thiabendazole, 4-hydroxy-7-methoxy-3-phenylcoumarin, 4-hydroxy-6,7-dimethylcoumarin, 6,7-dimethoxycoumarin, 4-(bromomethyl)-6,7-dimethoxycoumarin, and 1-(2-methylpiperidin-1-yl)-3-phenylprop-2-en-1-one show potent antifungal and antiaflatoxigenic activities against Aspergillus flavus. Inhibitory mode of antiaflatoxigenic action by 4-hydroxy-7-methyl-3-phenyl coumarin is based on the downregulation of aflD, aflK, aflQ, and aflR in aflatoxin biosynthesis. The inhibitory mode of antiaflatoxigenic action by 2,3-dihydrobenzofuran is based on the inhibition of the transcription factor (aflS) in the aflatoxin biosynthesis pathway. Complete inhibition of growth at 1 mg/ml