Phosphorus-31 NMR studies of the kinetics of bisalkylation by isophosphoramide mustard: comparisons with phosphoramide mustard
摘要:
31P nuclear magnetic resonance spectroscopy was used to measure the pKa (4.28 +/- 0.2) of isophosphoramide mustard (IPM) at 20 degrees C and to study the kinetics and products of the decomposition of IPM at a solution pH value of ca. 7.4 and at temperatures between 20 and 47 degrees C in the presence of nucleophilic trapping agents. At 37 degrees C, the half-life for the first alkylation was ca. 77 min and ca. 171 min for the second alkylation; these data may be compared with those for phosphoramide mustard (Engle, T.W.; Zon, G.; Egan, W.J. Med. Chem. 1982, 25, 1347), wherein the half-lives for the first and second alkylations are approximately the same (18 min). The rate of fragmentation of aldoifosfamide to IPM and acrolein was also studied by NMR spectroscopy (pH 7.0; 37 degrees C; 0.07 M phosphate); under the noted conditions, the half-life of aldoifosfamide was found to be ca. 60 min.
Racemic mixtures and laevorotatory enantiomers of cis- and trans-4-hydroperoxyifosfamide and 4-hydroperoxybromofosfamide possess high antitumour activity both in vitro and in vivo. However, no major differences in biological activity were observed among these stereoisomers. (C) 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.
Takamizawa,A. et al., Heterocycles, 1977, vol. 7, p. 1091 - 1130
作者:Takamizawa,A. et al.
DOI:——
日期:——
Synthesis, stereochemistry and antitumor activity of 4-hydroperoxyisophosphamide (NSC-227114) and related compounds.
4-Hydroperoxyisophosphamide and its analogues were simply synthesized by ozonolysis reactions of O-(3-butenyl)-N, N'-bis (2-chloroethyl) phosphorodiamidate and related O-(3-butenyl) phosphoramidates. An acid-catalyzed isomerization of 4-hydroperoxyisophosphamide proceeded with inversion of its phosphorus configuration giving 2-epi-4-hydroperoxyisophosphamide. Both isomers readily afforded C4-substituted isophosphamide derivatives by reactions with nucleophilic agents and acid. L1210 antileukemic activities were tested for the isomers and some analogues revealing that the C4-hydroperoxylation of isophosphamide resulted in a marked enhancement of its activity and that the inverted stereochemistry of an alkylating functionality at the phosphorus atom is also effective in promoting the antitumor action as an alternative activated species of isophosphamide.
Phosphorus-31 NMR studies of the kinetics of bisalkylation by isophosphoramide mustard: comparisons with phosphoramide mustard
作者:Jila H. Boal、Margaret Williamson、Victoria L. Boyd、Susan M. Ludeman、William Egan
DOI:10.1021/jm00128a018
日期:1989.8
31P nuclear magnetic resonance spectroscopy was used to measure the pKa (4.28 +/- 0.2) of isophosphoramide mustard (IPM) at 20 degrees C and to study the kinetics and products of the decomposition of IPM at a solution pH value of ca. 7.4 and at temperatures between 20 and 47 degrees C in the presence of nucleophilic trapping agents. At 37 degrees C, the half-life for the first alkylation was ca. 77 min and ca. 171 min for the second alkylation; these data may be compared with those for phosphoramide mustard (Engle, T.W.; Zon, G.; Egan, W.J. Med. Chem. 1982, 25, 1347), wherein the half-lives for the first and second alkylations are approximately the same (18 min). The rate of fragmentation of aldoifosfamide to IPM and acrolein was also studied by NMR spectroscopy (pH 7.0; 37 degrees C; 0.07 M phosphate); under the noted conditions, the half-life of aldoifosfamide was found to be ca. 60 min.