ABSTRACT
Thyroid diseases affect a considerable portion of the population, with hypothyroidism being one of the most commonly reported thyroid diseases. Levothyroxine (T4) is clinically used to treat hypothyroidism and suppress thyroid stimulating hormone secretion in other thyroid diseases. In this work, an attempt to improve T4 solubility is made through the synthesis of ionic liquids (ILs) based on this drug. In this context, [Na][T4] was combined with choline [Ch]+ and 1-(2-hydroxyethyl)-3-methylimidazolium [C2OHMiM] + cations in order to prepare the desired T4-ILs. All compounds were characterized by NMR, ATR-FTIR, elemental analysis, and DSC, aiming to check their chemical structure, purities, and thermal properties. The serum, water, and PBS solubilities of the T4-ILs were compared to [Na][T4], as well as the permeability assays. It is important to note an improved adsorption capacity, in which no significant cytotoxicity was observed against L929 cells. [C2OHMiM][T4] seems to be a good alternative to the commercial levothyroxine sodium salt with promising bioavailability.
Subject(s)
Ionic Liquids , Thyroxine , Thyroxine/chemical synthesis , Thyroxine/pharmacokinetics , Thyroxine/toxicity , Biological Availability , Solubility , Ionic Liquids/chemical synthesis , Ionic Liquids/pharmacokinetics , Ionic Liquids/toxicity , L Cells , Animals , Mice , PermeabilityABSTRACT
It was previously reported that tetraiodothyroacetic acid (tetrac) inhibits angiogenesis by binding to the cell surface receptor for thyroid hormone on integrin αVß3. Therefore, we synthesized and evaluated two 64Cu-labeled tetrac derivatives and a Cy5.5-labeled tetrac derivative for tumor angiogenesis imaging. Tetrac was structurally modified to conjugate with 1,4,7,10-tetraazacyclododecane-N,N',Nâ³,Nâ³'-tetraacetic acid (DOTA) via its hydroxy or carboxylic acid end, and the resulting DOTA-conjugated tetrac derivatives were then labeled with 64Cu. Tetrac was also conjugated with Cy5.5 via its carboxylic acid end. All three tetrac derivatives (1-3) exhibited greater inhibitory activity than tetrac against endothelial cell tube formation. The U87MG cell binding of [64Cu]2 showed a time-dependent increase over 24â¯h and it was inhibited by 38% at 4â¯h in the presence of tetrac, indicating specificity of [64Cu]2 to the thyroid hormone receptor site on integrin αVß3. Positron emission tomography (PET) images of U87MG tumor-bearing mice injected with [64Cu]1 and [64Cu]2 revealed that high radioactivity accumulated in the tumors, and that the tumor uptake and tumor-to-nontarget uptake ratio were higher in small tumors than in large tumors. In addition, the Cy5.5-labeled tetrac derivative (3) displayed a strong near-infrared (NIR) signal in the tumors. Taken together, these results suggest that these ligands hold promise as imaging agents for visualization of tumor angiogenesis.
Subject(s)
Brain Neoplasms/diagnostic imaging , Carbocyanines/chemistry , Neovascularization, Pathologic/diagnostic imaging , Positron-Emission Tomography , Thyroxine/analogs & derivatives , Animals , Cells, Cultured , Copper Radioisotopes , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Molecular Structure , Neoplasms, Experimental/diagnostic imaging , Thyroxine/chemical synthesis , Thyroxine/chemistryABSTRACT
In the angiogenesis process, integrins, which are members of a family of cell surface transmembrane receptors, play a critical role particularly in blood vessel formation and the local release of vascular growth factors. Thyroid hormones such as l-thyroxine (T4) and 3,5,3'-triiodo-l-thyronine (T3) promote angiogenesis and tumor cell proliferation via integrin αvß3 receptor. At or near an arginine-glycine-aspartate (RGD) recognition site on the binding pocket of integrin αvß3, tetraiodothyroacetic acid (tetrac, a deaminated derivative of T4) is a thyrointegrin receptor antagonist and blocks the actions of T3 and T4 as well as different growth factors-mediated angiogenesis. In this study, we synthesized novel tetrac analogs by modifying the phenolic moiety of tetrac and tested them for their anti-angiogenesis activity using a Matrigel plug model for angiogenesis in mice. Pharmacological activity results showed that tetrac can accommodate numerous modifications and maintain its anti-angiogenesis activity.
Subject(s)
Angiogenesis Inhibitors/pharmacology , Antineoplastic Agents/pharmacology , Neoplasms/drug therapy , Neovascularization, Pathologic/drug therapy , Thyroxine/analogs & derivatives , Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/chemistry , Animals , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Cell Proliferation/drug effects , Disease Models, Animal , Dose-Response Relationship, Drug , Drug Screening Assays, Antitumor , Female , Humans , Mice , Mice, Inbred C57BL , Molecular Structure , Neoplasms/pathology , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/pathology , Neovascularization, Pathologic/pathology , Structure-Activity Relationship , Thyroxine/chemical synthesis , Thyroxine/chemistry , Thyroxine/pharmacologyABSTRACT
The tyrosine-based hormones 3,3',5-triiodo-l-thyronine (l-T3) and l-thyroxine (l-T4) that are produced by the thyroid gland control metabolic functions. Iodothyronine deiodinase enzymes convert l-T4 to l-T3, the form of thyroid hormone critical to genomic actions within cells and regulation of metabolism, and to reverse-l-T3, a hormone isoform that is largely inactive. We used tertiary amines in a study of deiodination based on derivatives of tetraiodothyroacetic acid (tetrac)-a naturally occurring derivative of l-T4-to mimic the action of the iodothyronine deiodinases and deiodination of the outer ring iodines. Deiodinated tetrac, MR-49, was found to be pro-angiogenic, with this activity exceeding that of l-T3 and l-T4 in a hemoglobin Matrigel® plug assay of angiogenesis. Tetrac is anti-angiogenic via several nongenomic pathways, and the present studies of MR-49 reveal the critical contribution of outer ring iodines to the angiogenic properties of thyroid hormone analogues, which may have utility as pro-angiogenic pharmaceuticals.
Subject(s)
Acetates/chemical synthesis , Angiogenesis Modulating Agents/chemical synthesis , Iodine/chemistry , Phenols/chemical synthesis , Thyroxine/analogs & derivatives , Acetates/chemistry , Acetates/pharmacology , Angiogenesis Modulating Agents/chemistry , Angiogenesis Modulating Agents/pharmacology , Animals , Cell Line, Tumor , Hemoglobins/antagonists & inhibitors , Hemoglobins/metabolism , Magnetic Resonance Spectroscopy , Male , Mice , Mice, Inbred BALB C , Neovascularization, Physiologic/drug effects , Phenols/chemistry , Phenols/pharmacology , Thyroxine/chemical synthesis , Thyroxine/chemistry , Thyroxine/pharmacologyABSTRACT
The type 1 iodothyronine deiodinase (1D-1) in liver and kidney converts the L-thyroxine (T4), a prohormone, by outer-ring (5') deiodination to biologically active 3,3',5-triiodothyronine (T3) or by inner-ring (5) deiodination to inactive 3,3',5'-triiodothronine (rT3). Sulfate conjugation is an important step in the irreversible inactivation of thyroid hormones. While sulfate conjugation of the phenolic hydroxyl group stimulates the 5-deiodination of T4 and T3, it blocks the 5'-deiodination of T4. We show that thyroxine sulfate (T4S) undergoes faster deiodination as compared to the parent thyroid hormone T4 by synthetic selenium compounds. It is also shown that ID-3 mimics, which are remarkably selective to the inner-ring deiodination of T4 and T3, changes the selectivity completely when T4S is used as a substrate. From the theoretical investigations, it is observed that the strength of halogen bonding increases upon sulfate conjugation, which leads to a change in the regioselectivity of ID-3 mimics towards the deiodination of T4S. It has been shown that these mimics perform both the 5'- and 5-ring deiodinations by an identical mechanism.
Subject(s)
Halogens/chemistry , Thyroid Hormones/chemistry , Thyroxine/analogs & derivatives , Triiodothyronine/chemical synthesis , Animals , Biocompatible Materials/chemistry , Biocompatible Materials/metabolism , Iodide Peroxidase/metabolism , Kinetics , Molecular Conformation , Static Electricity , Stereoisomerism , Sulfonic Acids/chemistry , Thyroxine/chemical synthesis , Thyroxine/chemistry , Triiodothyronine/chemistryABSTRACT
Novel thyroxine analogs with hindered phenol, amino and carboxylic acid groups have been synthesized and the effects of the synthesized compounds on angiogenesis using the chick chorioallantoic membrane and mouse matrigel models have been tested. Pharmacological profiles revealed that thyroxine tolerates numerous modifications on the amino group and remains active. These results provide the rationale for the selection of a novel thyroxine nanoparticle precursor.
Subject(s)
Angiogenesis Inhibitors/chemical synthesis , Angiogenesis Inhibitors/pharmacology , Thyroxine/chemical synthesis , Thyroxine/pharmacology , Animals , Chick Embryo , Mice , Models, Molecular , Thyroxine/analogs & derivativesABSTRACT
Novel Tetrac analogs were synthesized and then tested. Anti-angiogenesis efficacy was carried out using the Chick Chorioallantoic Membrane (CAM) model and the mouse matrigel model for angiogenesis. Pharmacological activities showed Tetrac can accommodate numerous modifications and maintain anti-angiogenesis activity.
Subject(s)
Angiogenesis Inhibitors/chemistry , Thyroxine/analogs & derivatives , Angiogenesis Inhibitors/pharmacology , Animals , Chick Embryo , Chorioallantoic Membrane/blood supply , Chorioallantoic Membrane/drug effects , Drug Evaluation, Preclinical , Fibroblast Growth Factors/pharmacology , Hemoglobins/analysis , Mice , Structure-Activity Relationship , Thyroxine/chemical synthesis , Thyroxine/chemistry , Thyroxine/pharmacologyABSTRACT
The structural elucidation of unknown pharmaceutical impurities plays an important role in the quality control of newly developed and well-established active pharmaceutical ingredients (APIs). The United States Pharmacopeia (USP) monograph for the API Levothyroxine Sodium, a synthetic thyroid hormone, features two high pressure liquid chromatography (HPLC) methods using UV-VIS absorption detection to determine organic impurities in the drug substance. The impurity profile of the first USP method ("Procedure 1") has already been extensively studied, however for the second method ("Procedure 2"), which exhibits a significantly different impurity profile, no wholistic structural elucidation of impurities has been performed yet. Applying minor modifications to the chromatographic parameters of USP "Procedure 2" and using various comprehensive structural elucidation methods such as high resolution tandem mass spectrometry with on-line hydrogen-deuterium (H/D) exchange or two-dimensional nuclear magnetic resonance spectroscopy (NMR) we gained new insights about the complex impurity profile of the synthetic thyroid hormone. This resulted in the characterization of 24 compounds previously unknown to literature and the introduction of two new classes of Levothyroxine Sodium impurities. Five novel compounds were unambiguously identified via isolation or synthesis of reference substances and subsequent NMR spectroscopic investigation. Additionally, Collision-Induced Dissociation (CID)-type fragmentation of identified major impurities as well as neutral loss fragmentation patterns of many characterized impurities were discussed.
Subject(s)
Deuterium Exchange Measurement/methods , Drug Contamination , Magnetic Resonance Spectroscopy/methods , Tandem Mass Spectrometry/methods , Thyroxine/analysis , Thyroxine/chemical synthesis , Chromatography, High Pressure Liquid/methods , Mass Spectrometry/methodsABSTRACT
A modified chloramine-T method is described for the preparation of several radioiodothyronines by an exchange reaction, which results in low specific activity preparations, or by an addition reaction, which yields radioiodothyronines with specific activities up to 7 mCi/microgram. Purification by paper chromatography is shown to be more convenient than by LH-20 chromatography and provides better resolution among the various thyronines. Radioiodothyronines with only a single iodine atom in the outer (3,5,3'-triiodothyronine and 3,3'-diiodothyronine) are stable for several months when stored in organic solvents. The least stable radioiodothyronines are those with two 125I atoms in the outer ring (3,3',5'-triiodothyronine (rT3) produced from 3-iodothyronine and thyroxine (T4) from 3,5-diiodothyronine). The stability of rT3 and T4 stored in human plasma at 4 C is much greater than when stored in buffer at the same pH. The use of high specific activity [125I]rT3 has permitted the development of a radioimmunoassay with a sensitivity of 1 pg rT3/ml incubation volume.
Subject(s)
Thyronines/chemical synthesis , Diiodothyronines/chemical synthesis , Iodine Radioisotopes , Thyronines/blood , Thyroxine/chemical synthesis , Triiodothyronine, Reverse/chemical synthesisABSTRACT
Around mid-1995, the Molecular Endocrinology Laboratory of the Regional Hospital (Malaga, Spain) began detecting an increase in TSH levels in the serum of patients under study to control the treatment of hypothyroidism with levothyroxine. Over a period of 5 months, of a total of 467 hypothyroid patients treated with Levothyroid, 53% had TSH levels higher than 6 microU/mL. The reliability of the biochemical results was verified by duplicating 56 randomly chosen samples from all those with high TSH levels and by an external control performed in four different laboratories. The amount of levothyroxine in the tablets was analyzed by RIA, high performance liquid chromatography, and their iodine contents. The lowest levels of levothyroxine found in the 50 micrograms Levothyroid tablets were those determined by RIA, with a mean value of 32.3 micrograms, resulting in a 35.3% loss of activity. The mean value of levothyroxine found in these same tablets by high performance liquid chromatography was 39.3 micrograms, amounting to a 21.3% loss in activity. The iodine showed no significant loss in these tablets, with a mean experimental value of 48 micrograms. The commercial laboratory withdrew lot J from the market, the one in which these deficiencies were found.
Subject(s)
Hypothyroidism/blood , Hypothyroidism/drug therapy , Thyrotropin/blood , Thyroxine/adverse effects , Adult , Chromatography, High Pressure Liquid , Congenital Hypothyroidism , Female , Humans , Immunoradiometric Assay , Luminescent Measurements , Male , Pregnancy , Pregnancy Complications , Radioimmunoassay , Tablets/chemistry , Thyroid Neoplasms/complications , Thyroxine/analysis , Thyroxine/chemical synthesisABSTRACT
Gd-C(4)-thyroxin-DTPA, a potential MRI contrast agent, was synthesized from Gd-DTPA and thyroxine, which interacts strongly with human serum albumin (HSA). It was characterized in water by its relaxometric properties and its stability versus zinc transmetalation. The affinity of the complex for HSA was studied by using three different methods: proton relaxometry, NMR diffusometry, and electrospray mass spectrometry. From the results, it appears that Gd-C(4)-thyroxin-DTPA exhibits a relatively high relaxivity (r(1) = 9.01 s(-1) mM(-1) at 1.5 T and 310 K), a good stability versus zinc transmetalation, and a strong interaction with HSA (K(a) approximately 10,000 M(-1) with two binding sites). The kinetics of the exchange between the bound and the free form of the complex was evaluated by the NMR diffusometry technique. Competition experiments have allowed the assignment of the chelate's binding site on HSA.
Subject(s)
Contrast Media/chemical synthesis , Organometallic Compounds/chemical synthesis , Serum Albumin/chemistry , Thyroxine/analogs & derivatives , Contrast Media/chemistry , Diffusion , Humans , Kinetics , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Organometallic Compounds/chemistry , Spectrometry, Mass, Electrospray Ionization , Thyroxine/chemical synthesis , Thyroxine/chemistrySubject(s)
Glycerolphosphate Dehydrogenase/metabolism , Thyroxine/pharmacology , Triiodothyronine/pharmacology , Animals , Body Weight/drug effects , Heart/anatomy & histology , Kidney/anatomy & histology , Kidney/enzymology , Lipid Metabolism , Liver/anatomy & histology , Liver/enzymology , Male , Methylation , Mitochondria/drug effects , Mitochondria/enzymology , Myocardium/enzymology , Organ Size , Oxygen Consumption/drug effects , Rats , Structure-Activity Relationship , Thyroid Gland/physiology , Thyroxine/chemical synthesis , Triiodothyronine/chemical synthesisSubject(s)
Thyroxine/chemical synthesis , Animals , Goiter/drug therapy , Methods , Rats , Thyroxine/therapeutic useSubject(s)
Thyroxine/chemical synthesis , Animals , Esters/chemical synthesis , Esters/therapeutic use , Ethers/chemical synthesis , Ethers/therapeutic use , Goiter/drug therapy , Infrared Rays , Optical Rotation , Rats , Spectrum Analysis , Structure-Activity Relationship , Thyroxine/therapeutic useSubject(s)
Naphthalenes/chemical synthesis , Thyroxine/chemical synthesis , Tyrosine/chemical synthesis , Animals , Ethers/chemical synthesis , Ethers/therapeutic use , Goiter/drug therapy , Iodine , Isomerism , Naphthalenes/therapeutic use , Oxidation-Reduction , Rats , Structure-Activity Relationship , Thyroxine/therapeutic use , Tyrosine/therapeutic useSubject(s)
Oxazines/chemical synthesis , Phenylalanine/analogs & derivatives , Thyroxine/analogs & derivatives , Adipose Tissue/anatomy & histology , Adipose Tissue/drug effects , Animals , Appetite/drug effects , Benzofurans/chemical synthesis , Benzofurans/pharmacology , Diet , Dioxoles/chemical synthesis , Dioxoles/pharmacology , Female , Heart/anatomy & histology , Heart/drug effects , Heart Rate/drug effects , Mice , Organ Size , Oxazines/pharmacology , Phenylalanine/chemical synthesis , Phenylalanine/pharmacology , Stimulation, Chemical , Thyroid Gland/drug effects , Thyroxine/chemical synthesis , Thyroxine/pharmacologyABSTRACT
Based on the examination of the crystal structure of rat TRbeta complexed with 3,5,3'-triiodo-l-thyronine (2) a novel TRbeta-selective indole derivative 6b was prepared and tested in vitro. This compound was found to be 14 times selective for TRbeta over TRalpha in binding and its beta-selectivity could be rationalized through the comparison of the X-ray crystallographic structures of 6b complexed with TRalpha and TRbeta.