[1]. Extracellular Concentration of L-Cystine Determines the Sensitivity to System xc- Inhibitors. Biomol Ther (Seoul). 2022 Mar 1;30(2):184-190.

[2]. Enhancement of antigen-specific immunoglobulin G production in mice by co-administration of L-cystine and L-theanine. J Vet Med Sci. 2007 Dec;69(12):1263-70.

[3]. Cystinuria and cystinosis are usually related to L-cystine: is this really the case for cystinosis? A physicochemical investigation at micrometre and nanometre scale. Comptes Rendus. Chimie, Volume 25 (2022) no. S1, pp. 489-502.

[4]. Cellular accumulation of L-cystine in rat kidney cortex in vivo. J Clin Invest. 1973 Feb;52(2):454-62.

[5]. Uptake of L-cystine via an ABC transporter contributes defense of oxidative stress in the L-cystine export-dependent manner in Escherichia coli. PLoS One. 2015 Apr 2;10(3):e0120619.

[6]. Fresh Medium or L-Cystine as an Effective Nrf2 Inducer for Cytoprotection in Cell Culture. Cells. 2023 Jan 12;12(2):291.

L-cysteine is the L-enantiomer of the sulfur-containing amino acid cysteine. It is used as a flour treatment agent, a human metabolite, a Saccharomyces cerevisiae metabolite, a mouse metabolite, and an inhibitor of EC 1.2.1.11 (aspartate semialdehyde dehydrogenase). It is a cysteine derivative of L-cysteine and a non-protein L-α-amino acid. It is the conjugate acid of the L-cysteine anion. It is the enantiomer of D-cysteine. It is the tautomer of the L-cysteine zwitterion. It is a covalently linked dimer, a non-essential amino acid formed by the oxidation of cysteine. Two cysteine molecules are linked by a disulfide bond to form cysteine. L-cysteine is present in or produced by Escherichia coli (K12 strain, MG1655 strain). L-cysteine has been reported in Spanish sage, soybean, and other organisms with relevant data. Cystine is not one of the 20 essential amino acids. Cystine is a sulfur-containing derivative formed by the oxidation of the thiol side chain of the cysteine amino acid. It has antioxidant properties, protecting tissues from radiation and pollution damage and slowing the aging process. It also contributes to protein synthesis. Cystine is abundant in many proteins in bone tissue and skin, and is also found in insulin and digestive enzymes such as chromaffinogen A, papain, and trypsinogen. (NCI04)
A covalently linked dimer, non-essential amino acid formed by the oxidation of cysteine. Two cysteine molecules are linked by a disulfide bond to form cystine.

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Drug Indications
L-cysteine is said to have anti-inflammatory properties, can combat various toxins, and may help treat osteoarthritis and rheumatoid arthritis. More research is needed before L-cysteine is approved for the treatment of any of these diseases. Research to date has primarily focused on animal models.

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Mechanism of Action
In certain situations, such as acetaminophen overdose, glutathione in the liver is depleted, subjecting tissues to oxidative stress and leading to loss of cellular integrity. L-Cysteine is a major precursor in the synthesis of glutathione.

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Pharmacodynamics
L-Cysteine is a covalently linked dimer, non-essential amino acid formed by the oxidation of cysteine. Two cysteine molecules are linked by a disulfide bond to form cystine. Cystine is a naturally occurring chemical in urine; when deposited in the kidneys, it can form stones (hard mineral deposits). Cystine is a compound formed by two cysteine molecules linked by a disulfide bond. Cystine is essential for the proper utilization of vitamin B6, and it also helps in the healing of burns and wounds, and can break down mucus deposits in diseases such as bronchitis and cystic fibrosis. Cystine also helps in the supply of insulin to the pancreas, which is essential for the absorption of carbohydrates and starches. It can increase glutathione levels in the lungs, liver, kidneys, and bone marrow, which may have an anti-aging effect on the body by reducing age spots, among other things.

C6H12N2O4S2

240.29

240.023

56-89-3

L-Cystine-d4;1192736-38-1;L-Cystine-34S2;113512-08-6;(S)-L-Cystine-15N2;L-Cystine-3,3'-13C2;2483736-13-4

67678

White to off-white solid powder

1.6±0.1 g/cm3

468.2±45.0 °C at 760 mmHg

260-261ºC

237.0±28.7 °C

0.0±2.5 mmHg at 25°C

1.653

1.23

4

8

7

14

192

2

C([C@@H](C(=O)O)N)SSC[C@@H](C(=O)O)N

LEVWYRKDKASIDU-IMJSIDKUSA-N

InChI=1S/C6H12N2O4S2/c7-3(5(9)10)1-13-14-2-4(8)6(11)12/h3-4H,1-2,7-8H2,(H,9,10)(H,11,12)/t3-,4-/m0/s1

(2R)-2-amino-3-[[(2R)-2-amino-2-carboxyethyl]disulfanyl]propanoic acid

NSC-13203; NSC 13203; Cystine

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

0.1 M NaOH : ~3.33 mg/mL (~13.86 mM)
0.1 M HCL : 2.5 mg/mL (~10.40 mM)
DMSO :< 1 mg/mL
H2O : < 0.1 mg/mL

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.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*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).

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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)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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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).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)