A NEW FLAVONOID GLYCOSIDE FROM ALLIUM CEPA L. VAR AGROGATUM DON

AIM　To investigate the chemical constituents from the bulb stems of the Chinese medicinal plant Allium cepa L. var. agrogatum Don. METHODS　The crude extracts of the bulb stem were purified by Sephadex LH-20 chromatography. IR, UV, MS, 1H, ¹³CNMR，¹H-¹H COSY，¹H-¹³C COSY and HMBC spectra were used to determine the structure of the isolated constituents. RESULTS　A new compound named quercetin 3′-methoxy-4′-O-β-D-glucopyranoside(I), together with three known compounds kaempferol(II), quercetin 4′-O-β-D-glucopyranoside(III) and quercetin 3,4′-di-O-β-D-glucopyranoside(IV) were isolated. CONCLUSION　Quercetin 3′-methoxy-4′-O-β-D-glucopyranoside(I) is a new compound, compounds II～IV were isolated from this plant for the first time.