Evidence for the Probable Final Steps in Aflatoxin Biosynthesis

Article abstract of DOI:10.1021/jo00095a016

The final steps in the biosynthesis of the potent environmental carcinogen aflatoxin B1 (8) are believed to involve the oxidative cleavage and rearrangement of O-methylsterigmatocystin (7) with loss of a C1-unit.The means by which this overall transformation occurs is not known and has been addressed using cell-free conversions of samples of radiolabeled 7 that were obtained by the incorporation of either <1-14C>- or <2-14C>acetate.The proportion of radioisotope detected in aflatoxin B1 relative to that of the C1-unit liberated (formaldehyde, formic acid, or carbon dioxide) was tested. <14C>Carbon dioxide alone was isolated in the proper stoichiometry to limit the possible mechanisms that can be acting at the conclusion of this biosynthetic pathway.