| Size | Price | Stock | Qty |
|---|---|---|---|
| 1mg |
|
||
| 5mg |
|
||
| 10mg |
|
||
| Other Sizes |
| Targets |
L-Threonine-13C4 targets the same pathways as unlabeled L-Threonine. L-Threonine is an essential amino acid that is a substrate for threonine aldolases (TA), which catalyze the reversible cleavage of threonine to glycine and acetaldehyde. It is also a substrate for threonine dehydrogenase, which converts it to 2-amino-3-oxobutanoate, a precursor for acetyl-CoA and glycine. L-Threonine is incorporated into proteins via translation, and it plays a role in maintaining protein structure due to its hydroxyl group (which can form hydrogen bonds) and its role in O-linked glycosylation (O-GlcNAcylation) of proteins. As a tracer, the 13C label allows researchers to track the fate of threonine carbons in metabolic pathways.
|
|---|---|
| ln Vitro |
Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as quantitative tracers while the drugs were being developed. Because deuteration may have an effect on a drug's pharmacokinetics and metabolic properties, it is a cause for concern [1].
As a stable isotope tracer, L-Threonine-13C4 is not used to measure biological activity in the traditional sense. Instead, it is added to cell culture media or administered to animals to track threonine metabolism, protein synthesis, and carbon flux. In vitro, L-Threonine (unlabeled) is used in cell culture media formulations as an essential amino acid for cell growth and protein synthesis. It is also used to study threonine aldolase activity and the conversion of threonine to glycine. The 13C-labeled version is used to quantify threonine catabolism: the conversion of threonine-13C4 to glycine-13C2 and acetaldehyde-13C2 (via threonine aldolase) or to acetyl-CoA-13C2 (via threonine dehydrogenase) is measured by LC-MS or GC-MS. Threonine aldolase has applications in the synthesis of chiral compounds. |
| ln Vivo |
In vivo, L-Threonine-13C4 is administered to animals to trace threonine metabolism, protein synthesis rates, and metabolic flux through the threonine catabolic pathways. L-Threonine is an essential amino acid that must be obtained from the diet, and it is required for growth, maintenance of body protein balance, and the synthesis of glycine, serine, and acetyl-CoA. In animals, L-Threonine deficiency leads to reduced growth and impaired immune function. The 13C-labeled version is used to quantify the conversion of threonine to glycine (which is important for neurotransmitter synthesis and glutathione production) and to acetyl-CoA (which enters the TCA cycle). It is also used to measure protein synthesis rates using the flooding dose method or steady-state isotope labeling. In nutritional studies, L-Threonine-13C4 is used to determine threonine requirements and the bioavailability of threonine from dietary proteins.
|
| Enzyme Assay |
For non-cellular assays (analytical quantification), L-Threonine-13C4 is prepared as a stock solution in water or 0.1 M HCl (1 mg/mL). For LC-MS/MS analysis, a calibration curve for L-Threonine is prepared in human plasma (0.1-1000 ng/mL) with a fixed concentration of L-Threonine-13C4 (e.g., 50 ng/mL). Sample preparation: 100 uL plasma + 20 uL internal standard + 380 uL acetonitrile for protein precipitation. After centrifugation, the supernatant is diluted with water (1:1) and injected onto a C18 column or a HILIC column with a mobile phase of 0.1% formic acid in water and acetonitrile (gradient elution). MRM transitions: L-Threonine 120→74 (loss of H2O), L-Threonine-13C4 124→78. For threonine aldolase (TA) activity assays, purified TA is incubated with L-Threonine-13C4 (1-20 mM) in 50 mM HEPES buffer (pH 7.5) containing pyridoxal phosphate (0.1 mM) for 30 minutes at 37degC. The labeled products (glycine-13C2 and acetaldehyde-13C2) are quantified by LC-MS or GC-MS. For threonine dehydrogenase assays, the enzyme is incubated with L-Threonine-13C4 and NAD+, and NADH production is measured at 340 nm, or the product (2-amino-3-oxobutanoate-13C4) is quantified by LC-MS.
|
| Cell Assay |
For cell-based assays, hepatocytes (e.g., HepG2 cells), neuronal cells (e.g., SH-SY5Y), or cancer cells are seeded in 6-well plates (1×10⁶ cells/well) in DMEM with 10% FBS. For metabolic labeling, cells are cultured in medium lacking unlabeled threonine and supplemented with L-Threonine-13C4 (10-100 uM) for 6-48 hours. Cell lysates are prepared in 80% methanol containing internal standards. 13C enrichment in threonine, glycine, serine, acetyl-CoA, and TCA cycle intermediates is analyzed by LC-MS/MS or GC-MS. For protein synthesis studies, cells are incubated with L-Threonine-13C4 for 1-24 hours, and the rate of incorporation into newly synthesized proteins is measured by MS analysis of hydrolyzed proteins. For studies of threonine catabolism, the conversion of threonine to glycine can be inhibited by using specific inhibitors of threonine aldolase.
|
| Animal Protocol |
For in vivo animal experiments, rats or mice are fasted overnight and then administered L-Threonine-13C4 orally (gavage) at a dose of 20-100 mg/kg or intravenously at 5-50 mg/kg. Blood samples are collected at multiple time points (0, 15, 30, 60, 90, 120 minutes) from the tail vein. Plasma is separated, and proteins are precipitated with methanol. At the end of the experiment, tissues (liver, kidney, brain, skeletal muscle) are harvested and homogenized. L-Threonine-13C4 and its metabolites (glycine, acetyl-CoA, TCA cycle intermediates) are analyzed by LC-MS/MS. For protein synthesis studies (flooding dose method), a large dose of L-Threonine-13C4 (150-300 mg/kg) is administered to achieve uniform labeling of the free amino acid pool, and the rate of incorporation into muscle and liver proteins is measured over 30-60 minutes. For nutritional studies, animals are fed a diet containing L-Threonine-13C4 for 7-14 days, and protein-bound threonine enrichment is measured in tissues to determine protein turnover rates.
|
| ADME/Pharmacokinetics |
L-Threonine-13C4 has a molecular weight of 123.09, with four carbon-13 atoms providing a mass shift of +4 Da relative to unlabeled L-Threonine (MW 119.12). The compound is a white crystalline powder with a melting point of 256degC (dec.). It is soluble in water (approximately 20 mg/mL) and dilute acids and bases. The 13C label is stable and non-radioactive. It should be stored as a powder at -20degC for up to 3 years, and in solution at -80degC for up to 6 months or at -20degC for up to 1 month. The compound is metabolically identical to unlabeled L-Threonine, so its pharmacokinetics follow that of L-Threonine: absorbed via amino acid transporters in the small intestine, distributed to all tissues, and incorporated into proteins or catabolized primarily in the liver, kidney, and intestinal mucosa via threonine aldolase and threonine dehydrogenase pathways.
|
| Toxicity/Toxicokinetics |
L-Threonine-13C4 is a stable isotope-labeled compound with minimal toxicity at analytical and tracer concentrations (mg per kg body weight in animals). The non-deuterated parent compound, L-Threonine, is an essential amino acid that is generally recognized as safe (GRAS) as a food additive and dietary supplement. At typical dietary intake levels (20-50 mg/kg/day), it is well-tolerated. High doses may cause mild gastrointestinal discomfort. In individuals with certain metabolic disorders (e.g., threonine metabolism disorders), accumulation of threonine or its metabolites may cause toxicity, but this is not relevant at tracer doses. The compound is non-radioactive and safe for research use with standard handling precautions for amino acids.
|
| References |
|
| Additional Infomation |
L-Threonine-13C4 is a research compound used as a stable isotope tracer, not an approved drug. It is not intended for therapeutic use and has not undergone clinical trials as a drug. Its primary applications are in metabolic research, including studying threonine metabolism (via threonine aldolase and threonine dehydrogenase pathways), glycine and acetyl-CoA biosynthesis, protein synthesis rates, and metabolic flux through the threonine catabolic pathway. The compound is also used to study the role of threonine in glycosylation (O-GlcNAcylation) and in the regulation of cellular metabolism. L-Threonine-13C4 is used as an internal standard for quantitative LC-MS analysis of L-Threonine in biological and clinical samples (e.g., for diagnosing threonine metabolism disorders). Available for research use only.
|
| Molecular Formula |
C4H9NO3
|
|---|---|
| Molecular Weight |
123.089780569077
|
| Exact Mass |
123.071
|
| CAS # |
55443-53-3
|
| Related CAS # |
L-Threonine;72-19-5
|
| PubChem CID |
101770510
|
| Appearance |
White to off-white solid powder
|
| LogP |
-2.9
|
| Hydrogen Bond Donor Count |
3
|
| Hydrogen Bond Acceptor Count |
4
|
| Rotatable Bond Count |
2
|
| Heavy Atom Count |
8
|
| Complexity |
93.3
|
| Defined Atom Stereocenter Count |
2
|
| SMILES |
[13C](O)(=O)[13C@H]([13C@H](O)[13CH3])N
|
| InChi Key |
AYFVYJQAPQTCCC-GGLUNYCGSA-N
|
| InChi Code |
InChI=1S/C4H9NO3/c1-2(6)3(5)4(7)8/h2-3,6H,5H2,1H3,(H,7,8)/t2-,3+/m1/s1/i1+1,2+1,3+1,4+1
|
| Chemical Name |
(2S,3R)-2-amino-3-hydroxy(1,2,3,4-13C4)butanoic acid
|
| HS Tariff Code |
2934.99.9001
|
| Storage |
Powder -20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: Please store this product in a sealed and protected environment, avoid exposure to moisture. |
| Shipping Condition |
Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)
|
| Solubility (In Vitro) |
H2O: 125 mg/mL (1015.52 mM)
|
|---|---|
| Solubility (In Vivo) |
Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.
Injection Formulations
Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)(e.g. IP/IV/IM/SC) *Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution. Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline) Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil) Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals). View More
Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)] Oral Formulations
Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium) Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals). View More
Oral Formulation 3: Dissolved in PEG400 (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 8.1241 mL | 40.6207 mL | 81.2414 mL | |
| 5 mM | 1.6248 mL | 8.1241 mL | 16.2483 mL | |
| 10 mM | 0.8124 mL | 4.0621 mL | 8.1241 mL |
*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.
Calculation results
Working concentration： mg/mL；
Method for preparing DMSO stock solution： mg drug pre-dissolved in μL DMSO (stock solution concentration mg/mL). Please contact us first if the concentration exceeds the DMSO solubility of the batch of drug.
Method for preparing in vivo formulation:：Take μL DMSO stock solution, next add μL PEG300, mix and clarify, next addμL Tween 80, mix and clarify, next add μL ddH2O，mix and clarify.
(1) Please be sure that the solution is clear before the addition of next solvent. Dissolution methods like vortex, ultrasound or warming and heat may be used to aid dissolving.
(2) Be sure to add the solvent(s) in order.
Products are for research use only; We do not sell to patients
Copyright 2020 InvivoChem LLC | All Rights Reserved
