Pharmacological action and application of vitamin B12
Product Category: Project
product description:Vitamin B12, also known as cobalamin, is one of the B vitamins. It is mainly found in animal food, such as viscera, liver, kidney and pig heart. Vitamin B12 is also found in lean meat, fish, milk and egg yolk. Vitamin B12 is not contained in plants, but c
Vitamin B12, also known as cobalamin, is one of the B vitamins. It is mainly found in animal food, such as viscera, liver, kidney and pig heart. Vitamin B12 is also found in lean meat, fish, milk and egg yolk. Vitamin B12 is not contained in plants, but can be synthesized by actinomycetes, human and animal intestinal bacteria. It is a complex organic compound in structure, containing trivalent cobalt Center of the porphyrin like plane of the Gulin ring. There are about five analogues of vitamin B12 in nature, which are mainly different from the groups connected with CO in the molecule, namely - CN, - Oh, - CH3, - NO2 and H2O, which have the same physiological activity.
Vitamin B12 participates in various metabolic processes in the form of coenzyme, promotes the formation and transfer of methyl group, participates in the isomerization of some compounds, maintains the reduction state of SH group, promotes the synthesis of DNA and protein, promotes the maturation of cells, maintains the normal function of nerve tissue, and when vitamin B12 is deficient, malignant anemia and damage of nervous system will occur, which can be used in clinical treatment Pernicious anemia, liver disease, neuritis, neuralgia, etc. are also used in feed industry to promote the growth of pigs, chickens and other livestock. Vitamin B12 is an essential vitamin for human and animals. Its unique function, complex structure and production conditions determine its more demanding production conditions. It is this kind of inaccessibility that makes its price very expensive. At present, the price of 97% vitamin B12 in the international market is 45000rmb / kg. For many years, people have been trying to reduce the cost of vitamin B12 by chemical way, but because of its huge and complex structure, although it has been successful in recent years, at the same time, chemists are in a new dilemma: too many by-products, difficult to purify. Therefore, people re-examine the production method of vitamin B12, and turn the focus to fermentation again. There are many strains that can produce vitamin B12, but as a secondary metabolite, there is no new breakthrough in the fermentation level all the time. In China, only in recent years, there have been two manufacturers, but their annual output is less than two tons, and the huge domestic demand market is slightly insufficient At present, more than 90% of the edible and medicinal vitamin B12 in the domestic market is imported. Therefore, there will be a huge market potential to realize the low cost of vitamin B12 in China.
[physical and chemical properties and structure] 
Vitamin B12 is a dark red crystal with a very high melting point (not melting at 320 ℃), odorless and tasteless, soluble in water, ethanol and acetone, insoluble in chloroform, acetone and ether, and its structure and properties are quite stable; in neutral solution, it can be destroyed by heat, acid, alkali, sunlight, oxidant and reductant.
Anti anemia drugs. It can be used for megaloblastic anemia and also for the auxiliary treatment of neuritis.
[usage and dosage] 
Intramuscular injection for the treatment of vitamin B12 deficiency, 25-100 μ G on the first day or 50-200 μ G on the next day for 2 weeks; if accompanied by nervous system performance, the daily dosage can be increased to 500 μ G. After that, intramuscular injection of 50-100 μ g twice a week was performed until the blood picture returned to normal. It can also be used for deep skin injection.
[adverse reactions] 
Occasionally, it can cause skin rash, pruritus, diarrhea and allergic asthma, and very few of them have anaphylactic shock; it can cause hypokalemia and hyperuricemia. It has been reported that vitamin B12 was lethal by intravenous injection.
[taboo / caution card] 
It is forbidden to use it in allergic, family hereditary retrobulbar neuritis and smoking amblyopia.
1. After intravenous administration, it will be discharged from urine rapidly, and there are fatal cases, so intravenous administration is forbidden;
2. In the treatment of megaloblastic anemia with large dose of vitamin B12, it is advisable to check whether there is a decrease in blood potassium at the beginning of 48h;
3. Antibiotics can affect the determination of vitamin B12 in serum and erythrocytes, especially the application of microbiological examination, which can produce false low value.
[preparation]  
1. Production strain:
3. Fermentation production:
1) extraction from antibiotic waste liquid: as early as 1952, t.r.wood et al. Found that the concentration of vitamin B12 in the whole culture medium could be greatly increased when Streptomyces griseus was cultured in the medium with cobalt compound, but the concentration of cobalt compound should be appropriate, too high concentration would produce toxicity to the cell; other studies showed that the addition of appropriate amount of cyanogen compound would cause toxicity to the cell It can also promote the content of B12 analogues in antibiotic waste liquid, but the dosage should be strictly controlled.
2) actinomycete fermentation: since it has been found that vitamin B12 can be extracted from antibiotic waste liquid, many scientists have turned their attention to the use of actinomycetes, mainly Streptomyces griseus and Streptomyces olivaceus, to ferment and produce vitamin B12. However, due to the production of streptomycin, the production of vitamin B12 has never been dominant. Therefore, it should be selected The key enzyme of streptomycin fermentation branch is produced and inhibited, which can greatly improve the yield of vitamin B12 and make it possible to produce a large amount of vitamin B12.
3) wastewater extraction: the wastewater treated by biological activated sludge method usually contains more B12. The dry activated sludge can be extracted with water first, then the solid particles can be filtered out, and then B12 can be separated and purified. The B12 obtained has the following characteristics: no need for pre culture, which greatly reduces the initial investment; large energy consumption, especially the key step of concentration will cause large