Zinc glycinate
[CAS# 14281-83-5]

Identification

• Classification: Biochemical >> Common amino acids and protein drugs
• Name: Zinc glycinate
• Synonyms: Zinc 2-aminoacetate; Bis(glycinato-N,O)zinc
• Molecular Formula: C₄H₈N₂O₄Zn
• Molecular Weight: 213.53
• CAS Registry Number: 14281-83-5
• EC Number: 238-173-1
• SMILES: C(C(=O)[O-])N.C(C(=O)[O-])N.[Zn+2]

Safety Data

• Hazard Symbols: GHS05;GHS07;GHS09 Danger
• Hazard Statements: H302-H315-H318-H400
• Precautionary Statements: P264-P264+P265-P270-P273-P280-P301+P317-P302+P352-P305+P354+P338-P317-P321-P330-P332+P317-P362+P364-P391-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Acute toxicity	Acute Tox.	4	H302
Serious eye damage	Eye Dam.	1	H318
Skin irritation	Skin Irrit.	2	H315
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Eye irritation	Eye Irrit.	2	H319

Discovory and Applicatios

Zinc glycinate is a coordination compound in which a zinc(II) ion is chelated by two glycinate ligands, the deprotonated form of the amino acid glycine. It is typically encountered as a crystalline solid that is soluble in water and has been studied for its stability and bioavailability as a source of dietary zinc. The structure is characterized by the bidentate coordination of each glycinate ligand through its amine nitrogen and carboxylate oxygen atoms, forming a stable chelate ring around the zinc center. This chelation reduces the reactivity of the free zinc ion and can enhance its stability in solution.

The compound’s preparation can be achieved by neutralizing glycine with a zinc(II) salt such as zinc oxide, zinc carbonate, or zinc acetate under controlled pH conditions. The reaction results in the replacement of protons on the glycine carboxylate groups with zinc, yielding the zinc glycinate complex. Control of stoichiometry and pH is important to obtain the desired 1:2 metal-to-ligand ratio and avoid the formation of basic zinc salts or polymeric species. The solid product can be isolated by evaporation or crystallization and may be further characterized by spectroscopic techniques such as infrared spectroscopy, which confirms metal–ligand coordination, and by elemental analysis.

Zinc glycinate has found applications mainly in the field of nutritional supplementation. Zinc is an essential trace element involved in numerous biological processes, including enzymatic catalysis, protein and DNA synthesis, immune system function, and wound healing. The glycinate form has been studied for its potential to improve zinc absorption in the gastrointestinal tract compared with inorganic zinc salts. Chelation with glycine may protect zinc from forming insoluble complexes with dietary components such as phytates, which can limit its bioavailability. For this reason, zinc glycinate is included in some dietary supplements and fortified foods designed to address or prevent zinc deficiency.

Beyond nutritional applications, zinc glycinate has been evaluated in agriculture as a source of zinc for plants. Foliar sprays or soil applications containing zinc in chelated form can supply this micronutrient more efficiently to crops, especially in soils with high pH where inorganic zinc salts are poorly soluble. Its use in animal feed supplementation follows similar principles, providing a stable and bioavailable form of zinc to support growth, reproduction, and immune health in livestock.

In the pharmaceutical and cosmetic sectors, zinc glycinate has been incorporated into topical formulations for skin care, where zinc plays a role in modulating inflammation and supporting barrier function. The mild nature of the glycine ligand makes it suitable for formulations intended for sensitive skin. Furthermore, research has explored the use of amino acid–chelated metals in drug delivery and antimicrobial treatments, with zinc glycinate being one of the candidates due to the known antimicrobial properties of zinc ions.

In industrial chemistry, while zinc glycinate itself is not a large-scale commodity chemical, its synthesis and stability are of interest in the broader context of metal–amino acid complexes, which have roles as catalysts, corrosion inhibitors, and in specialty coatings. The coordination chemistry of zinc with amino acids also serves as a model for understanding metal–protein interactions in biological systems.

References

2024. Zinc glycinate alleviates LPS-induced inflammation and intestinal barrier disruption in chicken embryos by regulating zinc homeostasis and TLR4/NF-?B pathway. Ecotoxicology and Environmental Safety, 272.
DOI: 10.1016/j.ecoenv.2024.116111

2023. Effect of combined in ovo administration of zinc glycine chelate (Zn-Gly) and a multistrain probiotic on the modulation of cellular and humoral immune responses in broiler chickens. Poultry Science, 102(9).
DOI: 10.1016/j.psj.2023.102823

2017. Effects of Zinc Glycinate on Productive and Reproductive Performance, Zinc Concentration and Antioxidant Status in Broiler Breeders. Biological Trace Element Research, 178(2).
DOI: 10.1007/s12011-016-0928-4