Pimecrolimus

White to beige powder. Soluble in DMSO (20mg/ml), DMF (20mg/ml) or ethanol (20mg/ml). Chemical. CAS: 137071-32-0. Formula: C43H68ClNO11. MW: 810.45. Synthetic. Pimecrolimus is a immunosuppressive natural ascomycin macrolactam that binds to macrophilin-12 (FKBP-12) and inhibits calcineurin as well as prolyl isomerase (rotamase). Presumably through these actions, it blocks the activation of T cells by allogeneic dendritic cells (IC50=0.55nM) without affecting dendritic cells. Moreover, pimecrolimus suppresses the generation of pro-inflammatory cytokines by T cells, the release of pre-formed inflammatory mediators from mast cells and the activation of eosinophils. These effects support the use of pimecrolimus in countering inflammatory skin diseases, such as atopic dermatitis (eczema) and psoriasis.