Quantitative Spin-trapping ESR Investigation of Alkoxyl Radical Derived from AAPH: Development of a Flow-injection Spin-trapping ESR System for the Oxygen Radical Absorbance Capacity Assay
Quantitative Spin-trapping ESR Investigation of Alkoxyl Radical Derived from AAPH: Development of a Flow-injection Spin-trapping ESR System for the Oxygen Radical Absorbance Capacity Assay
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DOI：
10.1007/s00723-015-0664-5
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发表时间：
2015-04
影响因子：
1
通讯作者：
A. Nakajima;Tomoko Yamaguchi;T. Yamashita;K. Kawai;Y. Miyake;K. Kanaori;K. Tajima
中科院分区：
文献类型：
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作者：
A. Nakajima;Tomoko Yamaguchi;T. Yamashita;K. Kawai;Y. Miyake;K. Kanaori;K. Tajima
建立了流动注射电子自旋共振（ESR）定量检测AAPH（2，2 ′-偶氮二（2，4-脒基丙烷）二盐酸盐）热分解产生的烷氧基自由基（RO·，R = C（CH 3）2-C（+NH 2Cl −）NH 2）的方法。考察了该体系的最佳测量条件，发现在冰水容器中淬灭控制自由基的形成是获得稳定准确结果的有效方法。该系统用于估算选定生物物质Trolox（6-羟基-2，5，7，8-四甲基色满-2-羧酸）、咖啡酸、4-羟基肉桂酸、肾上腺素、芸香苷、（+）-儿茶素、l-色氨酸和d-甘露醇等的清除烷氧自由基能力和吸收氧自由基能力值。由于烷氧基自由基与底物之间的反应速率常数kS不能明确确定，因此使用定义值γ50=kS/k1（k1，烷氧基自由基与自旋阱之间的反应速率常数）作为烷氧基自由基的底物反应参数。流动注射电子自旋共振（ESR）技术消除烷氧基自由基的方法可以有效地测定生物物质的γ 50值，是评价生物物质抗氧化能力的一种有价值的方法。
A flow-injection electron spin resonance (ESR) system was developed for the quantitative detection of an alkoxyl radical (RO·, R = C(CH3)2–C(+NH2Cl−)NH2) derived from AAPH (2,2′-azobis(2,4-amidinopropane) dihydrochloride) by thermal decomposition. Optimal measurement conditions for the system were examined, and it was found that the control of the radical formation by quenching in an ice-water vessel should be effective to obtain the stable and accurate results. The system was applied for the estimation of the alkoxyl radical-elimination ability and the oxygen radical absorbance capacity values of selected biosubstances, such as Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), caffeic acid, 4-hydroxycinnamic acid, epinephrine, rutin, (+)-catechin,l-tryptophane, andd-mannitol. As the rate constant for the reaction between alkoxyl radical and substrate,kS, could not be unequivocally determined, the defined value,γ50=kS/k1, (k1, the rate constant for the reaction between alkoxyl radical and spin trap) was used as a reaction parameter of substrate for alkoxyl radical. The flow-injection electron spin resonance system using alkoxyl radical elimination gave validγ50values for biosubstances, and the system should be a valuable method for the evaluation of the antioxidant ability.