Reaction between Peroxynitrite and Triphenylphosphonium-Substituted Arylboronic Acid Isomers: Identification of Diagnostic Marker Products and Biological Implications
Reaction between Peroxynitrite and Triphenylphosphonium-Substituted Arylboronic Acid Isomers: Identification of Diagnostic Marker Products and Biological Implications
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DOI：
10.1021/tx300499c
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发表时间：
2013-06-01
影响因子：
4.1
通讯作者：
Kalyanaraman, Balaraman
中科院分区：
文献类型：
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作者：
Sikora, Adam;Zielonka, Jacek;Kalyanaraman, Balaraman
芳香族硼酸与过亚硝酸根(ONOO-)反应迅速，生成主要产物苯酚。这个反应被用来监测细胞系统中ONOO的形成。以前，我们认为ONOO(-)与芳基硼酸盐(PhB(OH)(2))反应生成一个酚类产物(主路径)和一个自由基对PhB(OH)(2)O中心点-中心点中心点(NO2)-N中心点(次路径)。[Sikora，A.等人。(2011)化学。Toxicol资源。24,687-697]。在这项研究中，我们研究了一个大体积的三苯基膦(TPP)基团对ONOO和线粒体靶向的芳基硼酸盐异构体(o-，m-和p-MitoPhB(OH)(2))之间反应的影响。电子顺磁共振(EPR)自旋捕获实验的结果明确地表明，苯基中间体的存在来自间异构体和对位异构体，而不是来自邻位异构体。O-MitoPhB(OH)(2)与ONOO-反应生成的o-MitoPhNO(2)的产率不受苯基清除剂的影响，表明O-MitoPhB(OH)(2)O中心点自由基阴离子迅速裂解，生成的苯基在溶剂笼中与中心点NO2反应。DFT量子力学计算表明，o-MitoPhB(OH)(2)O中心点自由基阴离子的解离能垒明显低于m-MitoPhB(OH)(2)O中心点自由基阴离子和p-MitoPhB(OH)(2)O中心点自由基阴离子的解离能垒。硝化产物o-MitoPhNO(2)不是髓过氧化物酶在亚硝酸根和过氧化氢存在下产生的二氧化氮自由基，提示该硝化产物可作为ONOO-的诊断标志物。O-MitoPhB(OH)(2)与被激活以产生ONOO-的原始264.7巨噬细胞孵育，产生相应的苯酚o-MitoPh(OH)(2)以及诊断硝化产物o-MitoPhNO(2)。我们认为，本文报道的邻位异构体探针最适合于生物体系中ONOO-的特异性检测。
Aromatic boronic acids react rapidly with peroxynitrite (ONOO-) to yield phenols as major products. This reaction was used to monitor ONOO- formation in cellular systems. Previously, we proposed that the reaction between ONOO(-) and arylboronates (PhB(OH)(2)) yields a phenolic product (major pathway) and a radical pair PhB(OH)(2)O center dot-center dot center dot center dot(NO2)-N-center dot (minor pathway). [Sikora, A. et al. (2011 ) Chem. Res. Toxicol. 24 , 687 - 697]. In this study, we investigated the influence of a bulky triphenylphosphonium (TPP) group on the reaction between ONOO- and mitochondria-targeted arylboronate isomers (o-, m-, and p-MitoPhB(OH)(2)). Results from the electron paramagnetic resonance (EPR) spin-trapping experiments unequivocally showed the presence of a phenyl radical intermediate from meta and para isomers, and not from the ortho isomer. The yield of o-MitoPhNO(2) formed from the reaction between o-MitoPhB(OH)(2) and ONOO- was not diminished by phenyl radical scavengers, suggesting a rapid fragmentation of the o-MitoPhB(OH)(2)O center dot- radical anion with subsequent reaction of the resulting phenyl radical with center dot NO2 in the solvent cage. The DFT quantum mechanical calculations showed that the energy barrier for the dissociation of the o-MitoPhB(OH)(2)O center dot- radical anion is significantly lower than that of m-MitoPhB(OH)(2)O center dot- and p-MitoPhB(OH)(2)O center dot- radical anions. The nitrated product, o-MitoPhNO(2), is not formed by the nitrogen dioxide radical generated by myeloperoxidase in the presence of the nitrite anion and hydrogen peroxide, indicating that this specific nitrated product may be used as a diagnostic marker product for ONOO-. Incubation of o-MitoPhB(OH)(2) with RAW 264.7 macrophages activated to produce ONOO- yielded the corresponding phenol o-MitoPh(OH)(2) as well as the diagnostic nitrated product, o-MitoPhNO(2). We conclude that the ortho isomer probe reported here is most suitable for specific detection of ONOO- in biological systems