Name | Glycine |
Synonyms | Gly Glycine H-Gly-OH glycocoll L-Glycine Glycine BP GLYCINE USP BLOTTING BUFFER Aminoacetic acid GLYCINE TECHNICAL Glycine, Free Base USP24 GLYCINE USP24 Glycine (Food Grade) Glycine (Feed Grade) Glycine (Tech Grade) Glycine (Pharm Grade) |
CAS | 56-40-6 |
EINECS | 200-272-2 |
InChI | InChI=1/C2H5NO2/c3-1-2(4)5/h1,3H2,(H,4,5) |
InChIKey | DHMQDGOQFOQNFH-UHFFFAOYSA-N |
Molecular Formula | C2H5NO2 |
Molar Mass | 75.07 |
Density | 1.595 |
Melting Point | 240 °C (dec.) (lit.) |
Boling Point | 233°C |
Flash Point | 176.67°C |
JECFA Number | 1421 |
Water Solubility | 25 g/100 mL (25 ºC) |
Solubility | Soluble in water, solubility in water: 25g/100ml at 25°C; 39.1g/100ml at 50°C; 54.4g/10 Chemicalbook0ml at 75°C; 67.2g/100ml at 100°C. Extremely insoluble |
Vapor Presure | 0.0000171 Pa (25 °C) |
Appearance | White crystalline powder |
Color | <5 (200mg/mL)(APHA) |
Odor | Odorless |
Maximum wavelength(λmax) | ['λ: 260 nm Amax: 0.05', , 'λ: 280 nm Amax: 0.05'] |
Merck | 14,4491 |
BRN | 635782 |
pKa | 2.35(at 25℃) |
PH | 4(0.2 molar aqueous solution) |
Storage Condition | 2-8°C |
Stability | Stable. Combustible. Incompatible with strong oxidizing agents. |
Refractive Index | 1.4264 (estimate) |
MDL | MFCD00008131 |
Physical and Chemical Properties | Properties: white monoclinic or hexagonal crystals, or white crystalline powder. Odorless, with special sweet taste. Melting Point: 248 ℃ (decomposition) solubility in water: 25g/100ml at 25 ℃; 39.1g/100ml at 50 ℃; 75 C for 54.4g/100ml;100 C for 67.2g/100ml. It is extremely difficult to dissolve in ethanol, and about 0.06g is dissolved in 100g of anhydrous ethanol. Practically insoluble in acetone and ether. |
Use | Used as biochemical reagents for medicine, feed and food additives, nitrogen fertilizer industry as a non-toxic decarburizing agent |
Risk Codes | 33 - Danger of cumulative effects |
Safety Description | S22 - Do not breathe dust. S24/25 - Avoid contact with skin and eyes. |
WGK Germany | 2 |
RTECS | MB7600000 |
TSCA | Yes |
HS Code | 29224910 |
Toxicity | LD50 orally in Rabbit: 7930 mg/kg |
white or light yellow needle-like crystals. Sweet. It is soluble in water, lOOg anhydrous ethanol soluble about 0. 06G, soluble in 164 pyridine, almost insoluble in ether.
ammonia water and ammonium carbonate were mixed and heated on a water bath to prepare an aqueous chloroacetic acid solution, and the mixture was added dropwise thereto. The mixture was heated and incubated, and then cooled to crystallize to obtain a crude product. The crude product was dissolved in boiling water, methanol was added, and pure glycine was obtained by crystallization.
reagents for testing copper, gold, and silver. It is also used in pharmaceutical industry, biochemical research, preparation of tissue culture medium, nutritional supplements and so on.
almost non-toxic, guinea pigs, by oral administration, the lethal dose of LD 6.8~8. Og/kg. The patient was kept under closed storage.
Update Date: | 2022/11/12 12:49:22 |
FEMA | 3287 | GLYCINE |
pH range of acid-base indicator discoloration | 4 |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
the simplest amino acid | glycine is one of the 20 members of the amino acid series, it is a non-essential amino acid in the human body, which has both acidic and basic functional groups in the molecule, is a strong electrolyte in aqueous solution, and has a large solubility in a strong polar solvent, basically insoluble in non-polar solvents, but also has a high boiling point and melting point, through the adjustment of the pH of the aqueous solution can make glycine show different molecular morphology. The side Bond of glycine is a hydrogen atom. Glycine is not optically isomeric due to its alpha carbon which also has one hydrogen atom. Since the side Bond of glycine is very small, it can take up space that cannot be occupied by other amino acids, such as amino acids within the collagen helix. White crystals or pale yellow crystalline powder at room temperature. Has a unique sweet taste, can ease the acid, alkali taste, masking the bitter taste of added saccharin in food and enhance the sweet taste. If the human body intake of glycine is too much, not only can not be absorbed by the human body, but also will break the absorption balance of amino acids and affect the absorption of other amino acids, resulting in nutritional imbalance and affect health. The milk-containing beverage produced with glycine as the main raw material is likely to have adverse effects on the normal growth and development of adolescents and children. Density 1.1607. Melting point 232~236 °c (decomposition). Soluble in water, insoluble in ethanol and ether. It can react with hydrochloric acid to form hydrochloride. The presence of dry low-grade transport in the muscle. It can be formed by the action of monochloroacetic acid and ammonium hydroxide, and can also be hydrolyzed and refined from gelatin. |
Discovery History | amino acids are organic acids that contain amino groups and constitute the basic unit of proteins. Colorless crystals, high melting point (above 200 ℃), soluble in water, Amphoteric ionization characteristics, and ninhydrin reagent sensitive color reaction. In 1820, the most simple structure of glycine was found in the hydrolysates of proteins, and by 1940, there were about 20 kinds of amino acids in nature. They are essential for the synthesis of proteins in humans or animals and are mostly L-type α-amino acids. Amino acids are classified as neutral amino acids (glycine, alanine, leucine, isoleucine, valine, cystine, cysteine, methionine, threonine, serine, phenylalanine, tyrosine, tryptophan, proline and Hydroxyproline, etc.) this kind of amino acid molecule contains only one amino group and one carboxyl group; Acidic amino acids (glutamic acid, aspartic acid), this kind of amino acid molecule contains one amino group and two carboxyl groups; Basic amino acid (lysine, arginine) this kind of amino acid molecule contains diamino-carboxyl group; Histidine has nitrogen ring, is weakly basic, it is also a basic amino acid. Amino acids can be obtained from protein hydrolysis or chemically synthesized. Since the 60's, the industrial use of microbial fermentation production, such as monosodium glutamate factory has generally switched to fermentation production of glutamic acid. In recent years, the use of petroleum hydrocarbons and other chemical products as raw materials for amino acid fermentation to produce amino acids. |
content analysis | accurately weigh about 175mg of a sample pre-dried at 105 ℃ for 2H, put it in a 250m1 flask, after 50ml of glacial acetic acid was added and dissolved, 2 drops of crystal violet test solution (TS-74) were added and titrated with 0.1ml/L perchloric acid to the blue-green end point. At the same time, the blank test was carried out, and the necessary correction was made. Perchloric acid corresponds to 7.507mg of glycine (C2H5NO2) per mL of 0.1mol/L. |
toxicity | LD507930 mg/kg (rat, oral). Safe for use in food (FDA,§ 172.812, 2000). |
usage limit | as a source of amino acids, it accounts for 3.5% of the total protein in food (FDA,§ 172.320,2000). As a bitter masking agent after the addition of sodium saccharin in beverages, limited to 0.2% (based on the finished beverage); As a stabilizer of mono-and diglycerides in edible oils and fats, limited to 0.02%, diglyceride amounts (FDA § 172.812,2000). FEMA: Beverage, candy, baked goods, meat, sausage, broth, seasoning, all 150(mg/kg). |
production of glycine by biosynthetic method | in the late 80 s of the 20th century, the Japanese Mitsubishi company took the selected aerobic Agrobacterium, brevibacterium, Corynebacterium and other microorganisms are added to the medium containing carbon source, nitrogen source and inorganic nutrient solution for cultivation, and then the species are cultured at 25~45 ℃, at a pH of 4 to 9, ethanolamine is converted to glycine, and glycine is obtained by a concentrated neutralization ion exchange treatment. After entering the 90's of the 20th century, the technology of synthesizing glycine has made new progress in foreign countries. The Japanese Nitto Chemical Industry Company will cultivate the genus of pseudo-cell bacteria, casein, alcaligenes and other bacteria with 0.5% (mass fraction, dry weight) added to the glycine amine matrix, at 30 ℃, ph 7.9~8.1 under the condition of reaction 45H, almost all the glycine Amine was hydrolyzed to glycine, and the conversion rate was 99%. Although the biological method is still in the research stage, it has high selectivity and no pollution, so it will be a promising synthetic route. |
Use | for the pharmaceutical industry, biochemical tests and organic synthesis used as a buffer for the preparation of tissue culture media, the test of copper, gold and silver is used in medicine to treat myasthenia gravis and progressive muscle atrophy, hyperacidity, chronic enteritis, and hyperprolinemia in children. treatment of myasthenia gravis and progressive muscle atrophy; Treatment of gastric Ester excessive disease, chronic enteritis (often combined with antacids); Combination with aspirin, can reduce its irritation to the stomach; treatment of children with high proline; As a source of nitrogen for the production of non-essential amino acids, added to the mixed amino acid injection. glycine was mainly used as a nutritional additive in chicken feed. nutritional supplements. Mainly used for flavoring and other aspects. Flavor and alanine for alcoholic beverages, add: wine 0.4%, 0.2%, 1.0% of champagne. Other ingredients such as powder soup add about 2%; Distillers grains pickled food 1%. Because it can be a certain degree of shrimp, cuttlefish flavor, can be used for seasoning sauce. It has a certain inhibitory effect on the reproduction of Bacillus subtilis and Escherichia coli. Therefore, it can be used as a preservative for surimi products, peanut butter and the like, and the additive amount is 1% to 2%. Since glycine is a zwitterion having an amino group and a carboxyl group, the buffering action has a strong buffering property. The taste of salt and vinegar can play a role in the buffer. The addition amount is 0.3% ~ 0.7% for salted products and 0.05% ~ 0.5% for acid stains. Antioxidant effect (using its metal chelation) added to cream, cheese, margarine can extend the shelf life of 3 to 4 times. To stabilize the lard in baked goods, glucose 2.5% and glycine 0.5% may be added. The addition of 0.1% ~ 0.5% wheat flour in instant noodles can play a role in flavoring. It is used in medicine as an antacid agent (hyperacidity), a muscular dystrophy therapeutic agent, an antidote, and the like. It is also a raw material for the synthesis of amino acids such as threonine. According to China's GB 2760-96 can be used as spices. glycine, also known as amino acid, is an intermediate for the synthesis of pyrethroid insecticides in the production of pesticides, glycine ethyl ester hydrochloride, and can also be used for the synthesis of fungicide isourea and herbicide solid glyphosate, it is also used in fertilizer, medicine, food additives, spices and other industries. This product is used as a solvent for the removal of carbon dioxide in the fertilizer industry. In the pharmaceutical industry, it can be used as an amino acid preparation, a buffer for chlortetracycline and as a synthetic raw material for the anti-Parkinson's disease drug L-dopa, and also as an intermediate for ethyl imidazolate, it itself is also an adjuvant therapy, can treat nervous gastric acid too much, to inhibit gastric ulcer too much acid is also effective. In the food industry as a synthetic wine, brewing products, meat processing and cooling beverage formula and saccharin base, as a food additive, glycine can be used alone as a seasoning, can also be with sodium glutamate, DL-alanine, citric acid and the like were used in combination. In other industrial aspects, it can be added as a pH adjuster to a plating solution, or used as a raw material for other amino acids. It is used as a Biochemical reagent and solvent in organic synthesis and biochemistry. pharmaceutical and pesticide intermediates, chemical fertilizer to remove carbon dioxide solvent, electroplating solution, etc. chemical fertilizer industry as a solvent for removal of carbon dioxide. The pharmaceutical industry is used as a buffer of the gold mold, amino acid, for the preparation of L-type DOPA and other drugs, the food industry is used as a flavoring agent, saccharin to the bitter agent, used in brewing, meat processing, preparation of cool drink. In addition, it can also be used as a pH adjuster and for the preparation of plating solutions and the like. glycine is a component of the Tris-glycine and Tris-glycine-SDS running buffer used for polyacrylamide gel electrophoresis. Glycine is also a component of the western blot WT bin transfer buffer. used as biochemical reagents, used in medicine, feed and food additives, nitrogen fertilizer industry used as non-toxic decarburization agent |
production method | 1. In the Strecker method, formaldehyde reacts with sodium cyanide (or potassium cyanide) and ammonium chloride, and glacial acetic acid is added at the same time, and the crystallization of methylene amino acetonitrile is precipitated. The product was filtered and decomposed by adding ethanol in the presence of sulfuric acid to obtain aminoacetonitrile sulfate. The barium hydroxide is then added to decompose the barium salt of glycine. Finally, an amount of sulfuric acid was added to quantitatively precipitate the barium and filtered off. The filtrate was concentrated, left to cool, and glycine crystals were precipitated. 2. Monochloroacetic acid method ammonia water and ammonium bicarbonate were mixed and heated to 55 ° C., monochloroacetic acid aqueous solution was added and reacted at 55 ° C. For 2 hours. The residual ammonia was removed by heating to 80 °c and decolorized with activated carbon. The decolorizing solution was filtered, and 95% ethanol was added to precipitate glycine crystals. The crystals were filtered, washed with ethanol, and dried to obtain a crude product. The crude product was dissolved in hot water and recrystallized with ethanol to obtain the finished product. The yield was about 42%. 3. Extracting 25kg of waste silk from the silk hydrolysate, adding 6N industrial hydrochloric acid 75L, heating and refluxing at 110-120 ° C. For 22h, fully hydrolyzing until the Biuret reaction is not purple. After the end of hydrolysis, add a water, according to the 30-40g per liter of powdered activated carbon, stirred at 60 deg C for 30min. The impurities were filtered with polyester cloth in the filter cylinder to obtain about 150L of Brown hydrolysate. Firstly, the tyrosine in the hydrolysis solution was adsorbed by activated carbon, and then the glycine was separated by ion exchange column. At the same time, alanine and serine could be separated. In the above production method, The monochloroacetic acid method is relatively simple. In practice, glycine can be produced by adding monochloroacetic acid to an ammonia storage tank at room temperature for a long time. Industrial production, with urotropine solution as the medium, by a chloroacetic acid and high concentration of ammonia at 70 deg C for 2H, after methanol (or ethanol) precipitation, refined treatment can be white crystalline glycine, the yield of this method is 92-94%, and the content of the product is 99%. Raw material consumption quota: monochloroacetic acid (95%)1600kg/t, liquid ammonia 880kg/t, urotropine 350kg/t, methanol (95%)1100kg/t. In addition, using gelatin as raw material, through hydrolysis, purification filtration, drying can also be prepared glycine Its preparation method mainly includes stencker method and chloroacetic acid amination method. Formaldehyde, sodium cyanide and ammonium chloride were reacted together by Strecker method, and then glacial acetic acid was added to precipitate methylene amino acetonitrile. Methylene amino acetonitrile was added to ethanol in the presence of sulfuric acid to decompose to obtain amino acetonitrile sulfate; this sulfate was decomposed with barium hydroxide to obtain a barium salt of glycine; Then, the barium was precipitated by adding sulfuric acid, filtered, and the filtrate was concentrated. After cooling, glycine crystals were precipitated. HCHO[NaCN]→ [NH4Cl]CH2 = N-CH2CNCH2 = N-CH2CN[H2SO4]→[C2H5OH]H2NCH2CN · H1SO4H2NCH2CN · H2SO4[Ba(OH)2]→(NH2CH2COO)2Ba(NH2CH2COO)2Ba[H2SO4]→ H2NCH2COOH chloroacetic acid amination method ammonia and ammonium bicarbonate were mixed and heated to 55 ℃, chloroacetic acid aqueous solution was added, reaction 2H, and then heated to 80 ℃ to remove the remaining ammonia, decolorized with activated carbon, filtration. The decolorizing solution was added with 95% ethanol to precipitate glycine crystals, filtered, washed with ethanol, and dried to obtain a crude product. Then it is dissolved in hot water and recrystallized with ethanol to obtain the glycine product. ClCH2COOH[NH4HCO3]→[NH4OH] H2NCH2COOH in addition, there are extraction from silk hydrolysate, gelatin as raw material hydrolysis and other methods to prepare glycine. N-methyleneaminoacetonitrile was synthesized from formaldehyde, sodium cyanide and ammonium chloride, then amino-acetonitrilic sulfuric acid was synthesized with ethanol and sulfation, and barium hydroxide was synthesized, finally, it is obtained by the action of sulfuric acid. The cost of this method is low, but because of sodium cyanide (or hydrogen cyanide) relationship, the domestic is generally not used. From monochloroacetic acid plus excess ammonia. The technology of this method is mature and the raw materials are easily available. This method is widely used in China. The by-product ammonium chloride is removed by an ion exchange resin or by salting out glycine from methanol. Obtained from the hydrolysate of gelatin by isolation. glycine has no optical isomer, and synthetic methods are all used for its production. The synthesis method is briefly described below. (1) The Strecker method. Using formaldehyde, hydrogen cyanide, ammonia as raw materials, first synthesis of amino acetonitrile, and then in the decomposition of glycine. The crude hydrocyanic acid is synthesized from methane and ammonia, and then the formaldehyde solution is continuously absorbed into cyanuric acid, and the reaction solution and ammonia are reacted at 120 ℃ for 2min to generate amino acetonitrile, and finally the alkali solution is added for hydrolysis, glycine was obtained in an overall yield of 87%. (2)Bucherer method. The trioxymethylene was added to an aqueous solution of ammonium carbonate and sodium nitrile, dissolved with stirring at room temperature, and reacted at 80-85 ° C. For 3 hours. An aqueous hydantoin solution was obtained. Then 30% aqueous NaOH was added directly and the hydrolysis was carried out for 3H at 170 °c. Finally, glycine was obtained in 83.2% yield by treatment with a cation exchange resin. (3) a chloroacetic acid amination method. Mix ammonia and ammonium bicarbonate to 55 °c, The hydrolysis solution of monochloroacetic acid was added and reacted for 2H. The temperature was then raised to 80 °c to remove the remaining ammonia and decolorized with activated carbon. After filtration, 95% ethanol was added to the filtrate to crystallize glycine. After separation, it was washed with ethanol. The crude product was obtained after drying. The crude product was dissolved in hot water and recrystallized with ethanol to obtain the finished product with a yield of about 42%. (4) phase transfer catalysis method. 2kg of ammonia water was added into 1L of methanol, then 0.3kg of hexamethylene tetramine was added. After the solution was clarified, 2L of methanol dissolved in 10kg of chloroacetic acid was added, with a large number of crystal precipitation. When the temperature drops to room temperature and the liquid in the upper layer is clear, crystals are obtained by filtration, and the filtrate is left for 2 days, and some crystals can be precipitated. Add the above crude product into 2-3 times the amount of deionized water, heated to 70-75 ℃, dissolved after adding 2 times the volume of methanol, cooling precipitation of crystals, drying at 70 ℃ for 2H to obtain fine, product yield of 68.6%, purity of 99.6% method I. Amidation of monochloroacetic acid main reaction: side reaction: the ratio of ingredients: monochloroacetic acid: ammonia = 1:60,50 ℃, reaction 4H, yield of 84.50%; monochloroacetic acid: Ammonia: Carbon dioxide = 1:12:3,60 ℃, reaction 4H, yield 80.5%; Monochloroacetic acid: Formaldehyde: ammonia = 1:1.5:3, 30 ℃, reaction 4H, yield 92%; Monochloroacetic acid: ammonium bicarbonate: ammonia = 1:3.0:4.5, monochloroacetic acid, ammonium bicarbonate were dissolved in water, under stirring, mixing the two solutions, 45 ℃, adding ammonia, raise to 55 ℃, stir the reaction for 2H, heat to remove the remaining ammonia, decolorize with activated carbon, filter, add 95% ethanol to the filtrate, precipitate glycine crystals, filter the crystals, wash with ethanol, glycine was obtained. The crude product is dissolved in water, heated to 85 ℃, filtered to take the filtrate, and add 3 to 5 times the volume of 95% ethanol, placed in cold storage overnight, crystallization, filtration, take the crystals, wash them with ethanol, add distilled water 1-1.25 times the wet weight of the crystals, heat them above 80 ℃, dissolve them, add 3-5 times the volume of 95% ethanol, the crystals were cooled for 12h, and the crystals were collected by filtration, washed with 80% ethanol, and then dried to obtain a fine glycine product. The overall yield was 41.9% (calculated for monochloroacetic acid). Method two, the total yield of the synthesis method of formaldehyde as raw material is 31% ~ 50%. Bucherer method ammonium carbonate and sodium cyanide in aqueous solution, adding trioxymethylene, stirring at room temperature to dissolve, the reaction was carried out at 80~85 °c for 3H to obtain caprolactam. Then, 30% NaOH aqueous solution was added, hydrolyzed at 170 ° C. For 3H, and finally treated with cation exchange resin to obtain glycine. The yield was 83.2%. using monochloroacetic acid and ammonia as raw materials, after the reaction was completed at 60 ° C., carbon dioxide and ammonia were removed by heating to 80 ° C., and then the pure product was treated with activated carbon and recrystallized from methanol. |
toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |