TY - JOUR T1 - Structural elucidation of a mutagenic metabolite of 3-amino-1-methyl-5H-pyrido[4,3-b]indole. JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 292 LP - 296 VL - 9 IS - 3 AU - Y Yamazoe AU - K Ishii AU - T Kamataki AU - R Kato Y1 - 1981/05/01 UR - http://dmd.aspetjournals.org/content/9/3/292.abstract N2 - Metabolic activation of a tryptophan pyrolysate, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) by liver microsomes was studied. Trp-P-2 was converted to at least four metabolites (M-1 to M-4), which were separable by HPLC or TLC. Among them, the major metabolite (M-3) was extremely mutagenic to Salmonella typhimurium TA 98 in the absence of activating enzymes and the activity accounted for almost all mutagenic effects of Trp-P-2. Metabolite M-3 was identified as 3-hydroxyamino-1-methyl-5H-pyrido[4,3-b]indole by mass spectrometry and by conversion to the 4-chloro derivative of Trp-P-2 by treatment with hydrochloric acid. The latter compound was identified by NMR and mass spectrometry. ER -