|Company Name:||J & K SCIENTIFIC LTD. |
|Company Name:||Alfa Aesar |
|DL-Serine Chemical Properties|
|DL-Serine Usage And Synthesis|
|Non-essential amino acids the human body||Serine, also known as 2-amino-3-hydroxy-propionic acid, [beta] hydroxy-alanine, hydroxy-amino propionic acid, is a kind of neutral aliphatic amino acids containing hydroxyl groups with polarity but being uncharged, and belongs to nonessential amino acids for human body. It has a high content in sericin silk protein and fibroin protein. It can be formed from the methyl transfer reaction of glycine. It can also be converted to pyruvate or hydroxy pyruvate through deamination. It is also an important raw material for in vivo synthesis of choline and cysteine. |
In 1865, it was first isolated from the sulfuric acid hydrolysis solution of sericin. It has levo form and racemic form. Levo produced from the crystallization in water is the hexagonal tabular or prismatic crystals or white crystalline powder. It is odorless and has a sweet taste. It has a relative molecular mass being 105.09 and will be decomposed in 228 °C and subject to sublimation at 150 °C under vacuum condition. It has the optical rotation being-6.83°(10% aqueous solution). It is insoluble in organic solvents, insoluble in ethanol and ether, but soluble in acid and alkali, and easily soluble in water with the solubility being 25.4 (10 ℃), 38 (20 ℃), 48.5 (30 ℃), 60.5 (40 ℃), 72.0 ( 50 ℃), and 83.0 (60 ℃) and soluble in formic acid. It can be used for biochemistry and nutrition research and also be used as a raw material for the synthesis of cycloserine. It is distributed in various kinds of proteins, in particular in the silk proteins. It has a moderate content in the amino acid composition of marine plankton and is also presented in seawater, ocean sediments, in either free form and bound form exists in the seawater, ocean sediments and particulate matter. It can be separated and purified from protein hydrolyzate. It can also be prepared from α-bromo-β-methoxy-propionic acid which subjects to amination and demethylation.
Its racemate crystallized from water is monoclinic system white blades-like crystal. It has a relative density being 1.537, and is subject to decomposition at 246 ℃ and sublimation at 150 ℃ at high vacuum condition. It is soluble in water (g/l) 22.04 (0 °C), 50.23 (50 °C), 192 (75 °C), 322 (100 °C), but insoluble in ethanol, ether, benzene and acetic acid. It can generate hydrogen peroxide and ferrous sulfate to yield hydroxyl acetaldehyde and exhibit red color upon reaction with ferric chloride solution, and generate hydrochloride upon reaction with hydrochloric acid. In the presence of a dehydrating agent, it can have reaction with alcohol to generate serine ester.
The main purpose:
1. besides being used as the raw material in protein synthesis and providing carbon skeletons in the synthesis of purine, thymine, methionine and choline and other important substances. The compositions of the active centers of some kinds of enzymes as well as the operation of some plants glycolic acid pathway both require its participation.
2. Because of the special wetting, it is often used as a cosmetic additive, used in creams (moisturizing agents) for maintaining the water content in the stratum corneum, keeping the skin softness; it can be used as food additive and used as nutritional supplements; it can also be used as pharmaceutical raw materials and for infusion.
The above information is edited by the Chemicalbook of Dai Xiongfeng.
|Preparation||1, Extraction method; the protein rich in serine is subject to hydrolysis, and then purified by extraction with an ion exchange resin. |
2, Take glycolaldehyde, hydrocyanic acid and ammonia as raw materials for synthesis to obtain the amino nitrile, whose hydrolysis can produce serine.
3, Fermentation; take glucose as carbon source and glycine as a precursor, apply glycine-phile corynebacterium or whitish Sarcina, etc. can be obtained by fermentation. Alternatively, use methanol as carbon source, apply Pseudomonas MS31 or Pseudomonas 3ab for fermentation to make it.
4, Take acrylonitrile as raw material, go through chlorination for generating α, β-dichloro-propionitrile, then go through ammoniation to generate α-chlorine-β-amino propionitrile, and then generate aziridine-2-sodium carboxylate in alkali solution which go through highly acidic cation exchange resin to obtain DL-serine.
5, Take chloro-acetaldehyde as the raw material, perform reduction reaction of sodium bisulfite and then have reaction with alkaline for generating α-amino-β-chloroethane sulfonate, which subject to further cyaniding reaction through sodium cyanide to obtain α-amino-β--chloropropionitrile. Finally produce it according to acrylonitrile protocol.
6, it can be made through reaction between α-isocyanate acetamide and formaldehyde to form quinazoline intermediate and further direct hydrolysis.
7, Electrolytic reduction; further oxidize propionic acid ethyl ester to the corresponding oxime and then take lithium chloride as supporting electrolyte with each pole being lead and platinum for electrolytic reduction to obtain it.
8, take ethanolamine as the raw material, have oxidation reaction with hydrogen peroxide in the presence of sodium tungstate as the catalyst; further go through cyaniding reaction with sodium cyanide to produce aminonitrile which finally hydrolyzed in hydrochloric acid to obtain DL-serine.
|The amino acids composition of mulberry protein and silkworm protein||The amino acid composition of mulberry protein and silkworm protein is different with the content of six kinds of amino acids, alanine, methionine, glycine, tyrosine, phenylalanine and proline being presented at higher content in silkworm protein than mulberry protein, especially for the methionine, which is a kind of essential amino acids. The content of silkworm protein is 2.7 time as high as that of mulberry protein and therefore must be supplied from having large amount of food. In addition to other kinds of non-essential amino acids can either be derived from mulberry leaves or produce from de novo synthesis inside the body of silkworm. The silk protein produce inside the silkworm body is however, also different from silkworm protein with the percentage content of the non-essential amino acids glycine, alanine, serine and tyrosine being significantly larger which add up to 79.68%, while the content of these four proteins in silkworm protein only account for only 43.26% with particularly the increase of serine having the maximum amplitude. This demonstrates that the generation of silk proteins is not from silkworm proteins, but directly from the protein synthesis process inside the silk gland cells using the free amino acids in the blood as the raw material.|
The alanine and glycine presented in silkworm in large amount can be synthesized through the transfer of amino group from another kind of amino acids (glutamate or aspartate) to the pyruvate or glyoxylate, respectively, with the participation of transaminases. Alanine can be generated from the successive actions of glutamine transaminase, oxaloacetate decarboxylase and alanine aminotransferase. It may also be generated by ornithine aminotransferase (Xuting Sen et al., 1980). The silk gland tissue can use keto-malonate as amino acceptor for carrying out transamination reaction to generate amino malonic acid which is further converted to glycine under the catalysis of amino malonic acid decarboxylase (Zoubo Xiang et al., 1979). Glycine and serine can be converted to each other. Glucose can also generate serine via the glucose-3-phosphate-hydroxy-pyruvate. Serine can be used to generate alanine via pyruvate. Tyrosine can be generated from phenylalanine; cystine can be converted from methionine but with the reaction being reversible so that both phenylalanine and methionine are essential amino acids. When the feed is rich in cystine and tyrosine, the demand of phenylalanine and methionine can be reduced.
|Identification test||Take 5 mL of 0.1% sample solution, add l ml of ninhydrin test solution (TS-250), should generate blue-violet or purple color.
|Content Analysis||Accurately weigh 200 mg of sample to be dissolved in 50 ml of glacial acetic acid and 3 mL of formic acid. Use the glacial acetic acid liquid of 0.1mol/L perchloric acid for titration with the end being determined through potentiometer. At the same time, perform a blank test and make necessary calibration. Each ml of 0.1mol/L perchloric acid is equivalent to 10.51 mg of DL-serine (C3H7NO3).
|Chemical Properties||It is a kind of colorless monoclinic columnar or lamellae crystal. It is soluble in water (at 20 ℃, the water solubility is 380g/L), insoluble in ether and ethanol; pI: 5.68; Decomposition point: 246 ℃.
|Uses||1. It can be used for biochemical research, the preparation of tissue culture media, and as amino acids health food in the field of medicine. |
2. It can be used as nutritional supplements.
3. It can be used as biochemical reagents.
4. It can be used as pharmaceutical intermediates, or APIs.
|Chemical Properties||White crystalline powder|
|DL-Serine Preparation Products And Raw materials|