Metabolism of mutagenicity-deprived 3-fluoroquinoline: comparison with mutagenic quinoline

3-Fluorinated quinoline (3FQ), a non-mutagenic derivative of the potent mutagen quinoline, was metabolized with a microsomal enzyme fraction isolated from the 3-methylcholanthrene-treated rat liver. The metabolites were 3-fluoro-5,6-dihydroquinoline-5,6-trans-diol (72%), 3-fluoroquinoline 1-oxide (6%), 3-fluoro-5,6-dihydroquinoline-5,6-cis-epoxide (1%), and 4 unidentified metabolites (11%). Since this metabolic pattern is similar to that obtained with unfluorinated quinoline, the epoxidation of the benzene moieties of quinoline and 3-fluoroquinoline is most likely a detoxication process and not mutagenic activation.