[{"from": "human", "value": "Could you give me 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]"}, {"from": "gpt", "value": "The molecule is a prodrug of [DB00544] (5-FU), an antineoplastic agent used as the treatment of various cancers such as advanced gastric and colorectal cancers. It is a pyrimidine analogue used in combination therapies as an active chemotherapeutic agent in conjunction with [DB09257] and [DB03209], or along with [DB00544] as [DB09327]. Tegafur is usually given in combination with other drugs that enhance the bioavailability of the 5-FU by blocking the enzyme responsible for its degradation, or serves to limit the toxicity of 5-FU by ensuring high concentrations of 5-FU at a lower dose of tegafur. When converted and bioactivated to 5-FU, the drug mediates an anticancer activity by inhibiting thymidylate synthase (TS) during the pyrimidine pathway involved in DNA synthesis. 5-FU is listed on the World Health Organization's List of Essential Medicines."}]