Antioxidant Activity of the Anti-Inflammatory Compound Ebselen: A Reversible Cyclization Pathway via Selenenic and Seleninic Acid Intermediates
作者:Bani Kanta Sarma、Govindasamy Mugesh
DOI:10.1002/chem.200801258
日期:——
A revised mechanism that accounts for the glutathione peroxidase (GPx)-like catalytic activity of the organoseleniumcompound ebselen is described. It is shown that the reaction of ebselen with H(2)O(2) yields seleninicacid as the only oxidized product. The X-ray crystal structure of the seleninicacid shows that the selenium atom is involved in a noncovalent interaction with the carbonyl oxygen atom
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.