The technique based on monitoring oxygen consumption was applied to study 12 alkyl- and methoxy-substituted p-hydroquinones (QH(2)) as a chain-breaking antioxidant during the oxidation of styrene and methyl linoleate (ML) in bulk as well as ML oxidation in micellar solution of sodium dodecyl sulfate (SDS) at 37 degrees C. The antioxidant activities of QH(2) were characterized by two parameters: the rate constant k(1) for reaction of QH(2) with the peroxy radical LO(2)*: QH(2)+LO(2)*-->QH*+LOOH and the stoichiometric factor of inhibition, f, which shows how many kinetic chains may be terminated by one molecule of QH(2). In the case of styrene and ML oxidation in bulk, f values never exceed two; for the majority of QH(2), f was found to be significantly less than two due to the interaction of QH* with molecular oxygen. In the absence of superoxide dismutase (SOD), all the studied QH(2) displayed a very moderate if any antioxidant capability during ML oxidation in SDS micelles. When 20U/ml SOD was added, the majority of QH(2) showed a pronounced ability to inhibit ML oxidation, f parameter being ca. one. The features of QH(2) as an antioxidant in aqueous environment are suggested to associate with the reactivity of semiquinone (Q*(-)). Q*(-) reacts readily with molecular oxygen with formation of superoxide (O(2)*(-)); further reactions of O(2)*(-) result in fast depleting QH(2) and chain propagation. The addition of SOD results in purging a reaction mixture from O(2)*(-) and, as a corollary, in depressing undesirable reactions with the participation of O(2)*(-). With all the oxidation models, QH(2) were found to be very reactive to LO(2)*. The rate constants k(1) decreased progressively when going from the oxidation of styrene to ML oxidation in bulk and further to ML oxidation in SDS micelles.

中文翻译：

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取代了对氢醌作为脂质过氧化的抑制剂。

基于监测耗氧量的技术被应用于研究12个烷基和甲氧基取代的对氢醌（QH（2））作为苯乙烯和亚油酸甲酯（ML）以及ML的氧化过程中的链断裂抗氧化剂十二烷基硫酸钠（SDS）的胶束溶液在37摄氏度下氧化.QH（2）的抗氧化活性由两个参数表征：QH（2）与过氧自由基LO（2）反应的速率常数k（1） 2）*：QH（2）+ LO（2）*-> QH * + LOOH和化学计量的抑制因子f，它表示一分子QH（2）可以终止多少个动力学链。在苯乙烯和ML大量氧化的情况下，f值不得超过2。对于大多数QH（2），由于QH *与分子氧的相互作用，发现f明显小于2。在没有超氧化物歧化酶（SOD）的情况下，所有研究的QH（2）在SDS胶束的ML氧化过程中显示出非常适中的抗氧化能力。当添加20U / ml SOD时，大多数QH（2）表现出明显的抑制ML氧化的能力，f参数为ca。一。QH（2）在水性环境中作为抗氧化剂的功能建议与半醌（Q *（-））的反应性相关。Q *（-）容易与分子氧反应形成超氧化物（O（2）*（-））；O（2）*（-）的进一步反应导致QH（2）快速耗尽和链传播。SOD的添加会导致从O（2）*（-）清除反应混合物，并且必然会抑制O（2）*（-）参与的不良反应。在所有氧化模型中，发现QH（2）对LO（2）*具有很高的反应性。