ascomycin

Ascomycin is a macrocyclic lactone and a structural analog of tacrolimus, originally isolated from *Streptomyces hygroscopicus*. It is produced by Shandong Freda Biotech as a pharmaceutical intermediate, primarily for the synthesis of other immunosuppressive agents such as pimecrolimus. Ascomycin exerts its effect by binding to the intracellular receptor FKBP12 (FK506-binding protein). The resulting ascomycin-FKBP12 complex specifically binds to and inhibits calcineurin, a calcium-dependent protein phosphatase. This inhibition blocks the dephosphorylation of the nuclear factor of activated T-cells (NFAT), preventing its translocation into the nucleus and subsequent transcription of pro-inflammatory cytokines like interleukin-2 (IL-2). While it possesses intrinsic immunosuppressive and antifungal properties, its primary commercial role in this context is as a high-purity precursor for pharmaceutical manufacturing.

Other names

Immunomycin21-ethyl-FK506