STEREOSELECTIVITY OF IN-VITRO ISOPRENE METABOLISM

The stereoselectivity of the in vitro conversion of isoprene by liver enzymes of rats ana mice was determined. Isoprene was epoxidized by cy tochrome P450 of rats and mice to 2-isopropenyioxirane and 2-methyl-2- vinyloxirane with slight but different product enantioselectivity. Onl y with mouse liver microsomes was a distinct regioselectivity observed . Both monooxiranes were further epoxidized to 2-methyl-2,2'-bioxirane with substrate enantioselectivity, product diastereoselectivity, and with product enantioselectivity. The epoxide hydrolase-catalyzed hydro lysis with rat and mouse liver microsomes occurs with substrate enanti oselectivity. A better kinetic resolution was found for 2-isopropenylo xirane than for 2-methyl-2-vinyloxirane. While 2(R)-isopropenyloxirane was conjugated preferentially with glutathione, catalyzed by glutathi one S-transferase, no enantiomer differentiation takes place in the ca se of 2-methyl-2-vinyloxirane.