Biotransformation of fluorobiphenyl by Cunninghamella elegans

The fungus Cunninghamella elegans is a useful model of human catabolism of xenobiotics. In this paper, the biotransformation of fluorinated biphenyls by C. elegans was investigated by analysis of the culture supernatants with a variety of analytical techniques. 4-Fluorobiphenyl was principally transformed to 4-fluoro-4'-hydroxybiphenyl, but other mono- and dihydroxylated compounds were detected in organic extracts by gas chromatography-mass spectrometry. Additionally, fluorinated water-soluble products were detected by F-19 NMR and were identified as sulphate and beta-glucuronide conjugates. Other fluorobiphenyls (2-fluoro-, 4,4'-difluoro- and 2,3,4,5,6-pentafluoro-biphenyl) were catabolised by C. elegans, yielding mono- and dihydroxylated products, but phase II metabolites were detected from 4,4'-difluorobiphenyl only.