[{"from": "human", "value": "Could you give me a brief overview of this molecule? [C][=C][C][=Branch2][Ring1][O][=C][C][=C][Ring1][=Branch1][C][C][C][=C][N][C][=C][Ring1][Branch1][C][=Branch1][C][=O][N][C][=Branch1][Ring2][=N][Ring1][#Branch1][N][C][=Branch1][C][=O][N][C@@H1][Branch1][Branch2][C][C][C][=Branch1][C][=O][O][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule 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."}]