title: Stereoselectivity of in vitro isoprene metabolism.
abstract: The stereoselectivity of the in vitro conversion of isoprene by liver enzymes of rats and mice was determined. Isoprene was epoxidized by cytochrome P450 of rats and mice to 2-isopropenyloxirane and 2-methyl-2-vinyloxirane with slight but different product enantioselectivity. Only 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 hydrolysis with rat and mouse liver microsomes occurs with substrate enantioselectivity. A better kinetic resolution was found for 2-isopropenyloxirane than for 2-methyl-2-vinyloxirane. While 2(R)-isopropenyloxirane was conjugated preferentially with glutathione, catalyzed by glutathione S-transferase, no enantiomer differentiation takes place in the case of 2-methyl-2-vinyloxirane.
authors.affiliation: Institut für Organische Chemie der Universität, Tübingen, Federal Republic of Germany.
authors.forename: D
authors.initials: D
authors.lastname: Wistuba
authors.forename: K
authors.initials: K
authors.lastname: Weigand
authors.forename: H
authors.initials: H
authors.lastname: Peter
mesh_terms: D000818:Animals; D002070:Butadienes / Q000737:chemistry / Q000378:metabolism*; D002849:Chromatography, Gas; D004852:Epoxy Compounds / Q000378:metabolism; D005978:Glutathione / Q000378:metabolism; D045782:Hemiterpenes; D006868:Hydrolysis; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism; D010420:Pentanes; D051381:Rats; D011916:Rats, Inbred F344; D013237:Stereoisomerism
chemical_list: D002070:Butadienes; D004852:Epoxy Compounds; D045782:Hemiterpenes; D010420:Pentanes; C005059:isoprene; D005978:Glutathione