RESUMEN
AIM To study the flavonoids from the leaves of Astragalus membranaceus (Fish.) Bge..METHODS The ethyl acetate and n-butyl alcohol fractions of 75％ ethanol extract from A.membranaceus leaves were isolated and purified by silica,ODS and preparative HPLC column,then the structures of obtained compounds were identified by spectral data.RESULTS Thirteen compounds were isolated and identified as quercetin (1),quercetin-3-O-β-D-glucopyranoside (2),rhamnocitrin-3-O-β-D-glucopyranoside (3),rhamnocitrin-3-O-β-neohesperidoside (4),rhamnocitrin-3-O-3-D-glucopyranoside (1'''→2'')-β-D-apiofuranosyl (5),complanatuside (6),glycitein (7),4',7-dihydroxy-3-methoxy isoflavone (8),genistein (9),calycosin-7-O-β-D-glucopyranoside (10),genistin (11),glycitin (12),tiliroside (13).CONCLUSION Compounds 5,8,13 are isolated from genus Astragalus for the first time,and compound 2 is first isolated from this plant.