A NEW APPROACH TO VERSICOLORIN TYPE AFLATOXIN PRECURSORS

黄曲霉毒素是一类高度致癌的真菌毒素

The aflatoxins are a group of highly carcinogenic mycotoxins which are produced by various Aspergillus species, and which constitute serious health hazards as food contaminants. Their biogenesis, which is still not completely elucidated, involves a complex series of transformations starting from derivatives of 2-n-hexylanthraquinone. As part of this sequence, averufin is converted into versicolorin A in a process involving an unusual side-chain rearrangement. Recently, we discovered a new rearrangement of an alkyl-substituted anthraquinone which we believe represents the first chemical model for the crucial step in the averufin to versicolorin A transformation. Our present objective is to explore this new rearrangement in detail, with emphasis on the synthesis of compounds of the versicolorin type.