[{"from": "human", "value": "Could you provide a description of this molecule? [C][#C][C][C][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][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 folate analogue inhibitor of dihydrofolate reductase (DHFR) exhibiting high affinity for reduced folate carrier-1 (RFC-1) with antineoplastic and immunosuppressive activities. Pralatrexate selectively enters cells expressing RFC-1; intracellularly, this agent is highly polyglutamylated and competes for the folate binding site of DHFR, blocking tetrahydrofolate synthesis, which may result in depletion of nucleotide precursors; inhibition of DNA, RNA and protein synthesis; and apoptotic tumor cell death. Efficient intracellular polyglutamylation of pralatrexate results in higher intracellular concentrations compared to non-polyglutamylated pralatrexate, which is more readily effuxed by the MRP (multidrug resistance protein) drug efflux pump. RFC-1, an oncofetal protein expressed at highest levels during embryonic development, may be over-expressed on the cell surfaces of various cancer cell types."}]