Identification of the 11,12-dihydro-11,12-dihydroxybenzo(a)pyrene as a major metabolite produced by the green alga, Selenastrum capricornutum.

Benzo(a)pyrene metabolites were isolated after incubation of [14C]-benzo(a)pyrene with the green alga, Selenastrum capricornutum. A significant amount of radioactivity chromatographed in the dihydrodiol region which did not coelute with any of the previously identified dihydrodiol metabolites isolated from this system. Following characterization by mass spectrometry, fluorescence spectroscopy, and high pressure liquid chromatography, this metabolite was identified as the cis-11,12-dihydro-11,12-dihydroxybenzo(a)pyrene. This metabolite has not been identified previously as a metabolite formed in a plant system.