ChEBI: Pemetrexed is an N-acylglutamic acid in which the N-acyl group is specified as 4-[2-(2-amino-4-oxo-4,7-dihydro-1H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoyl. Inhibits thymidylate synthase (TS), 421 dihydrofolate reductase (DHFR), and glycinamide ribonucleotide formyltransferase (GARFT). It has a role as an antineoplastic agent, an antimetabolite, an EC 2.1.1.45 (thymidylate synthase) inhibitor, an EC 1.5.1.3 (dihydrofolate reductase) inhibitor and an EC 2.1.2.2 (phosphoribosylglycinamide formyltransferase) inhibitor. It is a pyrrolopyrimidine and a N-acyl-L-glutamic acid. It is a conjugate acid of a pemetrexed(2-).NCI Thesaurus (NCIt): Pemetrexed is 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.