L-Arginine L-pyroglutamate
Other Names: (2S)-2-amino-5-(diaminomethylideneamino)pentanoic acid; (2S)-5-oxopyrrolidine-2-carboxylic acid (1:1)

CAS Number: 56265-06-6
Sum Formula: C₁₁H₂₁N₅O₅
Molar Mass: 303.32 g/mol
Appearance: White to off-white crystalline powder

L-Arginine L-pyroglutamate is a 1:1 molecular complex (salt) composed of L-arginine, a basic amino acid, and L-pyroglutamic acid, a cyclic derivative of L-glutamic acid. This compound combines the basic guanidino group of arginine with the lactam functionality of pyroglutamate, leading to enhanced solubility and interesting properties useful in chemical, biochemical, and materials science applications.

Chemical and Physical Properties
Density: ~1.4 g/cm³ (estimated)
Melting Point: ~185–190°C (decomposes)
Boiling Point: Not applicable (decomposes)
Solubility in Water: Freely soluble
Solubility in Other Solvents: Slightly soluble in alcohol; practically insoluble in ether and nonpolar solvents
Odor: Odorless

Applications
Organic Synthesis: Used as an intermediate for peptide and amino acid derivative synthesis.
Biochemical Research: Studied for its dual functionalities involving nitrogen donation (arginine) and cyclic amide chemistry (pyroglutamate).
Material Science: Investigated for incorporation into biopolymers, hydrogels, and biofunctionalized materials.
Analytical Chemistry: Applied in studies related to amino acid complexation and stability profiling.
Surface Chemistry: Used to modify surfaces requiring multifunctional amino acid-based coatings.

Safety

This chemical does not meet GHS hazard criteria for 100% (2 of 2) of all reports.

Handling and Storage
Storage Conditions: Store in a tightly sealed container in a cool, dry, and well-ventilated place. Protect from moisture, heat, and strong oxidizing agents.
Handling Precautions: Avoid dust formation and contact with skin and eyes. Use appropriate PPE and standard laboratory safety procedures.