L-Thyroxine-13C9,15N

L-Thyroxine-13C9,15N is intended for use as an internal standard for the quantification of L-thyroxine (Cay-14116) by GC- or LC-MS. L-Thyroxine is a synthetic form of the thyroid hormone thyroxine. In vivo, L-thyroxine (0.9 and 2.7 µg) inhibits synthesis and release of thyrotropin induced by thyrotropin-releasing hormone (Cay-22917) from the anterior pituitary in mice. It also reverses decreases in levels of circulating thymic serum factor (FTS) and the number of T rosette-forming cells in an old age-induced mouse model of hypothyroidism. Formulations containing L-thyroxine have been used in the treatment of hypothyroidism.Formal Name: O-(4-hydroxy-3,5-diiodophenyl)-3,5-diiodo-L-tyrosine-carboxy,alpha,beta,1,2,3,4,5,6-13C9-15N. CAS Number: 1431868-11-9. Synonyms: L-T4-13C9,15N, Levothyroxine-13C9,15N. Molecular Formula: C6[13C]9H11I4[15N]O4. Formula Weight: 786.8. Purity: >98%. Formulation: (Request formulation change), A solid. Solubility: DMF: 0.14 mg/ml, DMSO: 2.5 mg/ml, DMSO:PBS (pH 7.2) (1:1): 0.50 mg/ml. SMILES: OC1=C(I)C=C(O[13C]2=[13C](I)[13CH]=[13C]([13CH2][13C@H]([15NH2])[13C](O)=O)[13CH]=[13C]2I)C=C1I. InChi Code: InChI=1S/C15H11I4NO4/c16-8-4-7(5-9(17)13(8)21)24-14-10(18)1-6(2-11(14)19)3-12(20)15(22)23/h1-2,4-5,12,21H,3,20H2,(H,22,23)/t12-/m0/s1/i1+1,2+1,3+1,6+1,10+1,11+1,12+1,14+1,15+1,20+1. InChi Key: XUIIKFGFIJCVMT-LPIUGHGLSA-N.