Identification of metabolites of benzo[b]fluoranthene.

The metabolism by rat liver 9000 x g supernatant of the environmental carcinogen benzo[b]fluoranthene was investigated. The major metabolites were identified, by comparison to synthetic samples, as 5- and 6-hydroxybenzo[b]fluoranthene and 4- and 7-hydroxybenzo[b]fluoranthene. The principal dihydrodiol metabolite formed under these conditions was trans-11,12-dihydro-11,12-dihydroxybenzo[b]fluoranthene, which was identified by comparison to the synthetic compound. 1,2-Dihydro-1,2-dihydroxybenzo[b]fluoranthene was identified, by its mass spectrum and by comparison if its u.v. spectrum to that of a synthetic model compound, 11-ethylidene-11H-benzo[b]fluorene. No evidence was obtained for the formation of 7b,8-dihydro-7,8-dihydroxybenzo[b]fluoranthene or trans-9,10-dihydro-9,10-dihydroxybenzo[b]fluoranthene. The latter would be the precursor to a bay region dihydrodiol epoxide of benzo[b]fluoranthene.