Abstract
Three new flavonol glycosides and a new xanthone were isolated from Polygala japonica HOUTT. with eight known compounds. Their structures were identified as 1,7-dihydroxy-3,4-dimethoxy-xanthone (1), kaempferol-7,4′-dimethyl ether (2), physcion (3), guazijinxanthone (4), rhamnetin (5), polygalin A (6), 3,5,7-trihydroxy-4′-methoxy-flavone-3-O-β-d-galactopyranoside (7), 3,5,3′-trihydoxy-7,4′-dimethoxy-flavone-3-O-β-d-galactopyranoside (8), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-galactopyranoside (9), 3,5,3′,4′-tetrahydroxy-7-methoxy-flavone-3-O-β-d-glucopyranoside (10), polygalin B (11), polygalin C (12). Among them, compound 4 is a new xanthone, and 6, 11 and 12 are new flavonol glycosides. Compounds 1, 4, 7 and 8 were tested for cytotoxic activity with MTT assays on five human tumor cell lines, K562, A549, PC-3M, HCT-8 and SHG-44. Compound 4 showed cytotoxic activity against all the five cell lines.
Acknowledgements
This project was supported by the 863 Foundation of China (No. 2003AA2Z3507) and the Scientific Foundation of Shanghai China (No. 02DZ19147, 03QMH1414, 04DZ19843, 04DZ19856 and 04DZ19857).