L - THREONINE

L-Threonine is an essential amino acid your body cannot synthesize, meaning it must be obtained through your diet. 
L-Threonine is vital for protein synthesis, collagen and elastin formation, immune function, and maintaining a healthy digestive tract. 
L-Threonine is also widely used as a dietary supplement.

CAS:    72-19-5
MF:    C4H9NO3
MW:    119.12
EINECS:    200-774-1

Synonyms
L-2-AMINO-3-HYDROXYBUTANOIC ACID;L(-)-THREONINE;H-THR-OH-THREONINE;L-THREONINE extrapure CHR;L-α-amino-β-hydroxy-butiric acid;L-β-hydroxy-2-aminobutyric acid;2-Amino-3-hydroxybutanoic acid, [R-(R*,S*)];(2S,3R)-L-Threonine

Isolation and identification of L-Threonine from the fiber protein hydrolyzate by W. C. Rose in 1935, has proved that it was the last essential amino acids. 
L-Threonine is extremely important physiological role in animals, because it is the second or third limiting amino acids for livestock. 
Such as promoting growth, enhance immune function, etc. 
Balancing the dietary amino acids to make the ratio of close to the ideal protein, and reducing the protein content of livestock feed requirements. 
Lacking of threonine, may lead to reduce feed intake, growth retardation, decrease feed efficiency, and suppress immune function and other symptoms. 
In recent years, lysine, methionine synthesis product has widely used in feed, threonine become the limiting factor affected animal performance gradually. 
Further study of threonine could help to the livestock and poultry production effectively.
L-Threonine cannot synthesize by animals, however, it is an essential amino acids for them to balance the composition of amino acids precisely to meet the need to animal growth, improve weight and lean meat, reduce the feed conversion. 
L-Threonine also can increase the value of feed raw materials of lower amino acid digestibility, and improve the production performance of low-energy feed. 
Besides, L-Threonine can reduce feed crude protein levels and improve feed nitrogen utilization, and reduce feed costs. 
So L-Threonine can be used for pigs, chickens, ducks and senior aquatic breeding and farming.
L-threonine is based on bio-engineering principles by using corn starch and other raw materials through submerged fermentation, refined and produced feed additives. 
L-threonine could adjust the balance of amino acid in feed, promote growth, improve meat quality and improve ncrease the value of feed raw materials of lower amino acid digestibility and produce the low protein feed, save protein resources, reduce the cost of feed ingredients, reduce the nitrogen content of manure and urine and decrease the concentration and release rate of animal building ammonia. 
L-threonine has used to add in piglet feed, pig feed, chicken feed, shrimp feed and eel feed widely.

L-Threonine is an amino acid that is used in the biosynthesis of proteins. 
L-Threonine contains an α-amino group (which is in the protonated −NH+3 form when dissolved in water), a carboxyl group (which is in the deprotonated −COO− form when dissolved in water), and a side chain containing a hydroxyl group, making it a polar, uncharged amino acid. 
L-Threonine is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. 
L-Threonine is synthesized from aspartate in bacteria such as E. coli.
L-Threonine is encoded by all the codons starting AC (ACU, ACC, ACA, and ACG).
L-Threonine sidechains are often hydrogen bonded; the most common small motifs formed are based on interactions with serine: ST turns, ST motifs (often at the beginning of alpha helices) and ST staples (usually at the middle of alpha helices).

L-Threonine is an essential amino acid that plays a crucial role in protein synthesis and various metabolic processes in living organisms. 
L-Threonine is classified as a polar, hydrophilic amino acid due to its hydroxyl (-OH) group, which contributes to its solubility in water. 
L-Threonine is one of the building blocks of proteins and is involved in the synthesis of other important biomolecules, including glycine and serine. 
L-Threonine's molecular formula is C4H9NO3, and it has a molecular weight of approximately 119.12 g/mol. 
L-Threonine is commonly found in various food sources, particularly in dairy products, meat, and certain grains. 
In addition to its nutritional importance, L-Threonine is also utilized in the pharmaceutical and biotechnology industries for the production of therapeutic proteins and as a dietary supplement. 
The CAS number 72-19-5 uniquely identifies L-Threonine in chemical databases, facilitating its study and application in various scientific fields.

L-Threonine Chemical Properties
Melting point: 256 °C (dec.) (lit.)
alpha: -28.4 º (c=6, H2O)
Boiling point: 222.38°C (rough estimate)
density: 1.3126 (rough estimate)
bulk density: 370kg/m3
refractive index: -28 ° (C=6, H2O)
FEMA: 4710 | L-THREONINE
storage temp.: 2-8°C
solubility: H2O: 50 mg/mL
form: powder
pka: 2.09(at 25℃)
color: Yellow
PH: 5-6 (100g/l, H2O, 20℃)
Odor: ADM L-Threonine is a high quality product specifically designed for the feed industry. Produced from advanced technology, ADM L-Threonine is composed of 100% isomerically pure L-Threonine, which translates into 100% bioavailability for swine, poultry, and other animals.mild savory
Odor Type: savory
biological source: non-animal source
Optical Rotation: [α]20/D 28.5±0.5°, c = 5% in H2O
Water Solubility: 90 g/L (20 ºC)
Merck: 14,9380
JECFA Number: 2119
BRN: 1721646
Stability: Stable. Incompatible with strong oxidizing agents.
Major Application: cell analysis
Cosmetics Ingredients Functions: HAIR CONDITIONING
ANTISTATIC
HAIR WAVING OR STRAIGHTENING
InChI: 1S/C4H9NO3/c1-2(6)3(5)4(7)8/h2-3,6H,5H2,1H3,(H,7,8)/t2-,3+/m1/s1
InChIKey: AYFVYJQAPQTCCC-GBXIJSLDSA-N
LogP: -2.94
CAS DataBase Reference: 72-19-5(CAS DataBase Reference)
NIST Chemistry Reference: Threonine(72-19-5)
EPA Substance Registry System: L-Threonine (72-19-5)
CAS Number Unlabeled: 72-19-5

Uses    
1.L-Threonine is an important nutritional supplement which could fortify cereals, pastries, dairy products, restore the body as fatigue, and promote growth and development like tryptophan. 
Due to its structure contained threonine hydroxyl,which could held the water on human skin and combined with the oligosaccharide chains to protect cell membranes. 
L-Threonine plays an important role in the body, promoted phospholipid synthesis and fatty acid oxidation in the Medicine field as well.
2.For biochemical research, the pharmaceutical amino acids could be a nutritional medicine to cure anemia primarily.
3.Amino acid as medicines is mainly used in amino acid infusion, comprehensive amino acid preparations and food nutrition fortifier.
Such as the lack of threonine can cause loss of appetite, weight loss, fatty liver, testicular atrophy, anterior pituitary cells, dyeing changes and bone development. 
Adverse reactions Contraindications: When an adult infusion 22.5g, can cause fever, headaches and other adverse reactions.
4.Nutritional supplements. 
To meet the need of cereal protein, L-lysine is the first, another is L-threonine. 
Even though the content of L-threonine is high, the binding between peptide and threonine is difficult to hydrolysis, and not easy to absorb and digest.
L-Threonine is also could be used in preparation of amino acid infusion and comprehensive amino acid preparations.
5.One of the essential amino acids in human body, L-Threonine can be used to improve nutrition and physical fitness.

Production method    
1.Hydrolysized the natural protein (sericin, casein, fibroin, etc.) with high content of Threonine, separated and refined by ion exchange resin.
L-Threonine were made from glycine copper and acetaldehyde reaction (see "DL-threonine"), in the resulting solution of DL-threonine inoculated within L-type crystals that only carry out the L-optical resolution and get L-histidine.

2.Direct fermentation method
Glucose as raw material, breeding auxotrophic synthesis and structural analogues feedback inhibition and repression to L-threonine acid production was 18g/L, Corynebacterium glutamic acid production was 14g/L, clayey race bacilli rate 14g/L.
Glucose [Brevibacterium, Corynebacterium glutamicum, clayey race bacillus] → L-threonine

3.Chemical synthesis
Threonine is a mixture of four optical isomers after chemical synthesis, named DL-threonine.
L-shaped threonine is the composition of protein, therefore Su should be separated from others, and further isolate the optical isomers to get L-threonine.
similar aldol reaction when Copper with glycine and acetaldehyde under alkaline conditions to get the mixture of Su copper body and other body. 
According to their stability and solubility, he copper removal can be seprate to DL-threonine, L-threonine was finally isolated.
Synthesis and amplification of the production process are described below.

Synthesis process    
Preparation glycine：monochloroacetic acid 189g (2 mol), formaldehyde solution 2100 ml (3.3mol), mixed and cooled to below 10 ℃, concentrated aqueous ammonia was added 750ml (10mol), control dropping, temperature did not exceed 10 ℃. 
After the addition of ammonia, keep 30 ℃, 4h. Concentrating under pressure to 300-400ml until crystallized. 
After washing, drying crude glycine, glycine crude were added about 1.5-2 times the amount of water, heated to soluble, add 1% activated charcoal decolorized; filtration, adding 2-2.5 times of the volume of methanol, placed in refrigerator overnight, crystals were collected by filtration and get glycine boutique. 
The recovery is about 60%-68%.

Preparation of glycine copper
Glycine 100g, added 7L water, heating 60 ℃ to make it soluble. Copper carbonate was slowly added to the solution 80g, at 60 ℃ incubated 1h. 
Filtrated the solution to remove unreacted copper carbonate before the solution become cold. 
The filtrate was collected to keep cooling naturally, precipitated blue needle-like crystals (with a molecular crystal water), crystals were collected by filtration and washed, 60 ℃ dried to get glycine copper, recovery is about 95%-98%.

Preparation of threonine copper
Glycine copper 52.5g, added 425ml of methanol and stirred to dissolve, then added 80ml of ethanol at a tempreture below 10 ℃, 5g of sodium hydroxide was added in in 90ml of methanol solution for pre-dissolved until the temperature is no longer raise, and kept it in 60 ℃ for reaction 1h. insolubles were filtered before the solution become cold, the filtrate was added glacial acetic acid 5.5ml, recovering methanol to dryness under reduced pressure, combined with 75ml of methanol was stirred overnight. 
Crystals were collected by filtration, washed, and dried to get the Su and other bodies threonine mixture of copper, recovery is about 68%-74%.

Copper removal
Threonine copper 427g, added 10% ammonium hydroxide solution 6L, completely dissolved, collected the filtration, adsorption on a cation exchange resin 732, washed with 2mol/L and water until the eluent ninhydrin did not react. 
Combined eluent and film concentrated to 1.5L, added 3L ethanol to make crystals and placed in the refrigerator overnight, the crystals were collected by filtration to get DL-threonine crude. Recovery is about 62%-73.8%.
DL-threonine crude 42g, added 126ml water to make it soluble by heating, bleached filter the filtrate, added 252ml of ethanol, cooled overnight, filtered and purified crystals were DL-threonine. Recovery is about 87%-91.3%.

Split, refining
the refining of DL-threonine 810g, DL-threonine 90g, added water 2.88L, slowly stirred (approximately 50r/min), and heated to above 95 ℃ until it has completely dissolved. 
Then cooled to 40 ℃, and 10% D-threonine of total amount of DL-threonine, and slowly cooled to 30 ℃ (15min per drop 1 ℃), crystallize D-threonine. 
The crystals were collected by filtration, and with 80 ℃ dried to get D-threonine. 
The filtrate was collected and split into D-threonine out the same amount of DL-threonine (approximately 150-170g), to keep the total volume constant, the same operation with the split D-threonine (but lower temperature is around 40 ℃, added L-threonine) to get L-threonine. 
This repeated operation can seprate D-threonine and L-threonine.
Merged D-threonine crude and L-threonine crude to refined, namely recrystallization. 
D-type and L-threonine addedwith water 4 times respectively, the solution was heated to 90 ℃, 1% active carbon, filtrate was collected before it cooled, added 2 times of volume of ethanol to cool, stirring occasionally, to precipitate crystals get D-threonine and L-threonine boutique, recovery is around 87.3%-91.6%.
L-threonine content of more than 95%, [α] 20D-26 °--29 °, paper chromatography showed one spot.