[Study on the chemical constituents of the active fraction of Polygonum capitatum].

The flavonoid-enriched fraction contains flavonols and their glycosides as its major components,which might be responsible for the biological effects of Polygonum capitatum. Compounds 1, 8 and 12 are isolated from the genus Polygonum for the first time; Compound 3 is isolated from Polygonum capitatum for the first time.