儿茶素单体EGC对胰脂肪酶的抑制作用及其机理研究  

Inhibitory Effect of Catechin Monomer EGC on Pancreatic Lipase and Mechanism

作　　者：满子意 凤怡 吴祥庭[1] MAN Ziyi;FENG Yi;WU Xiangting(College of Life and Environmental Science,Wenzhou University,Wenzhou 325035,China)

机构地区：[1]温州大学生命与环境科学学院,浙江温州325035

出　　处：《茶叶科学》2022年第6期863-874,共12页Journal of Tea Science

摘　　要：为研究儿茶素单体表没食子儿茶素(Epigallocatechin,EGC)对胰脂肪酶的抑制作用及机制,以干燥绿茶为原料,采用热水提取法、三氯甲烷脱色素和柱层析分离,得到EGC单体。采用扫描电子显微镜、傅里叶红外光谱、核磁共振氢谱对纯化的EGC单体进行结构表征,再通过滴定法研究EGC对胰脂肪酶的抑制作用及类型,然后通过荧光光谱法以及分子对接技术表征了EGC对胰脂肪酶结构的影响。结果表明,EGC以非竞争性方式对胰脂肪酶表现出抑制作用,并且抑制效果随EGC浓度的增加呈持续上升趋势,半抑制浓度为(1.62±0.085)mg·mL^(-1)。EGC对胰脂肪酶有荧光猝灭作用,可通过分子间氢键和疏水相互作用与酶中的氨基酸残基结合,导致酶的化学结构和空间构象发生变化,从而降低酶活性。EGC主要通过改变胰脂肪酶的化学结构和空间构象来抑制该酶活性,从而达到降血脂功效。In order to study the inhibitory effect and mechanism of epigallocatechin(EGC)on pancreatic lipase,EGC monomer was obtained from dry green tea by hot water extraction,chloroform depigmentation and column chromatography.The structure of purified EGC monomer was characterized by scanning electron microscope,Fourier transform infrared spectroscopy and~1H-NMR spectroscopy.The inhibitory effect and types of EGC on pancreatic lipase were studied by titration,and the effect of EGC on pancreatic lipase structure was characterized by fluorescence spectroscopy and molecular docking.The results show that EGC exhibited the inhibition on pancreatic lipase in a non-competitive manner.The inhibitory effect continued to rise with the increase of EGC concentration,and the half inhibitory concentration(IC)was(1.62±0.085)mg·mL.There was a fluorescence quenching effect of EGC on pancreatic lipase.EGC could bind to amino acid residues in the enzyme through intermolecular hydrogen bonds and hydrophobic interactions,resulting in the changes in chemical structure and spatial conformation of the enzymes,thus decreasing the enzyme activity.The results show that EGC mainly inhibited the activity of pancreatic lipase by changing the chemical structure and spatial conformation of pancreatic lipase,so as to achieve the hypolipidemic effect.

关 键 词：表没食子儿茶素 胰脂肪酶 分子间氢键 机制 

分 类 号：S517.1[农业科学—作物学] R735.2[医药卫生—肿瘤]