From Big Medical Encyclopedia

CATECHINS — organic compounds of the phenolic nature of a plant origin; have high biological activity, increase capillary resistance and regulate their permeability, in comparison with other kapillyaroukreplyayushchy substances (Rutinum, hesperidin, cythrene, esculin) have the maximum activity. Regularly coming to a human body with vegetable food, To. have systematic effect on all departments of a digestive tract and on cardiovascular system. To. are necessary and major components of food and represent connections with strongly expressed properties of citrin. Like other P-vitamin substances, To. show the highest biol, action in combination with ascorbic to - that. To. and ascorbic to - that, being Synergists, mutually activate each other. To. at addition to a diet of Guinea pigs promoted also accumulation ascorbic to - you in internals and tissues of these animals, in particular in adrenal glands and a spleen. To. detain removal of redoxon from an organism approximately twice. Kapillyaroukreplyayushchy action To. allows to apply them in a wedge, practice at a row patol, the states connected with the increased fragility and permeability of capillaries, napr at the bleeding ulcers, hemorrhagic cystitis, nephrites, hypostases of a vascular origin, a beam erythema, at some forms of an idiopathic hypertensia etc.

To. promote suppression of experimentally caused hyperfunction of a thyroid gland. Anti-oxidizing activity is inherent to them (e.g., To. protect adrenaline from oxidation). This property causes their anti-sclerous action. To. tea (see) have also antimicrobic properties therefore broth of green tea is appointed the patient with dysentery.

On a chemical structure To. treat flavonoids (see. Flavones ) also represent the most recovered group of these substances. To. are close to to anthocyanins (see) — to widespread colorants of plants.

To. — colourless crystal substances, bitter on taste, are well dissolved in water, alcohol, acetone, it is worse — on air. Idiosyncrasy To. their ability to be oxidized easily during the heating, solar lighting, in alkaline condition, and also under the influence of oxidizing enzymes is (polifenoloksidaza and peroxidases). To. contain in all parts of plants, especially there are a lot of them in wood of an acacia Acacia catechu, leaves of tea plants of Thea sinensis and Thea assamica, a peel, stones and crests of grapes, beans of cocoa, in many fruits and berries (apples, peaches, a quince, blackcurrant, a wild strawberry, a mountain ash, etc.). To fruits and berries K. impact tart relish. Are most studied To. a tea leaf which contents in draws reaches 25 — 30% for dry weight. Tannin of tea in the basic (for 98%) consists from To. During the processing of various vegetable raw materials — in production of tea, wine, cocoa, at preparation of fruits and berries — an important role is played by oxidizing transformations To. As a result of enzymatic and non-enzymatic transformations To. the painted products of their oxidation and polymerization which take part in creation of color and taste of foodstuff are formed. Primary

oxidates K. — quinones (see) — cause transformations of various connections, including amino acids and sugars, at the same time the aldehydes giving aroma to food and flavoring products are formed.

See also Bioflavonoida .

Bibliography: Bokuchava M. A. Biochemistry of tea and tea production, page 91, M., 1958; Zaprometov M. N. Biochemistry of catechins, M., 1964, bibliogr.; it, Fundamentals of biochemistry of phenolic connections, M., 1974.

M. A. Bokuchava, M. S. Ulyanova.