Mottley C, Mason R P
Department of Chemistry, Luther College, Decorah, Iowa 52101, USA.
J Biol Chem. 2001 Nov 16;276(46):42677-83. doi: 10.1074/jbc.M104889200. Epub 2001 Sep 6.
Lipoic acid and its reduced form, dihydrolipoic acid, are thought to be strong antioxidants. There are also reports of dihydrolipoic acid acting as a pro-oxidant under certain circumstances. This article reports the direct observation by ESR spectrometry of the disulfide radical anion and the spin trapping of the primary thiyl radical formed from the oxidation of dihydrolipoic acid through thiol pumping with phenol and horseradish peroxidase. The disulfide radical anion reacts rapidly with oxygen to form the reactive radical superoxide, which is also trapped. The radical species formed show a potential for pro-oxidant activity of this compound. Although antioxidants, in general, have been shown to have pro-oxidant potential, the pro-oxidant chemistry of dihydrolipoic acid has not been well characterized.
硫辛酸及其还原形式二氢硫辛酸被认为是强抗氧化剂。也有报道称二氢硫辛酸在某些情况下会作为促氧化剂起作用。本文报道了通过电子顺磁共振光谱法直接观察二硫自由基阴离子，以及通过用苯酚和辣根过氧化物酶进行硫醇泵浦氧化二氢硫辛酸形成的初级硫自由基的自旋捕获。二硫自由基阴离子与氧气迅速反应形成反应性自由基超氧阴离子，超氧阴离子也被捕获。所形成的自由基物种显示出该化合物具有促氧化活性的潜力。虽然一般来说抗氧化剂已被证明具有促氧化潜力，但二氢硫辛酸的促氧化化学性质尚未得到很好的表征。
