Paper Title :Enhancing the Catalytic Activity of Hydrolases for Aldol Reaction
Author :Benu Arora, Munishwar N. Gupta
Article Citation :Benu Arora ,Munishwar N. Gupta ,
(2018 ) " Enhancing the Catalytic Activity of Hydrolases for Aldol Reaction " ,
International Journal of Advances in Science, Engineering and Technology(IJASEAT) ,
pp. 54-60,
Volume-6, Issue-3, Spl. Iss-2
Abstract : Aldol reaction is one of the most useful methods for C-C bond formation in synthetic organic chemistry. The ability
of hydrolases (enzymes that usually catalyze hydrolytic reactions) to catalyze aldol reaction is an excellent example of the
catalytic promiscuity of this class of enzymes. In literature, the aldol reaction between p-nitrobenzaldehyde and acetone
catalyzed by lipases and proteases has been reported to be a slow reaction, often extending over a period of 5-6 days to achieve
> 90% conversion. In this work, a few simple yet effective approaches were used to speed up the same reaction. Water is
known to play a crucial role in this reaction. An initial optimization of the ratio of water: acetone present in the reaction
medium revealed that a 1: 1 mixture gave maximum conversion to the aldol product. At very low acetone concentrations, two
side products: p-nitrobenzyl alcohol and p-nitrobenzoic acid were also formed (arising from the redox reactions of the
substrate i.e. p-nitrobenzaldehyde). The effect of addition of a few polar organic co-solvents to the reaction medium at varying
concentrations was then studied. DMSO at a concentration of 30% (v/v) w.r.t. the total reaction volume was found to be the
best co-solvent. Screening of a number of commercially available lipases under this optimized reaction condition was also
carried out. The lipase from porcine pancreas showed maximum activity for the aldol reaction followed by the lipase from
Mucor javanicus. With this biocatalyst and medium optimization, >90% conversion was attained after just 24 hours. The same
reaction under the optimized conditions was then extended to the proteases. Finally, scope of this synthetic methodology was
expanded by using various substituted benzaldehydes as substrates.
Index Terms - Aldol reaction, Catalytic Promiscuity, Lipase, Organic Co-Solvents
Type : Research paper
Published : Volume-6, Issue-3, Spl. Iss-2
DOIONLINE NO - IJASEAT-IRAJ-DOIONLINE-14130
View Here
Copyright: © Institute of Research and Journals
|
|
| |
|
PDF |
| |
Viewed - 19 |
| |
Published on 2019-01-11 |
|