The synthesis and hydrolysis of a series of deoxyfluoro-d-glucopyranosyl phosphates
作者:Stephen G. Withers、David J. MacLennan、Ian P. Street
DOI:10.1016/s0008-6215(00)90028-4
日期:1986.10
for α- d -glucopyranosyl phosphate and the 2-, 3-, 4- and 6-deoxyfluoro derivatives, respectively. The hydrolysis of 2-deoxy-2-fluoro-α- d -glucopyranosyl phosphate was studied in more detail, and an activation entropy and enthalpy of 4.1 e.u. ( m reactant) and 113.5 kJ.mol −1 , respectively, were determined for hydrolysis in m HClO 4 at 60° The pH dependence of its hydrolysis was investigated, and rate
摘要描述了全部四种脱氧氟-α-d-吡喃葡萄糖基磷酸酯的合成。确定了其酸催化水解的速率常数,并且显示出氟取代在降低速率方面具有显著作用,特别是当取代邻近异头中心时。在25℃下在m HClO 4中测量的相对速率常数对于α-d-吡喃葡萄糖基磷酸酯和2-,3-,4-和6-脱氧氟衍生物分别为60.30:1.00:7.05:3.97:16.5。详细研究了2-脱氧-2-氟-α-d-吡喃葡萄糖基磷酸酯的水解,确定了4.1 eu(m反应物)和113.5 kJ.mol -1的活化熵和焓。在60°m HClO 4中的溶液中,研究了其水解的pH依赖性,并测定了单阴离子水解的速率常数(k M = 1。因此,提取了88×10 -6 s -1)和中性(k N = 6.23×10 -5 s -1)的物种。如所预期的,单阴离子的水解不受氟取代的显着影响。根据这些发现,合理化了几种机械上不同的酶利用这些氟化底物的能力或无能为力。