as cis-2 were much faster in plasma than in buffer. The cis-trans isomerization of cis-5 occurred by a specific-base-catalyzed process via iminocyclophosphamide (8) as a transient intermediate. In contrast, formation of cis- and trans-mafosfamide (5) from cis-2 and MESNA (sodium 2-mercaptoethanesulfonate) proceeded by an acid-catalyzed process via the hemithioacetal intermediate (6). The significance
顺式-Mafosfamide(顺式5)(ASTA Z7557)是顺式
4-羟基环
磷酰胺(顺式2)的稳定类似物,在pH 7.4和37℃的
磷酸盐
水溶液或血浆中快速分解。顺式的反应动力学-5是复杂的,会生成反式
磷酰胺(trans-5)和cis-2,随后在反应过程中消失。血浆中cis-5和cis-2的分解速率比在缓冲液中快得多。顺式5的顺反异构化是通过亚
氨基环
磷酰胺(8)作为过渡中间体通过特定碱催化的过程发生的。相反,由顺式2和
MESNA(2-巯基
乙磺酸钠)形成的顺式和反式
磷酰胺(5)是通过酸催化的过程经由半
硫缩醛中间体(6)进行的。