General base catalysis vs. medium effects in the hydrolysis of an RNA modelElectronic supplementary information (ESI) available: tables of primary kinetic data and derived rate constants. See http://www.rsc.org/suppdata/p2/b1/b109325h/
作者:Anthony J. Kirby、Robert E. Marriott
DOI:10.1039/b109325h
日期:2002.2.25
effects. Results are reported for the hydrolysis of 4-nitrophenoxymethyl uridine 3′-phosphate, which releases the chromophoric p-nitrophenolate on cleavage of the P–OCH2OAr bond. In the case of catalysis by imidazole, a bell-shaped dependence on the buffer ratio is explained in terms of a solvent effect on the background, hydroxide-catalysed reaction. Results for six other amine bases with pKa = 7 ±
的解释 缓冲 催化数据总是存在一定程度的不确定性,因为改变催化剂的浓度 催化剂必然改变媒介。的历史咪唑的催化反应 核糖核苷酸衍生物是潜在问题的经典例证,由于对离子强度和特定盐效应的显着敏感性,这些问题进一步复杂化。报道了4-硝基苯氧基甲基尿苷3'-磷酸的水解结果,该水解在P-OCH 2 OAr键断裂时释放发色性对硝基苯酚盐。在催化的情况下咪唑,对钟形的依赖 缓冲 比率用 溶剂 对背景的影响 氢氧化物-催化反应。其他六个结果胺p K a = 7±1的基数表明,在该系统中,非线性行为是准则,而非例外。