Benzo(a)pyrene metabolites formed by the action of yeast cytochrome P‐450/P‐448

Abstract
Benzo(a)pyrene metabolites have been identified by high‐pressure liquid chromatography after production by a cytochrome P‐450 in brewer's yeast disruptates. The major metabolites are 7,8‐dihydro‐7,8‐dihydroxy‐benzo(a)pyrene, 9‐hydroxybenzo(a)‐pyrene and 3‐hydroxybenzo(a)pyrene. Pretreatment of the yeast with benzo(a)‐pyrene, during its growth decreases the Michaelis constant (Km) of the enzyme for benzo(a)pyrene, using either NADPH or cumene hydroperoxide as a cofactor.