中文摘要：

以β-环糊精为酶模型，合成了具有谷胱甘肽过氧化物酶（GPx）活性的抗氧化模拟物6A，6A′-环己胺基-6B，6B′-二硒桥联-β-环糊精（6-CySeCD）．采用元素分析、红外光谱、^13C NMR和X光电子能谱进行了结构表征．该模拟物的稳态动力学表现出米氏动力学特征，其催化机制可能与天然酶遵循相同的乒乓机制，催化GSH还原H2O2的GPx活力为7．9U／μmol，比Ebselen（0．99U／μmol）高7．9倍，比6-SeCD（4．2U／μmol）高1．8倍，即环己胺定向引入增强了其活力．

英文摘要：

On the basis of structural understanding for GPx, supromolecular host molecules, were selected cyclodextrins, as the scaffolds of enzyme models, and introduce catalytic sites Se and cyclohexyl- amine near the Se sites by chemical modification. One system of GPx mimic：cyclodextrin-based GPx models, 6A, 6B-cyclohexylamine-6Al, 6B′- selenium-bridged β-cyclodextrin （6-CySeCD） was obtained. The structure of the mimic was characterized by means of elemental analysis, IR and 13CMR and its selenium content and valence were determined by means of x-ray photoelectron spectra. Double recioro- cal plots of the inititial velocity versus the concentration of substrates were a family of parallel lines, consistent with a Ping-Pang mechanism involving at least one covalent enzyme intermediate. The GPx activity of the mimic for reduction of H2O2 by glutathione is 7.9 U/μmol,which is 7.9 times of that of ebselen. The GPx activity of the mimic for reduction of H2O2 by glutathione is 1.8 times of that 6- SeCD （4.2 U/μmol）. Detailed steady-state kinetic studies demonstrated that the 6-SeCD followed a ping-pong mechanism similar to the naturally occurring GPx. Cyclohexylamine near the Se sites by chemical modification rose the activity of the mimic.