FK-506

FK-506 is a potent immunosuppressant in the same molecular class as cyclosporin A (Cay-12088) and rapamycin (Cay-13346). Its mechanism of action involves the formation of a high affinity complex (Ki = 0.2 nM) with FK-506 binding protein 12 (FKBP12). This complex then inhibits the activity of the calcium/calmodulin-dependent protein phosphatase, calcineurin, leading to disruption of T cell activation. The physiological effects of FK-506 also include regulation of nitric oxide neurotoxicity, neurotransmitter release, and regulation of Ca2+ release via the ryanodine and inositol-(1,4,5)-trisphosphate (IP3) receptors. In the latter case, FKBP12 forms a tight complex with both ryanodine and IP3 receptors which can be disrupted by FK-506, thereby rendering the receptors leaky to Ca2+.Formal Name: (3S,4R,5S,8R,9E,12S,14S,15R,16S,18R,19R,26aS)-5,6,8,11,12,13,14,15,16,17,18,19,24,25,26,26a-hexadecahydro-5,19-dihydroxy-3-[(1E)-2-[(1R,3R,4R)-4-hydroxy-3-methoxycyclohexyl]-1-methylethenyl]-14,16-dimethoxy-4,10,12,18-tetramethyl-8-(2-propen-1-yl)-15,19-epoxy-3H-pyrido[2,1-c][1,4]oxaazacyclotricosine-1,7,20,21(4H,23H)-tetrone. CAS Number: 104987-11-3. Synonyms: Tacrolimus. Molecular Formula: C44H69NO12. Formula Weight: 804.0. Purity: >99%. Formulation: (Request formulation change), A crystalline solid. Solubility: DMF: 30 mg/ml, DMSO: 20 mg/ml, Ethanol: 30 mg/ml, Ethanol:PBS (pH 7.2)(1:5): .15 mg/ml. SMILES: O=C([C@@](CCCC1)([H])N1C(C([C@@]2(O)[C@H](C)C[C@H](OC)[C@@](O2)([H])[C@@H](OC)C[C@@H](C)C/C(C)=C/[C@H]3CC=C)=O)=O)O[C@H](/C(C)=C/[C@H]4C[C@@H](OC)[C@H](O)CC4)[C@H](C)[C@@H](O)CC3=O. InChi Code: InChI=1S/C44H69NO12/c1-10-13-31-19-25(2)18-26(3)20-37(54-8)40-38(55-9)22-28(5)44(52,57-40)41(49)42(50)45-17-12-11-14-32(45)43(51)56-39(29(6)34(47)24-35(31)48)27(4)21-30-15-16-33(46)36(23-30)53-7/h10,19,21,26,28-34,36-40,46-47,52H,1,11-18,20,22-24H2,2-9H3/b25-19+,27-21+/t26-,28+,29+,30-,31+,32-,33+,34-,36+,37-,38-,39+,40+,44+/m0/s1. InChi Key: QJJXYPPXXYFBGM-LFZNUXCKSA-N.