, phases involved, surface chemistry, band gap, and photoluminescence using various analytical techniques, such as scanning electron microscopy, transmission electron microscopy, Brunauer, Emmett, and Teller surface-area measurement, X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible spectrophotometry, and spectrofluorometry, respectively. The photocatalytic activity of pure and silver oxide/silver-deposited nanocrystalline anatase titania has been measured by monitoring the degradation of methylene blue dye in an aqueous solution under ultraviolet-radiation exposure. Within the investigated Ag-concentration range, the maximum photocatalytic activity has been observed for 0.1 and 10 mol % Ag for the chemical-reduction (using stannous ions) and ultraviolet-reduction methods with the corresponding apparent first-order reaction-rate constant (k(app)) values of 0.228 and 0.151 min(-1), which are 3.5 and 2.3 times larger than that of pure nanocrystalline anatase fitania (0.065 min(-1)). The chemical-reduction method (using stannous ions), hence, appears to be more effective than the ultraviolet-reduction method for enhancing the photocatalytic activity of nanocrystalline anatase titania. Various factors such as the surface concentration of superoxide ions, oxygen-ion vacancies, and stannous ions as well as the amount of silver oxide/silver and tin oxide are observed to control the surface-adsorption of methylene blue and photoinduced electron/hole lifetime and, hence, variation in the photocatalytic activity as a function of silver concentration.

Comparison of feature selection and classification combinations for cancer classification using microarray data - Vijayan, V.; Bulsara, B.; Gadgil, Chetan J.; Gadgil, Mugdha (International Journal of Bioinformatics Research and Applications, 2009)

Composites of plasma treated poly(etherimide) films with gold nanoparticles and lysine through layer by layer assembly: a ``friendly-rough'' surface for cell adhesion and proliferation for tissue engineering applications - D'Britto, Virginia; Tiwari, S.; Purohit, V.; Wadgaonkar, P. P.; Bhoraskar, S. V.; Bhonde, Ramesh R.; Bhagavatula L. V. Prasad (Journal of Materials Chemistry, 2009)
A composite film fabricated by plasma treated poly(etherimide) with subsequent deposition of gold nanoparticles and lysine using layer by layer assembly has been demonstrated to be good for cell attachment and proliferation making it an attractive strategy for tissue engineering applications. As compared to the other methods the decrease in contact angle obtained here does not depend much on the plasma treatment thus affecting the polymer structure minimally. A combination of surface roughness provided by the gold nanoparticles and the presence of amine groups of lysine is hypothesized to be the reason for the features observed.

Conformational characterization of human eukaryotic initiation factor 2 alpha: a single tryptophan protein - Sreejith, R. K.; Yadav, Viveka Nand; Varshney, Nishant K.; Berwal, Sunil K.; Suresh, C. G.; Gaikwad, Sushama M.; Pal, Jayanta K. (Biochemical and Biophysical Research Communications, 2009)
The alpha-subunit of the human eukaryotic initiation factor 2 (heIF2 alpha), a GTP binding protein, plays a major role in the initiation of protein synthesis. During various cytoplasmic stresses, eIF2 alpha gets phosphorylated by eIF2 alpha-specific kinases resulting in inhibition of protein synthesis. The cloned and over expressed heIF2 alpha, a protein with a single tryptophan (trp) residue was examined for its conformational characteristics using steady-state and time-resolved tryptophan fluorescence, circular dichroism (CD) and hydrophobic dye binding. The steady-state fluorescence spectrum, fluorescence lifetimes (tau(1) = 1.13 ns and tau(2) = 4.74 ns) and solute quenching studies revealed the presence of trp conformers in hydrophobic and differential polar environment at any given time. Estimation of the alpha-helix and beta-sheet content showed: (i) more compact structure at pH 2.0, (ii) distorted alpha-helix and rearranged beta-sheet in presence of 4 M guanidine hydrochloride and (iii) retention of more than 50% ordered structure at 95 degrees C. Hydrophobic dye binding to the protein with loosened tertiary structure was observed at pH 2.0 indicating the existence of a molten globule-like structure. These observations indicate the inherent structural stability of the protein under various denaturing conditions. (C) 2009 Elsevier Inc. All rights reserved.
Keywords: Circular dichroism; heIF2 alpha; K562 cells; Molten globule; Steady-state and time-resolved fluorescence

Consequence of hazards on some petroleum storage tanks and model for off-site emergency plan - Biswajit, Ruj; Chattaraj, Pratim Kumar; Rehman, I; Ray, B. C. (Disaster Advances, 2009)
Explosions, fire and the release of toxic gase cause deaths and injuries to workers and the public, resulting in the evacuation of communities and adversely affecting the environment as a whole. The primary objective of the off-site emergency plan for a hazardous installation is the prevention of accidents. The prevention of accidents involving hazardous substances is the concern of everyone. The poolfire from a petroleum storage tank leads to fatal consequences. This paper highlights some salient features of the emergency scenario from four petroleum storage tanks situated in Budge Budge area, 24 Pgs(S), West Bengal, which ultimately lead to poolfire with enormous heat wave all around and their consequence analysis, affected areas, rescue and evacuation plans, communication and public information systems, roles and responsibilities of the district emergency authority, police, fire and medical authorities.
Keywords: MAH industries; Off-site emergency plan; Petroleum storage tank; Poolfire; radial distance

Copper (I) complexes of a thioether-functionalized short-bite aminobis(phosphonite) - Punji, Benudhar; Mague, Joel T.; Mobin, Shaikh M.; Balakrishna, Maravanji S. (Polyhedron, 2009)
Copper(I) complexes of short-bite aminobis(phosphonite), PhN{P(–OC10H6(μ-S)C10H6O–)}2 (1) have been synthesized. Reactions of 1 with an excess of CuX (X = Cl, Br, and I) afforded the ligand-bridged binuclear complexes, [PhN(PR-κP)2{Cu(μ-X)(MeCN)}2] (2, X = Cl; 3, X = Br; 4, X = I; R = –OC10H6(μ-S)C10H6O–), whereas treatment with 0.5 equiv. of [Cu(MeCN)4]PF6 produces the mononuclear bischelated cationic complex, [{PhN(PR-κP)2}2Cu](PF6) (5). Single crystal X-ray structures of complexes 3 and 4 are reported. Complex 3 shows strong π–π stacking interactions between the naphthyl moieties, whereas complex 4 shows ligand-supported Cu⋯Cu metallophilic interactions.

Copper-catalyzed synthesis of 2-unsubstituted, n-substituted benzimidazoles - Hirano, Keiichi; Biju, Akkattu T.; Glorius, Frank (Journal of Organic Chemistry, 2009)
An efficient copper-catalyzed intramolecular arylation of formamidines forming 2-unsubstituted benzimidazoles in excellent yields is reported. Sixteen examples bearing sterically demanding substituents on nitrogen like Mes, 2,6-diisopropylphenyl, or 2-tert-butylphenyl and tolerating various functional groups demonstrate the utility of this method.

Correlations of thermodynamic properties of aqueous amino acid-electrolyte mixtures - Saritha, C.; Satpute, Dilip B.; Badarayani, Rohini; Kumar, Anil (Journal of Solution Chemistry, 2009)
Suitable equations have been proposed to correlate thermodynamic properties, like mean ion activity coefficients, volumes and compressibilities, of amino acids in electrolyte solutions. An amino acid-electrolyte-water interaction parameter is extracted from the regression of the amino acid property values in aqueous electrolyte solution that is then transferred to an expression to correlate the properties of the electrolyte in mixtures. The single interaction parameter can successfully correlate the published data on mean ion activity coefficients, apparent molar volumes and compressibilities of amino acids as well as of electrolytes in their aqueous mixtures. The equations are tested against the large number of experimental data sets available in the literature.
Keywords: Amino acids; Electrolytes; Pitzer equation; Thermodynamic properties

Development of correlations for overall gas hold-up, volumetric mass transfer coefficient, and effective interfacial area in bubble column reactors using hybrid genetic algorithm-support vector regression technique: viscous newtonian and non-newtonian liq - Gupta, Prashant P.; Merchant, Shamel S.; Bhat, Akshay U.; Gandhi, Ankit B.; Bhagwat, Sunil S.; Joshi, Jyeshtharaj B.; Jayaraman, Valadi K.; Kulkarni, Bhaskar D. (Industrial & Engineering Chemistry Research, 2009)
The objective of this study was to develop hybrid genetic algorithm-support vector regression (GA-SVR)-based correlations for overall gas hold-up (epsilon(G)), volumetric mass-transfer coefficient (kt,a), and effective interfacial area (a) in bubble Column reactors for gas-liquid systems employing Viscous Newtonian and non-Newtonian systems as the liquid phase. The hybrid GA-SVR is a novel technique based on the feature 0 generation approach using genetic algorithm (GA). In the present study, GA has been used for nonlinear rescaling of attributes. These, exponentially scaled, are eventually subjected to SVR training The technique is an extension of conventional SVR technique, showing relatively enhanced results For this purpose an extensive literature search was done. From the published literature, 1629 data points for viscous Newtonian and 845 data points for VISCOUS non-Newtonian systems for cc;, 500 data points for viscous Newtonian and 556 data points for viscous non-Newtonian systems for k(L)a, and 208 data points for viscous non-Newtonian systems for a, respectively, were collected These data sets were collected spanning the years 1965-2007 Correlations were developed after taking into account all the parameters affecting epsilon(G), k(1)a, and a such as column and sparger geometry, gas-liquid properties, operating temperature, pressure, and Superficial gas and liquid velocities. The correlations thus developed gave prediction accuracies of 0.994 and 0.999 and average absolute relative errors (AARE) of 3.75 and 1.65% for viscous Newtonian and non-Newtonian systems for epsilon(G), prediction accuracies of 0.983 and 0.998 and AARE of 8 62 and 1.91% for viscous Newtonian and non-Newtonian systems for k(1)a, and prediction accuracy of 0.999 and AARE of 1% for viscous non-Newtonian systems for a, respectively. These correlations also showed much improved results when compared with all the existing correlations proposed in literature. To facilitate their usage, all the hybrid GA-SVR-based correlations have been uploaded on the web link http-//wwwesnips.com/web/UICT-NCL.

Diethyl [(5-chloro-2-hydroxyanilino)(4-chlorophenyl)methyl]phosphonate - Krishnaiah, M.; Babu, V. H. H. Surendra; Prasad, G. Syam; Reddy, C. Suresh; Puranik, Vedavati G. (Acta Crystallographica Section E-Structure Reports Online, 2009)
In the title compound, C17H20Cl2NO4P, the P atom is bonded in a distorted tetrahedral environment. The dihedral angle between the two benzene rings is 80.5 (1)degrees. In the crystal structure, intermolecular O-H center dot center dot center dot O and N-H center dot center dot center dot O hydrogen bonds link pairs of molecules into centrosymmetric dimers. These dimers, are in turn, linked by weak intermolecular C-H center dot center dot center dot O hydrogen bonds into one-dimensional chains along [010]. Additional stabilization is provided by very weak C-H center dot center dot center dot Cl interactions.

Dipolar S=O center dot center dot center dot C=O and C-H center dot center dot center dot O interactions in the molecular organization of 4,6-di-O-acetyl-2-O-tosyl-myo-inositol 1,3,5-orthoesters - Manoj, Kochunnoonny; Gonnade, Rajesh G.; Bhadbhade, Mohan M.; Shashidhar, M. S. (Acta Crystallographica Section C-Crystal Structure Communications, 2009)
In the absence of conventional hydrogen bonding, the molecules of 4,6-di-O-acetyl-2-O-tosyl-myo-inositol 1,3,5-orthoformate, C(18)H(20)O(10)S, (I), and 4,6-di-O-acetyl-2-O-tosyl-myo-inositol 1,3,5-orthobenzoate, C(24)H(24)O(10)S, (II), are associated via C-H center dot center dot center dot O interactions. Molecules of (II) are additionally linked via dipolar S=O center dot center dot center dot C=O contacts. It is interesting to note that the sulfonyl O atom involved in the dipolar S=O center dot center dot center dot C=O contacts does not take part in any other interaction, indicating the competitive nature of this contact relative to the weak hydrogen-bonding interactions.

Disproportionation of ethylbenzene in the presence of C-8 aromatics - Sharnappa, N.; Pai, S.; Bokade, Vijay V. (Journal of Natural Gas Chemistry, 2009)
The selective synthesis of p-diethylbenzene (p-DEB) by disproportionation of ethylbenzene (EB) in the presence of aromatics like m- and p-xylene isomers has been studied over a pore size regulated HZSM-5 catalyst. The industrial feed having different compositions of ethylbenzene and xylene isomers was used for the experimentation. Hence, they were expected to hinder the movement of reactant molecules both on the external surface and within the zeolite channels. It was observed that irrespective of the different feed compositions the concentration of the xylene isomers was intact in the product. There is no other byproducts formation like para-ethylmethyl benzene. The effects of varying the concentration of aromatic compounds in the feed on ethylbenzene conversion and product distribution over the parent and modified H-ZSM-5 catalyst have been discussed. Ethylbenzene disproportionation reaction follows the pseudo first order reaction with an activation energy of 8.6 kcal/mol.
Keywords: Catalyst; diethylbenzene; disproportionation; ethylbenzene; xylene isomers

Doping-induced microstructural, textural and optical properties of In2Ti1-xVxO5+delta semiconductors and their role in the photocatalytic splitting of water - Shah, Pallavi; Bhange, Deu S.; Deshpande, Aparna; Kulkarni, Mukund S.; Gupta, Narendra M. (Materials Chemistry and Physics, 2009)
The physicochemical properties of V-doped indium titanates (In2Ti1-xVxO5-delta, 0.0 <= x <= 0.2) were investigated by using XPS, powder XRD, UV-vis, SEM and luminescence spectroscopy techniques. The Rietveld refinement of XRD data revealed that even though the V-containing samples were isostructural with In2TiO5 (orthorhombic space group Pnma), a systematic x-dependent variation was noticeable in the Ti-O bond lengths in [TiO6] octahedral units, cell parameters and in the value of delta. XPS results confirmed the coexistence of V5+ and V4+ states, leading thereby to an enhancement in oxygen non-stoichiometry in the doped samples. A loading-dependent progressive shift from 400 to 750 nm was also observed in the onset of the absorption edge, indicating a significant narrowing of the band gap. Furthermore, the samples with higher V-content were comprised of the grain clusters having larger size and an irregular shape. The UV-vis. photoluminescence and thermoluminescence studies indicate that the doping-induced lattice defects may give rise to certain closely spaced acceptor/donor energy levels in between the band gap of host matrix. The indium titanates are found to serve as stable photocatalysts for water splitting under visible light, where oxygen was the major reaction product. The role of microstructural and morphological properties in the photocatalytic activity is discussed. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: In2Ti1-xVxO5+delta photocatalysts; Luminescence spectroscopy; Microstructure; Optical properties; Structure-activity relationship; water splitting

Effect of chirality of L/D-proline and prochiral glycine as the linker amino acid in five-atom linked thymidinyl-(alpha-aminoacid)-thymidine dimers - Seema Bagmare; D'Costa, Moneesha; Kumar, Vaijayanti A. (Chemical Communications, 2009)
The chirality of the amide linker in dimer blocks was found to have a profound effect on the orientation of base stacking interactions as studied by CD and NMR spectroscopy.

Efficient gamma-Fe2O3 catalyst for liquid phase air oxidation of p-hydroxybenzyl alcohol under mild conditions - Garade, Ajit C.; Bharadwaj, M.; Bhagwat, S. V.; Athawale, A. A.; Rode, C. V. (Catalysis Communications, 2009)
gamma-Fe2O3 (maghemite) particles were synthesized at 5 degrees C (LT, low temperature) and 95 degrees C (HT, high temperature) using a simple chemical protocol. The major reflection in XRD was observed to be of the gamma-Fe2O3 phase which was further supported by the XPS analysis. Fe3+ species were responsible for initiation of the oxidation of p-hydroxybenzyl alcohol. SEM revealed that the morphologies of the catalysts were different for samples prepared at two different temperatures. gamma-Fe2O3 (LT) showed the highest catalyst activity (84% conversion) for liquid phase air oxidation of p-hydroxybenzyl alcohol with 94% selectivity to the oxidation products at 370 K and ambient pressure conditions. (C) 2008 Elsevier B.V. All rights reserved.
Keywords: Air oxidation; gamma-Fe2O3; p-Hydroxybenzaldehyde; p-Hydroxybenzyl alcohol; scanning electron microscopy

Efficient, rapid, and regioselective bromination of anilines and phenols with 1-butyl-3-methylpyridinium tribromide as a new reagent/solvent under mild conditions - Borikar, Sanjay P.; Daniel, Thomas; Paul, Vincent (Tetrahedron Letters, 2009)
1-Butyl-3-methylpyridinium tribromide, [BMPy]Br(3) proves to be a highly efficient, regioselective reagent/solvent for nuclear bromination of various anilines and phenols. The synthesis and characterization of the room temperature ionic liquid [BMPy]Br(3) (2) is described. The bromination was carried out in the absence of organic solvents and in most cases the only extraction solvent needed was water. The spent 1-butyl-3-methylpyridinium bromide (1) was easily recycled. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Bromination; Ionic liquid; Regioselective; [BMPy]Br(3)

Enhanced nonvolatile resistive switching in dilutely cobalt doped TiO2 - Bogle, Kashinath A.; Bachhav, Mukesh N.; Deo, Meenal S.; Valanoor, Nagarajan; Ogale, Satishchandra B. (Applied Physics Letters, 2009)
Incorporation of dilute concentration of dopant having a valence state different than that of the host cation enables controlled incorporation proximity vacancy defects for local charge balance. Since nonvolatile resistive switching is a phenomenon tied to such defects, it can be expected to be influenced by dilute doping. In this work, we demonstrate that enhanced nonvolatile resistive switching is realized in dilutely cobalt doped TiO2 films grown at room temperature. We provide essential characterizations and analyses. We suggest that the oxygen vacancies in the proximity of immobile dopants provide well distributed anchors for the development of systematic filamentary tracks.
Keywords: cobalt; Doping; magnetic switching; random-access storage; titanium compounds; vacancies (crystal); valency

Enhanced solar-radiation induced photocatalytic activity of surface-modified nanocrystalline anatase-titania - Priya, R.; Baiju, K. V.; Shukla, S.; Biju, S.; Reddy, M. L. P.; Patil, K. R.; Warrier, K. G. K. (Catalysis Letters, 2009)
Sol-gel derived pure nanocrystalline (similar to 20-30 nm) anatase-titania has been surface-modified by depositing silver(I) oxide and silver (predominantly the former) via UV-reduction process. The pure and surface-modified nanocrystalline anatase-titania have been characterized using different analytical techniques for determining the average nanocrystallite size, phase-contents, surface-chemistry, as well as the absorption and photoluminescence characteristics. It is demonstrated that, the latter exhibits an enhanced solar-radiation induced photocatalytic activity as compared to that of the former as a result of the absorption in the visible-region and enhanced photo-induced e(-)/h(+) life-time, both caused by the surface-deposition of silver(I) oxide and silver.
Keywords: Nanocrystalline; Photocatalysis; Silver; sol-gel; titania; UV-reduction

Enhancing intermolecular benzoyl-transfer reactivity in crystals by growing a ``reactive'' metastable polymorph by using a chiral additive - Murali, Chebrolu; Shashidhar, Mysore S.; Gonnade, Rajesh G.; Bhadbhade, Mohan M. (Chemistry-A European Journal, 2009)
Racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate, which normally crystallizes in a monoclinic form (form I, space group P2(1)/n) could be persuaded to crystallize out as a metastable polymorph (form II, space group C2/c) by using a small amount of either D- or L- 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoformate as an additive in the crystallization medium. The structurally similar enantiomeric additive was chosen by the scrutiny of previous experimental results on the crystallization of racemic 2,4-di-O-benzoyl-myo-inositol-1,3,5-orthoacetate. Form II crystals call be thermally transformed to form I crystals at about 145 degrees C. The relative organization of the molecules in these dimorphs vary slightly in terms of the helical assembly of molecules, that is, electrophile (El)center dot center dot center dot nucleophile (Nu) and C-H center dot center dot center dot pi interactions, but these minor variations have a profound effect on the facility and specificity of benzoyl-group-transfer reactivity in the two crystal forms. While form II crystals undergo a clean intermolecular benzoyl-group-transfer reaction, form I crystals are less reactive and undergo non-specific benzoyl-group transfer leading to a Mixture of products. The role played by the additive in fine-tuning small changes that are required in the molecular packing opens up the possibility of creating new polymorphs that show varied physical and chemical properties. Crystals of D-2.6-di-O-benzoyl-myo-inositol-1,3,5-orthoformate (additive) did not show facile benzoyl-group-transfer reactivity (in contrast to the corresponding racemic compound) due to the lack of proper juxtaposition and assembly of molecules.
Keywords: Acylation; carbohydrates; Crystal growth; cyclitols; solid-state reactions

Eudragit (R) EPO based nanoparticle suspension of andrographolide: in vitro and in vivo - Bothiraja, C.; Pawar, Atmaram P.; Shaikh, Karimunnisa S.; Sher, Praveen (Nanoscience and Nanotechnology Letters, 2009)
Characteristic formulation of an isolated active phytoconstituent is of great therapeutic significance. The purpose of this work was to develop Eudragit (R) EPO based nanoparticle suspension of isolated andrographolide in order to increase its solubility and efficacy. Andrographolide was isolated from Andrographis paniculata and Its Nanoparticle suspension was prepared by precipitation technique. The 3(2) factorial design was used to study the effect of Eudragit (R) EPO and Pluronic (R) F-68 on characteristics of nanoparticle suspension. The optimized formulation was subjected to lyophilization. The nanoparticle suspension, lyophilized suspension and the redispersed lyophilized nanoparticle suspension were characterized by drug content, encapsulation efficiency, particle size, electrokinetic properties, DSC, PXRD, FTIR, TEM and in vitro drug release. Optimized batch showed particle size 255 +/- 9 nm with encapsulation efficiency 93.8 +/- 0.67% and zeta potential 29.3 +/- 3.4 mV. There was marked increase in drug dissolution with complete drug release within 10 minutes in nanoparticle suspension and redispersed naoparticle suspension as compared to pure drug. However, lyophilization retarded the drug release. The nanoparticle suspension and redispersed nanoparticle suspension also showed improved hepatoprotectivity as compared to andrographolide against CCl(4)-induced hepatotoxicity in rats. The results were confirmed by histopathological studies on hepatic lesions. Thus particle engineering can be used to improve pharmaceutical properties of phytoconstituents.
Keywords: Andrographolide; Eudragit (R) EPO; Hepatoprotective Activity; Nanoparticle Suspension; Pluronic (R) F-68

Evaluation of high performance liquid chromatography purified leptospiral antigen for the diagnosis of leptospirosis - Pol, Sae; Bharadwaj, Renu (Japanese Journal of Infectious Diseases, 2009)
Leptospirosis is a re-emerging infection, and often occurs in outbreaks. Early diagnosis is important for appropriate control measures and treatment. The sensitivity and specificity of the diagnostic test depends on the antigen, which is used for the detection of antibodies. In the present study, an effort was made to purify and characterize leptospiral antigens, and their performance in the laboratory was assessed. Leptospira biflexa semaranga, Patoc was subjected to processing by the heat extraction method, and the crude antigenic preparation was subjected to high-performance liquid chromatography for purification. The purified antigen fractions were subjected to enzyme-linked immunosorbent assay (ELISA) to determine their reactivity. Only the reactive fractions were tested for specificity by ELISA by allowing the fractions to react with positive sera of patients with non-leptospiral illness. H1, the purified antigen fraction of the heat-extracted preparation, was found to be the most reactive and specific of all fractions tested. The protein was found to have a molecular weight of 50 kDa. The performance of H1 in the laboratory was assessed by formulating an in-house ELISA using the H1 antigen. The results were compared with those of microscopic agglutination testing and commercial ELISA. The specificity and sensitivity of in-house ELISA using the H1 antigen were found to be 93.3 and 85.0%, respectively.

Field emission investigation of single Fe-doped SnO2 wire - Bhise, Ashok B.; Late, Dattatray J.; Sathe, Bhaskar R.; More, Mahendra A.; Mulla, Imtiaz S.; Pillai, Vijayamohanan K.; Joag, Dilip S. (Solid State Sciences, 2009)
Tin oxide submicronwires doped with Fe element were prepared by the thermal evaporation method. Morphological and structural characterizations revealed wires with sub micron size and crystalline in nature. The field electron emission from the single Fe:SnO2 wire was carried out in conventional field emission microscope. The Fowler-Nordheim plot obtained from I-V characteristics of the wire showed a linear behavior typical that of metal. The field enhancement factor estimated from the slope of the F-N plot is 7455 cm(-1), indicating that the field emission is from nanometric features of the emitter. A current density of 10 A/cm(2) has been obtained at an applied field of 4.845 x 10(3) V/mu m. The field emission current-time record at a current level of 1 mu A for more than 3 h duration is promising for various field emissions based applications. (C) 2009 Published by Elsevier Masson SAS.
Keywords: Current stability; Fe doped; field emission; SnO2

First- and second-order electrical properties computed at the FSMRCCSD level for excited states of closed-shell molecules using the constrained-variational approach - Bag, Arijit; Manohar, Prashant Uday; Vaval, Nayana; Pal, Sourav (Journal of Chemical Physics, 2009)
Fock space multireference coupled-cluster (FSMRCC) method emerged as an efficient tool to describe the electronic structure of nearly degenerate cases. Development of linear response has been one of the challenging problems in FSMRCC due to the multiple-root nature of the effective Hamiltonian. A response from any of the roots would span the space for getting the properties. Hence, all roots perturbed by the external field would proliferate the excited states. We recently developed the FSMRCC method for the efficient evaluation of analytic response properties using a constrained variation approach. In this paper, we present analytic dipole moments and polarizabilities of H2O, O-3, and CH+ molecules in low-lying excited states along with brief discussion of singlet triplet decoupling of (1,1) sector of FSMRCC resulting from spin adaptation. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3167796]

First ionic liquid-promoted Kabbe condensation reaction for an expeditious synthesis of privileged bis-spirochromanone scaffolds - Muthukrishnan, Murugan; Basavanag, U. M. V.; Puranik, Vedavati G. (Tetrahedron Letters, 2009)
A variety of privileged bis-spirochromanones were synthesized for the First time from 4,6-diacetyl resorcinol in one-pot by carrying out the Kabbe condensation in loom temperature ionic liquid [bbim]Br. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Bis-spirochromanone; Ionic liquid; Kabbe condensation; Morpholine

Functional delivery of siRNA in mice using dendriworms - Agrawal, Amit C.; Min, Dal-Hee; Singh, Neetu; Zhu, Haihao; Birjiniuk, Alona; von Maltzahn, Geoffrey; Harris, Todd J.; Xing, Deyin; Woolfenden, Stephen D.; Sharp, Phillip A.; Charest, Alain; Bhatia, Sangeeta N. (ACS Nano, 2009)

H(2)S gas sensitive indium-doped ZnO thin films: preparation and characterization - Badadhe, Satish S.; Mulla, Imtiaz S. (Sensors and Actuators B-Chemical, 2009)
High quality indium-doped ZnO (IZO) thin films (similar to 100 nm) have been deposited onto the glass substrates by using a conventional spray pyrolysis technique. Precursors such as zinc acetate, indium chloride with Brij-35 (polyoxyethylene lauryl ether) as a non-ionic surfactant were used. The morphology, crystal structure, elemental analysis and the gas response properties were investigated by using SEM, TEM, XRD, AFM and XPS techniques. The films show hexagonal wurtzite structure which reveal variations in (100). (00 2) and (10 1) intensities with indium doping. The crystallite size calculated by Scherrer formula was in the range of 30-50 nm. The SEM and AFM analysis show 50-70 nm sized grains, while the TEM confirms formation of grains by similar to 10nm sized particles. Their response towards various gases was measured at different operating temperatures and different levels of In-dopants. The 3 at% In-doped ZnO showed response as high as 13,000 for 1000ppm H(2)S at 250 degrees C. It exhibited fast response (similar to 2s) and recovery time (similar to 4 min). The gas response strongly depends on the morphology and indium concentration. The high gas response of IZO is explained on the basis of thickness dependent trap state density. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Hydrogen sulfide sensor; Indium oxide; Spray pyrolysis; thin film; Zinc oxide

High energy electron irradiation effects on polystyrene films - Mathad, R. D.; Kumar, H. G. Harish; Sannakki, B.; Ganesh, S.; Sarma, K. S. S.; Badiger, Manohar V. (Radiation Effects and Defects in Solids, 2009)
The effect of an 8MeV electron-beam on the structural, optical and dielectric properties of polystyrene films has been investigated respectively by means of Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-VIS) spectroscopy and electrical impedance (LCR) analysis over a radiation dose in the range of 50-250kGy using a Microtron accelerator. The FTIR spectral analysis shows no change in the overall structure of the irradiated polystyrene films, except a minor change in the intensity of a few peaks in the FTIR spectrum, indicating that polystyrene is resistant to electron-beam irradiation over the range of radiation doses investigated. The optical band gap analysis using the UV-VIS absorption spectra of the polystyrene shows a small decrease in the optical band gap (Eg) and the activation energy with an increase in electron doses. Further, the dielectric measurements over a frequency range of 100Hz to 1MHz for the electron-beam-irradiated polystyrene films show that both the dielectric constant and the dielectric loss increase with an increase in electron radiation dose, which may be ascribed to the formation of defect sites in the band gap of polystyrene as a consequence of molecular chain scission in the polymer films upon irradiation.
Keywords: electrons; optical spectroscopy; Polymers; radiation

Highly diastereoselective 1,3-dipolar cycloaddition of a D-galactose-derived nitrone with dimethyl maleate: synthesis of polyhydroxylated perhydroazaazulenes - Bande, Omprakash P.; Jadhav, Vrushali H.; Puranik, Vedavati G.; Dhavale, Dilip D. (Synlett, 2009)
An intermolecular 1,3-dipolar cycloaddition of a D-galactose-derived nitrone with dimethyl maleate was found to be perfectly diastereoselective at the nitrone carbon to give exclusive formation of isoxazolidine. The N-O bond reductive cleavage in isoxazolidine followed by lactam reduction afforded a pyrrolidine ring skeleton with sugar appendage that on acetonide cleavage and reductive amino-cyclization gave hitherto unknown hydroxymethyl-substituted hexa- and pentahydroxy perhydroazaazulenes.
Keywords: 1; 3-dipolar nitrone olefin cycloaddition (DNOC); diastereoselectivity; Iminosugars; inhibitors; nitrone

Highly efficient recyclable hydrated-clay supported catalytic system for atom transfer radical polymerization - Munirasu, Selvaraj; Aggarwal, Ravi; Baskaran, Durairaj (Chemical Communications, 2009)
Atom transfer radical polymerization of methacrylates has been performed using hydrated natural clay as a support for a CuBr(2)-ligand complex and the supported clay catalyst has been recycled for 21 batch polymerizations without losing its activity.

Hydrophosphonylation of activated alkenes and alkynes via fluoride ion activation in ionic liquid medium - Balaraman, Ekambaram; Srinivas, Venu; Swamy, K. C. Kumara (Tetrahedron, 2009)
A simple transition metal-free hydro/hydrothiophosphonylation of Baylis–Hillman adducts, substituted allyl bromides, allenylphosphonates and alkynes, promoted by fluoride ion in ionic liquid, is described. Clear-cut evidence for fluoride activation of the phosphite via pentacoordinate phosphorus is provided for the first time. Also, in a comparative reaction, the product obtained was different from that from the palladium catalyzed one. Structures of key products are proven by X-ray crystallography.

Identification of Indian pathogenic races of fusarium oxysporum f. sp ciceris with gene specific, ITS and random markers - Gurjar, Gayatri; Barve, Maneesha; Giri, Ashok P.; Gupta, Vidya (Mycologia, 2009)
In this study we demonstrate the synergistic use of gene-specific markers, ITS-RFLP, ISSR and AFLP for distinguishing Indian F. oxysporum f. sp. ciceris races. We also report for the first time that F. oxysporum f. sp. ciceris race 3, a wilt pathogen of chickpea in India, is actually E proliferatum based on phylogenetic analysis with EF-1 alpha sequence data. E oxysporum f. sp. ciceris races 1, 2 and 4 were easily distinguished from ``race 3'' (F. proliferatum) by PCR amplification with oligonucleotides designed from conserved regions of Hop78 transposon (Hop 78), cutinase (Cut), desaturase (Dst). F oxysporum f. sp. ciceris race 4 was distinguished with the xylanase 3 (xyl3) gene by absence of amplification product only in this race. The Xyl3 amplified-DNA fragment isolated and sequenced from E oxysporum f. sp. ciceris race I was similar to the F-xylanase (Xyl3) gene of E oxysporum f. sp. lycopersici. A TELD motif, which is characteristic of the F-xylanases family, was detected within the deduced amino acid sequence of F. oxysporum f. sp. ciceris. Similarly the F oxysporum f. sp. ciceris Hop78 DNA fragment, which identified ``race 3'' (E proliferatum), was homologous to the Hop78 transposon of E oxysporum f. sp. melonis, including the 100 amino acid conserved domain and the characteristic CCHC motif. The internal transcribed spacer region-restriction fragment length polymorphism (ITS-RFLP) approach along with intersimple sequence repeat (ISSR) method also differentiated ``race 3'' (F. proliferatum). Races 1 and 2 were identified by unique AFLP patterns. Sequence characterization of race-specific AFLP products revealed significant homologies of these sequences with metabolically important genes.
Keywords: AFLP; F. oxysporum f. sp ciceris races; gene specific amplification; ISSR; ITS-RFLP; race delineation; sequence characterization; translation elongation factor (EF-1 alpha)

In situ synthesis of water dispersible bovine serum albumin capped gold and silver nanoparticles and their cytocompatibility studies - Murawala, Priyanka; Phadnis, S. M.; Bhonde, Ramesh R.; Bhagavatula L. V. Prasad (Colloids and Surfaces B-Biointerfaces, 2009)
A simple and convenient one step room temperature method is described for the synthesis of bovine serum albumin (BSA) capped gold and silver nanoparticles. BSA reduces silver ions to silver nanoparticles but does not directly reduce gold ions to gold nanoparticles at room temperature and varying pH conditions. However, when silver and gold ions are simultaneously added to BSA, silver ions get reduced to metallic silver first and these in turn reduce gold ions to gold nanoparticles through a galvanic exchange reaction. The so synthesized silver and gold nanoparticles are easily water dispersible and can withstand addition of salt even at high concentrations. It is shown that the capped protein retains its secondary structure and the helicity to a large extent on the nanoparticles surface and that the protein capping makes the nanoparticles cytocompatible. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: Ag and Au nanoparticles; Bovine serum albumin; Cytocompatibility; Galvanic exchange reaction; Reductive synthesis

Incorporation of tin in different types of pores in SBA-15: synthesis, characterization and catalytic activity - Sasidharan, M.; Kiyozumi, Y.; Mal, N. K.; Paul, M.; Rajamohanan, P. R.; Bhaumik, Asim (Microporous and Mesoporous Materials, 2009)
Mesoporous Sn-SBA-15 has been synthesized by three different methods Such as conventional hydrothermal route, using cocatalyst NH4F and in the presence of organosilane precursor. All the materials are thoroughly characterized by powder X-ray diffraction (XRD), SEM. TEM. N-2 sorption and surface area measurements, diffuse-reflectance UV-visible and FTIR spectroscopy. TG-DTA and elemental analysis through ICP. Nitrogen adsorption data, XRD patterns, and TEM observations Suggests that the textural properties are retained during the isomorphous substitution of silicon by tin. ICP chemical analysis indicates that tin can be substituted in the range of S-l/S-n = 69-162. UV-visible spectra of samples synthesized by the cocatalytic approach exhibit unique absorption band at 213 nm characteristics of tin atom substituted in the smaller pores (2-3 nm) located inside the walls of mesopores. Further, an additional band at 224 nm can be assigned to Sri atoms located in the distorted tetrahedral position along the primary mesopores. In contrary, only one absorption band centered at 224 nm is observed for all the samples synthesized by conventional hydrothermal as well as in the presence of organosilane precursor. F-19 NMR spectra confirmed (no signal) the absence of occluded F- ions in the samples made with NH4F. Observed high catalytic activity in Baeyer-Villiger oxidation and Meerwin-Pondorf-Verly reduction under the liquid-phase conditions suggest the incorporation of a portion of tin in the smaller pores for the Sn-SBA-15 materials synthesized through cocatalyst method. (C) 2009 Elsevier Inc. All rights reserved.
Keywords: Baeyer-Villiger oxidation; catalysis; Functionalization of mesopores; Meerwin-Pondorf-Verly reduction; Sn-SBA-15

Interaction of alpha-mannosidase from aspergillus fischeri with glycosidase inhibitors, metal ions and group specific reagents - Shashidhara, K. S.; Gaikwad, S. M.; Khan, Mohammad Islam; Bharadwaj, Kishor Chandra; Pandey, G. (Research Journal of Biotechnology, 2009)
As an initial step towards using alpha-mannosidase as a target against anticancer drugs, inhibition studies of a model enzyme, class II alpha-mannosidase from Aspergillus fischeri in presence of polyhydroxy piperidine derived glycosidase inhibitors, metal ions and amino acid specific reagents were carried out to reveal the sensitivity of the enzyme. Three of the derivatives (Compound 20, 32 and 39)(11) showed competitive inhibition (K(i) =45, 48 and 235 mu M) and the binding of the inhibitors to the enzyme was entropically driven. Among the metal ions checked, Cu(++) (K(i) = 21nm) and Se(++) ions (K(i) = 32 mu M) showed noncompetitive and Co(++) (K(i) = 1.195 mM) showed competitive inhibition of the enzyme activity with insignificant change in the secondary structure of the protein. The above studies exhibit the Potential of the enzyme in studying anticancer drugs. Treatment of the enzyme with group specific reagents showed the presence of carboxylate, Arg and Cys at the active site. Substrate protection studies and kinetics of the modified enzyme confirmed the above results. Trp and His at the active site were observed to be in proximity.
Keywords: active-site; alpha-Mannosidase; Chemical modification; Glycosidase inhibitors; metal ions

Intermediate hamiltonian hilbert space coupled cluster method: theory and pilot application - Eliav, Ephraim; Borschevsky, Anastasia; Shamasundar, K. R.; Pal, Sourav; Kaldor, Uzi (International Journal of Quantum Chemistry, 2009)
The intermediate Hamiltonian state universal (Hilbert-space) coupled-cluster method is presented, using a formalism similar to that developed for the valence universal (Fock-space) approach. The method is expected to be applicable to many states not accessible by traditional multiroot multireference all-order size-extensive approaches. A pilot application to excited states of atomic beryllium shows good convergence and agreement with experiment and full CI values. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 2909-2915, 2009
Keywords: coupled cluster; Hilbert space; intermediate Hamiltonian

Isostructural molecular strings linked via conserved dipolar (ether) O center dot center dot center dot C=O short contacts in conformational polymorphs of racemic 2,4-di-O-acetyl-6-O-tosyl-myo-inositol 1,3,5-orthoesters - Manoj, Kochunnoonny; Gonnade, Rajesh G.; Bhadbhade, Mohan M.; Shashidhar, Mysore S. (CrystEngComm, 2009)
Conformational dimorphs of racemic 2,4-di-O-acetyl-6-O-tosyl-myo-inositol 1,3,5-orthoformate and its orthoacetate analogue were characterized using single crystal X-ray diffraction, thermal analysis and hot-stage microscopy techniques. In these polymorphs, the tosyl group adopted different conformations due to the rotation about the O-S bond. A significant variation in the torsion angle for the tosyl group (similar to 56 degrees) was observed for Form II crystal of the orthoformate derivative, which exhibited an intramolecular dipolar S=O center dot center dot center dot C=O (sulfonyl-carbonyl) short contact. An interesting feature in all conformational polymorphs is the formation of an isostructural string (despite the differences in the orientation of the tosyl group) linked via dipolar (ether) O center dot center dot center dot C=O contacts, which is further stitched by other weak interactions to form different layers in their crystal lattice.

LC-UV and LC-MS evaluation of stress degradation behaviour of tenatoprazole - Mahadik, Mahadeo V.; Bhusari, Vidhya K.; Kulkarni, Mahesh J.; Dhaneshwar, Sunil R. (Journal of Pharmaceutical and Biomedical Analysis, 2009)
In the present study, comprehensive stress testing of tenatoprazole was carried out according to ICH guideline Q1A (R2). Tenatoprazole was subjected to stress conditions of hydrolysis, oxidation, photolysis and neutral decomposition. Additionally, the solid drug was subjected to 50 degrees C for 60 days in dry-bath, and to the combined effect of temperature and humidity at 40 degrees C/75% RH. Extensive degradation was found to occur in acidic, neutral and oxidative conditions. Mild degradation was observed in basic conditions. The drug is relatively stable in the solid-state. The products formed under different stress conditions were investigated by LC and LC-MS. Successful separation of drug from degradation products formed under stress conditions was achieved on a Chemito ODS-3 column [C(18) (5 mu m, 250 mm x 4.6 mm, i.d.)] using methanol: 0.01 M acetate buffer pH 4.5 adjusted with glacial acetic acid (55:45) as the mobile phase at flow rate of 1 mL/min and the peak was detected using a UV detector set at 306 nm. The LC-MS m/z values and fragmentation patterns of degradation products formed under different stress conditions were studied and characterized through LC-MS fragmentation. Based on the results, degradation pathway for drug has been proposed. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: HPLC; Stability-indicating method; Stress studies; Tenatoprazole; Validation

Mannitol production from glycerol by resting cells of Candida magnoliae - Khan, Asiya; Bhide, Amey J.; Gadre, Ramchandra V. (Bioresource Technology, 2009)
Production of mannitol from glycerol by resting cells of Candida magnoliae under aerobic condition was investigated. The resting cells were Suspended in aqueous Solution of glycerol in Erlenmeyer flasks and incubated on rotary shaker. The samples were analyzed by ion exclusion-HPLC equipped with refractive index and UV detector. The resting cells of C. magnoliae produced mannitol from fructose, Sucrose and glycerol but not from glucose. Addition of yeast extract and/or potassium phosphate to the glycerol solution adversely affected its conversion to mannitol. The conversion of glycerol to mannitol was dependent on oxygen availability. Using testing cells, the yield of mannitol was as high as 45%. This is probably the first report of conversion of glycerol to mannitol by osmophilic yeast. (C) 2009 Elsevier Ltd. All rights reserved.
Keywords: Candida magnoliae; Glycerol; Mannitol production; Resting cells

Mesoporous silica immobilized cobalt complex: an efficient catalyst for epoxides ring opening by aromatic amines under ambient conditions - Bordoloi, Ankur; Hwang, Young Kyu; Hwang, Jin-Soo; Halligudi, Shivaraj B. (Catalysis Communications, 2009)
{Cobalt complex, CobpbH(2)Cl(2)2H(2)O [where
Keywords: beta-Amino alcohols; CobpbH(2)Cl(2)2H(2)O complex; Epoxide ring opening; Immobilization; SBA-15

MgCl2 center dot 4(CH3)(2)CHOH: a new molecular adduct and super active polymerization catalyst support - Thushara, K. S.; Mathew, Renny; Ajithkumar, Thalasseril G.; Rajamohanan, P. R.; Bhaduri, Sumit; Gopinath, Chinnakonda S. (Journal of Physical Chemistry C, 2009)
A new molecular adduct, MgCl(2 center dot)4(CH3)(2)CHOH, has been synthesized and characterized for structural aspects and demonstrated for super active ethylene polymerization activity with TiCl4 to ultrahigh molecular weight polyethylene in high yield.

Microwave-assisted synthesis and humidity sensing of nanostructured alpha-Fe2O3 - Deshmukh, Rupali G.; Badadhe, Satish S.; Mulla, Imtiaz S. (Materials Research Bulletin, 2009)
Nanocrystalline alpha-Fe2O3 has been prepared on a large-scale by a facile microwave-assisted hydrothermal route from a solution of Fe(NO3)(3)center dot 9H(2)O and pentaerythritol. A systematic study of the morphology, crystallinity and oxidation state of Fe using different characterization techniques. Such as transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy was performed It reveals. that nanostructured alpha-Fe2O3 comprises bundles of nanorods with a rhombohedral crystalline Structure. The individual nanorod has 8-10 nm diameter and similar to 50 nm length. The as-prepared nanostructured alpha-Fe2O3 (sensor) gives selective response towards humidity. The sensor shows high sensitivity, fast linear response to change in the humidity with almost 100% reproducibility. The sensor works at room temperature and rejuvenates without heat treatment. The as-prepared nanostructured alpha-Fe2O3 appears to be a promising humidity sensing material with the potential for commercialization. (C) 2008 Elsevier Ltd. All rights reserved.
Keywords: Chemical synthesis; Electrical properties; Nanostructures; Oxides; X-ray diffraction

Mitsunobu and related reactions: advances and applications - Swamy, K. C. Kumara; Kumar, N. N. Bhuvan; Balaraman, Ekambaram; Kumar, K. V. P. Pavan (Chemical Reviews, 2009)

MoO3/SiO2: an efficient and selective catalyst for the synthesis 1,3-dioxolane and 1,3-dioxane - Amrute, Amol P.; Sahoo, Suman; Bordoloi, Ankur; Hwang, Young Kyu; Hwang, Jin-Soo; Halligudi, Shiva B. (Catalysis Communications, 2009)
A series of MoO3/SiO2 catalysts with varying amounts of MoO3 has been synthesized and the catalytic activities of these were compared with the known solid acid catalysts in the synthesis of 1,3-dioxolane. MoO3/SiO2 catalyst showed a better activity and selectivity in 1,3-dioxolane synthesis compared to the other catalysts. MoO3/SiO2 catalyst system was further successfully applied for the synthesis of 1,3-dioxanes in the Prins cyclization of olefins and formaldehyde. The proposed catalyst was thermally stable and could be recovered and reused at least in four consecutive cycles with no significant loss in the substrates conversions and products selectivities. (C) 2009 Elsevier B.V. All rights reserved.
Keywords: 1; 3-Dioxolanes; Cycloaddition; MoO3/SiO2; Prins cyclization; Sol-gel method; solid acid catalysts

Nanoparticle-mediated targeting of MAPK signaling predisposes tumor to chemotherapy - Basu, Sudipta; Harfouche, Rania; Soni, Shivani; Chimote, Geetanjali; Mashelkar, Raghunath Anant; Sengupta, Shiladitya (Proceedings of the National Academy of Sciences of the United States of America, 2009)
The MAPK signal transduction cascade is dysregulated in a majority of human tumors. Here we report that a nanoparticle-mediated targeting of this pathway can optimize cancer chemotherapy. We engineered nanoparticles from a unique hexadentate-polyD, L-lactic acid-co-glycolic acid polymer chemically conjugated to PD98059, a selective MAPK inhibitor. The nanoparticles are taken up by cancer cells through endocytosis and demonstrate sustained release of the active agent, resulting in the inhibition of phosphorylation of downstream extracellular signal regulated kinase. We demonstrate that nanoparticle-mediated targeting of MAPK inhibits the proliferation of melanoma and lung carcinoma cells and induces apoptosis in vitro. Administration of the PD98059-nanoparticles in melanoma-bearing mice inhibits tumor growth and enhances the antitumor efficacy of cisplatin chemotherapy. Our study shows the nanoparticle-mediated delivery of signal transduction inhibitors can emerge as a unique paradigm in cancer chemotherapy.
Keywords: cancer; Signal transduction

NC palladacycles in the Heck arylation of ethylene: synthesis, structure and their reactivity - Atla, Shashi B.; Kelkar, Ashutosh A.; Puranik, Vedavati G.; Bensch, Wolfgang; Chaudhari, Raghunath V. (Journal of Organometallic Chemistry, 2009)
Monomeric cyclopalladated complexes with NC coordination using ligands 2-phenylpyridine, 2-phenylquinoline, 8-methylquinoline have been synthesized and the structures have been determined by single crystal X-ray structure analysis. The crystal structures of monomeric palladacycles prepared using benzophenone oxime, and 2-phenylpyridine have also been determined. The use of these complexes in the Heck arylation of ethylene with 2-bromo-6-methoxynaphthalne (BMN) to give 2-vinyl-6-methoxynapthalene which is an intermediate for the synthesis of anti-inflammatory drug Naproxen has been examined and also arylation of ethylene with 3-bromo-benzophenone and 4-bromo-isobutylbenzene was investigated. These palladacycles with NC coordination show excellent catalytic activity with a TOF > 4000 h (1). (C) 2008 Elsevier B.V. All rights reserved.
Keywords: alpha-Aryl propionic acids; Arylation; Palladacycle

N-heterocyclic carbene-catalyzed hydroacylation of unactivated double bonds - Hirano, Keiichi; Biju, Akkattu T.; Piel, Isabel; Glorius, Frank (Journal of the American Chemical Society, 2009)
An intramolecular N-heterocyclic carbene (NHC)-catalyzed hydroacylation of unactivated double bonds is reported. Systematic variation of the catalyst structure revealed an N-mesitylthiazolylidene annulated with a seven-membered ring to be especially reactive. This NHC enables a unique C−C bond-forming reaction to afford substituted chroman-4-ones in moderate to excellent yields, even ones containing all-carbon quaternary centers.

Nitric oxide reduction with ethanol on palladium surfaces: a molecular beam study - Nagarajan, Sankaranarayanan; Thirunavukkarasu, Kandasamy; Gopinath, Chinnakonda S.; Counsell, Jonathan; Gilbert, Lee; Bowker, Michael (Journal of Physical Chemistry C, 2009)
Nitric oxide (NO) reduction with ethanol has been carried out with molecular beam instruments in order to understand the influence of ethanol blended gasoline on NO reduction. Maximum NO reduction and nitrogen production was observed between 500 and 600 K. Oxidation products, CO, CO(2), and H(2)O were also observed. Beam switching experiments have been performed between fuel-rich and fuel-lean compositions to demonstrate that the NO reduction can be managed under net oxidizing conditions on Pd surfaces. Nitrogen production only occurs transiently on the relatively clean Pd surface in the oxygen-rich condition due to slow build up and blockage of the reaction by surface oxygen atoms. This shows the need to maintain relatively oxygen free surfaces to manage NO reduction under net-oxidizing conditions by beam oscillation between fuel-rich and fuel-lean compositions.