[{"from": "human", "value": "Please give me some details about this molecule. [C][C][=C][Branch1][=Branch1][C][=N][O][Ring1][Branch1][C][=Branch1][C][=O][N][C][=C][C][=C][Branch1][Branch1][C][=C][Ring1][=Branch1][C][Branch1][C][F][Branch1][C][F][F]"}, {"from": "gpt", "value": "The molecule is a derivative of isoxazole used for its immunosuppressive and anti-inflammatory properties.  As a prodrug, leflunomide is converted to an active metabolite, A77 1726, which blocks dihydroorotate dehydrogenase, a key enzyme of de novo pyrimidine synthesis, thereby preventing the expansion of activated T lymphocytes.  This agent also inhibits various protein tyrosine kinases, such as protein kinase C (PKC), thereby inhibiting cell proliferation. (NCI04)"}]