[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C][Branch1][Branch1][O][C][Ring1][Branch1][N][C][=C][Branch1][#Branch2][C][=Branch1][C][=O][N][C][Ring1][#Branch1][=O][F].[C][=C][Branch1][O][C][=Branch1][#Branch1][=C][N][C][Ring1][=Branch1][=O][Cl][O].[C][=Branch1][=C][=N][C][=Branch1][C][=O][N][C][=Branch1][C][=O][N][Ring1][Branch2][C][=Branch1][C][=O][O-1].[K+1]"}, {"from": "gpt", "value": "The molecule is an orally bioavailable fluoropyrimidine antagonist composed of tegafur combined with two modulators of 5-fluorouracil (5-FU) activity, gimeracil and potassium oxonate, in a molar ratio of 1:0.4:1. Tegafur is a prodrug of 5-fluorouracil, an antimetabolite that inhibits thymidylate synthase, DNA synthesis and cell division, and competes with uridine triphosphate, thus inhibiting RNA and protein synthesis. Gimeracil is a reversible inhibitor of dihydropyrimidine dehydrogenase (DPD), the liver enzyme responsible for rapid catabolism of 5-FU into inactive metabolites. Potassium oxonate preferentially localizes in the gut and inhibits the enzyme orotate phosphoribosyl-transferase (OPRT), thereby decreasing activation of 5-FU in the gut and activated 5-FU-related gastrointestinal toxicity."}]