[{"from": "human", "value": "Provide a description of this molecule. [C][N][Branch2][Ring1][Branch2][C][C][=C][N][=C][C][=Branch1][Ring2][=N][Ring1][=Branch1][C][=Branch1][=Branch2][=N][C][=Branch1][Ring2][=N][Ring1][#Branch1][N][N][C][=C][Branch2][Ring1][=C][C][=C][Branch1][=Branch1][C][=C][Ring1][=Branch1][Cl][C][=Branch1][C][=O][N][C@@H1][Branch1][Branch2][C][C][C][=Branch1][C][=O][O][C][=Branch1][C][=O][O][Cl]"}, {"from": "gpt", "value": "The molecule is a chlorinated methotrexate derivative.  Dichloromethotrexate inhibits the enzyme dihydrofolate reductase, thereby preventing the synthesis of purine nucleotides and thymidylates and inhibiting DNA and RNA synthesis.  This agent is metabolized and excreted by the liver. (NCI04)"}]