title: Metabolic pathways of 7,12-dimethylbenz[a]anthracene in hepatic microsomes.
abstract: High pressure liquid chromatography has enabled quantitative analysis of the in vitro metabolism of 7,12-dimethylbenz[a]anthracene, 7-methyl-12-hydroxymethylbenz[a]anthracene, 7-hydroxymethyl-12-methylbenz[a]anthracene, and 7,12-dihydroxymethylbenz[a]anthracene by 3-methylcholanthrene-induced and control rat liver microsomes. The following previously unrecognized metabolites have been tentatively identified: 5,6-dihydro-5,6-dihydroxy-7-methyl-12-hydroxymethylbenz[a]anthracene, 3-hydroxy-7,12-dihydrodihydroxymethylbenz[a]anthracene, 4-hydroxy-7,12-dihydrodihydroxymethylbenz[a]anthracene, and 8,9-dihydro-8,9-dihydroxy-7,12-dihydroxymethylbenz[a]anthracene. The epoxide hydratase inhibitor 1,2-epoxy-3,3,3-trichloropropane was found to eliminate all dihydrodiol formation and markedly inhibit the formation of several dimethylbenzanthracene metabolites. It is proposed that the tentatively identified 3-hydroxy and 4-hydroxy derivatives are formed by an enzymatic mechanism that does not involve epoxides as intermediates. The metabolic pathways of 7,12-dimethylbenz[a]anthracene in hepatic microsomal enzymes are proposed.
mesh_terms: D015127:9,10-Dimethyl-1,2-benzanthracene / Q000378:metabolism*; D000818:Animals; D001551:Benz(a)Anthracenes / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004852:Epoxy Compounds / Q000494:pharmacology; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D051381:Rats; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001551:Benz(a)Anthracenes; D004852:Epoxy Compounds; D015127:9,10-Dimethyl-1,2-benzanthracene