橡子仁萃取物成分分析及对α-淀粉酶、α-葡萄糖苷酶的抑制作用

为探索橡子仁萃取物的成分组成及对α-淀粉酶、α-葡萄糖苷酶的抑制作用，以栓皮栎橡子仁为材料，采用超声波辅助乙醇提取和有机溶剂萃取，制备橡子仁乙酸乙酯、正丁醇、水萃取物，通过紫外吸收光谱、高效液相色谱分析各萃取物的化学成分组成，通过抑制率测定、抑制动力学和荧光猝灭试验分析各萃取物的体外抑酶效果及作用机制。结果表明:三种橡子仁萃取物结构高度相似，主要为单宁类物质；乙酸乙酯萃取物含表儿茶素没食子酸酯、没食子酸、没食子儿茶素没食子酸酯等9种物质；正丁醇萃取物含表儿茶素没食子酸酯、儿茶素、没食子儿茶素没食子酸酯等16种物质；水萃取物含没食子酸、绿原酸等21种物质。三种橡子仁萃取物均可有效抑制α-淀粉酶、α-葡萄糖苷酶活性，乙酸乙酯、正丁醇、水萃取物对α-淀粉酶的半抑制浓度（IC₅₀）分别为1.047、1.122、4.031 mg/mL，对α-葡萄糖苷酶的IC₅₀值分别为0.014、0.028、0.037 mg/mL。三种萃取物对两种酶的酶抑制类型多为混合型抑制，荧光猝灭类型多是以静态猝灭为主，动态猝灭为辅的混合猝灭。

Composition Analysis and Inhibitory Effect against α-Amylase and α-Glucosidase of Acorn Kernel Extractions

In order to explore the component and inhibitory effects of extractions of acorn kernel on α-amylase and α-glucosidase, the ethyl acetate、N-butanol and water extractions of Quercus variabilis BI acorn kernelwere obtained by ultrasonic-assisted solvent extraction and separation. The composition of the extractions were analyzed by using UV spectroscopy, and high performance liquid chromatography (HPLC). The inhibitory effects of the extractions on α-amylase and α-glycosidase were investigated by using enzyme inhibition measurement, inhibition kinetics and fluorescence quenching. The results showed that three acorn kernel extractions were highly similar in chemical composition and were mainly tannin. The ethyl acetate extraction contained 9 different substances include epicatechin gallate, gallate and gallocatechin gallate and epigallocatechin gallate. N-butanol extraction contained 16 kinds of substances such as epicatechin gallate、gallocatechin and gallocatechin gallate.Water extraction contained 21 different substances include gallic acid and chlorogenic acid. The three extractions had obvious inhibitory effects on α-amylase and α-glycosidase, the half inhibitory concentrations (IC₅₀) of ethyl acetate, n-butanol, and water extractions on α-amylase were 1.047, 1.122 and 4.031 mg/mL respectively. The IC₅₀ values on α-glucosidase were 0.014, 0.028 and 0.037 mg/mL respectively. The inhibition of three extractions were mainly mixed and reversible, and the fluorescence quenching was mainly static quenching, and dynamic quenching was auxiliary.