[{"from": "human", "value": "Please give me some details about this molecule. [C][C][Branch2][Ring1][Branch2][N][Branch2][Ring1][C][C][=C][Branch1][Ring2][N][Ring1][=Branch1][N][=C][Branch1][=Branch1][N][C][Ring1][#Branch1][=O][N][C][=O][C][N][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][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 derivative of folic acid with chemoprotectant, antidote and synergistic activity. Leucovorin does not require metabolism by dihydrofolate reductase, the molecular target of folate antagonist-type chemotherapeutic drugs, and is converted to a tetrahydrofolate, which is the necessary folate for purine and pyrimidine synthesis. As this agent allows for some purine/pyrimidine synthesis to occur, the toxic effects of folic acid antagonist-type chemotherapeutic drugs are counteracted while still permitting the antitumor activity of the folic acid antagonist through dihydrofolate reductase inhibition. This agent also potentiates the effects of 5-fluorouracil and its derivatives by stabilizing the binding of 5-fluorouracil's converted form fluorodeoxyuridylic acid to its target enzyme thymidylate synthase, thus prolonging drug activity."}]