CYANOCOBALAMINE

From Big Medical Encyclopedia

CYANOCOBALAMINE (a synonym B12 vitamin) — Soa-(a-5,6-dimetilbenzi-midazolit) - Litter - tsianokobamid — the kobaltsoderzhashchy complex connection relating to the substances containing a korrinovy kernel — to korrinoida, is vitamin. Cyanocobalamine possesses antiper-nitsiozny action, influences a hemogenesis, participates in transfer of methyl groups, napr, at synthesis of methionine, and also in synthesis of nucleic acids (see) and in exchange of thetas-ragidrofoliyevoy to - you (see. Folic acid). At insufficiency of C. exogenous (alimentary) or endogenous character (see. A vitamin deficiency) develop Addison's anemia — Birmera (see. Pernicious anemia), changes in a spinal cord like a funicular myelosis (see), a polyneuropathy, etc., note an achlorhydria (see), lack of appetite, subfebrile temperature. In medicine of C. it is used as medicine. In crystalline state of C. it is received in 1948.

Biosynthesis of B12 vitamin is carried out only by microorganisms, among to-rykh the main role belongs to bacteria, actinomycetes and blue-green seaweed. Apparently, at the expense of the last B12 vitamin collects in a body of mollusks, fishes and other water animals; source of C. in an organism of land animals actinomycetes are. Very large amounts of this vitamin are formed during the bioscrubbling of drain waters (see) as a part of so-called active silt. B12 vitamin is synthesized also by intestinal microflora of animals and the person at a condition of keeping of cobalt as a part of feedstuffs. Only animal products are a source of B12 vitamin in food of the person; the richest of them on the content of B12 vitamin are the liver of fishes, beef liver and kidneys. In animal products of B12 vitamin contains (in mkg on 100 g of crude weight of a product): in beef liver — 50 — 130; beef kidneys — 20 — 50; cod livers — 40; a herring (fillet) — 13; to a haddock — 11; to a cod — 10; to a flounder — 10; to fish meal — 10 — 25; to beef — 2 — 8; to veal — 2; cheese — 1,4 — 3,6; cow's milk — 0,2 — 0,6; to pork — 0,1 — 5. The yolk of egg on average contains 1,2 mkg of B12 vitamin.

Main part of a molecule C. the cobalt complex of the nitrogenous macrocycle carrying the name «korrin» is. The kernel of a korrin contains four recovered pyrrol rings (or kernels) having in p-provisions (see Porphyrines) marked ny, acetamide and propionamidny deputies.

Pier. weight (weight) of C. it is equal to 1355,4. In pure form C. represents crystal powder of inodorous dark red color. C. has no accurately expressed temperature of melting: at a temperature over 200 ° it begins to darken and decay gradually, but does not melt up to 320 °. Powder C. it is hygroscopic, we will difficult dissolve in water (only 1,25% of substance at 25 are dissolved °), we will dissolve in 95% alcohol, it is almost insoluble on air, chloroform, acetone. C. diamagniten,

cobalt in a molecule C. has valency +3 and coordination number 6. The absorption spectrum of 0,002% of solution of B12 vitamin in water has the following maxima: 278+1 nanometers, 361 ±1 nma

of 548±2 nanometers. Ud. rotation „=

= - 59±9 ° and Y20643,8 = — 110 + 10 ° (1,98 mg of cyanocobalamine in 0,4 ml, waters). C. crystallizes from water or water solution of acetone. Its crystals have an appearance of red prisms and contain crystal water. In a crystal look at the room temperature and in the dark cyanocobalamine is steady. Aqueous solutions of C. are stablest at pH 4,0 — 6,0, they can without noticeable loss biol. activities to be exposed to autoclaving and then remain in the dark at the room temperature within several years. However the most modern method of sterilization of solutions of Vit-minav12 is their processing in the frozen state (in the soldered ampoules) ^-radiation.......... In caustic solutions C. is less steady: at pH 8,0 in several hours of heating at 100 ° it collapses approximately for 90%. Heating in 0,1 N caustic liquor destroys B12 vitamin, as well as its hydrolysis diluted or weak too to-tami. At hydrolysis by ascorbic acid (see). C. it is recovered to an inactive product. Thiamin (see) also inactivates B12 vitamin.

Industrial production of B12 vitamin is based on its micro-biol. synthesis by means of Propioni-bacterium shermanii synthesizing polyneuramin to a coenzymatical form i.e. in the form of an adenozilkobalamin, to-ry at after-treatment by potassium cyanide turns into steady cyanocobalamine. Release of B12 vitamin from fermentative solutions is carried out after hydrolysis of bacterial weight at pH 4,0 — 4,5 and temperature 80 — 90 ° by sorption of korrinoid on active coal and then on SG-1 cation exchanger (in H+ - a form) with the subsequent eluating (see Elution) ammoniac and borate buffer solution. For sedimentation of proteins eluate is processed aluminum potassium alum and further solution of potassium cyanide at pH 6,0 therefore a transfer of korrinoid in cyanocobalamine is made. Chemical purification of B12 vitamin is made by receiving its complex with resorcin and the subsequent decomposition of this complex and crystallization of B12 vitamin from water and acetonic solutions. Purity of crystal B12 vitamin at this way of cleaning is not lower than 95%.

Methods of qualitative test of C. are based on hromatografichesky (see the Chromatography), electrophoretic (see the Electrophoresis) and biological properties of B12 vitamin. Quantitative methods of determination of C. divide on chemical, physical. - chemical, mikrobiol. and enzymatic. Known chemical methods of quantitative determination of C. and its derivatives — cobalamines consist in quantitative definition of 5,6-di-methylbenzimidazole, cobalt or cyanide (see. Cyanhydric acid) after decomposition of C. The spectrophotometric method of quantitative definition (see the Range about a photo meter and I) consists in direct determination of C. to the maximum absorption at the wavelength of 361 ±1 nanometers, this method is accepted for quantitative definition of B12 vitamin and described in GFH. Mikrobiol. methods of quantitative definition of cobalamines are based on property of separate microorganisms grow only in the presence in a medium of cobalamines. Treat such microorganisms E. coli 113/3, LactobacilJus leichmannii, Ochromonas malhamensis, Euglena gracilis, etc. is suitable Euglena gracilis also for determination of content of C. in blood serum. Mikrobiol. methods have various sensitivity (from 4 • 10-9 to 1 * 10-15 g of V12v 1 vitamin of ml) depending on the used test microorganism. The simplest is the method with use of E. coli 113/3. In blood serum widely apply a method of radio isotope cultivation to quantitative definition of B12 vitamin, to-ry on sensitivity it is close to microbiological, and surpasses it in speed of performance.

Enzymatic methods of definition of cobalamines are exclusively sensitive and allow to define their pikomolyarny quantities. They began to be developed after opening in live organisms of coenzymatical forms of B12 vitamin — methylcobalamine and an adenozilkobalamin (see Coenzymes). For these methods use enzymes to a dioldegidrataz (propane-dioldegidratazu; KF 4.2.1.28), a gli-tseroldegidrataza (KF 4.2.1.30), etc., a coenzyme to-rykh is adenozilkobalamin. The enzymatic method is based that the amount of active enzyme (choloenzyme) is proportional to quantity of the coenzyme (Kov12, in this case — an adenozilkobalamina) added to surplus of an apoenzyme (a proteinaceous part of KOV «-dependent enzyme).

B12 vitamin is present at a human body and animals in three kofermentoaktivny forms: Oxycobalaminum, methylcobalamine and the adenozilkobalamin differing from each other in character (Z-aksial-nykh deputies in a molecule (instead of cyanogroup a r-axial ligand in their molecules are respectively an eye and - marked - or 5 '-dezoksiadenozilpy deputies). It is established that these three to - oh l of amine can turn each other. The most part of cobalamines in a human body and animals is in a form adenozil-and Oxycobalaminum. At healthy people the main form of B12 vitamin in a blood plasma is metilkoba-lamin. Oxycobalaminum is the main transport and deposited form of B12 vitamin. Metilko-balamin and adenozilkobalamin — coffee rmentny forms of B12 vitamin in structure of Kov12-or B12-dependent enzymes — participate in a catalysis of a large number of biochemical reactions, two of them — metilmalonil-KOA — mutazny (enzyme metilmalonil-KOA — mutase; KF 5.4.99.2) and me-tioninsintazny (enzyme methionine-synthase; KF 4.2.99.10) are found in the person and animals.

B12 vitamin is soaked up preferential in an ileal gut. Need of the person for B12 vitamin is very small and makes for adults and children from 11 years and

3 mkg a day are more senior (for pregnant women and nursing mothers — 4 mkg a day); for children aged up to 3 months — 0,3 mkg; 4 — 6 months — 0,4 mkg; 7 — 12 months — 0,5 mkg; 1 — 3 years — 1 mkg; 4 — 6 years — 1,5 mkg; 7 — 10 years — 2 mkg. As B12 vitamin is synthesized by intestinal microflora, as a rule, not deficit of C is the main reason for its insufficiency. in food, and various disturbances of its absorption. For absorption in intestines small fiziol. doses of B12 vitamin the so-called internal factor, an antianemic factor, or Kasl's factor is necessary (see Kasl factors). At education in a gleam of intestines of not physiologically high concentration of B12 vitamin, napr, as a result of reception of high doses of this vitamin, it can come to a blood stream without participation of an internal factor due to passive transfer and a pinocytic. Transport of cobalamines in a blood plasma is carried out by means of three transport proteins —

transcobalamines I, II and III. It is established that transkobal-amine I belongs to serumal and - to globulins, and transkobal-amine I — to r-globulins. The main manifestations of insufficiency of B12 vitamin are the disturbances of processes of a hemopoiesis leading to hyperchromic megaloblastichesky anemia (see), leukopenias (see), a neutropenia and thrombocytopenia (see). One of the reasons of development of a funicular myelosis is also a hypovitaminosis of B12. The interrelation between B12 vitamin and folic to - that in processes of a hemopoiesis is established. The essential role of coenzymatical forms of B12 vitamin is established not only for a hemopoiesis, but also for process of tumoral growth. According to experimental data, rapid growth of nek-ry tumors is connected with increase in contents in an organism of methylcobalamine and activity of enzyme of the metioninsintetaza catalyzing transformation of a gomotsi-stein into methionine.

Radioactive cyanocobalamine. Existence in a molecule C. cobalt allowed to receive radioactive B12 vitamin by inclusion 56so, b7so, 58so and 60so in composition of nutrient mediums, on to-rykh grew up the microorganisms synthesizing B12 vitamin. Isotopes of cobalt (see Isotopes) are used in diagnosis of various diseases. Besides, marked a telecobalt B12 vitamin is applied to quantitative definition of this polyneuramin to blood serum. For introduction of a radio isotope tag to B12 vitamin the most applicable isotopes of cobalt are 57so and 58so as the exposure dose in these cases is much less, than during the use, e.g., 60so. For introduction to molecules C. use also 32P and 14C. The first is added in the form of 32P-phosphate to a medium and quickly allocated marked korrino-ides; however short half-life 32P limits use of this method. Radiocarbon (see) is used for introduction to molecules of predecessors of B12 vitamin. Mechenny 13C korri-noida are widely applied in 13C-nuclear magnetic resonance-spectroscopy (cm, Nuclear magnetic resonance).

Cyanocobalamine as drug. As pharmaceuticals in medicine use cyanocobalamines, and also metabolic more active forms of B12 vitamin — Oxycobalaminum and Cobamamidum.

Cyanocobalamine (Suapo-cobalaminum; synonym: Antipernicin, So-bione, Vitaminum B12, etc.) represents crystal powder of inodorous dark red color, hydroscopic, difficult water soluble.

C. is effective antianemic remedy (see) and it is used for treatment of malignant anemia (see. Pernicious anemia), posthemorrhagic iron deficiency states (see. An iron deficiency anemia), aplastic anemias at children, anemias of alimentary and other origin (see Anemia). C. apply also at a radial illness (see), dystrophies at premature and newborn children after the postponed infections (see Dystrophy), at a spra (see), diseases of a liver, polyneurites (see), radiculitis (see), neuralgia (see), including epileptiform neuralgias (see), diabetic neuropathies, diseases of the central nervous system (an amyotrophic side sclerosis, encephalomyelitis, etc.), a Down syndrome (see Down a disease), at skin diseases, etc.

C. appoint inside (for improvement of absorption — with folic to - that), intramusculary, subcutaneously, intravenously and intralyumbalno.

At pernicious anemia of C. enter in injections on 100 — 200 mkg of 1 times in 2 days before remission (or daily within the first week to reticulocytic crisis). At pernicious anemia with the phenomena of a funicular myelosis and at macrocytic anemias with defeat of a nervous system — on 500 mkg and more (to 1000 mkg on an injection) in the first 7 — 10 days daily, and then at an interval of 3 — 5 — 7 days. For a maintenance therapy at funikulyarshsh a myelosis usually appoint 100 mkg of cyanocobalamine 2 times a month, and in the presence nevrol. symptoms — on 200 — 400 mkg 2 — 4 times a month. At posthemorrhagic and iron deficiency anemias appoint intramusculary 30 — 100 mkg of cyanocobalamine

2 — 3 times a week; at aplastic anemias at children — on 100 mkg daily; at anemias of alimentary character at early children's age and anemias at premature — on 30 mkg within 15 days. At diseases of a nervous system of C. appoint in the increasing doses from 200 to 500 mkg to an injection, as a maintenance therapy at improvement of a state on 100 mkg a day; a course of treatment to 2 weeks. At traumatic defeats of peripheral nerves of C. enter on 200 — 400 mkg of 1 times in 2 days within 40 — 45 days. At hepatitises, cirrhoses of a liver appoint (to adults and children) 30 — 60 mkg a day or on 100 mkg every other day within 25 — 40 days. At dystrophy at children of early age and after the postponed infections, at a Down syndrome and cerebral palsy of C. appoint 15 — 30 mkg every other day. At a spra, a radial illness, a diabetic neuropathy appoint 60 — 100 mkg daily within 20 — 30 days. At a funicular myelosis, an amyotrophic side sclerosis and multiple sclerosis of C. enter sometimes subarakhnoidalno 15 — 30 mkg, gradually increasing a dose to 200 — 250 mkg.

Usually C. it is transferred well. However at hypersensitivity to drug there can be allergic phenomena, nervous excitement, tachycardia, pains in heart. In these cases treatment of C. temporarily stop, and further appoint it in small doses — on 15 — 30 mkg. In the course of treatment of C. it is necessary to control coagulability of blood and to observe extra care, appointing him the patient with stenocardia and bent to a thrombogenesis. It is not necessary to appoint C also. the patient with acute tromboembolic episodes. Administration of solutions of cyanocobalamine, thiamin is not recommended joint (in one syringe) (see) and a pyridoxine (see), since contained in a molecule C. the ion of cobalt promotes destruction of these substances; C. can also strengthen the allergic reactions caused by thiamin, C. it is contraindicated at an erythremia, an erythrocyte ze.

Form of release: ampoules on 30; 100; 200 and 500 mkg in 1 ml of isotonic solution of sodium of chloride, i.e. on

1 ml 0,003; 0,01; 0,02 and 0,05% of solution; the tablets containing cyanocobalamine of 50 mkg and folic to - you are the 800th mkg. C. is also a part of polyvitaminic drugs. Storage: in the soldered ampoules in the place protected from light.

About to with and to about and l and m and N (Okhuso-balaminum; synonym: Hydroxycobalami-num, etc.) in comparison with C. is more active coenzymatical form, remains in an organism longer that is caused by its ability stronger to communicate from a belkakhma of a blood plasma and to be removed more slowly with urine. Oxycobalaminum to a lesser extent, than C., increases coagulability of blood.

Indications, doses, and contraindications to appointment the same, as for cyanocobalamine. Form vypus: ampoules on 1 ml containing 100; Oksikobat 500 and 1000 mkg amine. Storage: in the soldered ampoules

in the dark place.

To about and m and m and d (Cobamamidum; synonym: kobamidny coenzyme, Adeno-sylcobalamin, Coenzyme B12, etc.) — the most biologically active form of B12 vitamin.

Cobamamidum, having properties C., differs from it in the expressed anabolic activity. Unlike anabolic means of the hormonal nature (see. Anabolic steroids) drug does not cause side reactions.

At newborns, the premature or weakened children with the expressed hypotrophy, Cobamamidum stimulates activity food and formation of other reflexes, increases an increase of body weight, raises a muscle tone and a physical activity. Drug is effective in complex therapy of hypoxemic conditions of newborns; it promotes compensation of a metabolic acidosis, normalization an oxidizing reducer of ny processes. At neurotic anorexia at adults Cobamamidum improves appetite, stimulates activity of intestines, promotes increase in body weight, etc.

The drug is administered inside subcutaneously, intramusculary, intravenously. To newborns and children of the first year of life as anabolic means, and also at a hypoxia and anemia drug is usually appointed inside. A tablet without cover (1000 mkg) dissolve before the use in 25 m 5% of solution of glucose and give on 1 chayn. l. (200 mkg) in 30 min. prior to feeding of 5 times a day. Course of treatment of 7 — 10 days. To children years Cobamamidum are more senior appoint 500 mkg (in 50 ml of boiled water for half an hour to food) 2 — 3 times a day within 7 — 30 days. In hard cases the newborn the drug is administered intravenously on 500 mkg along with administration of solution of glucose, co-carboxylase and hydrosodium carbonate within 3 — 4 first days after the birth, in the next 6 — 7 days Cobamamidum is entered intramusculary in the same dose.

The adult at neurotic anorexia and an adynamy drug is appointed inside on 500 — 1000 mkg of 3 — 6 times a day (a daily dose to 3000 mkg) within 1 — 3 month.

Form of release: tablets on 500 and 1000 mkg without cover; tablets, coated, on 100, 500 and 1000 mkg; in ampoules in the form of the lyophilized powder on 100, 500 and 1000 mkg. Storage: in the dry, protected from light place.

Bibliography: And in and to at m about in V. M., etc.

Coenzymatical drug of B12 vitamin — Cobamamidum, Chemical - pharm. zhurn., t. 14, No. 7, page 115, 1980; Berezovsky V. M.

Chemistry of vitamins, page 577, M., 1973; Vitamins, under the editorship of M. I. Smirnov, page 264, M., 1974; Kanopkaytes. I. Cobalamines, Vilnius, 1978; Clinical pharmacology, under the editorship of V. V. Zakusov, page 363, M., 1978; Coenzymes, under the editorship of V. A. Yakovlev, page 291, M., 1973; Spi-richevv.b. and Barashnev Yu. And., Inborn disturbances of exchange of vitamins, page 92, M., 1977; Experimental vitaminology, under the editorship of Yu. M. Ostrovsky, page 438, Minsk, 1979; Friedrich W. Vitamin B12 und verwandte Corrinoide, Stuttgart, 1975; StroheckerR. H e n n i n g H. M. Vitamin assay, Wein-heim, 1965.

I. P. Rudakova; V. M. Avakumov (pharm.).

Яндекс.Метрика