Arginine, L-Arginine, 74-79-3

L-ARGININE

L-Arginine / Arginine / (S)-2-Amino-5-guanidinopentanoic acid
CAS Number: 74-79-3
EC Number: 200-811-1

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

L-Arginine is a semi-essential, basic amino acid that plays a critical role in numerous physiological processes. It is classified as "conditionally essential" because while the body can synthesize it under normal conditions, supplementation becomes necessary during periods of growth, illness, injury, or stress. L-Arginine is a precursor to nitric oxide (NO), a potent vasodilator that relaxes blood vessels and improves blood flow. It is also a key component of the urea cycle, facilitating ammonia detoxification, and is involved in protein synthesis, hormone secretion, and wound healing . L-Arginine appears as white crystals or a crystalline powder, is odorless, and has a bitter taste . It is highly soluble in water (182 mg/mL at 25°C) and forms a strongly alkaline solution . L-Arginine is widely used in pharmaceuticals, sports nutrition, dietary supplements, food products, and animal feed .

2. PHYSICAL AND CHEMICAL PROPERTIES

L-Arginine is a white, crystalline powder with a bitter taste. It has a melting point of approximately 244°C, at which it decomposes . It is highly soluble in water (182 mg/mL at 25°C) and forms a strongly alkaline solution . It is slightly soluble in ethanol . The pH of a 1% aqueous solution is approximately 10.5-11.0 . The specific optical rotation is +26.0 to +27.0° (c=8, 6N HCl) . The isoelectric point is 10.76. The pKa values are 2.17, 9.04, and 12.48 (guanidino group). Loss on drying is ≤ 0.3%, and residue on ignition is ≤ 0.1%. Heavy metals are ≤ 10 ppm (as Pb) .

3. CHEMICAL PROPERTIES AND REACTIONS

L-Arginine is a basic amino acid with a guanidino group in its side chain. This unique structure gives L-arginine its distinctive chemical properties and biological activities.

Acid-Base Properties:

L-Arginine has a carboxyl group (COOH), an amino group (α-NH₂), and a guanidino group. pKa values: 2.17 (pK1), 9.04 (pK2), and 12.48 (pK3, guanidino group).

Salt Formation:

L-Arginine forms salts with acids. The hydrochloride salt (L-Arginine HCl, CAS 1119-34-2) is commonly used in pharmaceutical and sports nutrition formulations due to its higher water solubility and stability.

Esterification:

L-Arginine can be esterified with alcohols to form arginine esters for pharmaceutical intermediates.

Acylation:

The amino group of L-arginine can be acylated to form N-acyl derivatives for peptide synthesis and pharmaceutical applications.

Transamidination:

L-Arginine participates in transamidination reactions, transferring its guanidino group to other molecules.

Thermal Decomposition:

Above its melting point, L-arginine decomposes, producing ammonia, carbon dioxide, and various nitrogen-containing compounds.

4. PRODUCTION METHODS

L-Arginine is produced industrially primarily through microbial fermentation and chemical synthesis from natural sources.

Detailed Production Process (Fermentation Method - Most Common):

1. Microorganism Cultivation: Genetically modified strains of Corynebacterium glutamicum or Escherichia coli that overproduce L-arginine are cultivated in fermentation vessels containing glucose as the carbon source, ammonia as the nitrogen source, and various mineral salts.

2. Fermentation: The microorganisms are grown under controlled conditions (temperature, pH, aeration, agitation) for 40-60 hours. During this time, the microorganisms convert the carbon source to L-arginine, which is secreted into the fermentation broth.

3. Harvesting: The fermentation broth is harvested, and the microorganisms are removed by filtration or centrifugation.

4. Purification: The L-arginine is purified from the broth using ion exchange chromatography, activated carbon treatment, and crystallization.

5. Crystallization: The purified L-arginine is crystallized from the solution, isolated by filtration, and washed.

6. Drying: The crystals are dried to reduce the moisture content to ≤ 0.3%.

7. Milling and Packaging: The dried crystals are milled to the desired particle size and packaged in 25 kg drums or bags.

5. PHYSIOLOGICAL FUNCTIONS AND HEALTH BENEFITS

L-Arginine is a semi-essential amino acid that plays numerous critical roles in the body. It is involved in protein synthesis, the urea cycle, nitric oxide synthesis, hormone secretion, and wound healing .

5.1. Nitric Oxide (NO) Synthesis and Cardiovascular Health

L-Arginine is the primary precursor to nitric oxide (NO), a key signaling molecule that regulates vascular tone, blood flow, and oxygen delivery . NO is synthesized from L-arginine by nitric oxide synthase (NOS) enzymes. This vasodilatory effect supports cardiovascular health, improves exercise performance, and enhances erectile function . L-Arginine is widely used in pre-workout supplements to produce the "pump" effect, where increased blood flow to muscles during exercise enhances performance .

5.2. Urea Cycle and Ammonia Detoxification

L-Arginine is a critical component of the urea cycle, which converts toxic ammonia (produced during protein metabolism) into urea, which is then excreted in urine . This is essential for preventing ammonia toxicity and maintaining normal liver function . L-Arginine is used in the treatment of hyperammonemia and liver disorders .

5.3. Protein Synthesis and Muscle Growth

L-Arginine is a key component of protein synthesis and supports muscle growth, repair, and recovery . It also stimulates growth hormone secretion from the pituitary gland, which is important for growth, development, and metabolism . L-Arginine supports wound healing by promoting collagen synthesis and tissue repair .

5.4. Immune Function

L-Arginine plays a role in immune function and is involved in spermatogenesis, contributing to male fertility .

6. APPLICATIONS AND INDUSTRIAL USES

L-Arginine has a wide range of applications in pharmaceuticals, sports nutrition, dietary supplements, the food industry, animal feed, and cosmetics.

6.1. Pharmaceutical and Medical Applications

L-Arginine is used in various pharmaceutical and medical applications. It is used to treat hyperammonemia, support liver regeneration, promote wound healing, and improve cardiovascular health and erectile function . It is also used in intravenous solutions for pituitary function testing and parenteral nutrition.

6.2. Sports Nutrition and Dietary Supplements

L-Arginine is widely used in sports nutrition and dietary supplements. It is a key component of pre-workout supplements for its vasodilatory effects, producing the "pump" sensation during exercise . It improves endurance, reduces fatigue, accelerates recovery, and supports muscle growth . L-Arginine is often combined with BCAAs, creatine, and other amino acids in sports nutrition products.

6.3. Food Industry

L-Arginine is used in the food industry as a nutrient supplement and flavor enhancer in functional foods, sports drinks, and protein bars .

6.4. Animal Nutrition

L-Arginine is used in animal nutrition as a feed supplement in semi-moist pet food production and livestock feed .

6.5. Cosmetics and Personal Care

L-Arginine is used in cosmetics and personal care products, particularly in anti-aging and skin repair formulations.

7. DOSAGE AND ADMINISTRATION

8. POTENTIAL SIDE EFFECTS AND WARNINGS

9. DRUG INTERACTIONS

10. NATURAL FOOD SOURCES OF L-ARGININE

11. SAFETY AND TOXICOLOGY

12. FIRST AID MEASURES

13. SAFETY INFORMATION (GHS CLASSIFICATION)

L-Arginine is not classified as a hazardous substance under GHS. However, fine powder may cause respiratory irritation.

Signal Word: WARNING

Hazard Statements (H-Codes):

Precautionary Statements (P-Codes):

14. FIREFIGHTING MEASURES

15. STORAGE AND HANDLING

L-Arginine should be stored below 25°C in cool, dry, well-ventilated areas, protected from moisture. It is slightly hygroscopic and should be protected from moisture. Containers should be kept tightly closed to prevent moisture absorption and contamination. Shelf life under proper storage conditions is typically 24-36 months.

Handling Notes:

• Avoid dust generation (use enclosed systems, local exhaust ventilation)

• Avoid contact with skin and eyes (use protective gloves and goggles)

• Avoid breathing dust (use dust mask or respirator)

• Keep away from ignition sources

• Do not allow material to become wet

16. TRANSPORT INFORMATION

L-Arginine is not classified as a dangerous good for transport. It is shipped in 25 kg bags, drums, or FIBCs. During transport, protect from moisture, impact, and excessive heat.

17. REGULATORY INFORMATION

Regulatory Status:

18. OTHER NAMES AND DATABASE IDENTIFIERS

Database Identifiers:

19. L-ARGININE INDUSTRY SUITABILITY TABLE

20. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

L-Arginine (C₆H₁₄N₄O₂, CAS 74-79-3) is a semi-essential, basic amino acid that plays a critical role in numerous physiological processes. It appears as white crystals or a crystalline powder, is odorless, and has a bitter taste . The molecular weight is 174.20 g/mol, melting point is approximately 244°C (decomposes), and water solubility at 25°C is 182 mg/mL . It is produced primarily through microbial fermentation using Corynebacterium glutamicum or Escherichia coli . L-Arginine is the precursor to nitric oxide (NO), a potent vasodilator that improves blood flow . It is also a key component of the urea cycle for ammonia detoxification and is involved in protein synthesis, hormone secretion, and wound healing . L-Arginine is widely used in pharmaceuticals (hyperammonemia treatment, cardiovascular support, erectile dysfunction, wound healing), sports nutrition (pre-workout supplements for the "pump" effect, endurance, recovery), dietary supplements, functional foods, and animal feed . It is considered GRAS (Generally Recognized as Safe) by the FDA . It is stored below 25°C in cool, dry, well-ventilated areas, protected from moisture . Packaging: 25 kg bags, drums, or FIBCs.

Key Properties:

Major Application Areas:

Key Safety Points:

• LOW TOXICITY: GRAS by FDA

• SLIGHTLY HYGROSCOPIC: Protect from moisture; store in tightly closed containers

• MILD IRRITANT: May cause mild skin and eye irritation

• STORAGE: Store below 25°C in cool, dry, well-ventilated area, protected from moisture

• PPE REQUIRED: Dust mask, safety goggles, protective gloves (for handling powder)

• SIDE EFFECTS: May cause gastrointestinal distress (bloating, diarrhea) at high doses

• DRUG INTERACTIONS: May interact with antihypertensive medications and nitrates

• CONTRAINDICATIONS: Herpes outbreaks; severe kidney disease

CRITICAL WARNINGS:

Nitric Oxide Precursor: L-Arginine is the primary precursor to nitric oxide (NO), a potent vasodilator that relaxes blood vessels and improves blood flow . This is the basis for its use in pre-workout supplements (the "pump" effect), cardiovascular support products, and erectile dysfunction treatments . NO synthesis occurs through the action of nitric oxide synthase (NOS) enzymes, which convert L-arginine to citrulline and NO.

Semi-Essential Amino Acid: L-Arginine is classified as a "conditionally essential" amino acid. While the body can synthesize it under normal conditions, supplementation becomes necessary during periods of growth, illness, injury, or stress . This makes it particularly important in wound healing, burn recovery, and critical illness.

Urea Cycle and Ammonia Detoxification: L-Arginine is a critical component of the urea cycle, which converts toxic ammonia (produced during protein metabolism) into urea for excretion . This is essential for preventing ammonia toxicity and maintaining normal liver function . L-Arginine is used in the treatment of hyperammonemia and liver disorders .

Growth Hormone Stimulation: L-Arginine stimulates growth hormone secretion from the pituitary gland . This supports growth, development, and metabolism . It is also used in intravenous solutions for pituitary function testing.

Drug Interactions: L-Arginine may interact with antihypertensive medications (additive hypotensive effect), nitrates (additive vasodilatory effect), and anticoagulants (increased bleeding risk) . Patients taking these medications should consult a healthcare professional before using L-arginine supplements.

Herpes Outbreaks: L-Arginine may exacerbate herpes simplex virus (HSV-1 and HSV-2) outbreaks because the virus requires arginine for replication . Patients with a history of herpes outbreaks should consult a healthcare professional before use.

Natural Food Sources: L-Arginine is naturally found in protein-rich foods including meat, poultry, fish, eggs, dairy products, soybeans, peanuts, and nuts . Plant-based protein sources are often lower in arginine, so supplementation may be beneficial for vegans and vegetarians.

Pregnancy and Lactation: L-Arginine is generally considered safe during pregnancy and lactation at recommended doses. However, as with all supplements, it is recommended to consult a healthcare professional before use.

Important Disclaimer: This Technical Data Sheet (TDS) is for informational purposes only. The information provided is based on available data and is believed to be accurate. However, the user is solely responsible for determining the suitability of the product for their specific application and for complying with all applicable regulations and safety requirements. For complete safety, handling, storage, and regulatory compliance information, always refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. Users are responsible for testing the product in their own processes and applications. All local, national, and international regulations must be followed when working with L-arginine. This is NOT a substitute for professional medical advice. Consult a healthcare professional before use, especially if taking medications, pregnant, or nursing.