The Reaction of Peroxynitrite with Organic Molecules Bearing a Biologically Important Functionality. The Multiplicity of Reaction Modes as Exemplified by Hydroxylation, Nitration, Nitrosation, Dealkylation, Oxygenation, and Oxidative Dimerization and Cleavage
作者:Nobuaki Nonoyama、Hiroshi Oshima、Chizuru Shoda、Hitomi Suzuki
DOI:10.1246/bcsj.74.2385
日期:2001.12
The reactions of peroxynitrite with a variety of organic molecules which include a biologically important functionality have been examined to construct a simple model for the peroxynitrite-induced in vivo transformations as well as a chemical probe for the active species involved therein. Phenols were found to undergo hydroxylation, nitration, oxidative dimerization, and oxidation to cyclohexadienones and quinones. The ring nitration of catechol was confirmed for the first time in the in vitro reaction of peroxynitrite. Dealkylation and N-oxide formation were the major reaction modes observed for N,N-dimethyl-p-toluidine. 1,2-Phenylenediamine gave benzotriazole in high yield. The electron-deficient C–C double bond in 1,4-naphthoquinone underwent epoxidation, while the electron-rich C–C double bond in α-methylstyrene suffered oxidative cleavage to acetophenone. The activated double bond in trans-stilbene underwent oxidative cleavage and epoxidation in parallel to give benzaldehyde and trans-stilbene oxide as the major products. The triple bond in diphenylacetylene was simply oxygenated to form benzil, together with trace amounts of ring nitration products. 1-Phenylethanol, imidazole, 2′-deoxyadenosine, and 2′-deoxyguanosine were all quite slow to react, while uracil and cytosine were almost inert to peroxynitrite. The reaction modes exhibited by peroxynitrite are too widespread and complicated to explain the whole mechanistic pathway in terms of a single active species. All reaction modes observed for the peroxynitrite to date could be classified into five categories according to their types: i) electron transfer type, ii) O-electrophilic type, iii) N-electrophilic type, iv) O-nucleophilic type, and v) radical type. Some of these may compete under certain conditions. The active species involved in each of these types of reactions are as follows: i) NO+, NO2, and OH, ii) ONOOH, iii) ONOOH and NO+, iv) OOH− and ONOO−, and v) NO2 and OH•.
我们研究了过亚硝酸与多种有机分子的反应,这些有机分子具有重要的生物功能,我们通过研究这些有机分子的反应,为过亚硝酸诱导的体内转化建立了一个简单的模型,并为其中涉及的活性物种提供了一个化学探针。研究发现,酚类会发生羟化、硝化、氧化二聚化以及氧化成环己二烯酮和醌类。儿茶酚的环硝化首次在过亚硝酸盐的体外反应中得到证实。脱烷基化和 N-氧化物的形成是 N,N-二甲基对甲苯胺的主要反应模式。1,2-苯二胺能产生高产率的苯并三唑。1,4-萘醌中电子缺乏的 C-C 双键发生了环氧化反应,而 α-甲基苯乙烯中电子丰富的 C-C 双键发生了氧化裂解,生成苯乙酮。反式二苯乙烯中的活化双键同时发生氧化裂解和环氧化反应,生成的主要产物是苯甲醛和反式二苯乙烯氧化物。二苯基乙炔中的三键经过简单的氧合反应生成苯偶姻,以及微量的环硝化产物。1-苯乙醇、咪唑、2′-脱氧腺苷和 2′-脱氧鸟苷的反应速度都相当慢,而尿嘧啶和胞嘧啶对过亚硝酸几乎没有反应。亚硝酸过氧化物所表现出的反应模式过于广泛和复杂,无法用单一的活性物种来解释整个机理途径。迄今观察到的所有过氧化亚硝酸盐反应模式可按其类型分为五类:i) 电子转移型;ii) 亲 O 电型;iii) 亲 N 电型;iv) 亲 O 核型;v) 自由基型。在某些条件下,其中一些可能会发生竞争。这些类型的反应中涉及的活性物种如下:i) NO+、NO2 和 OH;ii) ONOOH;iii) ONOOH 和 NO+;iv) OOH- 和 ONOO-;v) NO2 和 OH-。