Bioguided fractionation of Polygonum alpinum and isolation and structure elucidation of active compounds

Bioguided fractionation of the methanol extract of aerial parts from Polygonum alpinum L. ( Polygonaceae) was investigated using the exudation phase of inflammation in aseptic arthritis model, which is produced by carrageenan and radical-scavenging properties. Flavonoid-containing fractions showed anti-inflammatory and radical-scavenging activities. Therefore, isolation and structure elucidation of flavonoids were carried out. The eight flavonol glycosides, which were quercetin 3-O-arabinofuranoside (avicularin) (1), quercetin 3-O-beta-glucuronopyranoside (2), quercetin 3-O-alpha-rhamnopyranosyl (1 -> 6)-beta-glucopyranoside (3), quercetin 3-O-beta-galacturonopyranoside (4), quercetin 3-O-beta-glucopyranoside (5), kaempferol 3-O-beta-galactopyranoside (6), quercetin 3-O-beta-galactopyranoside (hyperoside) (7), and myricetin 3-O-beta-galactopyranoside (8), were isolated from the methanol herb extract of Polygonum alpinum. The structures were established by spectroscopic methods.