关于氯乙醛与某些tRNA成分反应的新观察结果。反应的稳定中间体、动力学和选择性。
New observations concerning the chloroacetaldehyde reaction with some tRNA constituents. Stable intermediates, kinetics and selectivity of the reaction.
作者信息
Biernat J, Ciesiołka J, Górnicki P, Adamiak R W, Kryzosiak W J, Wiewiórowski M
出版信息
Nucleic Acids Res. 1978 Mar;5(3):789-804. doi: 10.1093/nar/5.3.789.
The stable intermediates formed in the reaction of cytosine, cytidine and adenosine with chloracetaldehyde were isolated. The -CH2CH/OH/- bridge between the exo and endo nitrogen atoms of the parent base was found in these compounds by means of PMR spectroscopy. Their acid-induced dehydration resulted in formation of appropriate ethenoderivatives. The rate constants of the intermediate formation and its dehydration were found to be 38x10(-4) and 47x10(-4) /min-1/ for adenosine, and 33x10(-4) and 10x10(-4) /min-1/ for cytidine. The PH range of 4.5--5.0 was found to be optimum for both adenosine and cytidine reactions. The quantitative modification of these two nucleosides in the presence of guanosine may be achieved with high selectivity only at a low pH of 3.0--4.0 N6-methyladenosine and N4-methylcytidine react quantitatively with chloroacetaldehyde and the reaction rate is higher than in the case of the parent nucleosides. The structure of the reaction products was assigned on the basis of PMR spectroscopy.
分离出了胞嘧啶、胞苷和腺苷与氯乙醛反应形成的稳定中间体。通过核磁共振氢谱（PMR光谱）在这些化合物中发现了母体碱基外环和内环氮原子之间的-CH2CH/OH/-桥。它们在酸诱导下脱水生成相应的乙烯基衍生物。腺苷形成中间体及其脱水的速率常数分别为38×10⁻⁴和47×10⁻⁴ /min⁻¹，胞苷的则为33×10⁻⁴和10×10⁻⁴ /min⁻¹。发现4.5 - 5.0的pH范围对腺苷和胞苷的反应都是最佳的。只有在3.0 - 4.0的低pH值下，鸟苷存在时这两种核苷的定量修饰才能以高选择性实现。N⁶-甲基腺苷和N⁴-甲基胞苷与氯乙醛定量反应，且反应速率高于母体核苷。根据核磁共振氢谱（PMR光谱）确定了反应产物的结构。
Zotero 插件