- Efficient microwave-assisted esterification reaction employing methanesulfonic acid supported on alumina as catalyst
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A rapid and efficient protocol assisted by microwave irradiation for the synthesis of esters using methanesulfonic acid (CH3SO3H) supported on Al2O3 (AMA) as catalyst and free of solvent is described. The products were obtained in good yields and purity, with reduced reaction time, and the process is simple and environmentally benign. Copyright
- Fabian, Lucas,Gomez, Matias,Kuran, Juan A. Caturelli,Moltrasio, Graciela,Moglioni, Albertina
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p. 2386 - 2392
(2014/07/22)
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- Specific enzyme-catalyzed hydrolysis and synthesis in aqueous and organic medium using biocatalysts with lipase activity from Aspergillus niger MYA 135
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In the present study, the specific hydrolytic activity of three biocatalysts such as the constitutive mycelium-bound lipase, the induced mycelium-bound lipase and the lyophilized induced supernatant from A. niger MYA 135 was evaluated in both aqueous and organic media.A direct correlation between activity in water and n-hexane was not observed for the same hydrolytic reaction. The n-hexane/water activity ratio (RO/A) was applied to characterize the activity in organic medium. The three biocatalysts showed RO/A values higher than 1 for hydrolysis of long-chain fatty acid esters, demonstrating a higher specific hydrolytic activity in organic solvent than in water. A different behavior was observed during hydrolysis of middle-chain fatty acid esters, which was higher in aqueous medium (R O/Adw) observed in a reaction mixture containing propanol and p-nitrophenyl laurate. Finally, both p-nitrophenyl caprate (C10) and p-nitrophenyl laurate (C12) were preferentially methanolized by the lyophilized induced supernatant, being this lipase activity the most specific biocatalyst preparation under transesterification conditions. A selectivity-based analysis of each lipase preparation toward transesterification or hydrolysis in organic medium was evaluated as well. Springer Science+Business Media, LLC 2012.
- Romero, Cintia M.,Pera, Licia M.,Loto, Flavia,Baigori, Mario D.
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p. 1361 - 1368
(2013/01/15)
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- Synthesis, antimicrobial evaluation, QSAR and in silico ADMET studies of decanoic acid derivatives
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Various derivatives of decanoic acid (CD) have been synthesized and evaluated against Gram positive B. subtilis, S. aureus and Gram negative E. coli bacteria as well as against fungi C. albicans and A. niger. Quantitative structure activity relationship (QSAR) models for antimicrobial activities were developed using multiple linear regression and cross validated by leave one out (LOO) approach. QSAR studies indicated that activity against Gram positive bacteria was governed by lipophilicity of the compounds while topological steric nature of the molecule was deciding factor for antifungal activity. Further, in silico ADMET studies showed that compounds CD12, 19, 20 and 23 could be explored further for other activities.
- Kumar, Ashwani,Singh, Surender,Jain, Sandeep,Kumar, Parvin
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experimental part
p. 191 - 204
(2011/10/09)
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