2-位碲桥联环糊精的制备、表征及其谷胱甘肽过氧化物酶活性的研究

Synthesis and characterization of organotellurium-bridged cyclodextrin dimers with artificial glutathione peroxidase activities

该文以三种母体环糊精(CD),即α-、β-和γ-CD为修饰模板,将功能性基团有机碲引入到环糊精次面的2位羟基上,制备得到了三种具有谷胱甘肽过氧化物酶(GPX)活性的GPX模拟物。采用元素分析、红外光谱、核磁共振等手段对三种环糊精衍生物的结构进行了表征。运用GPX经典双酶体系法测定了三种环糊精衍生物的GPX活性,实验结果表明三者均具有很高的催化活性,其中2-位碲桥联γ-环糊精(2-Te-γ-CD)具有最高的GPX活性,其催化谷胱甘肽(GSH)还原过氧化氢(H2O2),叔丁基过氧化氢(t-BuOOH)和枯烯过氧化氢(CuOOH)的活力分别是传统"小分子硒酶"Ebselen的80.5,333.3和118.3倍。

On the basis of structural understanding for GPX, cyclodextrins was selected as the scaffolds of enzyme models, and cata- lytic sites Te was introduced by chemical modification. Three novel glutathione peroxidase （GPx） mimics based on organotellurium cyelodextrin dimer were synthesized. Their structures were identified by IR, 1HNMR and elemental analysis. The decomposition of a variety of structurally distinct hydroperoxides at the expense of glutathione （GSH）catalyzed by 2,2＇-ditellurobis （2-deoxy-y-cyclo- dextrin） （2-Te-γ-CD）, and by the corresponding derivatives of β-cyclodextrin （β-CD） and α-cyclodextrin was examined. Hydroper- oxides decomposing capacity of 2-Te-γ-CD was determined to be 80. 5,109. 8,149. 6 U/μmol, respectively, with hydrogen peroxide （ H2O2 ）, tert-butyl hydroperoxide （t-BuOOH） and cumene hydroperoxide （ CuOOH）, which was almost 80. 5,333.3,118. 3-fold than that of Ebselen.