甘草中黄豆黄苷的分离鉴定及其α-葡萄糖苷酶抑制活性

Research on Structure Identification of Glycitin from Glycyrrhiza and Its Inhibitory Activity Against α-Glucosidase

为掌握甘草中化合物的类型及确定药效成分,对甘草中化学成分进行分析研究。采用超声波方法提取甘草,对甘草水提液进行石油醚、乙酸乙酯萃取,通过硅胶柱色谱分离乙酸乙酯萃取物,采用高效液相色谱、红外光谱、质谱、核磁共振氢谱、核磁共振碳谱进行结构分析鉴定,并对分离产物进行α-葡萄糖苷酶抑制率测定,计算IC50值。经结构鉴定,从甘草的乙酸乙酯萃取物中得到1个异黄酮类化合物黄豆黄苷。该化合物为首次从甘草属植物中得到。体外检测表明,该化合物对α-葡萄糖苷酶的IC50为0.5646 mg·mL-1,抑制活性高于对照组阿卡波糖。

In order to confirm the types of compounds in licorice and its active ingredient, the chemical components of licorice are analyzed. The liquid of licorice is extracted by petroleum ether and ethyl acetate, the ethyl acetate extract is separated by silica gel column. The isolate is analyzed by color reaction, high performance liquid chromatography, infra-red spectroscopy, mass spectrometry, 1H nuclear magnetic resonance spectra and 13C nuclear magnetic resonance spectra structure identification. An isoflavone glycitin is isolated from the licorice, which has some inhibitory effect on ot-glucosidase. The compound has been isolated from Glycyrrhiza for the first time. The inhibition activity against α-glucosidase is tested in vitro, and this compound shows good inhibition effect on α- glucosidase with IC5o of 0.5646 mg· mL-1, better than the position control acarbose. The results of kinetic experiments show that the depressant effect of glycitin is non competitive inhibition and the constant of Km, is 8.1571 mol.L-1. The value of Ki is 1.318 mg.mL calculated by the Dixon equation.