A Simple and Efficient Strategy To Enhance the Antioxidant Activities of Amino-Substituted Glutathione Peroxidase Mimics
作者:Krishna P. Bhabak、Govindasamy Mugesh
DOI:10.1002/chem.200800963
日期:2008.9.26
The glutathione peroxidase (GPx) activities of some diaryl diselenides incorporating tertiary amino groups were studied with H(2)O(2), Cum-OOH, and tBuOOH as substrates and with PhSH as thiol co-substrate. Simple replacement of a hydrogen atom with a methoxy group dramatically enhances the GPx activity. The introduction of methoxy substituents ortho to selenium in N,N-dialkylbenzylamine-based compounds
以H(2)O(2),Cum-OOH和tBuOOH为底物,以PhSH为硫醇共底物,研究了一些掺入叔氨基的二芳基二硒化物的谷胱甘肽过氧化物酶(GPx)活性。用甲氧基简单替换氢原子可显着增强GPx活性。在基于N,N-二烷基苄胺的化合物中,将硒邻位的甲氧基取代基引入到硒中,使氨基的碱度非常适合催化。6-OMe基团的存在防止硒醇中可能发生SeN相互作用,从而增加其两性离子特性。甲氧基取代基还保护硒酸中间体中的硒免于过氧化成硒酸或不可逆地失活成硒酸衍生物。通过防止在硒中心的硫醇交换反应(通常会导致失活途径),其他取代基在硒烯基硫化物中间体中也起着至关重要的作用。引入甲氧基取代基后,硒烯基硫化物中间体中SeN相互作用的强度大大降低,这不仅减少了硒处的硫醇交换反应,而且增强了传入硫醇对硫的亲核攻击。硫醇对硒烯基硫醚中硫的简单攻击还可以防止硒烯基硫醚与H(2)O(2)之间的反应,后者可以再生硒酸(逆GPx循环)。