番石榴叶乙酸乙酯萃取物化学成分研究

目的:寻找番石榴叶乙酸乙酯萃取物中具有降糖活性的功能成分。方法:采用硅胶、羟丙基葡聚糖凝胶柱层析与溶剂重结晶法进行单体分离纯化;通过分析化合物的理化性质、核磁共振谱(nuclear magnetic resonance spectrum,NMR)、质谱(mass spectrum,MS)数据进行结构鉴定;建立降糖脂肪细胞模型评价主要单体的降糖活性。结果:从番石榴叶乙酸乙酯萃取物中共分得14个单体化合物,分别鉴定为:金丝桃苷(化合物1)、异槲皮苷(化合物2)、槲皮素-3-O-β-D-木糖苷(化合物3)、广寄生苷(化合物4)、番石榴苷(化合物5),槲皮素-3-O-(2’’-O-没食子酰基)-α-L-阿拉伯吡喃糖苷(化合物6),槲皮素(化合物7)、没食子酸乙酯(化合物8)、齐墩果酸(化合物9)、β-谷甾醇(化合物10)、isocaryolan-9-one(化合物11)、(-)-epiglobulol(化合物12)、t-cadinol(化合物13)和muurola-4,10(14)-dien-1-ol(化合物14)。降糖脂肪细胞模型测定结果表明,5种主要黄酮苷均具有降糖活性,其中以番石榴苷和广寄生苷降糖效果最好,40μmol/L浓度下促葡萄糖摄取值分别达到了(1.74±0.076)、(1.81±0.029)mmol/L。结论:化合物6、8、11~14为首次从该植物中分得,化合物11为一新的天然产物;番石榴苷和广寄生苷可能为番石榴叶主要降糖活性成分。

Chemical Constituents from Ethyl Acetate Extract of Psidium guajava Linn. Leaves

Objective: To explore the hypoglycemic constituents of ethyl acetate extract of Psidium guajava Linn. leaves.
Methods: The constituents were separated and purified by silica gel and Sephadex LH-20 column chromatography. The
structures were identified on the basis of their physicochemical properties and spectral data. The hypoglycemic activities
of five major flavonoid glycosides were tested in the hypoglycemic model of isolated rat adipocytes. Results: Fourteen
compounds were isolated and identified as hyperoside compound (1), isoquercitrin compound (2), quercetin-3-O-β-Dxylpyranoside
compound (3), avicularin compound (4), guaijaverin compound (5), quercetin 3-O-α-arabinopyranoside-2’’-
gallate compound (6), quercetin compound (7), ethyl gallate compound (8), oleanolic acid compound (9), β-sitosterol compound
(10), isocaryolan-9-one compound (11), (-)-epiglobulol compound (12), t-cadinol compound (13), and muurola-4,10 (14)-dien-
1-ol compound (14), respectively. At the same concentration of 40 μmol/L, avicularin and guaijaverin showed the most
potent hypoglycemic activity among five major flavonoid glycosides with the glucose uptake value at (1.81 ± 0.029) and
(1.74 ± 0.076) mmol/L respectively. Conclusions: Compounds 6, 8, 11 through 14 were isolated from this plant for the first
time and compound 11 was a new natural compound. Avicularin (4) and guaijaverin (5) may be the most potent hypoglycemic
compounds of guava leaves.