NMR spectroscopic studies of intermediary metabolites of cyclophosphamide. A comprehensive kinetic analysis of the interconversion of cis- and trans-4-hydroxycyclophosphamide with aldophosphamide and the concomitant partitioning of aldophosphamide between irreversible fragmentation and reversible conjugation pathways
作者:Gerald Zon、Susan Marie Ludeman、Joan A. Brandt、Victoria L. Boyd、Gunay Ozkan、William Egan、Kai Liu Shao
DOI:10.1021/jm00370a008
日期:1984.4
and 7.8 were equal to 0.030 +/- 0.004, 0.090 +/- 0.008, and 0.169 +/- 0.006 min-1, respectively. Replacement of the HC(O)CH2 moiety n 3 with HC(O)CD2 led to a primary kinetic isotope effect (kH/kD = 5.6 +/- 0.4) for k3. The apparent half-lives (tau 1/2) for cis-2, "3", and trans-2 under the standard reaction conditions, at "pseudoequilibrium" (constant ratio of cis-2/"3"/trans-2), were each equal to approximately
多核(31P,13C,2H和1H)傅立叶变换NMR光谱,无论有没有同位素富集的材料,都被用来鉴定和量化抗癌前药的以下中间(短时)代谢产物(随时间变化)环磷酰胺(1,方案I):顺式-4-羟基环磷酰胺(cis-2),其反式异构体(trans-2),醛基磷酰胺(3)和其醛-水合物(5)。在一组标准反应条件下(1 M 2,6-二甲基吡啶缓冲液,pH 7.4,37摄氏度),用4当量的硫代硫酸钠(4当量)合成顺式4-氢过氧环磷酰胺(顺式12,20 mM)的立体定向脱氧Na2S2O3)在大约20分钟后提供了cis-2、3、5和trans-2的“伪平衡”分布,即这些反应物的相对比例(57:4:9:30,在持续消失的过程中保持不变。没有检测到指示“亚氨基磷酰胺”(8)和烯醇6的NMR吸收信号(少于合成代谢物混合物的0.5-1%)。将计算机最小二乘拟合程序应用于各个31P NMR衍生的时间过程,以将cis-2、3加5(即“