Nagy I, Floyd R A
Arch Gerontol Geriatr. 1984 Dec;3(4):297-310. doi: 10.1016/0167-4943(84)90031-1.
The ADP-Fe(II)-H2O2 system generates OH free radicals which can be trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) thus yielding a measurable signal by electron spin resonance spectroscopy. The amount of DMPO-OH spin adduct formed under certain conditions decreased considerably, if dimethylaminoethanol (DMAE), p-chlorophenoxyacetic acid (PCPA) or centrophenoxine (CPH) were present in comparable concentrations to that of DMPO. It has been demonstrated that such an effect cannot be attributed to any interference of the tested compounds with the Fe(II) and its oxidability by H2O2. The reaction of DMAE with OH free radicals was demonstrated also by using other spin traps. These spin traps reacted with OH free radicals either not at all (phenyl-tert-butylnitrone, PBN) or only to a slight extent (alfa-pyridyl-l-oxide-N-tert-butylnitrone, 4-POBN). DMAE was also a competitive OH free radical scavenger with proline and hydroxyproline, both of which have recently been shown to react with OH free radicals to form nitroxyl free radicals. On the basis of the experimental results, the OH free radical scavenger property of DMAE can be regarded as firmly established. This result supports the molecular mechanism proposed for the explanation of the anti-aging effects of CPH in terms of the membrane hypothesis of aging.
ADP-亚铁（II）-过氧化氢体系会产生羟基自由基，这些自由基可被5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）捕获，进而通过电子自旋共振光谱产生可测量的信号。如果二甲基氨基乙醇（DMAE）、对氯苯氧基乙酸（PCPA）或盐酸甲氯芬酯（CPH）的浓度与DMPO相当，在特定条件下形成的DMPO-OH自旋加合物的量会大幅减少。已经证明，这种效应不能归因于受试化合物对亚铁（II）及其被过氧化氢氧化能力的任何干扰。通过使用其他自旋捕获剂也证明了DMAE与羟基自由基的反应。这些自旋捕获剂与羟基自由基根本不反应（苯基叔丁基硝酮，PBN）或仅轻微反应（α-吡啶基-1-氧化物-N-叔丁基硝酮，4-POBN）。DMAE还是脯氨酸和羟脯氨酸的竞争性羟基自由基清除剂，最近已证明这两种物质都会与羟基自由基反应形成硝酰自由基。基于实验结果，DMAE的羟基自由基清除剂特性可以被认为是确凿无疑的。这一结果支持了根据衰老的膜假说对CPH的抗衰老作用进行解释时所提出的分子机制。
