FLAVONOIDS IN THE LEAVES OF 28 POLYGONACEOUS PLANTS

Flavonoids in the leaves of twenty-eight species belonging to the Polygonaceae were studied. Thirty-three kinds of flavonoids were isolated, and eighteen kinds were obtained as crystals. Quercetin glycosides were commonly found in the family. In the quercetin glycosides, 3-O-rhamnoside was most frequently found: 3-O-glucuronide is also distributed widely. Myricetin glycosides were rare. Methylated flavonols were found in some species of the sections Echinocaulon and Persicaria. Eleven kinds of C-glycosylflavones were found in the present survey, and C-glycosylfavones were distributed in all species of the genus Rheum and in almost all species of the section Tiniaria. Rumex acetosella and Polygonum suffultum are exceptional, the former contains flavone glycoside and the latter C-glycosylflavones only, as main components.