鼠曲草提取物及组分对α–淀粉酶的抑制作用

Inhibition effects of extract and its compositions from Gnaphlium affine D.Don on α-amylase

采用分析型高效液相色谱仪对鼠曲草提取物进行分离、鉴定,并测定了鼠曲草提取物及其中3个组分对α–淀粉酶活性的影响。结果表明:从鼠曲草提取物中分离出7个组分,并鉴定出3个组分,分别为3,5–O–咖啡酰基奎宁酸,3,4–O–咖啡酰基奎宁酸,2′,4,4′–三羟基–6′–甲氧基–查尔酮–4′–O–β–D–葡萄糖;当α–淀粉酶质量浓度达到1.67 mg/m L时,鼠曲草提取物、3,5–O–咖啡酰基奎宁酸、3,4–O–咖啡酰基奎宁酸、2′,4,4′–三羟基–6′–甲氧基–查尔酮–4′–O–β–D–葡萄糖的抑制率分别为32.37%、84.53%、63.07%、71.22%,半抑制浓度IC50分别为2.71、0.90、1.28、1.16 mg/m L;对2′,4,4′–三羟基–6′–甲氧基–查尔酮–4′–O–β–D–葡萄糖进行动力学分析的结果显示,2′,4,4′–三羟基–6′–甲氧基–查尔酮–4′–O–β–D–葡萄糖为可逆非竞争性抑制类型。

Isolation and identification of composition from Gnaphlium affine D.Don extract were conducted with high performance liquid chromatography. Inhibition effects of extract and its three compositions on α- amylase activity were determined. The results showed that seven compositions were isolated from the extract and three of them were identified as 3,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, 2＇,4,4＇-trihydroxy -6＇-methoxychalcone-4＇-O-β-D- glucopyranoside. The inhibition rates of extract, 3,5-di-O-caffeoylquinic acid, 3,4-di-O-caffeoylquinic acid, and 2＇,4,4＇-trihydroxy -6＇-methoxychalcone--4＇-O-β-D-glucopyranoside were 32.37%, 84.53%, 63.07% and 71.22% respectively when the concentration of α- amylase was 1.67 mg/mL, and half inhibitory concentrations （IC_50） were 2.71, 0.90, 1.28 and 1.16 mg/mL. The kinetic analysis showed that the inhibition of 2＇,4,4＇- trihydroxy -6＇-methoxychalcone -4＇-O-β-D-glucopyranoside on α - amylase was reversible and non-competitive.