Valine, L-Valine, L(+)-alpha-Aminoisovaleric Acid, BCAA, 72-18-4

L-VALINE

L-Valine / Valine / (S)-2-Amino-3-methylbutanoic acid / BCAA
CAS Number: 72-18-4
EC Number: 200-773-6

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

L-Valine is an essential amino acid belonging to the branched-chain amino acid (BCAA) family, along with L-leucine and L-isoleucine. It is one of the nine essential amino acids that cannot be synthesized by the human body and must be obtained through diet or supplementation. L-Valine has a hydrophobic, aliphatic side chain and is a critical component of protein synthesis. It plays a vital role in muscle growth, tissue repair, nitrogen balance regulation, and nervous system function. The compound was first isolated from the valerian plant (Valeriana officinalis), from which it derives its name. L-Valine appears as a white, odorless, crystalline powder with a slightly sweet to bitter taste. It is soluble in water (88.5 g/L at 25°C) but insoluble in ethanol and ether. L-Valine is widely used in sports nutrition, dietary supplements, medical applications, functional foods, and child nutrition products.

2. PHYSICAL AND CHEMICAL PROPERTIES

L-Valine is a white, odorless, crystalline powder with a slightly sweet to bitter taste. Its density is 1.23 g/cm³ at 25°C. The melting point is approximately 315°C, at which it sublimes, and the boiling point is approximately 298°C, at which it decomposes upon heating. It is soluble in water (88.5 g/L at 25°C) with solubility increasing at higher temperatures, but it is insoluble in ethanol and ether. The specific optical rotation is +27.0 to +29.0° (c=8, 6N HCl), confirming the L-configuration. The pKa values are 2.32 (carboxyl group) and 9.62 (amino group), with an isoelectric point of 5.96. The nitrogen content is approximately 11.9% by weight. Typical enantiomeric purity is ≥ 98.0% L-form (often ≥ 99%). Loss on drying is ≤ 0.3%, and residue on ignition is ≤ 0.1%. Heavy metals are typically ≤ 10 ppm (as Pb). Chloride and sulfate contents are each ≤ 0.05%.

3. CHEMICAL PROPERTIES AND REACTIONS

L-Valine is a branched-chain amino acid (BCAA) with a hydrophobic, aliphatic side chain. Its chemical behavior is determined by its amino acid functional groups and the branched isopropyl side chain.

Acid-Base Properties:

L-Valine has both carboxyl (COOH) and amino (NH₂) groups. In aqueous solution, it has the following ionization equilibria:

• pKa₁ (COOH): 2.32 (carboxyl group deprotonation)

• pKa₂ (α-NH₂): 9.62 (amino group deprotonation)

• Isoelectric Point: 5.96

Esterification:

L-Valine can be esterified with alcohols to form valine esters, which are used in pharmaceutical intermediates:

C₅H₁₁NO₂ + ROH → C₅H₁₁NO₂·OR + H₂O

Acylation:

The amino group of L-valine can be acylated to form N-acyl derivatives, which are used in peptide synthesis and pharmaceutical applications:

C₅H₁₁NO₂ + RCOCl → C₅H₁₁NO₂·NHCOR + HCl

Transamination:

L-Valine participates in transamination reactions, where its amino group is transferred to α-ketoglutarate to form glutamate and α-ketoisovalerate.

Decarboxylation:

L-Valine can be decarboxylated by the enzyme valine decarboxylase to form isobutylamine.

Maillard Reaction:

Like other amino acids, L-valine can participate in Maillard reactions with reducing sugars, forming brown pigments and flavor compounds.

Thermal Decomposition:

At temperatures above 315°C, L-valine decomposes to produce volatile compounds including ammonia, carbon dioxide, and various nitrogen-containing compounds.

4. PRODUCTION METHODS

L-Valine is produced industrially primarily through fermentation processes using microorganisms that have been developed to overproduce L-valine.

Detailed Production Process (Fermentation Method - Most Common):

1. Microorganism Cultivation: Genetically modified strains of Corynebacterium glutamicum or Escherichia coli that overproduce L-valine are cultivated in fermentation vessels containing glucose or sucrose 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-valine, 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-valine is purified from the broth using a series of steps, including ion exchange chromatography, activated carbon treatment, and crystallization.

5. Crystallization: The purified L-valine 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 appropriate containers.

5. PHYSIOLOGICAL FUNCTIONS AND HEALTH BENEFITS

L-Valine is an essential branched-chain amino acid (BCAA) that plays numerous critical roles in the body. It is involved in protein synthesis, muscle growth and repair, nitrogen balance regulation, and nervous system function.

5.1. Protein Synthesis and Muscle Growth

L-Valine is one of the essential amino acids required for protein synthesis. It is incorporated into proteins during translation and is necessary for the formation of all proteins in the body. Along with leucine and isoleucine, L-valine plays a critical role in muscle protein synthesis, promoting muscle growth and development.

5.2. Exercise Performance and Recovery

L-Valine, as part of the BCAA group, is widely used in sports nutrition. It helps reduce muscle breakdown during exercise, supports protein synthesis, and accelerates post-exercise recovery. It may also help reduce exercise-induced muscle soreness and improve endurance.

5.3. Nervous System Function

L-Valine plays a role in nervous system function. It is involved in the synthesis of neurotransmitters and may support mental clarity, cognitive function, and stress reduction. It has been studied for its potential benefits in central nervous system disorders.

5.4. Liver and Metabolic Support

L-Valine supports liver function and has been used in the treatment of liver failure and certain metabolic disorders. It plays a role in ammonia detoxification through the urea cycle.

5.5. Other Health Benefits

6. APPLICATIONS AND INDUSTRIAL USES

L-Valine has a wide range of applications in human nutrition, animal nutrition, pharmaceuticals, and the food industry.

6.1. Sports Nutrition and Dietary Supplements

L-Valine is most commonly used in sports nutrition and dietary supplements. It is a key component of BCAA blends (along with leucine and isoleucine) and is found in protein powders, pre-workout supplements, post-workout supplements, and endurance products. It helps promote muscle growth, accelerate recovery, and reduce muscle breakdown.

6.2. Medical and Pharmaceutical Applications

L-Valine is used in medical and pharmaceutical applications for the treatment of liver failure, hepatic encephalopathy, metabolic disorders (such as maple syrup urine disease - MSUD), and certain neurological conditions. It is also used in amino acid infusion solutions for parenteral nutrition.

6.3. Food Industry

L-Valine is used in the food industry to fortify functional foods, protein bars, sports drinks, and child nutrition products. It improves the nutritional profile of these products and provides health benefits.

6.4. Animal Nutrition

L-Valine is used in animal nutrition as a supplemental amino acid in feed, although its use is limited due to cost considerations. It is used in poultry and aquaculture feed to support growth and production.

7. DOSAGE AND ADMINISTRATION

8. POTENTIAL SIDE EFFECTS AND WARNINGS

9. DRUG INTERACTIONS

10. NATURAL FOOD SOURCES OF L-VALINE

11. SAFETY AND TOXICOLOGY

12. FIRST AID MEASURES

13. SAFETY INFORMATION (GHS CLASSIFICATION)

Signal Word: WARNING

Hazard Statements (H-Codes):

Precautionary Statements (P-Codes):

14. FIREFIGHTING MEASURES

15. ACCIDENTAL RELEASE MEASURES

16. STORAGE AND HANDLING

L-Valine should be stored below 25°C in cool, dry, well-ventilated areas, protected from light and moisture. It is slightly hygroscopic and should be protected from moisture. Containers should be kept tightly closed to prevent moisture absorption and contamination. It is incompatible with strong oxidizing agents, strong acids, and strong bases. 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

17. TRANSPORT INFORMATION

L-Valine 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.

18. REGULATORY INFORMATION

Regulatory Status:

19. OTHER NAMES AND DATABASE IDENTIFIERS

Database Identifiers:

20. SUMMARY AND CRITICAL WARNINGS

SUMMARY:

L-Valine (C₅H₁₁NO₂, CAS 72-18-4) is an essential amino acid belonging to the branched-chain amino acid (BCAA) family, along with L-leucine and L-isoleucine. It appears as a white, odorless, crystalline powder with a slightly sweet to bitter taste. The molecular weight is 117.15 g/mol, density is 1.23 g/cm³, melting point is approximately 315°C (sublimes), and water solubility is 88.5 g/L at 25°C. It is produced primarily through fermentation using microorganisms such as Corynebacterium glutamicum or Escherichia coli. L-Valine plays critical roles in protein synthesis, muscle growth and repair, nitrogen balance regulation, and nervous system function. It is widely used in sports nutrition (BCAA supplements, protein powders, pre- and post-workout formulas), dietary supplements, medical applications (liver failure treatment, metabolic disorders, parenteral nutrition), functional foods, and child nutrition. The recommended supplement dose is typically 500-1,500 mg per day (as part of BCAA blends, 2,000-5,000 mg per day). It is considered GRAS (Generally Recognized as Safe) by the FDA, but high doses may cause gastrointestinal distress. It is stored below 25°C in cool, dry, well-ventilated areas, protected from light and moisture. Packaging: 25 kg bags, drums, or FIBCs.

Key Properties:

Major Application Areas:

Key Safety Points:

• LOW TOXICITY: GRAS (Generally Recognized as Safe) 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 light and moisture

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

• SIDE EFFECTS: May cause gastrointestinal distress at high doses

• CONTRAINDICATIONS: Maple syrup urine disease (MSUD); severe kidney or liver disease

• DRUG INTERACTIONS: May interact with levodopa (L-Dopa) and other Parkinson's medications

CRITICAL WARNINGS:

Essential BCAA: L-Valine is one of the three branched-chain amino acids (BCAAs) along with leucine and isoleucine. It cannot be synthesized by the body and must be obtained through diet or supplementation. BCAAs are unique because they are metabolized primarily in muscle tissue rather than the liver, making them critical for muscle protein synthesis and energy production during exercise.

Muscle Growth and Recovery: L-Valine plays a critical role in muscle protein synthesis and repair. It helps reduce muscle breakdown during exercise, supports nitrogen balance, and accelerates post-exercise recovery. In combination with leucine and isoleucine, L-valine is widely used in sports nutrition for muscle building and performance enhancement.

BCAA Synergy: L-Valine works synergistically with L-leucine and L-isoleucine. Leucine is the primary activator of the mTOR pathway (which stimulates muscle protein synthesis), while valine and isoleucine support the process. BCAA blends typically contain a 2:1:1 or 3:1:1 ratio of leucine:isoleucine:valine.

Nervous System Support: L-Valine is involved in nervous system function and may help reduce central fatigue during prolonged exercise. It competes with tryptophan for transport across the blood-brain barrier, which may help reduce serotonin production and delay the onset of fatigue.

Maple Syrup Urine Disease (MSUD): L-Valine is strictly contraindicated in patients with maple syrup urine disease (MSUD), a rare genetic disorder characterized by the inability to metabolize branched-chain amino acids. Accumulation of branched-chain amino acids and their toxic byproducts can lead to severe neurological damage and death.

Liver Failure Treatment: L-Valine is used in the treatment of liver failure and hepatic encephalopathy. It helps correct the amino acid imbalance often seen in liver disease and may improve neurological symptoms.

Drug Interactions: L-Valine may interact with levodopa (L-Dopa) by competing for transport across the blood-brain barrier. Patients taking L-Dopa for Parkinson's disease should consult a healthcare professional before taking L-valine supplements.

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

Pregnancy and Lactation: L-Valine 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-valine. This is NOT a substitute for professional medical advice. Consult a healthcare professional before use, especially if taking medications, pregnant, or nursing.