AFLAVARIN AND BETA-AFLATREM - NEW ANTI-INSECTAN METABOLITES FROM THE SCLEROTIA OF ASPERGILLUS-FLAVUS

Aflavarin [3], a new bicoumarin, and beta-aflatrem [11], an isomer of the tremorgen aflatrem, were isolated from the sclerotia of Aspergillus flavus. The structures were determined through a series of 1D and 2D nmr experiments, assisted by spectral comparisons with known compounds. Aflavarin exhibits potent antifeedant activity against the fungivorous beetle Carpophilus hemipterus. Beta-aflatrem causes a significant reduction in the growth rate of the corn earworm Helicoverpa zea. The presence of nominine [13] as a minor metabolite of A. flavus is reported for the first time.