Synthesis of 3-hydroxycyclophosphamide and studies related to its possible role in the metabolism of cyclophosphamide.
Hydrogenolysis of 3-(benzyloxy)cyclophosphamide (10) using Pd/C catalyst and ethyl acetate as solvent leads to the formation of 3-hydroxycyclophosphamide (3, approximately 20%) and cyclophosphamide (1, approximately 10%), accompanied by regioselective hydrogen-exchange reactions at the C-4 and C-5 positions in 3 and 1. A variety of oxidizing reagents and liver microsomal incubation failed to provide evidence (31P NMR) for conversion of 1 into 3, whereas identical incubation of 3 led to its reduction to 1. Compound 3 is stable at pH 6.5-8.2, 37 degrees C, and exhibits anticancer activity comparable to 1 when tested against L1210 leukemia in mice. Data are discussed with regard to a previously reported suggestion that metabolism of 1 may involved oxidation to give 3 followed by rearrangement of 3 to 2.
D000818:Animals; D000970:Antineoplastic Agents; D003520:Cyclophosphamide / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008862:Microsomes, Liver / Q000378:metabolism; D010084:Oxidation-Reduction; D051381:Rats
D000970:Antineoplastic Agents; C033255:3-hydroxycyclophosphamide; D003520:Cyclophosphamide