| Size | Price | Stock | Qty |
|---|---|---|---|
| 1mg |
|
||
| Other Sizes |
| Targets |
L-Citrulline-d4 has no independent pharmacological target as a stable isotope tracer. The unlabeled L-citrulline is an amino acid derived from ornithine in the catabolism of proline, glutamine, and glutamate, or from L-arginine via the arginine-citrulline pathway. L-Citrulline is an intermediate in the urea cycle, where it is converted to argininosuccinate by argininosuccinate synthetase (ASS), then to arginine by argininosuccinate lyase (ASL). It is also a precursor of nitric oxide (NO) through the arginine-NO pathway. L-Citrulline is used as a dietary supplement to increase arginine levels and improve NO production.
|
|---|---|
| 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/internal standard, L-Citrulline-d4 is not tested for in vitro pharmacological activity. It is added to biological samples for LC-MS/MS quantification of endogenous L-citrulline, or used as a tracer to study urea cycle function and NO pathway metabolism in cell cultures. The deuterium labeling at the 4,4,5,5 positions provides an M+4 mass shift optimized for balancing spectral separation from the unlabeled analyte while avoiding overlap with naturally occurring isotopologues, enabling precise tracking without interfering with cellular metabolic processes. |
| ln Vivo |
L-Citrulline-d4 has no independent in vivo pharmacological activity as a therapeutic agent. It is used in animal and human studies as a stable isotope tracer administered orally or intravenously to study urea cycle function, arginine bioavailability, and nitric oxide metabolism. The compound can be used to measure whole-body citrulline flux, arginine synthesis rate, and NO production via LC-MS/MS. L-Citrulline itself is also used clinically to assess small intestinal function (as a marker of enterocyte mass) and in metabolic disorders of the urea cycle.
|
| Enzyme Assay |
For in vitro LC-MS/MS quantification, L-Citrulline-d4 is dissolved in an appropriate solvent (water, 0.1% formic acid, or methanol) to prepare a stock solution (e.g., 1 mg/mL). The internal standard is added to biological samples (plasma, serum, cell lysates, culture media, urine) at a fixed concentration (e.g., 10-500 ng/mL). For plasma or serum samples, protein precipitation is performed by adding 3-5 volumes of methanol or acetonitrile containing the internal standard, followed by vortexing and centrifugation (10,000-15,000 rpm, 10 minutes). The supernatant is transferred and analyzed directly by LC-MS/MS in positive ion mode with multiple reaction monitoring (MRM). The citrulline/citrulline-d4 peak area ratio is used for quantification. For tracer studies, L-Citrulline-d4 is added to the culture medium as a metabolic tracer.
|
| Cell Assay |
For cell-based studies, cells (e.g., hepatocytes, endothelial cells, macrophages, or enterocytes) are cultured in standard medium (DMEM or RPMI-1640 with 10% FBS). For studies of urea cycle function or NO pathway metabolism, cells are treated with L-Citrulline-d4 at concentrations of 10-500 uM for labeling periods of 1-48 hours. At each time point, cells are harvested and lysed in 0.1% formic acid in methanol. After protein precipitation and centrifugation (10,000-15,000 rpm, 10 minutes), the supernatant is analyzed by LC-MS/MS to quantify ¹3C/2H-labeled citrulline, arginine, and citrulline-derived metabolites (argininosuccinate, NO metabolites). For studies of citrulline uptake and metabolism, the internal standard L-Citrulline-d4 can be added directly to the medium and its disappearance and metabolite appearance followed over time.
|
| Animal Protocol |
For in vivo tracer studies, L-Citrulline-d4 is administered to rodents via intravenous injection, intraperitoneal injection (50-200 mg/kg), or oral gavage (100-500 mg/kg). For urea cycle studies, L-Citrulline-d4 is often administered simultaneously with ¹3C-labeled precursors. Blood samples are collected at multiple time points (0, 15, 30, 60, 120, 240 minutes, and up to 24 hours). For studies of small intestinal function, blood samples are collected after oral administration and citrulline-d4 appearance is measured as a marker of enterocyte mass and function. At terminal time points, tissues (liver, kidney, small intestine, muscle) are harvested, snap-frozen in liquid nitrogen, and stored at -80degC. Tissues are homogenized in 0.1% formic acid in methanol, centrifuged, and analyzed by LC-MS/MS to quantify L-Citrulline-d4 and its metabolites. Metabolic flux analysis is performed by compartmental modeling.
|
| ADME/Pharmacokinetics |
L-Citrulline-d4 is an internal standard and tracer and does not have independent pharmacokinetic parameters. L-Citrulline is an endogenous amino acid with a plasma half-life of approximately 30-60 minutes in humans. It is absorbed from the small intestine (where it is produced from glutamine and proline), distributed to all tissues, and converted to arginine primarily in the kidney and liver. Normal plasma citrulline levels are 20-50 uM. Urinary excretion is minimal. The deuterated version is used to calibrate analytical methods and does not alter the ADME properties of the endogenous metabolite. L-Citrulline-d4 has a melting point of 216-218degC (decomposition) and requires storage at -20degC for long-term stability.
|
| Toxicity/Toxicokinetics |
L-Citrulline is a naturally occurring non-essential amino acid with low toxicity. The LD50 in rodents is >5,000 mg/kg. The deuterated version is chemically identical except for isotopic substitution and exhibits the same safety profile. Standard laboratory safety precautions for handling amino acids apply. Not intended for human consumption. High doses of L-citrulline (10-20 g/day) are generally well-tolerated but may cause mild gastrointestinal disturbances. No toxicity specific to the deuterium label is known.
|
| References | |
| Additional Infomation |
L-Citrulline-d4 is not a drug but a deuterium-labeled stable isotope tracer and internal standard. It has no approved therapeutic status, no clinical trial history as a separate agent, and is not intended for human consumption. This compound is used for research applications including as an internal standard for LC-MS/MS quantification of L-citrulline in plasma, serum, urine, and tissue samples, stable isotope tracer studies of the urea cycle and arginine-citrulline pathway, metabolic flux analysis of NO biosynthesis and arginine metabolism, studies of small intestinal function (citrulline is a marker of enterocyte mass), and research on urea cycle disorders (ornithine transcarbamylase deficiency, citrullinemia, argininosuccinic aciduria). L-Citrulline-d4 provides a defined M+4 mass shift optimized for balancing spectral separation from the unlabeled analyte (M+0) while avoiding overlap with naturally occurring M+2 isotopologues. Available with ≥98% purity, ≥95 atom% D, and isotopic enrichment >99%.
|
| Molecular Formula |
C6H13N3O3
|
|---|---|
| Molecular Weight |
175.185721158981
|
| Exact Mass |
179.12
|
| CAS # |
1217474-00-4
|
| Related CAS # |
L-Citrulline;372-75-8
|
| PubChem CID |
71308811
|
| Appearance |
White to off-white solid powder
|
| LogP |
-4.3
|
| Hydrogen Bond Donor Count |
4
|
| Hydrogen Bond Acceptor Count |
4
|
| Rotatable Bond Count |
5
|
| Heavy Atom Count |
12
|
| Complexity |
171
|
| Defined Atom Stereocenter Count |
1
|
| SMILES |
C([C@H](N)C(=O)O)C([H])([H])C([H])([H])NC(=O)N
|
| InChi Key |
RHGKLRLOHDJJDR-KKOAYFQZSA-N
|
| InChi Code |
InChI=1S/C6H13N3O3/c7-4(5(10)11)2-1-3-9-6(8)12/h4H,1-3,7H2,(H,10,11)(H3,8,9,12)/t4-/m0/s1/i1D2,3D2
|
| Chemical Name |
(2S)-2-amino-5-(carbamoylamino)-4,4,5,5-tetradeuteriopentanoic 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 |
| 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) |
May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples
|
|---|---|
| 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 | 5.7081 mL | 28.5404 mL | 57.0809 mL | |
| 5 mM | 1.1416 mL | 5.7081 mL | 11.4162 mL | |
| 10 mM | 0.5708 mL | 2.8540 mL | 5.7081 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
