Maurice M. Coombs

Identification of Monohydroxy metabolites of 15,16-dihydrocyclopenta(a)phenanthren-17-one and its carcinogenic 11-methyl homolog produced by rat liver preparations in vitro.

Abstract Incubation of 15,16-dihydrocyclopenta[a]phenanthren-17-one and its carcinogenic 11-methyl homolog with rat liver microsomes led to similar patterns of metabolites. The carcinogen was the more slowly metabolized, but both ketones gave the corresponding 15-hydroxy derivatives, together with small quantities of the isomeric 16-ols. The 11-hydroxymethyl-17-ketone also occurred as a minor carcinogen metabolite. Incubation of the carcinogen with rat liver homogenates caused more extensive metabolism. The ratio of mono-ols to more polar metabolites was similar with homogenates from untreated and methylcholanthrene-induced rats, but increased metabolism to polar derivatives was observed after phenobarbitone induction.