Enantioselectivities of yeast epoxide hydrolases for 1,2-epoxides

Kinetic resolution of homologous series of unbranched 1,2-epoxyalkanes (C-4 to C-12), 1,2-epoxyalkenes (C-4, C-6 and C-8), a 2,2-dialkylsubstituted ep oxide (2-methyl-1,2-epoxyheptane) and a benzyloxy-substituted epoxide (benz yl glycidyl ether) was investigated using resting cells of 10 different yea st strains. Biocatalysts with excellent enantioselectivity (E>100) and high initial reaction rates (>300 nmol/min/mg dry weight) were found for the 2- monosubstituted aliphatic epoxides C-6 to C-8. Yeast strains belonging to t he genera Rhodotorula, Rhodosporidium and Trichosporon all preferentially h ydrolyzed (R)-1,2-epoxides with retention of configuration. The epoxide hyd rolases of all the yeast strains are membrane-associated. (C) 1999 Elsevier Science Ltd. All rights reserved.