Liver microsomal metabolism of the environmental carcinogen 3-nitrofluoranthene. I. Phenolic metabolites

: The liver microsomal metabolism of the environmental carcinogen 3-nitrofluoranthene has been investigated. Five phenolic metabolites were isolated and characterized by their mass and NMR spectra as: 3-nitrofluoranthen-1-ol, 3-nitrofluoranthen-6-ol, 3-nitrofluoranthen-(7 or 10)-ol, 3-nitrofluoranthen-8-ol and 3-nitrofluoranthen-9-ol. While the microsomes isolated from Sprague-Dawley rat liver and C57B16 mouse liver preferentially metabolized the 3-nitrofluoranthene to 3-nitrofluoranthen-8-ol and 3-nitrofluoranthen-9-ol, the microsomes from Hartley guinea-pig liver preferentially metabolized 3-nitrofluoranthene to 3-nitrofluoranthen-6-ol. 3-Nitrofluoranthen-1-ol was a minor metabolite in each of the incubations. The results indicate the presence of the nitro group on fluoranthene directs the metabolism away from the C1-C5 positions, and more towards the C6-C10 positions.