Chemical constituents in roots of Astragalus membranaceus / 中草药

ABSTRACT

Objective: To study the chemical constituents in the roots of Astragalus membranaceus. Methods: The constituents were isolated and purified by silica gel, ODS, polyamide and Sephadex LH-20 column chromatography. Their structures were elucidated by NMR spectra. Results: Twenty-three compounds were isolated from the roots of A. membranaceus, covering 14 flavonoids, eight triterpenoid saponins and one phenylpropanoid. They were identified as 2'-methoxyisoliquiritigenin (1), echinatin (2), licochalcone B (3), 3', 4', 7-trihydroxyflavone (4), 4', 7-dihydroxyflavone (5), 3', 7, 8- trihydroxy-4'-methoxyisoflavone (6), 4-hydroxycinnamic acid (7), calycosin (8), formononetin (9), 2', 4, 4'-trihydroxychalcone (10), pendulone (11), liquiritigenin (12), pratensein (13), calycosin-7-O-β-D-glucopyranoside (14), ononin (15), astragaloside IV (16), cyclocanthoside E (17), isoastragaloside II (18), astragaloside II (19), astragaloside III (20), isoastragaloside I (21), brachyoside B (22), and cycloaraloside A (23). Conclusion: Compounds 1-7 are isolated from the plants of Astragalus Linn. for the first time.