Glycine
[CAS# 56-40-6]

Identification

• Classification: Biochemical >> Common amino acids and protein drugs
• Name: Glycine
• Synonyms: Aminoacetic acid; Gly; Iconyl; Monazol
• Molecular Formula: C₂H₅NO₂
• Molecular Weight: 75.07
• Protein Sequence: G
• CAS Registry Number: 56-40-6
• EC Number: 200-272-2
• SMILES: C(C(=O)O)N

Properties

• Density: 1.595
• Melting point: 182 °C
• Boiling point: 233 °C
• Water solubility: 25 g/100 mL (25 °C)

Safety Data

• Hazard Symbols: GHS07 Warning
• Safety Statements: S22;S24/25

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Eye irritation	Eye Irrit.	2	H319
Skin irritation	Skin Irrit.	2	H315
Specific target organ toxicity - single exposure	STOT SE	3	H335

Discovery and Applications

Glycine is the simplest of the 20 amino acids commonly found in proteins. It plays a vital role in various biological processes and has a wide range of applications in medicine, industry, and research.

Glycine was first discovered in 1820 by French chemist Henri Braconnot while studying gelatin. Braconnot hydrolyzed gelatin with sulfuric acid and isolated glycine, a sweet crystalline substance. This discovery was an important milestone in understanding the composition of proteins and the role of amino acids in biological systems.

Glycine has a molecular formula of C2H5NO2 and is characterized by a simple structure: there is only one hydrogen atom in the side chain. This makes glycine unique among amino acids as it is the only one that is achiral. Glycine is extremely soluble in water and has an isoelectric point of about 6.06.

Glycine performs a variety of essential functions in the body. It is a building block of proteins and is incorporated into peptides and proteins during translation. Glycine acts as an inhibitory neurotransmitter in the central nervous system, especially in the spinal cord, brainstem, and retina. It is the main component of collagen, the most abundant protein in the human body, which provides structural support for tissues. Glycine is involved in the synthesis of various biomolecules, including heme, purines, and creatine.

Glycine is used in a variety of medical applications. It is used as a dietary supplement to support muscle growth, improve sleep quality, and promote overall health. Glycine is a component of certain intravenous (IV) solutions and oral rehydration salts. It is also used as a buffering agent in antacids.

Industrially, glycine has a variety of uses. Glycine is used as a flavor enhancer and a component of artificial sweeteners. Its sweet taste and ability to mask bitterness make it valuable in food processing. It is used in the production of herbicides, such as glyphosate, which is one of the most widely used herbicides worldwide.

Glycine is widely used in biochemical research and laboratory applications. It is used in buffer solutions for electrophoresis and other biochemical techniques due to its buffering capacity in the physiological pH range. Glycine is a component of many cell culture media, supporting the growth and maintenance of cells in vitro.

Glycine is also used in the cosmetic industry and is included in formulations for its moisturizing and conditioning properties. Glycine helps improve skin elasticity and smoothness.

Glycine is generally recognized as safe (GRAS) by regulatory agencies. It is well tolerated and has low toxicity, making it suitable for use in a variety of applications, including food and pharmaceuticals. Glycine’s applications range from medical and industrial uses to research and cosmetics, highlighting its versatility. Its fundamental role in biological processes and its functional properties make it a valuable substance in multiple fields. As a naturally occurring amino acid, glycine is biocompatible and can be easily utilized or metabolized by the human body. This makes it an ideal candidate for use in the medical and therapeutic fields.

References

2025. Effects of environmentally relevant concentrations of glyphosate and aminomethylphosphonic acid on biotransformation and stress response proteins in the liver of zebrafish (Danio rerio). Comparative Biochemistry and Physiology Part D: Genomics and Proteomics, 49.
DOI: 10.1016/j.cbd.2024.101366

2025. Determination of α-methylenecyclopropylglycine in Shahi and China litchi cultivars at three different maturity stages: A quantitative study using liquid chromatography tandem mass spectrometry. Food Chemistry, 466.
DOI: 10.1016/j.foodchem.2024.140971

1857. Zur Chemie der Nebennieren. Archiv für pathologische Anatomie und Physiologie und für klinische Medicin, 13(3-4).
DOI: 10.1007/bf01939540