Aflatoxins are a family of highly toxic and carcinogenic secondary metabolites produced by certain strains of Aspergillus flavus and Aspergillus parasiticus. Biosynthetically, the aflatoxins are produced by a polyketide pathway. Most of the experimental data on aflatoxin biosynthesis are derived from 14C- and 13C-labeling experiments and use of blocked mutants. These data indicate that the general steps in aflatoxin biosynthesis are acetate → anthraquinones → sterigmatocystin → aflatoxin B1. Many details of the pathway remain unresolved; it is hoped that further research, particularly with cell-free systems, will improve our understanding of the mechanism of formation of these important fungal metabolites.
2Southern Regional Research Center.