CAS number：10098-89-2
molecular formula：C6H15ClN2O2
molecular weight：182.65
EINECS number：233-234-9

English synonyms

(2S)-2,6-bis(azanyl)hexanoi;L-Lysine,hydrochloride(1:);L-α,εdiamino-caproicacidmonohydrochloride;L-Lysine/hydrochloricacidChemicalbook,(1:x);(2S)-2,6-bis(azanyl)hexanoicacidhydrochloride;L-Lysinehydrochlori;L-LYSINEHCLFEEDGRADE;L-LYSINEHYDROCHLORIDESOLUTION

Related categories

API; Amino Acids; Pharmaceutical Raw Materials; Food Additives; Amino Acids; Basic Amino Acids; Biochemicals; Amino Acids; Alphabetic; Amino Acids, Peptides and Protei Chemicalbookns; Amino Acids Analytical Standards; L; LifeSciences Standards; ;Research raw materials;APIs

Introduction

L-Lysine is one of the 8 essential amino acids in the human body, which can promote human development, enhance immune function, and improve the function of central nervous tissue. Cerebral protective agent for the treatment of craniocerebral trauma, chronic cerebral ischemia and hypoxic diseases.

It is white crystal or crystalline powder, odorless and sweet. Since pure lysine is easy to absorb moisture and agglomerate, it is often made into hydrochloride for the convenience of separation, purification and application. Usually it is relatively stable (relative humidity below 60%), and when the relative humidity is above 60%, it will absorb moisture and agglomerate to form dihydrate. Easily soluble in water (40%, 35°C), almost insoluble in ethanol and ether, and decomposed when heated with reducing sugars such as glucose, resulting in an appetizing bread flavor. mp263-264Chemicalbook°C, isoelectric point 10.56, [α]25D+13.5°(H2O), [α]25D+26.0 (5mol/LHCl). Lysine is one of the essential amino acids in the human body. Nutritionists list it as "the first amino acid deficiency." It plays an important role in maintaining the ammonia balance of the human body. If the human body lacks lysine, it will cause protein metabolism disorders, and the nutritional requirements for lysine are higher during child development, disease recovery and pregnancy and lactation.

Amino acid drugs can promote children's growth and development, increase appetite and gastric acid secretion, and are used for children's recovery after illness and during pregnancy and lactation. In addition, there are lysine derivatives and compound preparations, all of which are amino acid drugs. Such as L-lysine acetate, lysine pirin for injection, lysine tablets, lysine chemicalbook chewable tablets, lysine dry syrup (for children), lysine-B12 chewable tablets (for children) ), lysine-B12 particles (for children), lysine-B12 mixture, etc. Adverse reactions: no obvious toxic and side effects. However, it should be used with caution in patients with hyperchloremia, acidosis and renal insufficiency.

●  The industrial production of lysine mainly adopts the direct fermentation of microorganisms. Lysine is the amino acid of the aspartic acid branch, and aspartokinase is the key enzyme, which is inhibited by the coordinated feedback of lysine and threonine. A single amino acid cannot completely inhibit the activity of the enzyme. The strains used are almost all Corynebacterium glutamicum, which is a homoserine auxotrophic variant and lacks homoserine dehydrogenase. Since aspartokinase is not inhibited by a single amino acid, the homoserine-deficient mutants limit the production of threonine and relieve its feedback inhibition. Therefore, lysine fermentation is carried out, and the yield of sugar in the production strain can reach more than 40%. The homoserine-deficient strain A.S.1.563 of the Institute of Microbiology of the Chinese Academy of Sciences has an acid production rate of 3.66% and a sugar yield of 30% in the pilot test, and cane molasses can be as high as 42%.

●  Corynebacterium glutamicum A.S.1.563 [seed medium] → [32℃, 17h, strain culture] strain [fermentation medium] → [32℃, 38h, fermentation] fermentation broth [732-NH resin] → [adsorption ] Adsorbate [aqueous ammonia (eluting)] → [pH8-14] eluate [concentration] → concentrate [HCl] → [pH4.9, 3 days] crude product [recrystallization and purification] → L-lysine Hydrochloride

●  The strains were cultured using Corynebacterium glutamicum A.S.1.563 provided by the Institute of Microbiology, Chinese Academy of Sciences. Under the conditions of 30-32°C, the strains were activated for 24 hours, cultured on a slant under the same conditions, and then first-level seed culture was carried out. The seed medium is: glucose 2%, corn steep liquor 2%, magnesium sulfate 0.05%, ammonium sulfate 0.4%, dipotassium hydrogen phosphate 0.1%, bean cake hydrolyzate 1%, inoculum size 5%, and cultured at 32°C for 17h.

●  The composition of the fermentation medium is: glucose 15%, ammonium sulfate 2%, dipotassium hydrogen phosphate 0.1%, Chemicalbook magnesium sulfate 0.04%, bean cake hydrolyzate 2%, urea 0.4%. The inoculum amount was 5%, cultured at 32°C for 38 hours, and the required ventilation rate was 1:0.3V/(V·min), stirred, and observed the biochemical metabolism curve during the fermentation process.

●  Adsorption, elution, concentration and crystallization. After heating the obtained fermentation broth at 80°C and stirring for 10min, when cooled to 40°C, take a sample to measure the acid content, and add H2SO4 to adjust the pH to 4-5. After precipitation for 2h, introduce 732- NH4+ resin column. When the acid content of the fermentation broth is about 2.5%, the ratio of resin volume to fermentation broth volume is 1:3. The flow rate of the upper column is controlled at 1000ml/min. When the pH value of the effluent gradually drops to 6-5.5 and the acid content is 0.5%, the resin is saturated. General adsorption 2-3 times.

●  The saturated resin was washed with non-salt water to remove bacterial cells and impurities until the effluent was clear. Then use 2.5mol/L ammonia water to absorb, the flow rate is 700-800ml/min, start to collect from pH8, about 1.5-2 times of the resin volume, stop collecting when the eluent pH is 13-14. The obtained eluting solution was heated to remove ammonia, the film was concentrated in vacuo to 21 ° Be, cooled, concentrated HCl was added to adjust the pH value to 4.9, left standing for 3 days for crystallization, filtered to obtain the crystallization, dried to obtain the crude product, and the mother liquor was concentrated and recovered.

●  Recrystallization and refining The crude product is dissolved in distilled water and made into 12°Be, and then the activated carbon with a weight of 10%-12% of the crude product is added (it is required that the activated carbon does not contain Ca2+, Mg2+, for this reason, the activated carbon should be pretreated with dilute HCl). The filtrate was collected by filtration, concentrated under reduced pressure (controlled at about 93.33kPa), and the humidity was 40-45°C until saturation. Allow to stand for natural cooling and crystallisation, filter to collect crystals, and dry at 60°C to obtain crude L-lysine salt with a yield of 50%.

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