Studies on flavonoids from Bidens pilosa / 中草药

ABSTRACT

Objective: To study the bioactive flavonoids from Bidens pilosa. Methods: Various chromatographic methods including silica gel and Sephadex LH-20 columns, middle pressure liquid chromatography, and high speed counter current chromatography were applied to isolating and purifying the compounds. Their structures were confirmed based on the physicochemical properties and spectral data. Results: Six compounds were isolated from the ethyl acetate extract of B. pilosa, and their structures were identified as 2(R/S)-isookanin-3, 4'-dimethyl ether-7-O-β-D-glucopyranoside (1a-1b), quercetin-3, 4'-dimethyl ether-7-O-glucoside (2), quercetin 3, 4'-dimethyl ether-7-O-rutinoside (3), (Z)-6-O-(6'-O-acetyl-β-D-glucopyranosyl)-6, 7, 3', 4'-tetrahydroxyaurone (4), maritimein (5), and okanin 4-methyl ether-3'-O-β-glucoside (6). Conclusion: Compound 1a-1b is a novel compound named bidenoside H.