L-THR
L-Threonine
CAS: 72-19-5;6028-28-0
Molecular Formula: C4H9NO3
L-THR - Names and Identifiers
| Name | L-Threonine |
| Synonyms | Thr L-THR H-THR-OH H-Thr-OH Threonine H-L-THR-OH L-Threonin L-Threonine L-THREONINE L(-)-THREONINE H-THR-OH-THREONINE (2S,3R)-(-)-Threonine L-Threonine, USP Grade L-Threonine, allo-Free 2-Amino-3-hydroxybutanoic acid L-2-Amino-3-hydroxybutyric acid L-2-AMINO-3-HYDROXYBUTYRIC ACID L-2-AMINO-3-HYDROXYBUTANOIC ACID (2S,3R)-2-Amino-3-hydroxybutyric acid 1-(4-fluorophenyl)-2,5-dimethyl-1H-pyrrole-3-carbaldehyde semicarbazone |
| CAS | 72-19-5 6028-28-0 |
| EINECS | 200-774-1 |
| InChI | InChI=1/C4H9NO3/c1-2(6)3(5)4(7)8/h2-3,6H,5H2,1H3,(H,7,8)/t2?,3-/m0/s1 |
| InChIKey | AYFVYJQAPQTCCC-GBXIJSLDSA-N |
L-THR - Physico-chemical Properties
| Molecular Formula | C4H9NO3 |
| Molar Mass | 119.12 |
| Density | 1.3126 (rough estimate) |
| Melting Point | 256 °C (dec.) (lit.) |
| Boling Point | 222.38°C (rough estimate) |
| Specific Rotation(α) | -28.4 º (c=6, H2O) |
| Flash Point | 162.936°C |
| JECFA Number | 2119 |
| Water Solubility | 90 g/L (20 ºC) |
| Solubility | Soluble in water, insoluble in most organic solvents such as absolute ethanol, ether and chloroform |
| Vapor Presure | 0mmHg at 25°C |
| Appearance | Crystalline powder |
| Color | Yellow |
| Merck | 14,9380 |
| BRN | 1721646 |
| pKa | 2.09(at 25℃) |
| PH | 5-6 (100g/l, H2O, 20℃) |
| Storage Condition | 2-8°C |
| Stability | Stable. Incompatible with strong oxidizing agents. |
| Refractive Index | -28 ° (C=6, H2O) |
| MDL | MFCD00064270 |
| Physical and Chemical Properties | white orthorhombic or crystalline powder. Odorless and slightly sweet. It melts and decomposes at 253 °c. Soluble in water at high temperature, 25°C solubility of 20.5g/100ml. The isoelectric point was PH 6.16. Insoluble in ethanol, ether and chloroform. yellow-white crystalline powder |
| Use | Threonine is an important nutritional fortifier, can strengthen grains, cakes, dairy products, and tryptophan as to restore human fatigue, promote the effect of growth and development. In medicine, because the structure of threonine contains hydroxyl groups, it has a water-holding effect on human skin, and combines with oligosaccharide chains, which plays an important role in protecting cell membranes, in vivo can promote the synthesis of phospholipids and fatty acid oxidation. |
L-THR - Risk and Safety
| Hazard Symbols | Xi - Irritant |
| Risk Codes | 36/37/38 - Irritating to eyes, respiratory system and skin. |
| Safety Description | S24/25 - Avoid contact with skin and eyes. S37/39 - Wear suitable gloves and eye/face protection S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. |
| WGK Germany | 3 |
| RTECS | XO8590000 |
| TSCA | Yes |
| HS Code | 29225000 |
| Hazard Note | Irritant |
L-THR - Nature
Open Data Verified Data
White Crystal or crystalline powder, odorless, slightly sweet taste. Soluble in water, difficult to dissolve in organic solvents such as ethanol. The chemical properties are relatively stable.
Last Update：2024-01-02 23:10:35
L-THR - Preparation Method
Open Data Verified Data
with crotonic acid or glycine as raw material. Glucose or starch can also be used as a raw material, and the product can be refined by fermentation through Escherichia coli, Brevibacterium flavum, glutamic acid bacterium or Corynebacterium crenatum.
Last Update：2025-06-10 22:55:16
L-THR - Application
Open Data Verified Data
As a dietary supplement, fenamic acid is an essential amino acid. Threonine is often added to the feed of juvenile piglets and poultry, and is the second limiting amino acid in pig feed and the third limiting amino acid in poultry feed. Added to wheat, barley and other grains based feed.
Last Update：2025-08-19 16:24:40
L-THR - Safety
Open Data Verified Data
- Adult once instillation of 22. 5G can cause fever, Head Pain and other adverse reactions.
- under shading, sealed and preserved.
Last Update：2022-01-01 11:10:22
L-THR - Reference Information
| FEMA | 4710 | L-THREONINE |
| NIST chemical information | information provided by: webbook.nist.gov (external link) |
| EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
| essential amino acids | threonine is determined by W.C.Rose was isolated and identified from the fibrin hydrolysate in 1935. It has been proved to be the last essential amino acid, which is the second or third limiting amino acid of livestock and poultry, it has an extremely important physiological role in the animal body. Such as promoting growth, improving immune function, etc.; The balance of dietary amino acids, the proportion of amino acids closer to the ideal protein, thereby reducing the requirements of livestock and poultry feed protein content. Lack of threonine, can lead to animal feed intake decreased, growth retardation, feed utilization decreased, immune function suppression and other symptoms. In recent years, lysine and methionine products have been widely used in feed. Threonine has gradually become a limiting factor affecting animal production performance. Further research on threonine is helpful to effectively guide livestock and poultry production. threonine is an amino acid that can not be synthesized by animals themselves, but it is very needed. It can be used to accurately balance the amino acid composition of feed, meet the needs of animal growth and maintenance, and improve weight gain and lean meat rate, reduce the ratio of feed to meat; Can improve the nutritional value of feed raw materials with low amino acid digestibility, improve the production performance of low energy feed; Can reduce the crude protein level of feed, improve the nitrogen utilization rate of feed, reduce the cost of feed; can be used for pig, chicken, duck and advanced aquatic breeding and breeding. L-threonine is the use of biological engineering principles, using corn starch and other raw materials through liquid fermentation, refined and the production of feed additives. It can adjust the balance of amino acids in feed, promote growth, improve meat quality, improve the nutritional value of feed raw materials with low amino acid digestibility, produce low protein feed, help save protein resources, reduce the cost of feed raw materials, reduce nitrogen content in livestock manure and urine, ammonia concentration and release rate in livestock and poultry houses. Widely used to add piglet feed, pig feed, broiler feed, shrimp feed and eel feed. FIG. 1 shows the molecular structure of threonine. |
| physiological function | amino acids are the constituent units of proteins, which are composed of peptides, the peptide chain of peptides is composed of amino acids. Different proteins are composed of peptide chains with different sequences and lengths of amino acids. Genes associated with inheritance are actually also chains of amino acids in different sequences. at present, there are 28 kinds of amino acids related to the human body. Of these 28 kinds of amino acids, 9 (about 32%) are required to be supplied directly by the amino acids of dietary protein, they cannot be synthesized in the human body from other amino acids in the proteins ingested. These are leucine, isoleucine, valine, lysine, methionine, tryptophan, threonine, phenylalanine and histidine. Among them, histidine is still controversial. It is generally believed that for infants under 4 years of age, histidine is an essential amino acid, older age can be synthesized. Non-essential amino acids are not trivial, and sometimes they are more important than essential amino acids. For example, taurine, arginine and glutamine are important in certain diseases or stress conditions and are therefore conditionally essential amino acids. threonine is an essential amino acid that helps the body maintain protein balance. It plays a role in the formation of collagen and elastin. When threonine is used in combination with aspartic acid and methionine, it can resist fatty liver. Threonine is found in the heart, central nervous system and skeletal muscle and prevents the accumulation of fat in the liver. It can promote the production of antibodies to strengthen the immune system. In food, the threonine content in cereals is low, so vegetarians are prone to threonine deficiency. |
| catabolism | in the catabolism of the body, threonine is the only one that does not undergo deamination and transamination, rather, amino acids are converted directly to other substances by threonine dehydratase, threonine dehydrogenase and threonine aldolase, for example threonine can be converted to butyryl-CoA, succinyl-CoA, serine, glycine, etc. In addition, threonine excess can improve the activity of lysine-α-ketogluconic acid reductase, and adding appropriate amount of threonine in the diet can eliminate the decrease of body weight gain caused by lysine excess, protein/deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)/DNA ratios are reduced in muscle tissue. The addition of threonine also mitigates the growth inhibition caused by an excess of tryptophan or methionine. It is reported that most of the absorption of threonine by chickens is in the duodenum, and threonine absorbed by mutters and glandular stomach is rapidly converted into liver protein and deposited in the body. However, the detailed mechanism of how threonine is involved in protein synthesis is still unclear. |
| content analysis | accurately weigh about 200mg of sample, dissolve in 3ml formic acid and 5ml glacial acetic acid, two drops of crystal violet test solution (TS-74) were added and titrated with 0.1mol/L perchloric acid until the green end point or the blue color completely disappeared. Perchloric acid corresponds to 11.91mg of L-threonine (C4H9NO3) per mL of 0.1mol/L. |
| toxicity | LD503098 mg/kg (rat, intraperitoneal injection). |
| usage limit | accounts for 5.0% of the total protein in food (FDA,§ 172.320,2000). |
| Use | threonine is an important nutrient fortifier for the fortification of cereals, cakes, dairy products, like tryptophan, it has the effect of restoring human fatigue and promoting growth and development. In medicine, because the structure of threonine contains hydroxyl groups, it has a water-holding effect on human skin, and combines with oligosaccharide chains, which plays an important role in protecting cell membranes, in vivo can promote the synthesis of phospholipids and fatty acid oxidation. used in biochemical research, medicine as amino acid nutrition drugs, mainly used in the treatment of anemia. amino acid drugs. Mainly used for amino acid infusion, comprehensive amino acid preparation, food Nutrition Fortifier. Such as the lack of threonine can cause loss of appetite, weight loss, fatty liver, testicular atrophy, anterior pituitary cell staining changes and affect bone development. Adverse reaction taboo: Adult once infusion of 22.5g, can cause fever, Head Pain and other adverse reactions. nutritional supplements. Cereal protein in addition to the need to supplement L-lysine, followed by L-threonine. This is because the content of L-threonine is large, but the combination of threonine and peptide in the protein is difficult to hydrolyze, and it is not easy to digest and absorb. It is also used for the preparation of amino acid infusion and comprehensive amino acid preparation. One of the essential amino acids of the human body, can be used to improve nutrition, improve physical fitness. biochemical study. Tissue culture medium was prepared. |
| production method | The natural proteins (sericin, casein, fibroin, etc.) with high threonine content are hydrolyzed, obtained by separation and purification with ion exchange resin. DL-threonine is prepared by reacting copper glycinate with acetaldehyde (see "DL-threonine"), and L-form crystals are seeded in the resulting DL-threonine solution, L-amino acid was obtained by performing optical rotation disassembly only for L. method 1. With glucose as raw material, direct fermentation was used to select feedback inhibition and repression in the synthesis of auxotrophic and structural analogs, and the L-threonine acid production rate was 18g/L, corynebacterium glutamicum, acid production rate of 14g/L, the rate of 14g/L. Glucose [Brevibacterium flavum, Corynebacterium glutamicum, mycete, etc.] → L-threonine Method II, chemical synthesis method threonine obtained by chemical synthesis is a mixture of four optical isomers, DL-threonine. Wherein the amino acid constituting the protein is L-threonine, it is necessary to separate the threonine from the other body, and then further carry out optical isomer resolution to obtain L-threonine. Using copper glycine in alkaline conditions with acetaldehyde, similar aldol condensation reaction, synthesis of threonine copper threonine, threonine and other body two mixtures, according to the stability and solubility of different, DL-threonine can be separated from the threonine by copper removal, and L-threonine can be obtained by final resolution. Now the production process of small test synthesis and scale-up are introduced as follows. Small test synthesis process glycine preparation of monochloroacetic acid 189g (2mol), formaldehyde solution 2100ml (3.3mol), mixed and cooled to below 10 ℃, Dropwise adding concentrated ammonia water 750ml (10mol), the droplet acceleration was controlled so that the temperature did not exceed 10 °c. After the addition of ammonia water, the temperature was 30 degrees C, 4H. It was concentrated under reduced pressure to 300-400ml, and crystals were precipitated. After washing and drying to obtain crude glycine, add about 1.5-2 times the amount of water to the crude glycine, heat to make it fully soluble, Add 1% activated carbon for decoloration; Filter the filtrate, then add 2-2.5 times the volume of methanol, put in the refrigerator overnight, filter to take crystals, to obtain glycine fine product. The yield was about 60%-68%. Preparation of copper glycinate 100g of glycine was taken, 7L of water was added, and the whole was dissolved by heating at 60 °c. Then 80g of basic copper carbonate was added slowly and incubated at 60 °c for 1H. Unreacted basic copper carbonate was removed by hot filtration. The filtrate was collected and allowed to cool naturally to precipitate blue needle-like crystals (containing 1 molecule of crystal water). The crystals were collected by filtration, washed and dried at 60 ° C. To obtain copper glycinate in a yield of 95%-98%. Preparation of copper threonine take copper glycinate 52.5g, add ml of methanol and stir to dissolve, then add 80ml of ethanol below 10 °c, until the temperature no longer rises, further, 5g of sodium hydroxide was preliminarily dissolved in 90ml of methanol solution, and the reaction was incubated at 60 ° C. For 1 hour. The insoluble matter was filtered off while hot, and 5.5ml of glacial acetic acid was added to the collected filtrate. Methanol was recovered under reduced pressure to dryness, stirred and dispersed with additional 75ml of methanol, and then cooled overnight. The crystals were collected by filtration, washed and dried to give a mixture of threonine and isothreonine copper in 68%-74% yield. Copper removal, refining take 427G of the above copper threonine, add 6L of 10% ammonia hydroxide solution, dissolve all of it, filter and collect the filtrate, adsorb with 732 cation exchange resin, It was washed with 2mol/L aqueous ammonia and water until the eluent did not develop color to ninhydrin. The eluate was combined, the film was concentrated to 1.5L, and 3L of ethanol was added to precipitate crystals. The crystals were placed in a refrigerator overnight, and the crystals were filtered to obtain crude DL-threonine. The yield ranged from 62% to 73.8%. 42g of crude DL-Threonine was taken and heated with 126ml of water to make it fully soluble. The filtrate was removed by decolorization and filtration, and 252ml of ethanol was added to cool overnight, and the crystals were filtered to obtain refined DL-threonine. The yield ranged from 87% to 91.3%. Separation and Purification the purified DL-threonine 810G, DL-threonine 90g and water 2.88L were mixed, stirred slowly (about 50r/min), and heated to 95 ° C. Or higher to dissolve all of them. Then cool to 40 ° C, and add 10% of the total amount of DL-threonine D-threonine as a variety, slowly cooled to 30 ° C (an average of 1 ° C per 15min), crystalline D-Threonine was precipitated, and the crystals were collected by filtration and dried at 80 ° C. To obtain D-threonine. The filtrate was collected, and DL-threonine (about 150-170g) equivalent to the D-threonine resolved was added, and the total volume was kept constant, the same procedure as for the resolution of D-threonine (except that when the temperature was lowered to 40 ° C., the seed crystals added were L-threonine), L-Threonine was obtained. Thus, D-threonine and L-threonine can be separated by repeating the operation. The corresponding crude D-threonine and crude L-threonine were combined and purified separately, I .e., recrystallized. Take D-and L-threonine respectively, add 4 times Water respectively, Heat 90 ℃ to completely dissolve, Decolorizing with 1% activated carbon, filtering and collecting the filtrate while hot, adding 2 times the volume of ethanol to cool, stirring from time to time, precipitating crystals, obtaining D-threonine and L-threonine fine products, the yield ranged from 87.3% to 91.6%. The content of L-Threonine was above 95%, [α]20D-26 ° -29 °, and paper chromatography showed a spot. Amplification of the production process of glycine as raw material, first with the basic copper carbonate reaction to generate copper glycine, at this time of its alpha-H activity, under alkaline conditions, the interaction of copper glycinate and acetaldehyde can undergo a similar cross-aldol condensation reaction to form DL-threonine copper (containing threonine and erythritol), which is then subjected to ion exchange, the DL-Threonine was separated by copper removal, and finally D-threonine and L-threonine were resolved by induced crystallization. The reaction is as follows: preparation of copper glycinate in a 500L reaction tank, put 50kg of glycine, add 350L of water, 40kg of basic copper sulfate insulation 60 ℃ 1H, filter discarded unreacted copper salt, collect filtrate, the mixture was left to cool overnight, and the crystals were filtered and dried at 60 ° C. To obtain blue copper glycinate. Preparation of copper threonine in a 1000L reaction tank, 75kg of copper glycine was added, and then 600L of methanol was added, After stirring to dissolve it, add 120L of acetaldehyde and 90L5%KOH methanol solution, keep stirring at 60 ℃ for 1H, filter out the insoluble matter, add 5.5L of glacial acetic acid to the filtrate, and recover the methanol to dryness under reduced pressure, after stirring and dispersing with 75L of water, the mixture was allowed to stand at 5 ° C. Overnight, the crystals were removed by filtration, washed and drained to obtain a mixture of threonine copper and threonine copper. Ion exchange and copper removal to obtain DL-threonine 40kg of the above-mentioned threonine copper and 10% L of ammonia water 1000L were respectively put into a 2000L reaction tank, and stirred to dissolve, the filtrate was filtered onto a 732 cation exchange column (×) and washed with 2mol/L ammonia water and then deionized water. The eluents were combined, the film was concentrated to 150L, 300L of ethanol was added, stirred and cooled to 5 °c for crystallization overnight. The crystals were filtered and dried at 80 ° C. To obtain crude DL-threonine. Concentrate and refine 40kg DL-threonine crude product into 500L reaction tank, with DL-threonine as raw material, react with Chloroacetyl Chloride under alkaline condition, concentrate under reduced pressure and extract with acetone, finally, the product was resolved by acylase I. |
| toxic substance data | information provided by: pubchem.ncbi.nlm.nih.gov (external link) |
Last Update：2024-04-09 18:58:34
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View History
L-THR
TCPO
Pramipexole Impurity 54
RARECHEM AK HB 0030
C.I. 18965
9002-85-1
L-Mannose
13446-09-8
40787-48-2
109-75-1
TCPO
Pramipexole Impurity 54
RARECHEM AK HB 0030
C.I. 18965
9002-85-1
L-Mannose
13446-09-8
40787-48-2
109-75-1