Computer-assisted designed “selenoxy–chinolin”: a new catalytic mechanism of the GPx-like cycle and inhibition of metal-free and metal-associated Aβ aggregation
作者:Zhiren Wang、Yali Wang、Wenrui Li、Zhihong Liu、Zonghua Luo、Yang Sun、Ruibo Wu、Ling Huang、Xingshu Li
DOI:10.1039/c5dt02130h
日期:——
Using support from rational computer-assisted design, a novel series of hybrids designed by fusing the metal-chelating agent CQ and the antioxidant ebselen were synthesized and evaluated as multitarget-directed ligands.
Chemistry Related to the Catalytic Cycle of the Antioxidant Ebselen
作者:Kai N. Sands、Austin L. Burman、Esther Ansah-Asamoah、Thomas G. Back
DOI:10.3390/molecules28093732
日期:——
formation of benzaldehyde. Oxidation of ebselen seleninic acid did not afford a selenonium seleninate salt as previously observed with benzene seleninic acid, but instead generated a mixture of the seleninic and selenonic acids. Thiolysis of ebselen with benzyl thiol was faster than oxidation by ca. an order of magnitude and produced a stable selenenyl sulfide. When glutathione was employed, the product
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
Ebselen as a peroxynitrite scavenger in vitro and ex vivo
We have previously shown that peroxynitrite (PN) selectively impaired prostacyclin (PGI,)dependent vasorelaxation by tyrosine nitration of PGI, synthase in an in situ model (Zou MH, Jendral M and Ullrich V, Br] Pharmacol 126: 1283-1292, 1999). By using this established model, we tested whether or not ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one which reacts rapidly with the anionic form of PN, affected PN inhibition of PGI(2) synthase. Administration of ebselen (1 to 50 mu M) to bovine coronary strips 5 min Frier to PN (1 mu M) treatment neither prevented PN-triggered vasoconstriction nor the inhibition of PGI(2) release. In line with these results, ebselen affected neither PN inhibition of the conversion of [C-14]-PGH(2) into 6 keto PGF(1 alpha) nor the nitration of PGI(2) synthase in bovine aortic microsomes. Following the hypothesis that a reaction of ebselen with cellular thiols could have caused the inefficiency of ebselen, we observed that free ebselen quickly reacted with thiols in both coronary strips and in aortic microsomes to form two metabolites, one of which was identified as the ebselen-glutathione adduct, whereas the other had a similar retention time to that of the ebselen-cysteine adduct. The nitration of phenol by PN in a metal-free solution could be blocked more efficiently in the presence of ebselen or glutathione alone than in the presence of both, indicating that like selenomethionine and other selenocompounds, ebselen-thiol adducts were less reactive towards PN than ebselen itself. Further evidence came from the results that ebselen became effective in preventing the inhibition and nitration of PGI(2) synthase after thiol groups of microsomal proteins were previously oxidized with Ellman's reagent. We conclude that in cellular systems ebselen is present as thiol adducts and thus loses its high reactivity towards PN, which is required to compete with the nitration of PGI, synthase. BIOCHEM PHARMACOL 59;2: 153-160, 2000. (C) 1999 Elsevier Science Inc.
Fisher, Hartmut; Dereu, Norbert, Bulletin des Societes Chimiques Belges, 1987, vol. 96, # 10, p. 757 - 768
作者:Fisher, Hartmut、Dereu, Norbert
DOI:——
日期:——
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