Effects of N-substitution on the activation mechanisms of 4-hydroxycyclophosphamide analogs
作者:Chul Hoon Kwon、Richard F. Borch
DOI:10.1021/jm00127a016
日期:1989.7
which can reclose to the cis- or trans-4-hydroxy isomers or undergo base-catalyzed beta-elimination to generate the corresponding phosphoramide mustard products 4. In contrast to the general acid catalysis observed for ring opening of 2a and 2d, the N-(chloroethyl)-substituted analogues 2b and 2c undergo specific base-catalyzed ring opening. This mechanistic difference was also illustrated by the rapid
比较了N-取代的4-羟基环磷酰胺类似物4-羟基异磷酰胺(2b),4-羟基三磷酰胺(2c)和3-甲基-4-羟基环磷酰胺(2d)的活化机理与未取代的母体化合物2a的活化机理。顺式2b,-2c和-2d的反应动力学与2a的反应动力学在质量上相似,因为它们分别对相应的醛磷酸酰胺中间体3进行开环反应,该中间体可以与顺式或反式-4-羟基异构体重合或经历碱催化的β-消除反应生成相应的磷酰胺芥末产物4。与2a和2d开环观察到的一般酸催化相反,N-(氯乙基)取代的类似物2b和2c经历了特定的碱催化开环。通过在酸性条件下2a和2d与2-巯基乙磺酸钠(Mesna)的快速反应,得到了4-(烷硫基)取代的环磷酰胺衍生物5a和5d,也说明了这种机理上的差异。在这些条件下,化合物2b和2c不会与Mesna反应生成5b和5c。处于平衡状态的醛/水合物分数和体外对L1210细胞的细胞毒性均以大于2c大于2b大于2a大于2d的