Introduction of Z-GP scaffold into procarbazine reduces spermatoxicity and myelosuppression

Incorporation of carbobenzoxy-glycylprolyl (Z-GP) to either α or β position of the hydrazine moiety in procarbazine (Pcb) has been carried on in 5-steps process. The overall yield was 32.7%. The new entity Z-GP-Pcb was confirmed targeting to fibroblast activation protein-α (FAPα). Z-GP-Pcb may be hydrolyzed by either isolated rhFAPα or tumor homogenate. It was shown far less cytotoxicity against NCI-H460 cell line than Pcb. Z-GP-Pcb was displayed the potency to reduce spermatoxcity in H22-bearing mice. The mechanism may be ascribed to the blockade of dehydrogenation by α-glycerolphosphate dehydrogenase. This candidate was further proved equal antitumor activity to Pcb. However, the introduction of Z-GP scaffold decreased myelosuppression. All the evidences support that Z-GP-Pcb is a better antitumor agent than Pcb.     

Cytochrome P-450- and Peroxidase-Dependent Activation of Procarbazine and Iproniazid in Mammalian Cells

Metabolism of hydrazine derivatives, procarbazine and iproniazid, to reactive free radical intermediates has been studied using spin-trapping techniques in intact human promyelocytic leukemia (HL60) and mouse hepatic cell lines. While HL60 cells have been shown to contain both myeloperoxidase and cytochrome P-450 enzymes, the hepatic cell line shows only cytochrome P-450 activity. Both peroxidases and cytochrome P-450 have been reported to catalyze biotransformation of hydrazines. Procarbazine and iproniazid were rapidly metabolized in these cell lines to methyl and isopropyl radicals, respectively. However, in HL60 cells, procarbazine was metabolized by myeloperoxidase while iproniazid was metab olized mostly by the cytochrome P-450 system. In the hepatic cells, both of these compounds were metabolized by the P-450 system.     

Cytochrome P-450- and Peroxidase-Dependent Activation of Procarbazine and Iproniazid in Mammalian Cells

Metabolism of hydrazine derivatives, procarbazine and iproniazid, to reactive free radical intermediates has been studied using spin-trapping techniques in intact human promyelocytic leukemia (HL60) and mouse hepatic cell lines. While HL60 cells have been shown to contain both myeloperoxidase and cytochrome P-450 enzymes, the hepatic cell line shows only cytochrome P-450 activity. Both peroxidases and cytochrome P-450 have been reported to catalyze biotransformation of hydrazines. Procarbazine and iproniazid were rapidly metabolized in these cell lines to methyl and isopropyl radicals, respectively. However, in HL60 cells, procarbazine was metabolized by myeloperoxidase while iproniazid was metab olized mostly by the cytochrome P-450 system. In the hepatic cells, both of these compounds were metabolized by the P-450 system.