抗氧化药物依布硒啉已在实验室和临床试验中得到广泛研究。它通过与谷胱甘肽或其他硫醇还原来破坏过氧化氢的催化机制很复杂,并且一直是争论不休的主题。在对几个关键步骤的重新研究过程中,我们发现构成依布硒啉第一个氧化产物的亚硒酰胺经历了容易的可逆甲醇分解,生成不稳定的亚硒酸酯和两种二聚产物。在与苯甲醇的反应中,亚硒酰胺产生了一种苯甲酯,该苯甲酯很容易通过硒氧化物消除反应,并形成苯甲醛。依布硒酸的氧化并没有像之前用苯硒酸观察到的那样得到硒酸盐,而是产生了硒酸和硒酸的混合物。依布硒啉与苄基硫醇的硫解比 ca 的氧化快。一个数量级并产生稳定的硒基硫化物。当使用谷胱甘肽时,产物迅速歧化为谷胱甘肽二硫化物和依布硒化物。S-苄基硒基硫化物的氧化,或亚硒酰胺与苄基硫醇的硫解作用,提供了一种瞬时硫醇亚硒酸盐,它也很容易经历硒氧化物消除。当同时存在硫醇和三乙胺催化时,S-苄基衍生物很容易歧化。当暴露于环境光或紫外线 (360
Mechanistic investigations on the efficient catalytic decomposition of peroxynitrite by ebselen analogues
作者:Krishna P. Bhabak、Amit A. Vernekar、Surendar R. Jakka、Gouriprasanna Roy、Govindasamy Mugesh
DOI:10.1039/c0ob01234c
日期:——
In this study, ebselen and its analogues are shown to be catalysts for the decomposition of peroxynitrite (PN). This study suggests that the PN-scavenging ability of selenenyl amides can be enhanced by a suitable substitution at the phenyl ring in ebselen. Detailed mechanistic studies on the reactivity of ebselen and its analogues towards PN reveal that these compounds react directly with PN to generate highly unstable selenoxides that undergo a rapid hydrolysis to produce the corresponding seleninic acids. The selenoxides interact with nitrite more effectively than the corresponding seleninic acids to produce nitrate with the regeneration of the selenenyl amides. Therefore, the amount of nitrate formed in the reactions mainly depends on the stability of the selenoxides. Interestingly, substitution of an oxazoline moiety on the phenyl ring stabilizes the selenoxide, and therefore, enhances the isomerization of PN to nitrate.