分蘖葱头中新黄酮苷的结构鉴定

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。

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-beta-D-glucopyranoside(I), together with three known compounds kaempferol(II), quercetin 4'-O-beta-D-glucopyranoside(III) and quercetin 3,4'-di-O-beta-D-glucopyranoside(IV) were isolated. CONCLUSION: Quercetin 3'-methoxy-4'-O-beta-D-glucopyranoside(I) is a new compound, compounds II-IV were isolated from this plant for the first time.