Antimetabolite

Antimetabolites are chemical compounds that resemble the natural metabolite in their chemical structure, but whose pathway inhibit (inhibitor ). Result is a disruption of the normal enzyme function in a metabolic pathway or biological process. Antimetabolites can be effective cytostatics ( disturbed process: mitosis) or, for example immunosuppressants ( disturbed process: immune response).

They usually displace the reacted metabolites from the active site of the enzymes, but can not usually due to the structure difference be implemented (competitive inhibition). Will they yet implemented, they lead to an accumulation of undesirable substances present in free form or incorporated into macromolecules. This also leads to malfunctions or even the death of the cell.

Many antimetabolite are chemical analogues of amino acids ( such as azaserine ) or base analogs of DNA. The effect of some antibiotics (for example, puromycin ) is based on the principle.

• Folic acid antagonists: methotrexate, pemetrexed
• Purine and Purinnucleosidanaloga: 6- mercaptopurine, 6 -thioguanine
• Pyrimidine and Pyrimidinnucleosidanaloga: fluorouracil, cytarabine, gemcitabine, tegafur, capecitabine