Definition

The disodium salt of a synthetic pyrimidine-based antifolate. Pemetrexed binds to and inhibits the enzyme thymidylate synthase (TS) which catalyses the methylation of 2′-deoxyuridine-5′-monophosphate (dUMP) to 2′-deoxythymidine-5′-monophosphate (dTMP), an essential precursor in DNA synthesis.