L-Carnosine
Other Names: β-Alanylhistidine, (2S)-2-(3-Aminopropanamido)-3-(3H-imidazol-4-yl)propanoic acid, β-Alanyl-L-histidine

CAS Number: 305-84-0
Sum Formula: C₉H₁₄N₄O₃
Molar Mass: 226.24 g/mol
Appearance: White to off-white crystalline powder

L-Carnosine is a naturally occurring dipeptide composed of β-alanine and L-histidine. It contains both an imidazole ring and a free amino group, making it highly reactive towards carbonyl compounds. It is widely studied in chemical, biochemical, and material science applications for its buffering capacity and antioxidant properties.

Chemical and Physical Properties
Density: ~1.5 g/cm³ (estimated)
Melting Point: ~253°C (decomposes)
Boiling Point: Not applicable (decomposes)
Solubility in Water: Freely soluble (~25 g/L at 25°C)
Solubility in Other Solvents: Slightly soluble in alcohol; practically insoluble in ether and chloroform
Odor: Odorless

Applications
Peptide Chemistry: Used as a building block in the synthesis of bioactive peptides and peptide-based materials.
Material Science: Incorporated into hydrogels, coatings, and polymers for enhanced antioxidant and metal-chelating properties.
Analytical Chemistry: Studied in carbonyl trapping and metal ion detection systems.
Organic Synthesis: Applied as a nucleophilic component in reactions involving imidazole and peptide linkages.
Coordination Chemistry: Acts as a ligand in complexation with transition metals for catalytic or stabilization purposes.

Safety

This chemical does not meet GHS hazard criteria for 99% (104 of 105) of all reports.

Handling and Storage
Storage Conditions: Store in a tightly sealed container in a cool, dry, and well-ventilated place. Protect from light, heat, and moisture.
Handling Precautions: Avoid dust formation and direct exposure to eyes and mucous membranes. Use appropriate PPE and standard laboratory handling practices.