BIOFLAVONOIDS

From Big Medical Encyclopedia

BIOFLAVONOIDS (vitamin P) — group of biologically active agents having ability to normalize permeability of capillaries.

The carbon skeleton of a fenilbenzopiran is the cornerstone of chemical structure of B. Common feature of B. is also existence in their molecules of several phenolic hydroxyls which can be metilirovana or are connected by a glycosidic linkage to the remains of sugars: glucose, rhamnoses, ramnoglyukoza. It is known apprx. 500 various B. Vazhneyshimi from them derivatives of flavan are: the d-catechin and l-epikatekhin representing stereoisomers 3,5,7,3', 4' - pentaoxyflavan (see. Catechins ); derivatives of flavone (see. Kvertsetin , Flavones ): meletin (3,5,7,3', 4' - pentaoxyflavan) and its glycosides — quercitrin (meletin-3-ramnozid) and Rutinum (meletin-3-ramnoglyukozid), and also derivatives of flavanone:

gesperetin (5,7,3' - trioksi-4' - me-taoksiflavanon) and it 7-ramnoglyukozidgesperidin, and also eriodiktin. Besides, B. with the opened piranovy ring are known: chalcones and dihydrochalcones. Biol, activity of vitamin P also coumarins (esculin) have and anthocyans (see).

B.'s most — crystal substances of yellow, flavovirent or orange color, insoluble on air, chloroform and benzene. Catechins are well dissolved in water. Rutinum and meletin are almost insoluble in a cold water, difficult rastvorima in a boiling water and alcohols, are dissolved in the diluted alkalis.

B. are products of plant origin. Leaves of tea, flowers and leaves of a buckwheat, a Sophora Japanese, fruits of a citrus, a dogrose, a black-fruited mountain ash are especially rich with them. These plants serve as raw materials for production of medical drugs B. Significant amounts of B. contain also in red pepper, blackcurrant, a wild strawberry, raspberry, cherry, a sea-buckthorn, some grades. apples, plums and grapes. In animal fabrics B. are not found.

B. have ability to increase durability of circulatory capillaries, normalizing their permeability. For the first time this property was revealed in 1936 A. Szent-Gyorgyi who established that the drugs of lemon juice and red pepper containing substances of the flavonovy nature cure the hemorrhagic diathesis at people which is not giving in to treatment ascorbic to - that. These connections received the name vitamin P (on the first letter of the word permeability — permeability). Further symptoms of P-avitaminosis at the person and experimental animals were described. The clinical picture of P-avitaminosis at people, across Scarborough (N. of Scarborough), is characterized by shoulder and legs pains, especially during the walking, the general weakness, slackness, bystry fatigue. Small intradermal hemorrhages (petechias) arising spontaneously, especially on the sites which are exposed to pressure and the appointments disappearing later B belong to more specific displays of P-avitaminosis. Unlike the small hemorrhages caused by B.'s lack, extensive hemorrhages in hypodermic cellulose and muscles at a scurvy recover only ascorbic to - that. For detection of P-avitaminosis use Nesterov's tests, Landis, etc., helping to estimate permeability of capillaries by impact on skin of the dosed positive or negative pressure. Need of the person for vitamin P is not known though need of arrival of B. with food, probably, does not raise doubts. Except B., similar action on capillaries oxyderivatives of coumarin and simpler possess polyphenols (see), in particular gallic to - that, and also some products of exchange of B., napr, phloroglucinol and protokhatekhovy to - that that gives the grounds to combine all these substances in the general group of the polyphenols having P-vitamin activity. As the large number of connections of the polyphenolic nature possesses the action strengthening capillaries, many researchers consider this effect as pharmakodinamichesky, but not vitamin. Against B.'s reference to vitamins also that circumstance that these connections do not collect in the found quantities in animal fabrics testifies, and are exposed to an oxidative breakdown with formation of aromatic oxyacids and other simple products up to carbon dioxide gas.

Concerning the mechanism of kapillyaroukreplyayushchy action of B. a number of the points of view, any of which is not conventional, is stated. According to one of the earliest hypotheses true kapillyaroukreplyayushchy action possesses adrenaline (see), and B.'s role consists in its protection from oxidation in adrenokhry. Other hypothesis connects kapillyaroukreplyayushchy properties B. with their braking action on hyaluronidase (see). However convincing data on similar action of B. in the conditions of the whole organism are absent. The third hypothesis connects B.'s activity with participation in exchange of redoxon. In favor of similar representations these Saint-Dyyordyi demonstrate that vitamin P is active only in the presence of at least traces ascorbic acid (see), and also data on ekonomiziruyushchy action of B. concerning redoxon. This action of B. can be caused by their ability to slow down oxidation ascorbic to - you, catalyzed by ions of heavy metals, with to-rymi B. forms chelate complexes.

On the other hand, according to E. F. Shamraya and V. V. Fedurov (1968), B. take part in enzymic oxidation ascorbic to - you in dehydroascorbic, edges is the transport form of vitamin C which is easily getting through biol, membranes.

The essential role in the mechanism of action of B. can belong to their antioxidant properties, in particular ability slow down peroxide splitting of lipids. Many B. possess antitiaminovy action.

Bioflavonoids as drugs

have Practical application as medicines: a) Rutinum received from flowers and leaves of a buckwheat and also from a Sophora Japanese; b) the complex of catechins received from leaves of a tea plant and called conditionally by citrin; c) the meletin received for the medical purposes from Rutinum; d) vitamin P from a citrus; e) vitamin P from a black-fruited mountain ash; e) vitamin P from a thorough-wax mnogozhilchaty.

B. not only make specific impact on capillary system, but have as well other properties. There are data that P and S vitamins in certain ratios have the expressed antimicrobic activity. From nonspecific properties of drugs of group of vitamin P of special attention their positive influence on a hemopoiesis and a nek-swarm deserves the normalizing impact on the level of blood pressure at an idiopathic hypertensia. It is established that some of drugs B., napr, Rutinum, are capable to reduce a physical activity of a stomach and to reduce the spastic tension of muscles of intestines, to have antiinflammatory and antiallergenic effect.

The medicines containing B. apply to prevention and treatment hypo - and avitaminosis of P and at the diseases which are followed by disturbance of permeability of blood vessels and their increased fragility: hemorrhagic diathesis, retinal apoplexies of an eye, a capillary toxicosis, a radial illness, an arachnoiditis, at some infectious diseases, and also for prevention and treatment of the defeats of a vascular wall connected using anticoagulants (Dicumarinum, Phenilinum and their analogs), salicylates, arsenous connections, lead, chloroform, etc. Some of drugs of group of citrin., napr, meletin, apply as auxiliary prophylactic at the vascular complications caused by atherosclerosis (a myocardial infarction, a stroke, retinopathies), and also at radiation therapy of malignant new growths. Along with vitamin P appoint ascorbic to - that.

Drugs of group of vitamin P should be used with care the patient with the increased coagulability of blood. Rutinum is appointed by the adult on 0,02 — 0,05 g by 2 — 3 times a day. Course of treatment of 2 — 3 weeks. Forms of release: powder, tablets on 0,02 g. Meletin for prevention is applied on 0,02 g by 2 — 3 times a day, in the medical purposes — on 0,02 g of 3 — 5 times a day during 5 — 6 weeks. Forms of release: powder, tablets on 0,02 g.

Vitamin P from leaves of a tea plant is appointed on 0,05 g by 2 — 3 times a day. Course of treatment of 15 — 20 days. Forms of release: powder, tablets on 0,05 g.

Vitamin P from fruits of a black-fruited mountain ash is appointed on 0,05 g by 2 — 3 times a day. Course of treatment of 20 — 25 days. Forms of release: powder, tablets on 0,05 g.

Vitamin P from a thorough-wax of much zhilchatoy («Buplerinum») is applied on 0,03 g by 2 — 3 times a day. Forms of release: the powder, tablets containing 0,03 g of citrin, and tablets containing 0,03 g of vitamin P and 0,05 g ascorbic to - you.


Bibliography: Bioflavonoids and permeability of capillaries, the lane with English, under the editorship of M. N. Zaprometov, M., 1957, bibliogr.; Vitamin P — its properties and use, in book: Vitamin, resources and their use, under the editorship of V. N. Bukin and M. N. Zaprometov, Saturday. 4, M., 1959; Polyneuramins food and prevention of a vitamin deficiency, under the editorship of V. V. Efremov, M., 1969; Shamray E. F. and F e Durov V. V. Citrin, Usp. sovr. biol., t. 65, century 2, page 186, 1968, bibliogr.; Chemistry of flavonoid compounds, ed. by T. A. Geissman, N. Y., 1962; S with a r b o-г about u g h H. and. B and with h and and with h A. L. Vitamin P, Vitam, and Horm., v. 7, p. 1, 1949.

B. B. Spirichev; B. M. Avakumov (pharm.).

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