Mechanism of the Nitrosation of Thiols and Amines by Oxygenated <sup>•</sup>NO Solutions: the Nature of the Nitrosating Intermediates
作者:Sara Goldstein、Gidon Czapski
DOI:10.1021/ja9536680
日期:1996.1.1
the autoxidation of •NO, indicating that the rate of the autoxidation of •NO is unaffected by the presence of thiols and amines. The nitrosation by •NO takes place only in the presence of oxygen, and therefore the rate of the formation of S-nitrosothiols from thiols and oxygenated •NO solution is relatively slow in biological systems. Under physiological conditions where [•NO] < 1 μM and ...
研究了生理 pH 值下含氧•NO 溶液对各种硫醇和吗啉的亚硝化作用。使用停流技术测定亚硝基化合物的形成速率和产率。该过程的化学计量已确定,由 4•NO + O2 + 2RSH/2RR'NH → 2RSNO/2RR'NNO + 2NO2- + 2H+ 给出。动力学研究表明,速率定律是-d[O2]/dt = k1[•NO]2[O2],其中k1 = (2.54 ± 0.26) × 106 M-2 s-1 和-d[•NO]/dt = 4k1[•NO]2[O2],其中 4k1 = (1.17 ± 0.12) × 107 M-2 s-1,与存在的底物类型无关。动力学结果与•NO 的自氧化得到的结果相同,表明•NO 的自氧化速率不受硫醇和胺的存在的影响。•NO 的亚硝化作用仅在氧气存在下发生,因此,在生物系统中,硫醇和氧化•NO 溶液形成S-亚硝基硫醇的速率相对较慢。在生理条件下 [•NO] < 1 μM