Antifungal of modified neolignans from Mitrephora wangii Hu

Chromatographic separation of leaves and twigs from M. wangii had led to the isolation of conocarpan ( 1 ) and 3′-methoxyconocarpan ( 2 ). These structures were assigned on the basis of spectroscopic methods. Compound 1 was modified by organic reactions and the modified compound 5 exhibited potent antifungal, Pyricularia oryzae . The method used poisoned food technique with mycelial growth inhibition for 14 days, 57 % (100 ppm). Compound 5 was stronger than mancozeb which the fungi toxicity drug used as a positive control.