65882-95-3Relevant academic research and scientific papers
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 ...
Zon, Gerald,Ludeman, Susan Marie,Brandt, Joan A.,Boyd, Victoria L.,Oezkan, Gunay,et al.
, p. 466 - 485 (2007/10/02)
Multinuclear (31P, 13C, 2H, and 1H) Fourier-transform NMR spectroscopy, with and without isotopically enriched materials, was used to identify and quantify, as a function of time, the following intermediary (short-lived) metabolites of the anticancer prodrug cyclophosphamide (1, Scheme I): cis-4-hydroxycyclophosphamide (cis-2), its trans isomer (trans-2), aldophosphamide (3), and its aldehyde-hydrate (5).Under a standard set of reaction conditions (1 M 2,6-dimethylpyridine buffer, pH 7.4, 37 deg C), the stereospecific deoxygenation of synthetic cis-4-hydroperoxycyclophosphamide (cis-12, 20 mM) with 4 equiv of sodium thiosulfate (Na2S2O3) afforded, after ca.20 min, a "pseudoequilibrium" distribution of cis-2, 3, 5, and trans-2, i.e., the relative proportions of these reactants (57:4:9:30, respectively) remained constant during their continual disappearance.NMR absorption signals indicative of "iminophosphamide" (8) and enol 6 were not detected ( "3" trans-2, as well as the rate constant (k3) for the irreversible fragmentation of 3.The values of k3 at pH 6.3, 7.4, 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 in 3 with HC(O)CD2 led to a primary kinetic isotope effect (kH/kD = 5.6 +/- 0.4) for k3.The apparent half-lives (τ*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 ca.38 min, which is considerably shorter than the widely cited colorimetrically derived half-lives reported by earlier investigators.The values of τ*1/2 for cis-2, "3", and trans-2 were affected by pH in the same manner as that found for k3 but were relatively insensitive to the presence of either K(+), Na(+), Ca(2+), or Mg(2+).The presence of certain primary amines led to marked decreases in τ*1/2 and, in some cases, the formation of acyclic adducts of aldehyde 3.The relatively stable adduct formed from 3 and tris(hydroxymethyl)aminomethane (Tris) at pH 7.4 and 37 deg C gave rise to a 31P NMR signal that other investigators have mistakenly ascribed to 2. 31P NMR spectroscopy was also used to examine, in considerable detail, the manifold effects of N-acetyl-L-cysteine upon the chemistry of 2, "3", and 4, which featured the formation of a mixture of diastereomeric, acyclic ...
Mass spectrometric characterization of activated N-(2-chloroethyl)amino oxazaphosphorine derivative.
Przybylski,Ringsdorf,Lenssen,Peter,Voelcker,Wagner,Hohorst
, p. 209 - 215 (2007/10/08)
The hydroperoxy and several alkylthio derivatives of the antitumor agents cyclophosphamide (2-bis(2-chloroethyl)amino tetrahydro-2H-1,3,2-oxazaphosphorine 2-oxide), ifosfamide (3-(2-chloroethyl)-2-(2-chloroethylamino)tetrahydro-2H-1,3,1-oxazaphosphorine 2-oxide) and trofosfamide (3-(2-chloroethyl)-2-(bis(2-chloroethyl)amino)tetrahydro-2H-1,3,2-oxazaphosphorine 2-oxide) were characterized by electron impact and field desorption mass spectrometry. The compounds, which are stabilized derivatives of the activated hydroxylated intermediates of cyclophosphamide (ifosfamide, trofosfamide), could be identified as 4-hydroperoxy and 4-alkylthio oxazaphosphorines. The existence of diastereomers of these products was demonstrated by thin-layer chromatography and f.d. mass spectra. Derivatization with benzylmercaptan was found to be an appropriate method for the quantitative isolation and mass spectral identification of the activated metabolic intermediates of cyclophosphamide from biological material. Using this reaction, 4-hydroxycyclophosphamide and its acyclic tautomer, aldophosphamide, which are too unstable for direct identification, were detected in urine and serum of patients treated with 3H-cyclophosphamide.
