Four new biflavonoids-robustaflavone 4'-methyl ether (1), robustaflavone 7,4'-dimethyl ether (2), 2",3" -dihydrorobustaflavone 7,4', -dimethyl ether (3), and 2",3" '-dihydrorobustaflavone 7,4', 7"-trimethyl ether (4)-as well as two known biflavonoids, robustaflavone and amentoflavone, and three