Synthesis and Properties of Diuridine Phosphate Analogues Containing Thio and Amino Modifications
作者:James B. Thomson、Bhisma K. Patel、Victor Jiménez、Klaus Eckart、Fritz Eckstein
DOI:10.1021/jo960795l
日期:1996.1.1
pH 9, indicating that attack on the phosphorus by the 2'-oxo anion is rate-limiting in the hydrolysis mechanism. In contrast, the rate of uridylyl (3'-5') 5'-amino-5'-deoxyuridine (UpnU) hydrolysis fell from a value of 1802 x 10(-)(6) s(-)(1) at pH 5 to 140 x 10(-)(6) s(-)(1) at pH 7.5, where it remained constant up to pH 11.5, thus indicating an acid-catalyzed reaction. The analogue 2'-amino-2'-deoxyuridylyl
为了研究为什么用2'-氨基取代2'-羟基会阻止水解,合成了磷酸二尿苷(UpU)的几种类似物。设计这些类似物以研究2'-取代基和5'-离去基团对水解速率的影响。所有类似物都比UpU对酸碱催化的水解更加不稳定。在6到9的pH范围内,尿嘧啶(3'-5')5'-硫代5'-脱氧尿苷(UpsU)的水解速率以对数线性方式从5 x 10的值上升。 (-)(6)s(-)(1)在pH 6到3200 x 10(-)(6)s(-)(1)在pH 9时,表明2'-氧代阴离子对磷的攻击在水解机理中是限速的。相反,尿酸(3'-5')5'-氨基-5'的比率 -脱氧尿苷(UpnU)水解从pH 5的1802 x 10(-)(6)s(-)(1)降至pH 7.5的140 x 10(-)(6)s(-)(1) ,在高达11.5的pH值下保持恒定,因此表明是酸催化的反应。与amUpT的水解稳定性相反,类似物2'-氨基-2'-脱氧尿苷(3