The Fenton oxidation mechanism: reactivities of biologically relevant substrates with two oxidizing intermediates differ from those predicted for the hydroxyl radical.
The Fenton oxidation mechanism: reactivities of biologically relevant substrates with two oxidizing intermediates differ from those predicted for the hydroxyl radical.
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芬顿氧化机制：生物相关底物与两种氧化中间体的反应性与羟基自由基的预测不同。
DOI：
10.1073/pnas.91.14.6604
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发表时间：
1994
影响因子：
11.1
通讯作者：
Peterc . Fords
中科院分区：
文献类型：
--
作者：
David A. Wink;Raymond W. Nims;Joseph E. Saavedra;W. E. Utermahlen;Peterc . Fords
动力学探针的应用，允许一个确定生物相关的基板与氧化中间体的芬顿试剂（H2 O2加Fe 2+在酸性水溶液中）的相对反应性进行了说明。这些结果导致的结论是，有两个关键的中间体具有非常不同的反应模式。一种（X）是H_2O_2与Fe ~（2+）直接反应生成的铁配合物，它与N-亚硝基二甲胺反应，在450 nm处产生强的瞬态吸收。这提供了一个灵敏的分光光度探针的竞争反应性对X的生物相关的底物，如核酸成分和氨基酸。第二中间体（Y）通过其将Ru（bpy）2+3离子（bpy = 2，2 '-联吡啶）氧化成具有中心在500 nm处的吸收带的产物来探测。在没有其他底物的情况下，Ru（bpy）2+3以与Ru浓度无关的速率被氧化，但是产物产率由于与可以拦截X的底物的竞争反应而降低。竞争研究表明，X和Y的反应模式是明显不同于羟基自由基，中间体通常在芬顿氧化的讨论中调用的模式预测。这些数据需要重新评估芬顿试剂氧化生物底物的机制。
The application of kinetic probes that allow one to determine relative reactivities of biologically relevant substrates with oxidizing intermediates in the Fenton reagent (H2O2 plus Fe2+ in acidic aqueous solution) is described. These results lead to the conclusion that there are two key intermediates with very different reactivity patterns. One (X) is proposed to be an iron complex formed via direct reaction of H2O2 with Fe2+, which reacts with N-nitrosodimethylamine to generate a strong transient absorption at 450 nm. This provides a sensitive spectrophotometric probe of the competitive reactivities toward X of biologically relevant substrates such as nucleic acid components and amino acids. The second intermediate (Y) is probed by its oxidation of the Ru(bpy)2+3 ion (bpy = 2,2'-bipyridine) to a product with an absorption band centered at 500 nm. In the absence of other substrates, Ru(bpy)2+3 is oxidized at rates independent of the Ru concentration, but the product yield is diminished by competing reactions with substrates that can intercept X. Competition studies demonstrate reactivity patterns for X and Y that are clearly distinct from the pattern predicted for the hydroxyl radical, the intermediate commonly invoked in discussions of Fenton oxidations. These data require reevaluation of the mechanisms by which the Fenton reagent oxidizes biological substrates.
DOI：
10.1073/pnas.78.11.6858
发表时间：
1981-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
AMES, BN;CATHCART, R;HOCHSTEIN, P
通讯作者：
HOCHSTEIN, P
影响因子：
56.9
作者：
IMLAY, JA;CHIN, SM;LINN, S
通讯作者：
LINN, S