Used as a biochemical reagent and food additive, Used for biochemical research, the preparation of tissue culture, and used as amino acids nutrition medicine.
Endogenous agonist at the inhibitory glycine receptor.
White crystalline powder
It takes up to 8.4% of total protein quantity(FDA，§172.320，2000).
1ml ninhydrin (TS-250) was added to 5ml sample solution (0.1%) should produce red purple or violet color. 200mg Periodic acid was added to the above solution and heated. Dissolving a sample of about 500 rag in 10 ml water, adding 200 mg of Periodic acid and heating, should produce the smell of formaldehyde.
ChEBI: The L-enantiomer of serine.
L-Serine can be obtained by a variety of methods. Methods common seen are as follows:
1. Obtain it though the hydrolysis of protein with a high content of L – Serine and recycled by ion exchange resin;
2. Obtain it by the reaction between ethyl formate and ethylhippurate;
3. Obtain it by using carbohydrate as the starting material through zymotechnics;
4. In alkaline condition, the raw material of DL-serine and chloracetyl chloride reacted, then, extracted with ethyl acetate after drying by distillation, treated by active carbon, chiral separated by acylation enzyme to obtain the product;
The raw material of silkworm cocoon was hydrolyzed in acid condition and separated and purified with ion exchange water. process engineering: silkworm cocoon [acid hydrolysis]→[HCl, 110℃, 24h] hydrolysate [deacidification,decoloration]→[732resin，ammonia，pH3.5-8] eluant [fractionation]→[717 resin] drips [Concentration, crystallization, and refined]→[film evaporation]→L-serine
Acid hydrolysis: Adding 30 kg silkworm cocoon to a crock, then adding 150 L HCl With a concentration of 6 mol/L, stirting heating to 110 ℃ for 24 h, after cooling below 60 ℃, filtering and washing the filter residue with pure water of five times the amount of filtrate, at five times the filtrate volume of washing, merging the washing liquor into the filtrate to obtain 800 L of aqueous solution.
Deacidification and liquid-removal: 100L of hydrolysate flows through H + type 732 cation exchange resin column (150 mm x 2000 mm polyvinyl chloride, filled with 25L resin for each of the 2 columns) from top to bottom with a flow velocity of 100-120ml/min,
, then washed with purified water to remove pigments to obtain clear liquid without Cl-.0.3 mol/L ammonia flows through the column from top to bottom with a flow velocity of 80-100ml/min till outflow of amino acids, collecting the eluent within pH3.5-8. Finally, 1 mol/L of ammonia was used to wash Tyrosine followed by deammoniation, concentration and crystallization to obtain crude tyrosine.
The above eluent was separated with 4 regular OH-type 717 Anion exchange resin columns:
Column1 50mm×2000mm, filled with 24L resin (polyvinyl chloride)
Column2 150mm×1800mm, filled with 22L resin (polyvinyl chloride)
Column3 150mm×1600mm, filled with 20L resin (polyvinyl chloride)
Column4 150mm×1400mm, filled with 10L resin (polyvinyl chloride)
Firstly, the pH value of the eluent was adjusted to 7-8 with 1mol/L NaOH Solution. Then, the eluent was separated in the first column with the flow rate of 120-150 ml/min until the saturation of the resin and washed to neutral with pure water. Column1 and column2 were connected in series, eluted using 0.1 mol/L HCl with the flow rate of 80-100 ml/min, collected 25 reagent Bottles ((1000 ml/bottle）until the appearance of amino acid in effluent. Colunm 4 was then connected in series and the elution process was continued. About 50 reagent Bottles were collected until the appearance of amino acid in effluent and the pH value of the eluent reached 2-3.
Paper chromatography was used to purify and collect extracts containing serine.
After concentration, crystallization, and refinement, the above extraction was evaporated and concentrated until crystallization occurrence. After cooling, anhydrous ethanol which is 2 times the amount of the extraction was added, stored in a refrigerator overnight, and dried after crystal precipitation to obtain L-Serine. The yield is about 4% Calculated on cocoon.
Fermentation with precursor addition
The in vivo metabolism speed of L-Serine is very fast and direct fermentation production is difficult. Generally, the method of fermentation with precursor addition is adopted. The precursors mainly include glycine, betaine and glyceric acid, among which Fermentation with glyceric acid precursor has been industrialized. Producing strains include anaerobic type and Methylotrophs.
Heterotroph, glycine produced L-Serin
glycine [Glycine rod acid , Butane Nocardia or white sarcina]→[fermentation] L-Serine.
Methylotrophs glycine produced L-Serin
glycine[pseudomonas, Hyphomicrobium or Methanol assimilation Arthrobacter globiformis] →[fermentation] L-Serine.
7. Chemical synthesis:
DL-Serine can be synthesized by using glycolaldehyde as raw material and
and chiral separated to obtain L-Serine.
Synthesis by using glycolaldehyde as raw material
Synthesis by using diethyl bromomalonate as raw material
Synthesis by using Vinyl compounds as raw material
8. Enzymatic method:
Chemically synthesized DL-2 Oxazolidine-4-carboxylic acid (DL-OOC)
was used as raw material to produce L – serine under the catalysis of
testosterone pseudomonas produced L-OOC hydrolase or Bacillus subtilis
produced OOC racemase.
DL-2-Oxazolidine-4-carboxylic acid (DL-OOC)[L-OOC hydrolase or racemase]→L-serine
It can be used in food safely (FDA，§172．320，2000).
A likely impurity is glycine. Crystallise L-serine from H2O by adding 4volumes of EtOH. Dry and store it in a desiccator. It sublimes at 160-170o/0.3mm with 99.7% recovery, and unracemised [Gross & Gradsky J Am
Six-sided flaky crystal or prismatic crystal, soluble in water(20℃，25g/100ml water)
Same as "DL-serine (01126)"