Biosynthetic production of [14C]aflatoxins

A method for producing large amounts of ring-labeled [14C] aflatoxins using Aspergillus parasiticus cultures is reported. Conditions were optimized as to mold incubation medium, time of incubation, and 14C-acetate: glucose ratio. The yield of labeled aflatoxins was 1.2% of the [1-14C] acetate precursor; 60% of this was aflatoxin B1 having a specific radioactivity of 158.5 μCi/μmole.