Neoflavonoids fromPolygonum perfoliatum

Four neoflavonoids, 3,4-dihydro-4-(4'-hydroxyphenyl)-5,7-dihydroxycoumarin (1), 3,4-dihydro-5-hydroxy-7-methoxy-4-(4'-methoxyphenyl)coumarin (2), 3,4-dihydro-5-hydroxy-4-(4'-hydroxyphenyl)-7-methoxycoumarin (3), and 3,4-dihydro-5,7-dihydroxy-4-(4'-methoxyphenyl)coumarin (4), were isolated from the whole plant of Polygonum perfoliatum. Neoflavonoids 1, 2, and 4 were known compounds, but 3 is a new member of this class.