Kinetics of Spin Trapping Superoxide, Hydroxyl, and Aliphatic Radicals by Cyclic Nitrones
作者:Sara Goldstein、Gerald M. Rosen、Angelo Russo、Amram Samuni
DOI:10.1021/jp048441i
日期:2004.8.1
Spin trapping coupled with electron paramagnetic resonance (EPR) spectroscopy has surfaced as one of the most specific and reliable methods for identifying free radicals in biological systems. Despite extensive studies focused on the kinetics of radical trapping by cyclic nitrones, the mechanism has not been fully elucidated. Moreover, major controversies still persist even regarding the efficiency
自旋捕获与电子顺磁共振 (EPR) 光谱相结合已成为识别生物系统中自由基的最具体和最可靠的方法之一。尽管广泛的研究集中在环状硝酮的自由基捕获动力学,但其机制尚未完全阐明。此外,即使关于捕获反应的效率和速率常数,主要争议仍然存在。本研究使用脉冲辐解来研究 5,5-dimethyl-1-pyrroline N-oxide 1 (DMPO) 和含酯衍生物 5-tert-butoxycarbonyl-5-methyl-1-pyrroline N- 的反应。氧化物 4,与 •OH、O2•-、CO2•-、•C(OH)(CH3)2、•CH2OH 和•CH3。结果表明,激进的诱捕比以前意识到的要复杂得多。与 EPR 相结合的辐射化学实验表明,大约 30% 的 •OH 在 2 位添加到硝酮 1 和 4,产生相应的持久性氨氧基。剩余的 •OH 自由基形成瞬态中间体...