PHYLLOQUINONES

From Big Medical Encyclopedia

FILLOHINONY — group of the connections derivative of 2-methyl-1,4-naphthoquinone having activity of phthiocol.

Biol. role F. and other vitamins of group K (see Vitamins) it is caused by their participation in process of a blood coagulation. Phthiocol is necessary for education in a liver of functionally active forms of a prothrombin (a factor of II), proconvertin (a factor of VII), and also factors of IX and X of the corresponding inactive proteins predecessors (see. Coagulant system of blood). In medicine as medicine broad application is found by water-soluble synthetic drug of phthiocol Vikasolum (see).

the oil hardening at f — 20 °, g°kip 115 — 145 ° at 0,0002 mm of mercury. Absorption spectrum natural F. in petroleum ether it is characterized by maxima at

243, 248, 261, 270 and 328 nanometers. Natural ^Ф. it is optically active, [a]D21 = — 0,71 °. Except natural F., a row synthetic F is known., the izoprenoidny links of CH2 differing with number (from 1 to 5) — CH2-CH(CH3)-CH2

in a side chain.

A dress with F. menakhinona (multiprenilmenakhino-na) _ connections of a number of K2 vitamin with the unsaturated poliizoprenoidny side chain containing various number from-prenilnykh links of CH2 — СН = C(CH3) — — CH2 — in particular menakhinon-4 >[K2t2o vitamin] with 4 izoprenilny links in a side chain and menakhinon-7 enter into group of phthiocol [K2 vitamin (zb or 2-metil-Z-farnezildigeranil-1,4-nafto quinone, the outdated name — farnoquinone] with 7 ’izoprenilny links in a side chain. Menakhinon-7 — yellow ^кристаллическое substance sl°at 53,5 — 54,5 ° и£ °kip 200 ° at 0,0002 mm of mercury. (with decomposition). The absorption spectrum of menakhinon is similar to an absorption spectrum F., but is less intensive.

Except F. and menakhinon, carry also deprived side isoprenoid to the substances making group of phthiocol - ache chains 2-methyl-1,4-нафто quinone (Menadionum, K3 vitamin), to-ry crystallizes in the form of citreous needles with t°njl 106 — 106 5 ° and maxima of absorption at 244’ 253, 263 and 325 nanometers.

All connections of group of phthiocol are water-insoluble, well rastvorima in organic solvents, easily are oxidized oxygen of air.

Natural F. is waste product of plants. Menakhinona are produced by microorganisms, and also are formed in an organism of animals and the person of Menadionum or T. by building of a side izoprenoidny chain or its replacement. In tissues of the highest animals and the person from substances of group of phthiocol it is most spread menakhinon-4 [

K2 vitamin (autonomous area)).

Biochemical mechanism of effect of substances of group of phthiocol, including and T., in processes of a blood coagulation it is mediated by their participation as a coenzyme in reaction of 7-karbo-ksilirovaniya remains of glutamic acid (see) and their transformations into the remains 7-karboksiglutamino-howl to - you in a molecule of proteins - the pre-shestvennikov blood-coagulation factors stated above. As a result the respective sites of molecules of proteins predecessors gain ability to the binding of ions of Sa2+ necessary for normal implementation of process of a blood coagulation. Substances of group of phthiocol participate in at - carat - boksilirovanii the remains glutaminic to - you in a molecule of a glycoprotein of osteocalcine — one of proteins of a bone tissue connecting calcium and also in molecules of other kaltsiysvyazyvayushchy proteins.

Biol. activity of substances of group of phthiocol is recommended to express in fillokhinonovy equivalents, i.e. in milligrams or micrograms of natural phylloquinone (vitamin of Kh).

PHYLOGENESIS 323


Of foodstuff nek-ry vegetables are richest with substances of group of phthiocol (in mkg in 1 g of dry weight): spinach (40 — 60),

color and white cabbage (20 — 34), tomatoes (4 — 8), and also nettle (34). From meat products a lot of phthiocol contains a liver of a pig (4 — 8 mkg on 1 g of dry weight).

The phthiocol coming to a human body with foodstuff is quite enough for a covering of need for it; besides, it is synthesized by intestinal microflora therefore a hypovitaminosis To occurs at the person rather seldom. Usually a hypovitaminosis To is caused by disturbance of absorption of phthiocol at diseases of intestines (at hron. enterita, coloenterites), disturbances of education and biliary secretion (at infectious and toxic hepatitises, cirrhosis, cholelithiasis, tumors of a pancreas, dyskinesia of bilious ways), operational removal of a part of intestines, malabsorption of fats, etc.

Insufficiency of phthiocol can develop also at long reception of antibiotics (see) or sulfanamide drugs (see), to-rye oppress the intestinal microflora synthesizing this vitamin. Functional insufficiency of phthiocol can arise at reception of the anticoagulants (see) representing antivitamins K like Dicumarinum, Phenilinum and other. to-rye are widely used at treatment of a number of diseases.

Insufficiency of phthiocol at the person and animals leads to disturbance of a fibrillation and development of the hemorrhagic syndrome caused by a prothrombinopenia and, as a result, delay of transformation of fibrinogen into fibrin because of oppression of synthesis of a prothrombin, and also synthesis of factors of VII, IX and X (see. Vitamin deficiency).

By a hypovitaminosis To the hemorrhagic disease of newborns can be caused, edges especially often arises at premature, newborn with pre-natal asphyxia and an intracranial injury (see. Hemorrhagic diathesis, at children). Insufficiency of phthiocol at newborns is a consequence of immaturity of their gepa-tobiliarny system and imperfection of the mechanism of absorption of lipids, in particular phthiocol, in intestines, and also absence in intestines of newborns of the microflora synthesizing this vitamin.

Need of newborns for phthiocol in the first days of life makes 10 — 12 mkg. Effective daily dose of Vikasolum (sodium salt bisulfite derivative 2-metil-!, 4 naphthoquinones), eliminating a prothrombinopenia and curing a hemorrhagic disease at newborns, it is equal to 1 — 2 mg (in 2 — 3 receptions) within 3 — 4 days. Definition of need for phthiocol at adults presents great difficulties because of its synthesis by intestinal microflora. According to a number of researchers, this requirement is equal to 70 — 140 mkg a day. At patients with mechanical jaundice and disturbance of digestion of phthiocol the effective daily dose of Vikasolum eliminating a prothrombinopenia makes 10 — 15 mg.

As indicators of security of an organism with phthiocol serve the tests reflecting a condition of coagulant system of blood, first of all a prothrombin ratio (see the Prothrombin time), and also the content in blood of a prothrombin and other blood-coagulation factors depending on phthiocol.

For quantitative definition F. and other vitamins of group K use spektrofotometrichesky (see the Range about photometry), Coca

rimetrichesky (see Colorimetry) and flyuorimetrichesky (see Flyuori-metriya) methods. Concentration F. and menakhinon at their definition the spectrophotometer iches to them meta d and mi after preliminary chromatographic fractionation and cleaning is measured on absorption at 248 nmg Menadionum — at 244 nanometers.

For definition of connections of group of phthiocol began to use with success methods of solution chromatography of high-res (see the Chromatography).

Bibliography: Vitamins, under the editorship of M. I. Smirnov, M., 1974; Experimental vitaminology, under the editorship of Yu. M. Ostrovsky, page 58, Minsk, 1979; S u t t i e J. W. The metabolic role of vitamin K, Fed. Proc., v. 39, p. 2730, 1980; The vitamins, ed.

by W. H. Sebrell a. R. S. Harris, v. 3, N. Y. — L., 1967. V. B. Spirichev.

Яндекс.Метрика