title: Inactivation of a diol epoxide by dihydrodiol dehydrogenase but not by two epoxide hydrolases.
abstract: The mutagenicity of r-8,t-9-dihydroxy-t-10, 11-oxy-8,9,10,11-tetrahydrobenz[a]anthracene (BA-8,9-diol 10, 11-oxide) toward Salmonella typhimurium TA 100 is not decreased by the presence of large amounts of highly purified microsomal or cytosolic epoxide hydrolase. However, highly purified dihydrodiol dehydrogenase inactivates this diol epoxide, which is a major DNA-binding metabolite of benz[a]anthracene. The K-region epoxide, benz[a]anthracene 5,6-oxide (BA 5,6-oxide) is efficiently  inactivated by microsomal epoxide hydrolase, is much less readily inactivated by cytosolic epoxide hydrolase, and is not inactivated by dihydrodiol dehydrogenase. This inactivation of a diol epoxide by dihydrodiol dehydrogenase points to a new significance of this enzyme and a new level of control for diol epoxides.
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism*; D001551:Benz(a)Anthracenes / Q000378:metabolism* / Q000494:pharmacology; D004851:Epoxide Hydrolases / Q000378:metabolism; D008658:Inactivation, Metabolic; D009152:Mutagenicity Tests; D009154:Mutation / Q000187:drug effects; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; D012486:Salmonella typhimurium / Q000187:drug effects
chemical_list: D001551:Benz(a)Anthracenes; D010088:Oxidoreductases; D000429:Alcohol Oxidoreductases; C023125:dihydrodiol dehydrogenases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C116788:cis-1,2-dihydro-1,2-dihydroxynaphthalene dehydrogenase; D004851:Epoxide Hydrolases