Complaint
| summarize | Vitamin B12, VB12 for short, also known as cobalamin, one of the B vitamins, is a kind of cobalt containing gololin complex organic compounds, containing cobalt trivalent located in the center of the gololin ring plane similar to porphyrin. It is the largest and most complex vitamin molecule found so far, and it is the only vitamin containing metal ions. Its crystal is red, so it is also called Chemicalbook red vitamin. Plants do not contain VB12, nor can they make it. Liver is the best source of VB12, followed by milk, meat, eggs, fish, etc. VB12 is an essential coenzyme in the synthesis of RNA and DEoxyrna. The deficiency of VB12 in vivo can cause pathological changes of the nervous system such as peripheral nerve and central encephalopathy. |
| character | Vitamin B12 is an isooctahedral compound containing cobalt ions. Its central structure is a planar corrinring composed of four pyrroles connected to each other. The molecule of vitamin B12 consists of three parts: a golene ring chelated with four N atoms and a central cobalt ion; 5, 6 - dimethyl benzene and imidazole (5, 6 - dimethylbenzimidazole DMBI) by N - 7 cobalt atoms and ions are connected as low vitamin B12 molecules (alpha) ligands, besides DMBI by phosphate groups and propanol (aminopropanol),propyl alcohol and pyrrole side chain covalently linked; Adenosylgroup or methylgroup is linked to cobalt ions to form the upper (β) ligand of the vitamin B12 molecule. |
| physiological function | 1. Improve the availability of folic acid, with folic acid synthesis methionine (from homocysteine synthesis) and choline, the production of purine in the process of synthesis of cobalamin precursor such as methyl cobalamin and coenzyme B12, involved in the methylation of many important compounds. When vitamin B12 is deficient, the transfer of methyl groups from methyltetrahydrofolate is reduced, leaving folate in an unusable form, leading to folate deficiency. 2. Maintain the metabolism and function of nerve myelin sheath. Vitamin B12 deficiency can cause neurological disorders, spinal cord degeneration, and can cause severe psychiatric symptoms. Vitamin B12 deficiency can lead to peripheral neuritis. The early signs of vitamin B12 deficiency in small Chemicalbook children are abnormal mood, dull expression, sluggish reaction, and finally anemia. 3. Promote the development and maturation of red blood cells. Methylmalonyl-coa is converted to succinyl-CoA, which is involved in the tricarboxylic acid cycle. Succinyl-coa is involved in the synthesis of heme. 4. Vitamin B12 is also involved in the synthesis of deoxynucleic acid (DNA), metabolism of fats, carbohydrates and proteins, and increase the synthesis of nucleic acid and protein. An overview of vitamin B12, traits, physiological functions, applications, etc., is compiled by the Eastern editors of Chemicalbook. (2016-01-22) |
| use | 1. Medical and health applications 2. Application in feed 3. Applications in other areas |
| content analysis | Transfer approximately 30mg of the accurately weighed sample with water to a 1000mL volumetric flask and mix with water. In addition, pharmacopoeia grade reference standard sample of vitamin B12 was weighed accurately, dissolved in water, and then diluted gradually to a standard solution with a concentration of about 30μg/ mL. Using water as blank test, the absorbance of the two solutions in 1cm colorimetric cell at the maximum absorption wavelength (about 361nmChemicalbook) was measured simultaneously with a suitable spectrophotometer. The content of vitamin B12(C63H88CoNl4O14P) in the sample (mg) was calculated according to the following formula. Vitamin B12 content (mg)=C×Au/As, where C is the concentration of the reference standard solution, the unit is μg/ mL; Au and As are the absorbance of the sample solution and the reference standard solution respectively. |
| Gb14880-94: Infant food, fortified beverage 10-15 μg/kg. FDA, § 184.1945 (2000) : limited to (3MP. GB2760 -- 2002(μg/kg)Chemicalbook: Soft drink 0.6 ~ 1.8; Ready-to-eat breakfast cereals, 5-10; Jelly 2.0 ~ 6.0; Cocoa powder and other flavor nutritional solid drinks, 1 ~ 6.6(the corresponding nutritional milk drinks to reduce the amount of dilution). |
