Figure 2. Production of aflatoxin B1 and B2 (AFB1 and AFB2, respectively) by Aspergillus flavus (IMI 190) cultures after treatment with different concentrations (5, 10 µg/ml and control) of the biflavonoids 6,6"-bigenkwanin (I), tetradimethoxybigenkwanin (II), amenthoflavone (III), and 7,7"-dimethoxyagastisflavone (IV). Three replicates were performed for each dilution. The four biflavonoids showed inhibitory activity on AFB1 and AFB2 production (P<0.001). The A. flavus used with control produced 188.6 µg/ml of AFB1 and 12.58 µg/ml of AFB2 while the fungus treated with biflavonoids I, II, III and IV at 5 µg/ml concentration produced 56.58, 42.65, 37.42 and 45.19 µg/ml of AFB1, respectively, and 2.38, 2.87, 1.88 and 3.17 µg/ml of AFB2, respectively. At 10 µg/ml concentration, the results obtained were 22.58, 22.29, 18.41 and 27.56 µg/ml of AFB1 and 2.34, 0.75, 1.11 and 1.55 µg/ml of AFB2 for compounds I, II, III and IV, respectively.