分蘖葱头中新黄酮苷的结构鉴定

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

摘要: 目的　研究百合科植物分蘖葱头（Allium cepa L. var agrogatum Don）鳞茎的黄酮类化学成分。方法　利用Sephadex LH-20柱色谱进行分离纯化。从分蘖葱头中分离得到4个化合物，用IR，UV，MS，¹HNMR，¹³CNMR，¹H-¹H COSY，¹H-¹³C COSY和HMBC等光谱鉴定化合物。结果　经光谱鉴定化合物结构为：槲皮素3′-甲氧基-4′-O-β-D-葡吡喃糖苷(I)、山奈酚(II)、槲皮素4′-O-β-D-葡吡喃糖苷(III)和槲皮素3,4′-二-O-β-D-葡吡喃糖苷(IV)。结论　化合物I为新的黄酮苷类化合物，命名为分蘖葱头苷甲（Alliumoside A）； II,III和IV为首次从该植物中分得。

Abstract: 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.