@article { ISI:000226424000029, title = {Epoxidation of styrene by anhydrous hydrogen peroxide over boehmite and alumina catalysts with continuous removal of the reaction water}, journal = {Journal of Molecular Catalysis A-Chemical}, volume = {227}, number = {1-2}, year = {2005}, month = {MAR}, pages = {217-222}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

Boehmite and alumina (obtained from the boehmite by its calcination at different temperatures 300-900degreesC) are active and stable catalysts for the selective epoxidation of styrene by anhydrous H2O2 to styrene oxide with continuous removal of the reaction water. Influence of the catalyst (boehemite) calcination temperature, H2O2/styrene ratio and catalyst loading on the styrene conversion and selectivity for styrene oxide. phenyl acetaldehyde. benzaldehyde and benzoic acid in the epoxidation has been investigated. In the presence of water. the catalyst shows very poor activity and selectivity in the epoxidation. The catalyst also catalyses H2O2 decomposition and hence has optimum loading for obtaining high-styrene conversion in the epoxidation. (C) 2004 Elsevier B.V. All rights reserved.

}, keywords = {Alumina, anhydrous hydrogen peroxide, boehmite, Epoxidation of styrene, Styrene oxide}, issn = {1381-1169}, doi = {10.1016/j.molcata.2004.10.025}, author = {Choudhary, Vasant R. and Patil, N. S. and Chaudhari, Nitin K. and Bhargava, Suresh Kumar} } @article { ISI:000225723800036, title = {Extracellular nuclease from a thermophile, streptomyces thermonitrificans: production, purification and partial characterization of - double strand preferential - deoxyribonuclease activity}, journal = {Process Biochemistry}, volume = {40}, number = {3-4}, year = {2005}, month = {MAR}, pages = {1271-1278}, publisher = {ELSEVIER SCI LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

A thermophilic strain of Streptomyces themionitrificans produced high levels of extracellular nuclease (designated as nuclease Stn beta) when grown on nutrient broth glucose medium. Maximal nuclease activity (51 U ml(-1)) was obtained, in 40 h, when the culture was grown on modified NBG medium at 45 degreesC. The enzyme was purified to homogeneity with an overall recovery of 5.6\% and a specific activity of 10,833. The relative molecular mass of the purified enzyme, determined by gel filtration, was 22.4 kDa and it showed an obligate requirement for Mn2+ for activity. The optimum pH and temperature of nuclease Stn beta were 8.0 and 45 degreesC, respectively. The enzyme was inhibited by Mg2+ CO2+, Cu2+, Zn2+ and Hg2+, inorganic phosphate, pyrophosphate, dithiothreitol, beta-mereaptoethanol, EDTA and NaCl. Nuclease Stn beta was stable to high concentrations of urea and organic solvents but susceptible to low concentrations of SDS and guanidine hydrochloride. Nuclease Stn beta is a multifunctional enzyme with substrate specificity in the order of dsDNA \> ssDNA much greater than RNA. The end products of dsDNA hydrolysis were predominantly oligonucleotides (85-90\%) and small amounts of 5{\textquoteright} mononucleotides (10-15\%) suggesting an endo mode of action. (C) 2004 Elsevier Ltd. All rights reserved.

}, keywords = {Characterization, Endonuclease, extracellular nuclease, production, Purification, Streptomyces thermonitrificans}, issn = {1359-5113}, doi = {10.1016/j.procbio.2004.05.015}, author = {Patil, N. S. and Deshmukh, Satej S. and Shankar, V.} } @article { ISI:000317558000024, title = {Epoxidation of styrene by t-butyl hydroperoxide over gold nanoparticles supported on Yb2O3: effect of gold deposition method, gold loading, and calcination temperature of the catalyst on its surface properties and catalytic performance}, journal = {Journal of Catalysis}, volume = {300}, year = {2013}, month = {APR}, pages = {217-224}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

Surface properties and epoxidation performance of Au/Yb2O3 catalyst are influenced by the method of gold deposition [viz. deposition-precipitation (DP), homogeneous deposition-precipitation (HDP) or impregnation], gold loading (0.9-6.6 wt\%), and the catalyst calcination temperature (400-900 degrees C)]. The catalyst showed the best epoxidation performance when it was prepared by the HDP method and calcined at 500 degrees C. The Au/Yb2O3 catalyst even after calcination at 900 degrees C showed good activity and epoxide selectivity. Both Au-0 and Au3+ surface species were found in the catalyst calcined at 800 degrees C, but only Au-0 species were observed at the lower calcination temperatures (\<600 degrees C). The selectivity for styrene oxide increased continuously with the reaction temperature (from 75 degrees C to 97 degrees C) and time (1-5 h), indicating that styrene oxide did not undergo secondary reactions under these conditions. (C) 2013 Elsevier Inc. All rights reserved.

}, keywords = {Au/Yb2O3 catalyst, Epoxidation of styrene, gold nanoparticles, Styrene oxide, tert-Butyl hydroperoxide}, issn = {0021-9517}, doi = {10.1016/j.jcat.2013.01.002}, author = {Choudhary, Vasant R. and Dumbre, Deepa K. and Patil, N. S. and Uphade, B. S. and Bhargava, Suresh Kumar} }