Enantioselective biotransformations of racemic 2-aryl-3-methylbutyronitriles using Rhodococcus sp. AJ270

Rhodococcus sp. AJ270 is a useful biocatalyst for the synthesis of some enantiopure S-(+)-2-aryl-3-methylbutyric acids and R-(+)-2-aryl-3-methylbutyramides from the hydrolysis of 2-aryl-3-methylbutyronitriles under mild conditions. The nitrile-hydrolyzing enzymes involved in this novel microorganism are very sensitive to the steric effect of the para-substituent on the aromatic ring. While the nitrile hydratase displays a low S-enantioselectivity against nitriles, the amidase has a strict S-enantioselectivity against 2-aryl-3-methylbutyramides.