Identification of aldophosphamide as a metabolite of cyclophosphamide in vitro and in vivo in humans.

Aldophosphamide (NSC 254), a putative key metabolite of cyclophosphamide, has now been isolated as a cyanohydrin derivative from an incubation mixture of cyclophosphamide with mouse liver microsomes in vitro and from the plasma of a cyclophosphamide-treated patient. The cyanohydrin has been shown to be identical with an authenic synthetic sample by mass spectrometry and combined gas chromatography-mass spectrometry.