The anti-inflammatory compounds of Polygonum bistorta: isolation and characterisation.

A bioassay-guided technique has been used to isolate anti-inflammatory compounds from the dried rhizomes of Polygonum bistorta, for structural identification. Anti-inflammatory activity was detected using the carrageenan-induced rat paw oedema. Two compounds were isolated which significantly suppressed the inflammatory response. Spectral data from EIMS and NMR together with some physical characteristics revealed the identities of the two active compounds as 5-glutinen-3-one and friedelanol. The results indicate that these two compounds largely account for the anti-inflammatory actions of the rhizomes of P. bistorta.