Five flavonoid glycosides, 4'-O-methylisoscutellarein 7-O-[6"'-acetylallopyranosyl(1----2)glucopyranoside], 4'-O-methylisoscutellarein 7-O-allopyranosyl(1----2)glucopyranoside, 3'-hydroxy-4'-O-methylisoscutellarein 7-O-[6"'-acetylallopyranosyl(1----2) glucopyranoside], and hypolaetin-8-glucoside