Antimetabolites, Antineoplastic

Antimetabolites are compounds that are structurally similar to normal metabolites or coenzymes. Their main action is to combine with the enzymes necessary for the synthesis of normal metabolites, thereby interfering with the synthesis of nucleic acids and inhibiting the growth and proliferation of tumor cells. Some antimetabolites have feedback inhibition that can blocks the synthesis of metabolite precursors. The main anti-metabolites are anti-folic acid, anti-purine and anti-pyrimidine, acting on the cell S, and belong to the cell cycle-specific drugs. As there is no significant difference between the tumor tissue and normal tissue metabolism process, so the anti-metabolite has poor selectivity and are quite toxic for the proliferated-faster normal tissues, such as bone marrow, gastrointestinal mucosa, reproductive system and hair . Although most of the anti-metabolites inhibit cell DNA synthesis, their role points are different, so the anti-metabolites generally don’t have the cross-resistance for each other.

---