Tryptophan, L-Tryptophan, Tryptasin, Trofan, 73-22-3, 80206-30-0

L-TRYPTOPHAN

L-Tryptophan / L-Triptofan / Tryptasin / Trofan / Essential Amino Acid / 3-Indol-3-ylalanine
CAS Number: 73-22-3 (standard); 80206-30-0 (alternative/special grade)
EC Number: 200-795-6

1. PRODUCT IDENTIFICATION AND CHEMICAL IDENTITY

L-Tryptophan is one of the nine essential amino acids that the human body cannot synthesize on its own and therefore must be obtained through diet or supplementation. Chemically, it is an aromatic amino acid consisting of an α-amino acid attached to an indole ring. L-Tryptophan is the precursor to important neurotransmitters such as serotonin and melatonin, making it crucial for the regulation of mood, sleep patterns, appetite, and cognitive functions. It appears as a white to yellowish crystalline powder, is odorless, and has a flat taste. As an essential amino acid, it is required for protein synthesis and also contributes to the synthesis of niacin (vitamin B3) in the body. L-Tryptophan is naturally found in protein-rich foods such as turkey, chicken, eggs, dairy products, soy products, nuts, and seeds. It is also produced synthetically or through fermentation for various applications including sports nutrition, dietary supplements, pharmaceuticals, and animal feed.

2. PHYSICAL AND CHEMICAL PROPERTIES

L-Tryptophan is a white to yellowish crystalline powder that is odorless and has a flat taste. It has a melting point of approximately 289°C, at which it decomposes. The boiling point is not applicable because it decomposes upon melting. Its solubility in water is low (approximately 11.4 g/L at 20°C), but it is soluble in dilute acids (such as citric acid) and alkali hydroxide solutions (such as sodium hydroxide and potassium hydroxide). The specific optical rotation is -30.0 to -33.0° (c=1, H₂O), confirming the L-configuration. The pKa values are 2.38 (carboxyl group) and 9.39 (amino group), with an isoelectric point of 5.89. The nitrogen content is approximately 13.7% by weight. Typical moisture content is ≤ 0.5%, and residue on ignition is ≤ 0.3%. Heavy metals are typically ≤ 10 ppm (as Pb). Particle size typically ranges from 100-500 µm, depending on the application.

3. CHEMICAL PROPERTIES AND REACTIONS

L-Tryptophan is an aromatic amino acid containing an indole ring. Its chemical behavior is determined by the amino acid functional groups (carboxyl and amino) and the reactivity of the indole ring.

Acid-Base Properties:

L-Tryptophan is an amino acid with both carboxyl (COOH) and amino (NH₂) groups. In aqueous solution, it has the following ionization equilibria:

• pKa₁ (COOH): 2.38 (carboxyl group deprotonation)

• pKa₂ (α-NH₂): 9.39 (amino group deprotonation)

• Isoelectric Point: 5.89

Oxidation:

L-Tryptophan reacts with oxidizing agents to form various oxidation products. The indole ring is sensitive to oxidation.

Decarboxylation:

L-Tryptophan is decarboxylated by the enzyme decarboxylase to form tryptamine:

C₁₁H₁₂N₂O₂ → C₁₀H₁₂N₂ + CO₂ (tryptamine)

Hydroxylation:

L-Tryptophan is hydroxylated by the enzyme tryptophan hydroxylase to form 5-hydroxytryptophan (5-HTP):

C₁₁H₁₂N₂O₂ + O₂ → C₁₁H₁₂N₂O₃ (5-HTP)

Decarboxylation (from 5-HTP):

5-HTP is decarboxylated by the enzyme aromatic L-amino acid decarboxylase to form serotonin:

C₁₁H₁₂N₂O₃ → C₁₀H₁₂N₂O + CO₂ (serotonin)

Melatonin Synthesis:

Serotonin is converted to melatonin (N-acetyl-5-methoxytryptamine) through N-acetylation and O-methylation.

Maillard Reaction:

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

Thermal Decomposition:

At temperatures above 289°C, L-tryptophan decomposes to form indole, ammonia, carbon dioxide, and various nitrogen-containing compounds.

4. PRODUCTION METHODS

L-Tryptophan is produced industrially primarily by three methods: fermentation, chemical synthesis, and enzymatic synthesis.

Detailed Production Process (Fermentation Method - Most Common):

1. Microorganism Cultivation: Genetically modified strains of Corynebacterium glutamicum or Escherichia coli that overproduce L-tryptophan 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-tryptophan, 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-tryptophan is purified from the broth using a series of steps, including ion exchange chromatography, activated carbon treatment, and crystallization.

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

6. Drying: The crystals are dried to reduce the moisture content to ≤ 0.5%.

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-Tryptophan is an essential amino acid that plays a role in many critical physiological functions. One of its most important roles is as a precursor to bioactive compounds such as the neurotransmitter serotonin and the hormone melatonin.

5.1. Serotonin Production and Mood Regulation

Serotonin is a crucial neurotransmitter involved in mood, emotion, appetite, and sleep regulation. L-Tryptophan is the direct precursor to serotonin in the brain. Adequate L-tryptophan intake helps maintain healthy serotonin levels. Low serotonin levels are associated with depression, anxiety, irritability, and other mood disorders. L-Tryptophan supplementation may help alleviate these symptoms by increasing serotonin levels.

5.2. Sleep Quality and Melatonin Production

Melatonin is a hormone that regulates the sleep-wake cycle (circadian rhythm). L-Tryptophan contributes to melatonin production through the serotonin pathway. L-Tryptophan supplementation can improve sleep quality, reduce the time to fall asleep, and alleviate symptoms of sleep disorders such as sleep apnea.

5.3. Cognitive Functions

Serotonin also plays a role in cognitive functions. Adequate serotonin levels are important for memory, learning, and concentration. L-Tryptophan supplementation may support cognitive performance.

5.4. Appetite and Weight Management

Serotonin is involved in appetite regulation. Higher serotonin levels can reduce appetite and increase feelings of satiety. L-Tryptophan supplementation may aid in weight management.

5.5. Other Health Benefits

6. APPLICATIONS AND INDUSTRIAL USES

L-Tryptophan has a wide range of applications in human nutrition, animal nutrition, pharmaceuticals, and various industrial sectors.

6.1. Dietary Supplements and Human Nutrition

L-Tryptophan is widely used as an ingredient in dietary supplements. It is found in formulations designed to improve sleep quality, enhance mood, reduce stress, support athletic performance, aid weight management, and support cognitive functions. It is often combined with other ingredients such as 5-HTP, melatonin, magnesium, and B vitamins.

6.2. Animal Nutrition and Feed Additives

L-Tryptophan is used as an essential amino acid supplement in animal nutrition. It is often a limiting amino acid in grain-based feeds. Supplementation improves the amino acid profile of the feed, promotes growth, and improves feed conversion efficiency.

6.3. Pharmaceutical Industry

L-Tryptophan is used in the pharmaceutical industry as an intermediate and component in various drug formulations. As a neurotransmitter precursor, it is an important component in the development of antidepressant and sleep-regulating medications. It is also used in amino acid infusion solutions for parenteral nutrition.

6.4. Food Industry

L-Tryptophan is used in the food industry for fortification and functional food applications. It is added to sports nutrition products, infant formulas, cereals, snacks, and beverages to improve the amino acid profile and provide health benefits.

6.5. Personal Care and Cosmetics

L-Tryptophan is used in skin and hair care products for its nourishing and reparative properties.

7. DOSAGE AND ADMINISTRATION

8. POTENTIAL SIDE EFFECTS AND WARNINGS

9. DRUG INTERACTIONS

10. NATURAL FOOD SOURCES OF L-TRYPTOPHAN

11. SAFETY AND TOXICOLOGY

1989 L-Tryptophan Incident:

In 1989, a contaminated batch of L-tryptophan produced in Japan caused an outbreak of eosinophilia-myalgia syndrome (EMS), a serious illness. Over 1,500 people became ill and 37 died. The issue was traced to an impurity (1,1'-ethylidene-bis-L-tryptophan) formed due to a change in the production process. Following this incident, L-tryptophan supplements were banned in the US for several years. Today, L-tryptophan is produced under strict quality control standards and is considered safe, but this incident highlights the importance of contamination risk in production processes.

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-Tryptophan should be stored below 25°C in cool, dry, well-ventilated areas, protected from light. 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-Tryptophan 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-Tryptophan (C₁₁H₁₂N₂O₂, CAS 73-22-3) is one of the nine essential amino acids that the human body cannot synthesize and must obtain through diet or supplementation. It appears as a white to yellowish crystalline powder that is odorless and has a flat taste. The molecular weight is 204.23 g/mol, melting point is approximately 289°C (decomposes), and water solubility is low (approximately 11.4 g/L at 20°C). It is produced through fermentation using microorganisms such as Corynebacterium glutamicum or Escherichia coli. L-Tryptophan is the precursor to important neurotransmitters such as serotonin and melatonin, making it critical for the regulation of mood, sleep patterns, appetite, and cognitive functions. It is used in dietary supplements for sleep support, mood support, athletic performance, weight management, and PMS/PMDD management. It is also used as an animal feed supplement, pharmaceutical intermediate, and food fortification ingredient. The recommended supplement dosage is typically 500-3,000 mg per day (depending on purpose and individual needs). It is considered GRAS (Generally Recognized as Safe) by the FDA, but high doses may cause gastrointestinal distress, dizziness, and drowsiness. It can interact with certain medications such as antidepressants and sedatives. It is stored below 25°C in cool, dry, well-ventilated areas, protected from moisture and light. 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

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

• SIDE EFFECTS: May cause gastrointestinal distress, dizziness, drowsiness at high doses

• DRUG INTERACTIONS: Interactions with antidepressants (SSRIs, MAOIs), sedatives; risk of serotonin syndrome

• CONTRAINDICATIONS: Severe liver or kidney disease; pregnancy and lactation (medical supervision)

CRITICAL WARNINGS:

Essential Amino Acid: L-Tryptophan is one of the nine essential amino acids that the body cannot synthesize. It must be obtained through diet or supplementation. Deficiency can lead to low serotonin levels, sleep disorders, mood changes, and other health issues.

Serotonin Precursor: L-Tryptophan is the direct precursor to serotonin in the brain. Serotonin is a crucial neurotransmitter involved in mood, emotion, appetite, and sleep regulation. Adequate L-tryptophan intake helps maintain healthy serotonin levels. Low serotonin levels are associated with depression, anxiety, irritability, and other mood disorders.

Melatonin Precursor: L-Tryptophan contributes to melatonin production through the serotonin pathway. Melatonin is a hormone that regulates the sleep-wake cycle (circadian rhythm). L-Tryptophan supplementation can improve sleep quality and reduce the time to fall asleep.

1989 EMS Incident: In 1989, contaminated L-tryptophan supplements caused an outbreak of eosinophilia-myalgia syndrome (EMS). This incident highlights the importance of product safety and quality control. Today, L-tryptophan is produced under strict quality control standards and is considered safe.

Drug Interactions - Serotonin Syndrome: L-Tryptophan may increase the risk of serotonin syndrome when taken with SSRIs, MAOIs, triptans, and other serotonergic drugs. Serotonin syndrome is a potentially life-threatening condition caused by excessive serotonin levels. Symptoms include agitation, confusion, tachycardia, hyperthermia, muscle rigidity, and convulsions. Individuals taking these medications should consult a healthcare professional before using L-tryptophan supplements.

Dosage and Administration: The recommended dose varies depending on the purpose and individual needs. For sleep support, typical doses range from 1,000-3,000 mg before bedtime. For mood support, typical doses range from 1,000-3,000 mg per day (divided doses). High doses (up to 6,000 mg/day) should be used under medical supervision. Taking with food may reduce gastrointestinal side effects.

Natural Food Sources: L-Tryptophan is naturally found in protein-rich foods such as turkey, chicken, eggs, dairy products, soy products, nuts, and seeds. Consuming these foods can help maintain healthy L-tryptophan levels.

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