Kinetic resolution of (R,S)-2,2-dimethylcyclopropanecarboxamide by Delftia tsuruhatensis ZJB-05174: Role of organic cosolvent in reaction medium

Both enantioselectivity and catalytic activity were greatly enhanced in Delftia tsuruhatensis ZJB-05174 catalyzed kinetic resolution of 2,2-dimethlycyclopropanecarboxamide in the presence of ethanol and acetonitrile. The enantiomeric ratio (E) rose from 27 to 140 and 90 by addition of 5% acetonitrile and ethanol, respectively. In the scaled-up biotransformation, the reaction time was shortened to 1.33 h with an ees of 99% and 12.4 g of optically pure product (43.5% total yield) was afforded. These results indicated that addition of cosolvent was a simple and practical tool to improve amidase properties and would be extensively applied in amidase-catalyzed bioprocess.

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► Addition of MeCN enhanced both stereospecificity and activity of amidase.
► Concentration of cosolvent has profound influence on amidase activity and stability.
► Space-time yield of the bioprocess was improved by adding low concentration of MeCN.