L-thyroxine

From DrugPedia: A Wikipedia for Drug discovery

Contents 1 Description 2 General Properties 3 PhysioChemical Properties 4 External Links

Description

The major hormone derived from the thyroid gland. Thyroxine is synthesized via the iodination of tyrosines (MONOIODOTYROSINE) and the coupling of iodotyrosines (DIIODOTYROSINE) in the THYROGLOBULIN. Thyroxine is released from thyroglobulin by proteolysis and secreted into the blood. Thyroxine is peripherally deiodinated to form TRIIODOTHYRONINE which exerts a broad spectrum of stimulatory effects on cell metabolism. Thyroxine, or 3,5,3',5'-tetra­iodothyronine (often abbreviated as T₄), a form of thyroid hormones is the major hormone secreted by the follicular cells of the thyroid gland.

T₄ is transported in blood, with 99.95% of the secreted T₄ being protein bound, principally to thyroxine-binding globulin (TBG), and, to a lesser extent, to transthyretin and serum albumin. T₄ is involved in controlling the rate of metabolic processes in the body and influencing physical development. Administration of thyroxine has been shown to significantly increase the concentration of nerve growth factor in the brains of adult mice.<ref>Walker et al. (27 April 1979) Thyroxine increases nerve growth factor concentration in adult mouse brain. Science. Vol. 204, No. 4391. pp. 427 - 429.</ref>

Note: Thyroxine is a prohormone and a reservoir for the active thyroid hormone triiodothyronine (T₃) which is about four times more potent. T₄ is converted in the tissues by deiodinases to T₃. The "D" isomer is called "Dextrothyroxine"<ref>Template:MeshName</ref> and is used as a lipid modifying agent.<ref>Template:ATC</ref> The half-life of thyroxine once released into the blood circulatory system is about 1 week.

The hormone was synthesised in 1927 by British chemists Charles Robert Harington and George Barger.

General Properties

*Molecular Weight

776.87

*Molecular Formula

C₁₅H₁₁I₄NO₄

*IUPAC NAME

(2S)-2-amino-3-[4-(4-hydroxy-3,5-diiodophenoxy)-3,5-diiodophenyl]propanoicacid

*Canonical Smiles

C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)CC(C(=O)O)N

*Isomeric Smiles

C1=C(C=C(C(=C1I)OC2=CC(=C(C(=C2)I)O)I)I)C[C@@H](C(=O)O)N

PhysioChemical Properties

*Melting Point

235.5(EXP)

*LogP

4.12(EST)

*Water Solubility

1.05E-04(EST) at 25C

External Links

• [1]Pubchem
• [2]]1ICT,[[3]]1IE4,[[4]]1HK1,[[5]]1HK2,[[6]]1HK3,[[7]]1HK4,[[8]]1HK5,[[9]]1SN0,[[10]]1Y0X,[[11]]2CEO,[[12]]2ROX,[[13]]2RIW,[[14]]1ETA,[[15]]1ETB,
• [16]KEGG Compound
• [17]Human Metabolome DataBase
• [18]Drugbank