Calcitriol

Calcitriol is a vitamin D3 receptor agonist and active metabolite of vitamin D3 (Cay-11792). It is formed via a multi-step process, in which vitamin D3 undergoes hydroxylation to 25-hydroxy vitamin D3 (Cay-9000683) in the liver, followed by further hydroxylation at the 1alpha-position in the kidney. Calcitriol binds to the vitamin D3 receptor (Kd = 16 pM) and induces differentiation of U937 acute monocytic leukemia cells (EC50 = 2,000 pM). It induces cell cycle arrest at the S phase and apoptosis in primary adenomatous and hyperplastic human parathyroid cells when used at a concentration of 10 nM. Calcitriol (0.65 nmol/animal) increases bone calcium mobilization in chicks on a low calcium diet. It stimulates calcium absorption in the intestines in a chick model of rickets induced by a vitamin D3-deficient diet when administered at a dose of 25 µg/animal. Formulations containing calcitriol have been used in the treatment of hypocalcemia.Formal Name: (1R,3S,5Z)-4-methylene-5-[(2E)-2-[(1R,3aS,7aR)-octahydro-1-[(1R)-5-hydroxy-1,5-dimethylhexyl]-7a-methyl-4H-inden-4-ylidene]ethylidene]-1,3-cyclohexanediol. CAS Number: 32222-06-3. Synonyms: 1,25-dihydroxy Cholecalciferol, 1alpha,25-dihydroxy Cholecalciferol, 1,25-dihydroxy Vitamin D3, 1alpha,25-dihydroxy Vitamin D3. Molecular Formula: C27H44O3. Formula Weight: 416.6. Purity: >97%. Formulation: (Request formulation change), A crystalline solid. Solubility: DMSO: 50 mg/ml, Ethanol: 1 mg/ml, Methanol: 50 mg/ml. lambdamax: 214, 265 nm. SMILES: O[C@@H](C[C@H](O)C/1=C)CC1=C\C=C2[C@@](CC[C@@]3([C@H](C)CCCC(C)(O)C)[H])([H])[C@]3(C)CCC\2. InChi Code: InChI=1S/C27H44O3/c1-18(8-6-14-26(3,4)30)23-12-13-24-20(9-7-15-27(23,24)5)10-11-21-16-22(28)17-25(29)19(21)2/h10-11,18,22-25,28-30H,2,6-9,12-17H2,1,3-5H3/b20-10+,21-11-/t18-,22-,23-,24+,25+,27-/m1/s1. InChi Key: GMRQFYUYWCNGIN-NKMMMXOESA-N. Origin: Synthetic.