L-LEUCINE – L-LÖSİN

CAS Number: 61-90-5
EC Number (EINECS): 200-522-0
Molecular Formula: C₆H₁₃NO₂
Molecular Weight: 131.17 g/mol
Chemical Class: Essential amino acid (branched-chain amino acid - BCAA)

SECTION 1: CHEMICAL IDENTITY AND DEFINITION

Parameter	Information
Chemical Name (IUPAC)	(S)-2-Amino-4-methylpentanoic acid
Other Names	L-Leucine, Leucine, 2-Amino-4-methylpentanoic acid, L-α-Amino-4-methylpentanoic acid, (S)-α-Amino-4-methylpentanoic acid
Chemical Formula	C₆H₁₃NO₂
Molecular Weight	131.17 g/mol
CAS Number	61-90-5
EC Number (EINECS)	200-522-0
Chemical Class	Essential amino acid (branched-chain amino acid - BCAA)
Appearance	White, crystalline powder
Odor	Odorless
Taste	Slightly bitter
Physical State (20°C)	Solid (crystalline powder)
Optical Activity	L-form (natural, biologically active)
Solubility	Slightly soluble in water (~22 g/L at 25°C); insoluble in ethanol and ether

SECTION 2: PHYSICAL PROPERTIES

Property	Value
Appearance	White, crystalline powder
Odor	Odorless
Taste	Slightly bitter
Molecular Weight	131.17 g/mol
Melting Point	~293 °C (decomposes)
Density	~1.23 g/cm³
Solubility in Water (25°C)	Slightly soluble (~22 g/L)
Solubility in Ethanol	Insoluble
Solubility in Ether	Insoluble
pH (1% solution)	5.5 – 6.5
Specific Rotation [α]D²⁰	+14.5° to +16.5°
pKa₁ (COOH)	2.36
pKa₂ (NH₃⁺)	9.60
Isoelectric Point	5.98

SECTION 3: CHEMICAL PROPERTIES

Property	Information
Chemical Formula	C₆H₁₃NO₂
Molecular Weight	131.17 g/mol
Chemical Class	Essential amino acid (branched-chain amino acid - BCAA)
Functional Groups	Amino (-NH₂), carboxyl (-COOH)
Structure	α-amino acid with branched isobutyl side chain
SMILES	CC(C)CC(C(=O)O)N
InChI Key	ROHFNLRQFUQHCH-YFKPBYRVSA-N
Optical Activity	L-form (natural, biologically active)
Stability	Stable under normal storage conditions
Hygroscopicity	Low
Incompatible Materials	Strong oxidizing agents, strong acids, strong bases

Chemical Structure:

    NH₂
     |
CH₃-CH-CH₂-CH-COOH
    |
    CH₃

(L-Leucine / (S)-2-Amino-4-methylpentanoic acid)

SECTION 4: BIOLOGICAL SIGNIFICANCE

Parameter	Description
Essential Amino Acid	Cannot be synthesized by the human body; must be obtained from diet
BCAA Member	One of three branched-chain amino acids (leucine, isoleucine, valine)
Muscle Protein Synthesis	Primary activator of the mTOR pathway; initiates muscle protein synthesis
Muscle Growth	Most anabolic of all amino acids; critical for muscle hypertrophy
Recovery	Supports post-exercise muscle recovery and repair
Regulatory Role	Regulates protein metabolism; inhibits protein breakdown
Glucose Metabolism	May improve insulin sensitivity and glucose metabolism
Metabolism	Metabolized primarily in muscle tissue (not liver)

SECTION 5: BCAA COMPARISON

Property	L-Leucine	L-Isoleucine	L-Valine
Chemical Formula	C₆H₁₃NO₂	C₆H₁₃NO₂	C₅H₁₁NO₂
Molecular Weight	131.17 g/mol	131.17 g/mol	117.15 g/mol
Side Chain	Isobutyl	Sec-butyl	Isopropyl
Anabolic Effect	Strongest	Moderate	Moderate
mTOR Activation	Primary activator	Weak	Weak
Muscle Growth	Most critical	Important	Important
Energy Production	Moderate	Highest	Moderate
Common BCAA Ratio	2:1:1	1	1

SECTION 6: APPLICATION AREAS

6.1. Sports Nutrition (Highest Suitability)

Application	Function
BCAA Formulations	Most critical component; typically used in 2:1:1 ratio
Muscle Protein Synthesis	Activates mTOR pathway; initiates muscle growth
Muscle Recovery	Accelerates post-workout recovery
Pre-Workout Supplements	Prevents muscle breakdown during exercise
Post-Workout Supplements	Stimulates muscle protein synthesis
Protein Powders	Enriched with leucine for enhanced anabolic effect
Intra-Workout Drinks	Maintains performance; reduces fatigue

6.2. Dietary Supplements

Application	Function
Amino Acid Blends	Component in complete amino acid formulations
Protein Powders	Leucine-fortified protein supplements
Weight Management	Supports lean muscle mass preservation
General Health	Supports muscle maintenance

6.3. Medical Applications (Research Stage)

Application	Function
Sarcopenia	Age-related muscle loss prevention
Cachexia	Cancer-related muscle wasting treatment
Liver Disease	Hepatic encephalopathy research
Glucose Metabolism	Insulin sensitivity studies
Metabolic Research	Amino acid metabolism studies

6.4. Food Industry

Application	Function
Functional Foods	Fortified foods and beverages
Sports Drinks	Performance-enhancing beverages
Protein Bars	High-protein snack formulations

6.5. Research & Biochemistry

Application	Function
Amino Acid Metabolism	Metabolic pathway studies
Protein Synthesis	Mechanism of protein synthesis research
Enzyme Studies	Enzyme-substrate interaction research

SECTION 7: TYPICAL DOSAGE

Application	Recommended Daily Dose
Muscle Building (Athletes)	2-5 g/day (as part of BCAA 2:1:1)
General BCAA Supplementation	3-6 g/day
Post-Workout	2-3 g
Pre-Workout	2-3 g
Therapeutic Use	1-3 g/day (under supervision)
Typical BCAA Ratio	2:1:1 (Leucine:Isoleucine:Valine)

SECTION 8: QUALITY SPECIFICATIONS (FOOD GRADE)

Parameter	Specification (USP / Ph. Eur. / FCC)
Appearance	White, crystalline powder
Identification	Positive (IR, HPLC)
Assay (on dried basis)	98.5 – 101.5%
Specific Rotation [α]D²⁰	+14.5° to +16.5°
Loss on Drying	≤ 0.5%
Residue on Ignition	≤ 0.1%
pH (1% solution)	5.5 – 6.5
Chlorides (Cl)	≤ 0.02%
Sulfates (SO₄)	≤ 0.02%
Heavy Metals (as Pb)	≤ 10 ppm
Lead (Pb)	≤ 2 ppm
Arsenic (As)	≤ 3 ppm
Mercury (Hg)	≤ 1 ppm
Cadmium (Cd)	≤ 1 ppm
Ammonium (NH₄)	≤ 0.1%
Other Amino Acids	≤ 0.5%
Chiral Purity (HPLC)	≥ 99.0%

SECTION 9: MICROBIOLOGICAL SPECIFICATIONS

Parameter	Specification
Total Aerobic Mesophilic Bacteria	≤ 1,000 CFU/g
Yeast and Mold	≤ 100 CFU/g
Salmonella spp.	Negative in 25g
Escherichia coli	Negative in 10g
Staphylococcus aureus	Negative in 1g
Pseudomonas aeruginosa	Negative in 1g

SECTION 10: STORAGE AND SHELF LIFE

Parameter	Information
Storage Conditions	Cool (15-25°C), dry, well-ventilated area
Container Requirements	Tightly closed, original packaging
Protect From	Moisture, strong oxidizing agents, strong acids, strong bases
Shelf Life	24-48 months (unopened original packaging)

SECTION 11: PACKAGING OPTIONS

Packaging Type	Quantity	Material
Aluminum foil bag	1-5 kg	Laminated aluminum
PE-lined kraft paper bag	25 kg	Kraft paper + PE
Plastic pail	20-25 kg	HDPE
Fiber drum	25-50 kg	HDPE + PE
Big-Bag	500-1000 kg	Polypropylene (with PE liner)

SECTION 12: SAFETY AND HEALTH INFORMATION

GHS Classification (Bulk Powder)

Hazard Class	Category
Not classified as hazardous	-

Hazard Statements

Code	Statement
None	Not classified as hazardous

Precautionary Statements

Code	Statement
P261	Avoid breathing dust
P280	Wear protective gloves/eye protection
P305+P351+P338	IF IN EYES: Rinse cautiously with water for several minutes; remove contact lenses if present and easy to do; continue rinsing

SECTION 13: TOXICOLOGICAL INFORMATION

Parameter	Value
Oral LD50 (Rat)	> 5,000 mg/kg
Skin Irritation	Non-irritant
Eye Irritation	Mild irritant
Skin Sensitization	Non-sensitizer
Carcinogenicity	Not classified
Mutagenicity	Negative in standard tests
Reproductive Toxicity	No evidence of adverse effects
GRAS Status	Generally recognized as safe (GRAS)

SECTION 14: FIRST AID MEASURES

Exposure Route	Action
Inhalation	Move to fresh air. If respiratory irritation persists, seek medical attention.
Skin Contact	Wash with plenty of soap and water.
Eye Contact	Rinse immediately with plenty of water for at least 15 minutes. Seek medical attention.
Ingestion	Rinse mouth. Drink plenty of water. Seek medical attention.

SECTION 15: REGULATORY STATUS

Region / Authority	Status
European Union	Approved as food supplement ingredient
USA (FDA)	GRAS (Generally Recognized as Safe)
Turkey	Approved as food supplement ingredient
EFSA	Approved; nutritional substance
JECFA	Approved

SECTION 16: TRANSPORT INFORMATION

Parameter	Information
UN Number	Not regulated (not dangerous goods)
Hazard Class	Not applicable
Packing Group	Not applicable
ADR/RID	Not regulated
IMDG Code	Not regulated
IATA (Air)	Not regulated
Marine Pollutant	No

SECTION 17: FIRE-FIGHTING MEASURES

Parameter	Information
Fire Hazard	Combustible organic solid
Suitable Extinguishing Media	Water spray (mist), CO₂, dry chemical powder
Specific Hazards	When heated, emits CO, CO₂, nitrogen oxides
Decomposition Products	CO, CO₂, NOx
Protective Equipment	Self-contained breathing apparatus (SCBA), full protective clothing

SECTION 18: ACCIDENTAL SPILLAGE AND CLEANUP

Parameter	Information
Personal Protection	Nitrile gloves, protective goggles, dust mask (N95)
Cleaning Methods	Collect mechanically (sweep or spatula)
Environmental Precautions	Prevent entry into drains, soil, and surface waters
Waste Disposal	According to local regulations; landfilling at licensed facilities

SECTION 19: OTHER NAMES AND SYNONYMS

Type	Name
Turkish Names	L-Lösin, Lösin, Dallı Zincirli Aminoasit
English Names	L-Leucine, Leucine, Branched-Chain Amino Acid (BCAA)
Chemical Names	(S)-2-Amino-4-methylpentanoic acid, L-α-Amino-4-methylpentanoic acid
Abbreviation	Leu, L
CAS Number	61-90-5
EC Number	200-522-0

SECTION 20: SUMMARY AND CRITICAL NOTES

Product Summary

Parameter	Value
Product	L-Leucine
CAS Number	61-90-5
Appearance	White, crystalline powder
Molecular Weight	131.17 g/mol
Primary Function	Muscle protein synthesis activator
GRAS	Yes
BCAA Ratio	2:1:1 (Leucine:Isoleucine:Valine)

Critical Notes

Most Anabolic Amino Acid: Leucine is the most potent amino acid for stimulating muscle protein synthesis.
mTOR Activator: Primary activator of the mTOR pathway, which initiates muscle protein synthesis.
Essential Amino Acid: Cannot be synthesized by the human body; must be obtained through diet or supplementation.
BCAA Member: One of three branched-chain amino acids (leucine, isoleucine, valine); metabolized in muscle tissue (not liver).
Key for Athletes: Critical for muscle growth, recovery, and performance in sports nutrition.
Typical Ratio: Commonly used in 2:1:1 ratio (leucine:isoleucine:valine) in BCAA supplements.
Taste: Slightly bitter taste; often masked in flavored formulations.
Slightly Soluble: Limited solubility in water (~22 g/L at 25°C); insoluble in ethanol and ether.
Safety: Generally recognized as safe (GRAS); well-tolerated at recommended doses.
Regulatory Status: Approved as food supplement ingredient in EU, USA, and Turkey.

IMPORTANT DECLARATION: This Technical Data Sheet (TDS) is for informational purposes only and has been prepared based on available technical data. The user is responsible for determining the product's suitability for their specific application and for complying with all local, national, and international regulations. For complete safety, storage, use, transport, waste, and regulatory compliance information, refer to the official Safety Data Sheet (SDS/MSDS) provided by the manufacturer/supplier. This document does not replace medical advice.

Leucine, L-Leucine, 61-90-5

L-LEUCINE – L-LÖSİN

Images

Do you have questions? Let us help!