GLYCINE (56-40-6)

GLYCINE (56-40-6) is the CAS-registered identity of glycine, H2NCH2COOH, the smallest and only achiral proteinogenic amino acid, produced industrially by chemical synthesis as a white crystalline powder in technical, food and pharmaceutical grades for glyphosate and fine chemical synthesis, metal finishing, feed and mineral chelates, food, supplements, pharmaceuticals, cosmetics and laboratory buffers.
Glycine is a preferred raw material for chemists and formulators because it is inexpensive, available in very high purity, highly water-soluble, practically non-toxic and bifunctional, with one amino group and one carboxyl group that allow it to buffer, chelate metals, form salts and esters, and react as a building block.
Aminoacetic acid behaves as a zwitterion (H3N+CH2COO−) in water and in the crystal, so its chemistry is controlled by pH: it can be protonated to the glycinium cation, deprotonated to the glycinate anion, coordinated to metal ions through nitrogen and oxygen, or acylated, esterified and condensed into peptides.

CAS No: 56-40-6
EC No: 200-272-2
Molecular formula: C2H5NO2
Molecular weight: 75.07 g/mol
Linear formula: H2NCH2COOH
Appearance: White crystals or crystalline powder
Melting point: approx. 233 °C (decomposes)
Solubility in water: approx. 25 g/100 g water at 25 °C

COMMON PRODUCT & CHEMICAL NAMES OF GLYCINE (56-40-6):

GLYCINE (56-40-6), Glycine, GLYCINE, Aminoacetic Acid, Amino Acetic Acid, 2-Aminoacetic Acid, Aminoethanoic Acid, 2-Aminoethanoic Acid, Glycocoll, Glycocol, Gly, G, Glycinum, Acide Aminoacétique, Glycin, Glicina, Glisin, Glycine Technical Grade, Glycine Food Grade, Glycine Feed Grade, Glycine USP, Glycine EP/BP, Glycine JP, Glycine FCC, E640, INS 640

The number in GLYCINE (56-40-6) is its CAS Registry Number, the most reliable way to identify the substance in purchase orders, SDS and customs documents. Glycine, aminoacetic acid and 2-aminoethanoic acid are equivalent chemical names, glycocoll is a historic name, Glicina, Glycin and Glisin are the Spanish/Italian, German and Turkish forms. Grade designations such as USP, EP, JP and FCC refer to the pharmacopoeia or food standard that the GLYCINE (56-40-6) lot complies with.
Several related substances have their own CAS numbers and must not be substituted for GLYCINE (56-40-6): glycine hydrochloride (6000-43-7), sodium glycinate (6000-44-8), glycine ethyl ester hydrochloride, glycylglycine, N-acetylglycine, sarcosine (N-methylglycine), betaine (trimethylglycine), metal glycinates and glyphosate.

WHAT IS GLYCINE (56-40-6)?

In terms of volume, GLYCINE (56-40-6) is one of the most important amino acids made by chemical synthesis rather than fermentation. The largest share of technical-grade GLYCINE (56-40-6) goes into the production of the herbicide glyphosate, further large uses are feed and mineral chelates, food and beverages, pharmaceuticals and personal care.
2-Aminoethanoic acid is attractive for industry for simple reasons. It is a small, stable crystalline solid that does not need special storage, it dissolves readily in water to give near-neutral solutions, and it does not have optical isomers, so there is no need to control chirality. Its low toxicity and natural occurrence make GLYCINE (56-40-6) acceptable in food, pharmaceuticals and cosmetics, while its reactivity makes it a useful intermediate.

Biologically, glycine accounts for about one third of the amino acids in collagen and gelatin, is a precursor of creatine, glutathione, heme and purines, conjugates bile acids and benzoic acid (forming hippuric acid), and acts as a neurotransmitter. These functions explain why GLYCINE (56-40-6) is also widely sold as a nutritional ingredient.

STRUCTURE AND SOLID-STATE CHEMISTRY OF GLYCINE (56-40-6)

Zwitterion: in crystals of GLYCINE (56-40-6), the molecules are present as H3N+CH2COO− and are linked by strong hydrogen bonds, which explains the high melting (decomposition) temperature and insolubility in non-polar solvents.
Polymorphs: GLYCINE (56-40-6) crystallises in three ambient-pressure polymorphs. The alpha form (monoclinic) is the usual commercial form obtained from water, the gamma form is the thermodynamically most stable form at room temperature and crystallises, for example, from acidic or basic solutions, the beta form is metastable. Polymorphism matters in crystallisation processes and in pharmaceutical development.
Achirality: the central carbon of GLYCINE (56-40-6) carries two hydrogen atoms, so there is no stereocentre and no L- or D-form.

CAS NO, EC / EINECS NO AND CHEMICAL IDENTIFICATION OF GLYCINE (56-40-6)

Product name: GLYCINE (56-40-6)
Chemical name: Glycine (aminoacetic acid)
CAS No: 56-40-6
EC / EINECS No: 200-272-2
Molecular formula: C2H5NO2
Molecular weight: 75.07 g/mol
SMILES: NCC(O)=O, zwitterion: [NH3+]CC([O-])=O
InChI: InChI=1S/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5)
InChIKey: DHMQDGOQFOQNFH-UHFFFAOYSA-N
PubChem CID: 750
EU food additive: E640 (glycine and its sodium salt)
INCI: Glycine
Customs (commonly used HS heading): 2922 (amino acids)
Chemical class: Alpha-amino acid, achiral

PHYSICAL AND CHEMICAL PROPERTIES OF GLYCINE (56-40-6)

Appearance: White, odourless crystals or crystalline powder
Taste: Sweet
Melting point: approx. 233 °C, with decomposition
Density: approx. 1.6 g/cm³ (alpha form)
pKa values: 2.34 (COOH), 9.60 (NH3+)
Isoelectric point: approx. 5.97
pH of a 5 % aqueous solution: approx. 5.9–6.4
Solubility in water (approximate literature values, g per 100 g water): 0 °C: 14, 25 °C: 25, 50 °C: 39, 75 °C: 54, 100 °C: 67
Solubility in alcohols: very low (sparingly soluble in ethanol, practically insoluble in higher alcohols)
Solubility in non-polar solvents: Practically insoluble (ether, hydrocarbons)
Bulk properties: Free-flowing crystalline powder, non-hygroscopic under normal conditions
Thermal behaviour: Decomposes on melting, forming 2,5-diketopiperazine, ammonia, carbon oxides and other products

Because the solubility of GLYCINE (56-40-6) rises steeply with temperature, it is purified by cooling crystallisation, and concentrated solutions should not be cooled below their saturation temperature during storage.

REACTIONS OF GLYCINE (56-40-6)

Acid–base and salt formation: GLYCINE (56-40-6) forms glycine hydrochloride with HCl and sodium glycinate with NaOH.
Metal complexation: GLYCINE (56-40-6) forms five-membered chelate rings with metal ions through its amino nitrogen and carboxylate oxygen, examples are copper(II) bisglycinate, iron(II) bisglycinate, zinc bisglycinate and magnesium bisglycinate.
Esterification: with alcohols and acid, GLYCINE (56-40-6) forms glycine esters, usually isolated as hydrochlorides (for example glycine methyl or ethyl ester hydrochloride).
Acylation: with acid chlorides, GLYCINE (56-40-6) forms N-acylglycines, for example hippuric acid (with benzoyl chloride), N-acetylglycine and N-acyl glycinate surfactants (such as sodium cocoyl glycinate).
Alkylation: methylation leads to sarcosine, N,N-dimethylglycine and betaine.
Peptide formation: condensation gives glycylglycine and higher peptides, heating gives the cyclic dipeptide 2,5-diketopiperazine.
Reaction with aldehydes: GLYCINE (56-40-6) forms Schiff bases with aldehydes and takes part in Maillard reactions with reducing sugars (browning and flavour formation).
Reaction with nitrous acid: gives glycolic acid and nitrogen (basis of the Van Slyke amino nitrogen determination).
Phosphonomethylation: reaction with formaldehyde and phosphorous acid derivatives is the basis of glyphosate production via the glycine route.

GRADES AND TYPICAL SPECIFICATIONS OF GLYCINE (56-40-6)

Pharmaceutical grade (USP / Ph. Eur. / JP): for infusions, irrigation solutions, oral and parenteral drug products and excipient use. Typical requirements include an assay of about 98.5–101.5 % on dried basis, low limits for chloride, sulphate, ammonium, iron and heavy metals, loss on drying and residue on ignition of about 0.1–0.2 % max., and controlled related substances. The current monograph of the chosen pharmacopoeia applies.
Food grade (FCC / E640): for flavouring, buffering and food supplements, specifications follow the FCC and the EU food additive specifications (Regulation (EU) No 231/2012).
Feed grade: for premixes and chelate manufacture.
Technical grade: for glyphosate and other chemical synthesis, metal finishing and industrial uses, typically about 98.5 % or higher, with specifications adapted to the process.

Exact specifications and certificates for each grade of GLYCINE (56-40-6) are available on request from Ataman Kimya.

APPLICATIONS OF GLYCINE (56-40-6) BY INDUSTRY

AGROCHEMICALS
Technical GLYCINE (56-40-6) is a main raw material for glyphosate production by the glycine process, and an intermediate for other active substances such as iprodione and imiprothrin.

METAL AND ELECTRONICS INDUSTRIES
The amino acid acts as a complexing agent and buffer in copper and nickel plating, electroless plating and copper chemical-mechanical planarisation (CMP) slurries in semiconductor manufacturing, where it complexes dissolved copper and controls removal rates.

CHEMICAL SYNTHESIS
Glycine is a building block for amino acid derivatives, peptides, N-acyl glycinate surfactants, metal glycinates, pharmaceutical intermediates (for example for some antibiotics) and research chemicals.

ANIMAL NUTRITION
Aminoacetic acid is the ligand in metal glycinate chelates (iron, zinc, copper, manganese) used in feed premixes, in some low-protein poultry diets, glycine is also supplemented directly.

FOOD AND BEVERAGES
In the EU, GLYCINE (56-40-6) is permitted as flavour enhancer E640. It gives a mild sweetness, rounds off salty and sour tastes, masks bitter aftertastes of some sweeteners, and acts as a buffer. In the USA its use in food is regulated by 21 CFR 172.812 under specific conditions.

DIETARY SUPPLEMENTS
2-Aminoethanoic acid is sold as powder or capsules and used in collagen, amino acid, sleep-support and sports nutrition blends. Health-related claims must follow the applicable regulations.

PHARMACEUTICALS AND MEDICAL PRODUCTS
Pharmaceutical-grade GLYCINE (56-40-6) is used in amino acid infusions, in non-electrolytic irrigation solutions for some urological procedures, as a buffer and stabiliser in tablets and buffered analgesics and antacids, and as an excipient and bulking agent in lyophilised biologics and vaccines.

COSMETICS AND PERSONAL CARE
As INCI Glycine, it is used as a buffering, skin-conditioning and hair-conditioning ingredient in creams, serums, masks, shampoos and conditioners, glycine is part of the skin's natural moisturising factor. The amino acid is also a ligand in aluminium zirconium tetrachlorohydrex Gly antiperspirant actives and the starting material for glycinate surfactants.

LABORATORY AND BIOTECHNOLOGY
Glycine is a component of Tris-glycine electrophoresis buffers and transfer buffers, glycine–HCl elution and stripping buffers, glycine–NaOH buffers, and a quenching agent for formaldehyde and glutaraldehyde in fixation and crosslinking.

WHICH PROBLEMS DOES GLYCINE (56-40-6) SOLVE?

- An inexpensive, high-purity amine building block without chirality issues is needed → GLYCINE (56-40-6).
- Copper must be kept in solution and its dissolution rate controlled in plating or CMP → GLYCINE (56-40-6) complexes copper.
- A mineral source with good stability for feed or supplements is needed → GLYCINE (56-40-6) forms metal glycinates.
- A protein band separation system needs a defined ion front → GLYCINE (56-40-6) is the trailing ion in Tris-glycine SDS-PAGE.
- Bitter or harsh aftertaste in a product → GLYCINE (56-40-6) adds mild sweetness and rounds off taste.
- Excess aldehyde after fixation → GLYCINE (56-40-6) quenches it.

THINGS TO CONSIDER WHEN USING GLYCINE (56-40-6)

- Specify the CAS number and grade in orders to avoid confusion with glycine salts, esters or derivatives.
- Match the grade to the application: technical grade is not intended for food, feed or pharmaceutical use.
- Control temperature in concentrated solutions to avoid crystallisation.
- Consider the Maillard reaction in heated systems containing reducing sugars.
- Do not use glycine-containing buffers for reactions with aldehydes, NHS esters or other amine-reactive reagents, because GLYCINE (56-40-6) will react with them.
- In crystallisation processes, control polymorphism if a defined crystal form is required.
- Check local food, feed, supplement and cosmetic regulations for permitted uses and claims.

INITIAL FORMULATION APPROACHES WITH GLYCINE (56-40-6)

The added percentage compositions are illustrative laboratory starting mixtures, not validated commercial recipes. Percentages are by weight and total 100.00 %. Final concentrations, pH, suitability and regulatory compliance must be established through testing. Mass percentages do not define exact molarity without the actual final volume.

1. TRIS-GLYCINE SDS RUNNING BUFFER (CLASSIC LAEMMLI SYSTEM, 1×)
Illustrative initial components (% w/w):
Purified water: 98.155806 %
Tris base: 0.302850 %
Glycine: 1.441344 %
Sodium dodecyl sulphate (SDS): 0.100000 %
Total: 100.000000 %
These mass fractions are calculated for a nominal solution density of 1.00 kg/L using 121.14 g/mol for Tris and 75.07 g/mol for glycine. Confirm actual final volume when preparing the stated molar buffer, these are not exact molar concentrations defined solely by mass.

25 mM Tris base, 192 mM GLYCINE (56-40-6) and 0.1 % SDS in purified water, the pH is about 8.3 without adjustment. A 10× stock is often prepared without SDS or with 1 % SDS and diluted before use.

2. GLYCINE–NAOH BUFFER, PH AROUND 9.5–10
Illustrative initial components (% w/w):
Water: 99.0041 %
Glycine: 0.7507 %
Sodium hydroxide (100 % basis): 0.2452 %
Total: 100.0000 %
This is an illustrative partial-neutralisation mixture for evaluation near pH 9.8, not a guaranteed pH specification. The nominal glycine level corresponds to 0.1 M only at a solution density of 1.00 kg/L. Measure final pH and volume, adjust the alkali and balance any change against water. Add alkali slowly to water with cooling and suitable eye and skin protection.

Prepare 0.1 M GLYCINE (56-40-6) in water and titrate with sodium hydroxide solution to the desired pH within the range of about 8.6–10.6. Use it for alkaline enzyme assays or as an alkaline buffer where amines are acceptable.

3. TASTE-ROUNDING IN A BEVERAGE OR SUPPLEMENT POWDER
Illustrative initial components for a beverage screening trial (% w/w):
Pre-established beverage base: 99.90 %
Glycine (food grade): 0.10 %
Total: 100.00 %
The 0.10 % glycine level is an illustrative sensory screening point, not a legal maximum or universal recommended dosage. The beverage base must already have its own defined composition. Confirm permitted use and assess taste, stability and the finished product's preservation requirements.

Add GLYCINE (56-40-6) at a low level to a beverage or powdered drink containing high-intensity sweeteners, minerals or bitter actives, and evaluate the taste profile in sensory tests. Check that the use complies with E640 or other local food additive rules.

These are starting points, quantities and conditions must be validated for each application.

ALTERNATIVES TO GLYCINE (56-40-6)

L-Alanine: similar small amino acid with different taste and buffering.
Glycine hydrochloride or sodium glycinate: salt forms of glycine for specific pH or solubility needs.
Betaine and sarcosine derivatives: related N-methylated compounds.
Iminodiacetic acid, EDTA, citrate, gluconate: alternative complexing agents for plating and cleaning.
Tris, bicine, tricine and phosphate buffers: alternative laboratory buffers.
Sucralose, stevia and other sweetness modifiers: alternatives for taste masking.

HOW DOES GLYCINE (56-40-6) WORK AT THE MOLECULAR LEVEL?
 
Glycine (56-40-6) is the smallest amino acid, consisting of an amino group and a carboxyl group attached to a single carbon that carries only hydrogen atoms as its side chain. With no bulky or reactive side group, aminoacetic acid behaves almost entirely through its two ionisable groups, its very small size and its ability to bind metals. These features explain its roles in food, pharmaceuticals, laboratory work and the body.
 
Zwitterion and solubility: In water and in the solid state, the molecule exists mainly as a zwitterion, with a positively charged ammonium group and a negatively charged carboxylate group on the same molecule. This internal salt structure gives strong interactions with water, high water solubility and a high melting point with decomposition, while making the amino acid almost insoluble in non-polar solvents.
 
Buffering behaviour: Each ionisable group can gain or lose a proton. The carboxyl group buffers in the acidic range and the amino group buffers in the alkaline range, while the zwitterion dominates in between. Glycine-based buffers are therefore used at low or high pH rather than near neutrality. In foods, this ability to take up or release protons also softens sharp acidic or salty taste impressions.
 
Taste effect: Aminoacetic acid has a pleasant sweet taste and is perceived through sweet taste receptors. When added to foods and beverages, it rounds out flavour, reduces perceived bitterness or metallic notes from ingredients such as some sweeteners, and supports savoury and salty profiles. This combination of sweetness and buffering explains its use as a flavour enhancer and taste modifier.
 
Metal chelation: The amino nitrogen and one carboxylate oxygen can bind the same metal ion and form a stable five-membered ring. Two glycine molecules bound to one divalent ion give metal bisglycinates, for example of iron, zinc, magnesium or calcium. In these chelates the mineral is protected from reacting with other food components, which is why glycinate forms are used in mineral fortification and supplements.
 
Reaction with reducing sugars: The free amino group reacts with carbonyl groups of reducing sugars in the Maillard reaction. Under heat, this pathway forms brown pigments and aroma compounds, so the amino acid can contribute to colour and roasted flavour in processed foods and flavour systems.
 
Reaction with aldehydes: The same primary amine reacts readily with formaldehyde and glutaraldehyde. Glycine (56-40-6) is therefore used to quench excess aldehyde after crosslinking or fixation steps, and to scavenge free aldehyde in some formulations.
 
Use in protein work: In Tris–glycine electrophoresis buffers, the charge of the glycinate ion changes with pH between gel layers, this shift in mobility concentrates proteins into sharp bands before separation. In freeze-dried protein and peptide products, the amino acid acts as a bulking agent that crystallises during freezing and helps form a stable, elegant cake. Its small zwitterionic structure can also help stabilise proteins in solution by influencing their hydration.
 
Role in the body: Glycine is a building block of proteins and is especially abundant in collagen, where its small size allows the tight packing of the triple helix. It is also used to build glutathione, creatine, haem and purines, and to conjugate bile acids. In the central nervous system, it acts as an inhibitory neurotransmitter by opening chloride channels of glycine receptors, mainly in the spinal cord and brain stem, and as a co-agonist at NMDA-type glutamate receptors.
 
Its performance in a given system depends on concentration, pH, temperature, the presence of metal ions and sugars, and the other ingredients used. Glycine (56-40-6) dosage and process conditions should therefore be confirmed through laboratory trials.

QUALITY CONTROL AND PURCHASING CRITERIA FOR GLYCINE (56-40-6)

- CAS 56-40-6 and EC 200-272-2 on all documents
- grade and standard: technical, feed, FCC/E640, USP, Ph. Eur., JP
- assay and loss on drying
- chloride, sulphate, ammonium, iron and heavy metals
- residue on ignition
- pH of a 5 % solution and clarity/colour of solution
- particle size distribution (crystals, powder, fine powder)
- microbiological quality for food and pharmaceutical grades
- certificates: GMP, DMF/CEP (pharmaceutical), halal, kosher, non-GMO, allergen and residual solvent statements
- COA, TDS and SDS

Specifications, certificates and samples of GLYCINE (56-40-6) are available on request from Ataman Kimya.

STORAGE AND HANDLING OF GLYCINE (56-40-6)

Keep GLYCINE (56-40-6) in its original, tightly closed packaging in a dry, cool and well-ventilated warehouse, away from moisture, heat sources, direct sunlight and strong oxidisers. Stack bags on pallets and protect them from damage. Avoid generating dust during filling and emptying, use local exhaust where needed and keep areas clean to prevent dust accumulation. Food and pharmaceutical grades should be handled with dedicated, clean equipment. The shelf life of the supplied grade is available on request from Ataman Kimya.

SAFETY OF GLYCINE (56-40-6)

Aminoacetic acid is generally not classified as hazardous under the EU CLP Regulation and is not dangerous goods for transport. Its acute oral toxicity is very low (rat LD50 about 7.9 g/kg).
Dust can cause mechanical irritation of eyes and airways, wear safety glasses and, for dusty operations, a dust mask.
First aid: fresh air after inhalation of dust, rinse eyes with water, wash skin with water, after swallowing large amounts, rinse the mouth and drink water.
Fire: combustible solid, extinguish with water spray, foam, dry powder or CO2, combustion produces nitrogen and carbon oxides. Fine dust may form explosive mixtures with air.
Environment: readily biodegradable, naturally occurring.
The SDS of the supplied GLYCINE (56-40-6) grade is available on request from Ataman Kimya.

BUYING GLYCINE (56-40-6)

2-Aminoethanoic acid is commonly supplied in 25 kg multi-wall paper bags or woven bags with PE liner, in fibre drums for pharmaceutical grades and in big bags for technical customers. When ordering, please give the CAS number, grade and standard, particle size, quantity, packaging and the documents needed (for example COA, DMF/CEP, halal or kosher certificates). Available grades and lead times are available on request from Ataman Kimya.

SUPPLY OF GLYCINE (56-40-6) FROM ATAMAN KIMYA

Ataman Kimya supplies GLYCINE (56-40-6) in technical, feed, food and pharmaceutical grades to agrochemical, chemical, metal finishing, feed, food, supplement, cosmetic and pharmaceutical manufacturers. Ataman Kimya provides SDS, TDS, COA and regulatory documentation and supports grade selection and logistics. For prices and samples, please contact Ataman Kimya.

FREQUENTLY ASKED QUESTIONS ABOUT GLYCINE (56-40-6)

WHAT DOES 56-40-6 MEAN?
It is the CAS Registry Number of glycine (aminoacetic acid).

WHICH EC NUMBER BELONGS TO GLYCINE (56-40-6)?
EC 200-272-2.

WHAT IS THE DIFFERENCE BETWEEN TECHNICAL AND PHARMACEUTICAL GLYCINE (56-40-6)?
Both are the same molecule, pharmaceutical grade meets pharmacopoeia limits for purity, impurities and microbiology and is produced under GMP, while technical grade is intended for industrial synthesis and applications.

WHY IS GLYCINE (56-40-6) USED IN GLYPHOSATE PRODUCTION?
Glyphosate is N-(phosphonomethyl)glycine, in the glycine process, glycine provides the amino acid backbone.

IS GLYCINE (56-40-6) HYGROSCOPIC?
Under normal conditions it is practically non-hygroscopic, but it should still be stored dry.

AT WHAT PH IS GLYCINE (56-40-6) NEUTRAL OVERALL?
At its isoelectric point of about pH 6.0, where the zwitterion dominates.

CAN GLYCINE (56-40-6) BE AUTOCLAVED IN SOLUTION?
Glycine solutions are heat stable and are sterilised in pharmaceutical production, but heating with reducing sugars causes Maillard browning.

IS GLYCINE (56-40-6) THE SAME AS GLYCINE HYDROCHLORIDE?
No. Glycine hydrochloride is a salt with CAS 6000-43-7.

GLYCINE (56-40-6) – TECHNICAL SUMMARY

Product name: GLYCINE (56-40-6)
Chemical name: Glycine (aminoacetic acid)
CAS No: 56-40-6
EC No: 200-272-2
Molecular formula: C2H5NO2
Molecular weight: 75.07 g/mol
Appearance: White crystals or crystalline powder
Melting point: approx. 233 °C (dec.)
Water solubility: approx. 14 g/100 g (0 °C), 25 g/100 g (25 °C), 67 g/100 g (100 °C)
pKa: 2.34 / 9.60, isoelectric point approx. 5.97
pH (5 % solution): approx. 5.9–6.4
Grades: Technical, feed, food (FCC/E640), pharmaceutical (USP/EP/JP)
Main uses: Glyphosate and chemical synthesis, metal plating and CMP, feed and mineral glycinates, food and supplements, pharmaceuticals, cosmetics, laboratory buffers
Hazard classification: Generally not classified (CLP)
Storage: Dry, closed, room temperature

GLYCINE (56-40-6) can be sourced from ATAMAN KİMYA. For further information and supply inquiries about GLYCINE (56-40-6), please contact ATAMAN KİMYA.