Cytostatic drug biotransforms

The evidence of the effect of complexation was established by the absence of an absorption band at 3191 cm (N-H stretching characteristic of a purine function in Azathioprine) e.g., the aminogroup is involved in the formation of the metal complex. The anticancer action of purine derivatives was discovered in 1949. This cytostatic drug biotransforms to 6-mercaptopurine in the body. ... 

German investigators (Brock et al) worked on the creation of alkylating pro-drugs that have cytostatic activity after specific biotransformation in the tumor tissue. Cyclophosphamide (CTX) has well pronounced antitumor activity with the broadest spectrum. It is metabolized to the cytotoxic phosphoamide mustard. In normal tissues with high enzyme level cyclophosphamide is converted to its inactive metabolites (Fig. 2). These differences in biotransformation can explain the relative selectivity of cyclophosphamide towards... 

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