[{"from": "human", "value": "Provide a brief overview of this molecule. [C][C][C@@H1][/C][=C][Branch2][#Branch1][#C][\\C][C@@H1][Branch2][#Branch1][=Branch2][C][C@@H1][Branch2][#Branch1][C][C@@H1][C@H1][Branch2][=Branch1][O][C][C@H1][Branch2][=Branch1][Branch1][C@@][Branch1][Ring2][O][Ring1][=Branch1][Branch2][Branch1][O][C][=Branch1][C][=O][C][=Branch1][C][=O][N][C][C][C][C][C@H1][Ring1][=Branch1][C][=Branch1][C][=O][O][C@@H1][Branch1][#C][C@@H1][Branch1][O][C@H1][Branch1][#Branch1][C][C][Ring2][Ring1][#C][=O][O][C][/C][=Branch1][P][=C][/C@@H1][C][C][C@@H1][Branch1][=Branch2][C@@H1][Branch1][Ring2][C][Ring1][=Branch1][O][C][Cl][/C][O][C][O][C][O][C][C][/C]"}, {"from": "gpt", "value": "The molecule is a 33-epi-chloro-derivative of the ascomycin macrolactam with immunosuppressant property. Pimecrolimus binds to the receptor macrophilin-12 (FKBP-12) forming a complex that blocks the calcium-dependent signal transduction cascade mediated by calcineurin. Via dephosphorylation, calcineurin is the enzyme responsible for activating nuclear factor of activated T-cells (NF-AT), a T cell transcriptional regulatory factor. As a consequence, the synthesis and release of Th1- (T helper 1) and Th2- (T helper 2) type cytokines, and other inflammatory mediators from T-cells and mast cells are blocked and the expression of signals essential for the activation of inflammatory T-lymphocytes is inhibited. However, pimecrolimus mode of action is cell-selective and does not affect Langerhans' cells/dendritic cells and primary fibroblasts."}]