【摘要】 研究桐花树叶乙酸乙酯提取物对α-葡萄糖苷酶活性的抑制作用。桐花树叶70%醇提取物经萃取获得石油醚部位、二氯甲烷部位、乙酸乙酯部位、正丁醇部位、水部位5个部位。对各部位进行多酚含量、总黄酮含量、DPPH·清除活性测定,从中筛选出活性物质含量高、自由基清除活性较强的桐花树叶乙酸乙酯提取物,对其用α-葡萄糖苷酶进行体外活性抑制作用试验,通过酶促动力学方法与绘制Lineweaver-Burk曲线,推断桐花树叶乙酸乙酯提取物的酶抑制类型,所得的结果与阿卡波糖进行比较。结果表明:桐花树叶乙酸乙酯部位和桐花树叶水部位对α-葡萄糖苷酶均有抑制作用,且抑制作用均优于阿卡波糖,其半抑制浓度(IC50)分别为40.59μg/m L和60.79μg/m L。桐花树叶乙酸乙酯提取物抑制类型为混合Ⅱ型抑制,对游离酶(E)的抑制常数(Ki)为0.245 mg/m L,对酶-底物络合物(ES)的抑制常数(Kis)为0.023 mg/m L。更多还原

【Abstract】 Study on α-glucosidase inhibitory activity of the ethyl acetate extract from leaves of Aegiceras corniculatum. The petroleum from leaves of Aegiceras corniculatum ether part obtained from the extraction of 70 % alcohol extract and methylene chloride and ethyl acetate, n-butanol part, water five parts. Polyphenol content determination, for each part to determination of flavonoids content and DPPH·scavenging activity, the sifting high content of active substance, radical scavenging activity stronger the ethyl acetate extracted from leaves of Aegiceras corniculatum with alpha glycosidase enzymes activity inhibition in vitro experiments, through enzymatic dynamics method with Lineweaver-Burk curve drawing, deduce the ethyl acetate extracted from leaves of Aegiceras corniculatum of the type of enzyme inhibition, the results comparing with acarbose. Results showed that ethyl acetate parts from leaves of Aegiceras corniculatum and water area from leaves of Aegiceras corniculatum of alpha glycosidase enzymes had inhibitory effect, and inhibition were better than acarbose, its half inhibitory concentration(IC50) were 40.59 μg/m L and 60.79 μg/m L. The ethyl acetate extracted from leaves of Aegiceras corniculatum inhibit type to mixed type Ⅱ suppression, the inhibition of the free enzyme(E) constant(Ki) 0.245 mg/m L, on the complex enzyme-substrate(ES) inhibition of constant(Kis) 0.023 mg/m L.更多还原