Proline (Pro) is one of the components of plant proteins and can be found widely in the plant body in free state. Under stress conditions such as drought and salinity, proline accumulates in large quantities in many plants. In addition to serving as an osmoregulatory substance in the plant cytoplasm, the accumulated proline also plays an important role in stabilizing the structure of biomacromolecules, lowering cell acidity, relieving ammonia toxicity, and acting as an energy reservoir to regulate cellular redox potential.
Under adverse conditions (drought, salinity, heat, cold and freezing), the proline content in plants increases significantly. The proline content in plants reflects the plant's stress tolerance to a certain extent, and drought-resistant varieties tend to accumulate more proline. Therefore, the determination of proline content can be used as a physiological indicator for drought-resistant breeding. In addition, because proline is extremely hydrophilic, it can stabilize protoplasmic colloids and metabolic processes in tissues, thus lowering the freezing point and having the effect of preventing cell dehydration. Under low temperature conditions, the increase of proline in plant tissues can improve the cold resistance of plants, therefore, it can also be used as a physiological indicator of cold resistance breeding. According to a recent study from the University of Illinois, the repetition of a simple amino acid in the protein center of tooth enamel makes teeth stronger and more resilient.
In amphibians and animal models, the researchers compared proline repeats. They found that when the repeats were short, as in frogs, the teeth would not produce enamel prisms, structures that are important for tooth strength. In contrast, when the protein repeats are long, they aggregate a series of molecules to help enamel crystals grow.
The findings are published in the December 21, 2009, online edition of PLoS Biology. Tom Diekwisch, a professor of biology who led the study, describes the proline repeats as surprising and important for understanding the structure and function of many natural proteins, such as mucins, antifreeze proteins, amyloid proteins, prion proteins, etc. etc.
Tooth enamel is surrounded by foamy protein clumps as it grows, and the size of the protein foam varies in different animals, from 5 nanometers in cows to 20 nanometers in rats, and 40 nanometers in frogs. This finding suggests that the longer the proline repeat fragment, the larger the protein foam. In addition, the smaller the protein foam, the longer the enamel crystals.
The researchers hope that these findings will contribute to other important areas of science, including the treatment of degenerative neurological diseases. In addition, the findings may help in the design of new tooth enamel so that people can have a healthy enamel layer.
Product Uses
Use 1 is used in amino acid injections, compound amino acid infusion, food additives, nutritional supplements, etc.
Use 2 is used in biochemical research, and is used in medicine for malnutrition, protein deficiencies, gastrointestinal disorders, scalded wounds, and post-surgical protein supplementation.
Use three nutritional supplements. Flavor agent, and sugar *** heat amino-carbonyl reaction, can generate a special flavor substances. According to our GB 2760-86 regulations can be used as a spice.
Use four amino acid drugs. It is one of the raw materials of compound amino acid infusion, which is used for protein supplementation after malnutrition, protein deficiency, severe gastrointestinal disorders, burns and surgery.
Use five pharmaceutical raw materials and food additives.
Applications
Used in amino acid injection, compound amino acid infusion, food additives, nutritional supplements, etc.
Method of preparation
Method 1 is obtained by hydrolysis of gelatin with acid and chromatography of ion exchange resin.
Method two gelatin, casein and other proteins hydrolysate, treated with ion exchange resin, and then with picric acid or Reineckeatesalt (Reineckeatesalt) treatment of neutral amino acid part of the precipitation of L-proline only, and finally with anhydrous ethanol plus isopropanol recrystallization and obtained. It was obtained by fermentation of Corynebacteriumacetoacidophilum XQ-3 (selected by Central Research Institute of Wuxi University of Light Industry) with ammonium chloride as nitrogen source. The acid yield is about 60g/L.
Method III L-Proline has two methods of production. One is the direct fermentation method, the use of glucose and yellow Pseudobacillus mutans or Corynebacterium glutamicum wild strain, by microbial fermentation to obtain L-proline; The second is the chemical synthesis method, with glutamic acid as raw material, and anhydrous ethanol in the sulfuric acid-catalyzed esterification, and the addition of triethanolamine will be aminosulfate free out of the glutamate - ?± - ethyl ester. Then reduce glutamic acid-δ-ethyl ester with metal reducing agent potassium borohydride to get the crude proline, and finally its separation and purification can get the crude proline. Small test process esterification Weigh 147g of L-glutamic acid, put into a three-necked bottle, add 1L of anhydrous ethanol, stirring and cooling to 0 ℃, and then dropwise add 80ml of H2SO4, stirring at 0-5 ℃ to react for 1h, and then continue to react at room temperature for 1h, and the reaction is all clear. Add triethylamine dropwise to pH 8-8.5 at 20 ℃, white crystals were precipitated, stirred at room temperature for another 1h, static cooling at 5 ℃ filtration, take the crystals, washed with 95% ethanol, drained and dried in vacuum, obtained glutamic acid-δ-ethyl ester about 141 g. Melting point 178-180 ℃, yield 80%-83%. [α]32D+29.8 (C=1g/ml 10% HCl). Reduction In a three-necked flask put glutamic acid - δ - ethyl ester 175g, add distilled water 875ml, stirring and cooled to 5 ℃, and then add KBH4 53.9g in stages, about 1h added, room temperature and then reacted for 1h, keep warm at 50 ℃ reaction for 3h. Cooled to 0 ℃, add 6mol / L HCl adjusted to pH4, filtration to take the filtrate, that is, to obtain the crude L - proline aqueous solution. Separation and purification of ion exchange resin-alumina column chromatographic separation method The crude L-proline aqueous solution, with a flow rate of 4ml/min into the loading of 732-H+ type resin exchange column (1g acid feeding need 10ml resin). The column was first rinsed to neutrality with distilled water and then eluted with 1 mol/L ammonia to collect the eluate containing the L-proline segment (controlled by silica gel G thin-layer chromatography). The eluate was concentrated to dryness under reduced pressure, then dissolved with a small amount of water and passed into a neutral alumina column, and then eluted with 60% ethanol in water (still controlled by silica gel G thin-layer chromatography). The collected eluate is concentrated to dryness under reduced pressure, then washed several times with anhydrous ethanol, slightly cooled and then added anhydrous ether, cooled and filtered to take the crystals, dried in vacuum to obtain L-proline. Melting point 220-222 ° C (decomposition), yield about 28%. [α]24D-82.4 (C=1g/ml, H2O). Pentachlorophenol precipitation desorption separation method into salt Put the crude aqueous solution of proline in the reaction flask, heating to 50 ℃, dropwise addition of pentachlorophenol ethanol solution (0.111 mol/70 ml of ethanol), and keep warm and stirring for 5h, let cooled to 0 ℃, filtration to take the crystals, washed with a small amount of iced water, pumped dry, drying to get the complex salt, melting point 240-242 ℃, precipitation rate of 95%. Analysis of the compound salt 38.4g, put into a three-necked bottle, add 200ml of distilled water, ammonia 20ml, room temperature stirring 8h, cooled to 0 ℃ and filtered to extract the filtrate, the filtrate is concentrated under reduced pressure, add 100ml of distilled water, filtration to extract the filtrate, add activated carbon decolorization. Ether extraction, separated from the aqueous layer, continue to concentrate to dry, with anhydrous ethanol decolorization several times, and then add a small amount of anhydrous ethanol wet, add 2 times the amount of anhydrous ether, cooling crystallization, filtration to take the crystals, vacuum drying, to get the finished product of L-Proline. Enlarge the production process esterification L-glutamic acid 15kg, anhydrous ethanol 100L into the 200L reaction tank, cooled to 0 ℃, stirring conditions dropwise addition of concentrated H2SO4 8.1L, keep 0 ℃, stirring reaction for 1h, and then keep warm at 25 ℃ stirring reaction for 1h, add triethylamine so that the pH is 8.0-8.5. Stirring for 1h, there is a white precipitate. Cooled to 5 ℃, filtered to take the precipitate, washed with 50L of 95% ethanol, the precipitate was dried in vacuum at 50 ℃, to get L-glutamic acid-δ-ethyl ester. Reduction The obtained L-glutamic acid-δ-ethyl ester was put into a 100L reaction tank, 70L of water was added, stirring and cooling to 5 ℃, 4.3kg of KBH4 was added in 1h, heated and held at 200 ℃, stirring and reacting for 1h, and then heated and held at 50 ℃, stirring and reacting for 3-4h, cooled to 0 ℃, adjusted the pH to 4.0 with 6mol/L of HCl, and filtered to take filtrate to get the crude solution of L-proline. L-Proline crude solution was obtained by filtering and taking the filtrate. Precipitation Put L-proline crude solution into 100L reaction tank, heat to 50℃, slowly add 7L 1.5mol/L ethanol solution of PCP under constant stirring, keep warm for 5h reaction at 50℃, precipitate crystals when cooled to 0℃, filter and take the crystals, and then pump dry to get compound salt. Analysis, refinement Put the compound salt into 100L reaction tank, add 3% ammonia 20L, room temperature stirring reaction 7-8h, cool down to 0 ℃ filtration, precipitation with a small amount of ice water wash, drain, wash and filtrate combined, and then concentrated to dry under reduced pressure, with 10L of deionized water stirring to dissolve, filtration of filtrate, and add 0.5% activated carbon, heated to 70 ℃, stirring decoloration of 1h, filtration of filtrate, let it cool down to 0 ℃, add equal volume of ethyl alcohol, filtered, let it cool down to 0 ℃, let it cool down, let it cool down, let it cool down. To 0 ℃, add an equal volume of ether extraction, separated from the aqueous layer, concentrated to dry under reduced pressure, add 10L anhydrous ethanol dehydration 3 times, pumped dry, the precipitate add 2L anhydrous ethanol stirring, and then add 10L of ether, cooled to 0 ℃, filtration to take the precipitate, vacuum pumping ether, 80 ℃ drying, to get the finished product of L-Proline.
Material Safety Data Sheet (MSDS)
First Aid Measures
IngestedIf the victim is awake and alert, give 2-4 cupfuls, milk or water. Seek immediate medical attention.
Inhalation Immediately from the scene to fresh air. If not breathing, administer artificial respiration. If breathing is difficult, give oxygen. Obtain medical assistance.
Skin for at least 15 minutes while rinsing skin with plenty of soap and water Remove contaminated clothing and shoes. If irritation worsens or persists, seek medical assistance.
Eyes Immediately flush eyes with plenty of water for at least 15 minutes, lifting upper and lower eyelids from time to time. Obtain medical assistance.
Treatment
Wash thoroughly after handling operations. Use with adequate ventilation. Reduce dust generation and accumulation. Avoid contact with skin and eyes. Keep container tightly closed. Avoid ingestion and inhalation.
Hazard Identification
The toxicological properties of this substance by inhalation have not been adequately investigated.
Dermal hazard is low for usual industrial handling.
EyesNo concerns about eye irritation and other potential effects have been identified. Contact may cause transient eye irritation.
The toxicological properties of ingestion of this substance have not been adequately investigated.
EXPOSURE CONTROLS/PERSONAL PROTECTION
PERSONAL PROTECTION EYES: Wear appropriate protective eyewear or chemical safety goggles, OSHA's Eye and Face Protection Regulation 29 CFR 1910.133 or European Standard EN 166.SKIN: Wear appropriate protective gloves to prevent skin contact. Clothing: Wear appropriate protective clothing to prevent skin contact.
Respirators follow OSHA respirator regulations 29 CFR 1910.134 or European Standard EN 149. always use a NIOSH or European Standard EN 149 approved respirator as necessary.
Effects of exposure may irritate eyes, skin and respiratory tract. Expect low ingestion hazards.
Fire Fighting Measures.
Flash Point 106
Fighting fires under pressure requires wearing self-contained breathing apparatus equipment, MSHA/NIOSH (or equivalent), and full body protective clothing. Sufficient concentrations of dust can form explosive mixtures with air. Combustion produces toxic gases. Extinguishing Agents: For small fires, use water spray, chemical dry powder, carbon dioxide, or chemical foam. Use the most appropriate extinguishing agent.
Accidental Spill Handling Measures
Sweep up small spills/leaks and place in a suitable container for disposal. Avoid dusty conditions. Provide good ventilation.
Stability and Reactivity
Sale No. 31
Stability is stable at normal temperature and pressure.
Incompatibility with strong oxidizing agents.
Decomposes nitrogen oxides, carbon monoxide, carbon dioxide.
Storage and transportation characteristics
Store in a cool, dry, well-ventilated place away from incompatible substances.
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