Flavonoids with anticomplement activity from Persicaria lapathifolia

Persicaria lapathifolia Gray (Polygonaceae) is a common weed in Korea. This plant and other Persicaria species including P. orientale and P. pubescens have been used as an analgesic and stomachic as well as for the treatment of rheumatoid arthritis and malaria. During the screening program of plant extracts, MeOH extract of P. scabrum showed anticomplement activity and the MeOH extract was partitioned with hexane, chloroform, ethyl acetate, and buthanol. EtOAc fraction showed strong activity and activity guided separation yielded eight flavonoids. Two known galloylated and a novel ferulloylated flavonoid glycosides showed strong anticomplement activity. Other flavonoid glycosides, kaempferol 3-O-${\alpha}$-$\sub$L/-arabinopyranoside, kaempferol 3-O-${\beta}$-$\sub$D/-glucopyranoside, kaempferol 3-O-${\beta}$-$\sub$D/-galactopyranoside, quercetin 3-O-${\alpha}$-$\sub$L/-arabinopyranoside, quercetin 3-O-${\beta}$-$\sub$D/-glucopyranoside, quercetin O-${\beta}$-$\sub$D/-galactopyranoside did not showed anicomplement activity.