176021-33-3Relevant academic research and scientific papers
Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
, p. 10422 - 10426 (2020/07/24)
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
Microbial deracemization of α-substituted carboxylic acids: Control of the reaction path
Kato, Dai-Ichiro,Miyamoto, Kenji,Ohta, Hiromichi
, p. 2965 - 2973 (2007/10/03)
A novel approach to preparing optically active α-substituted carboxylic acids using the whole cells of Nocardia diaphanozonaria JCM 3208 is described. When 2-phenylthiopropanoic acid and 2-methyl-3-phenylpropanoic acid were subjected to the reaction under aerobic conditions, the oxidation reaction proceeded preferentially rather than deracemization of these substrates. Herein, we report the design of reaction conditions to increase the deracemization activity in preference to oxidation reactions. In addition, we have successfully detected a metabolic intermediate in the reaction mixture of 2-methyl-3-phenylpropanoic acid, which indicates that the deracemization is a competitive reaction against the α-oxidation pathway of fatty acid metabolism.
Enantioselective hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues using a penicillin G acylase-based HPLC monolithic silica column
Massolini, Gabriella,Calleri, Enrica,Lavecchia, Antonio,Loiodice, Fulvio,Lubda, Dieter,Temporini, Caterina,Fracchiolla, Giuseppe,Tortorella, Paolo,Novellino, Ettore,Caccialanza, Gabriele
, p. 535 - 542 (2007/10/03)
A technique based on liquid chromatography has been developed to facilitate studies of enantioselectivity in penicillin G acylase (PGA)-catalyzed hydrolysis of some 2-aryloxyalkanoic acid methyl esters and isosteric analogues. PGA was covalently immobilized on an aminopropyl monolithic silica support to create an immobilized HPLC-enzyme reactor. Two sets of experimental data were drawn to calculate the enantioselectivity (E) of the kinetically controlled enantiomer-differentiating reaction, the degree of substrate conversion and the enantiomeric excess of the product. The developed enzymatic reactor was coupled through a switching valve to an achiral analytical column for separation and quantitation of the hydrolysis products. The enantiomeric excess was determined off-line on a PGA-chiral stationary phase. In this way, highly precise E values were determined. A computational study related to the hydrolysis of the considered racemic esters was also carried out in order to unambiguously clarify both the substrate specificity and the enantioselectivity displayed by PGA.
Differential eudismic ratios in the antagonism of human platelet function by phenoxy- and thiophenoxyacetic acids
Romstedt,Lei,Feller,Witiak,Loiodice,Tortorella
, p. 107 - 114 (2007/10/03)
The antilipidemic drug clofibric acid (CPIB) exhibits antiplatelet effects. In order to examine the role of enantioselectivity and hydrophobicity, the mono(desmethyl) enantiomers of 2-(4-chlorophenoxy)propanoic acid (CPPA), related butanoate homologs, 2-(
