TANNINS (tannins) — esters of aromatic acids, most often gallic (3,4,5-trihydrobenzoic) acid, with carbohydrates; treat tanning agents, in medicine are applied generally as the pharmaceuticals possessing the knitting and antiinflammatory action. Representatives of group T. a so-called Chinese tannin, the Turkish tannin and gamamelitanin are. Structure of T. it was found out by hl. obr. E. Fischer.
The Chinese tannin (gallotanin) represents mix of poligal-loilny derivatives glucose (see), all five hydroxylic groups a cut are acylated gallic, - gallic and (perhaps) trigallovy to-tami (on average 9 remains gallic to - you are the share of each molecule of sugar).
The Turkish tannin contains less remains gallic to - you (on average 5 — 6 on a molecule) and is even more heterogeneous, than Chinese. Its molecule contains the remains hexa-hydrodiphenic and ellagic to - the t attached by glycosidic linkages.
Gamamelitanin — the tanning agent received in crystalline state from Hamamelis virginiana bark represents di-galloilgeksozu, i.e. sugar, in a molecule to-rogo two hydroxylic groups are acylated by the remains gallic to - you. For a gamamelitanin the formula is offered:
Tanning agents of tea (see), a noble chestnut, leaves sumach belong to the tanning agents having complex structure (Rhus cotinus and Rhus coriaria L.), etc.
Tannins in the nature contain in bark of different types of an oak and in so-called nutgalls — outgrowths on leaves of nek-ry species of the Oak.
Solutions T. have ability to besiege (to curtail) proteins. This property T. along with their antiseptic properties connected with existence in molecules T. phenolic hydroxylic groups, of the tanning action of these connections on skin, including and on skin of hands, edge after processing by solution 'T is also the cornerstone. becomes dense (coagulation of protein) and not giving in to action of microorganisms. Ability of T. to curtail proteins, i.e. to form so-called albuminates, is the cornerstone also of their knitting action (see. Astringents ).
A tannin as drug
the Tannin as drug (Tanninum, Acidum tannicum) represents light yellow or brownish amorphous powder with a peculiar smell, astringent taste. Sumach and a sumac receive it from nutgalls (Gallae turcicae) of an oak of Asia Minor or from leaves of plants (Cotinus coggygria Scop.) this. sumach (Anacardiaceae). Powder T. let's easily dissolve in water and alcohol, it is bad — in organic solvents (ether, chloroform, benzene), solutions T. in water form rainfall with proteins, alkaloids, gelatinous, salts of heavy metals. The film of albuminates arising at contact of solution T. with a mucous membrane or a wound surface, protects sensitive nerve terminations of the subject fabrics from irritation, there is a reduction of pain, local narrowing of blood vessels, restriction of secretion and consolidation of cellular membranes leading to subsiding of the phenomena inflammations (see).
T. apply at inflammatory processes in an oral cavity, a nose, a pharynx, a throat in the form of rinsings (1 — 2% spirit or water and 10% glyceric solution) and greasings (5 — 10% solution), at burns, ulcers, cracks, decubituses, grazes, etc. (3 — 5 — 10% of ointment and solutions). In T. do not appoint since first of all it interacts with proteins of a mucous membrane of a stomach. It is not necessary to appoint T. and in enemas at cracks in a rectum. T. often use at poisoning with salts of heavy metals, with to-rymi drug forms the insoluble residues not capable to be soaked up in blood in intestines. In this case recommend to make a gastric lavage of 0,5% water solution T. (with morfipy, cocaine, atropine, nicotine, physostigmine T. forms unstable connections therefore they need to be deleted as soon as possible from a stomach).
Form of release — powder, store in densely corked glass jars.
T. is a part of antiseptic liquid of Novikov and a photoprotective film (the liquid which is quickly drying during the drawing on skin and applied to protection against ultraviolet rays). The photoprotective film is stored in banks of dark glass, the joint venture. B (see. Fotozashchitny means ).
As astringent in medicine apply also connection T. with albumine — Tannalbinum (see).
T. in combination with ascorbic acid (see), so-called Galascorbinum (Galascorbinum), apply for the purpose of normalization of carbohydrate and phosphoric exchanges in a liver at various intoxications, reduction of dehydration at radiation therapy, etc.
Bibliography: Zaprometov M. N. Fundamentals of biochemistry of phenolic connections, M., 1974; Karrer P. A course of organic chemistry, the lane with it., page 669, JI., 1960; Kretovich B.JT. Fundamentals of phytochemistry, M., 1971; Ma shko century y M. D. Pharmaceuticals, p.1, page 300, M., 1977; M e c of l of e r D. Biokhimiya, the lane with English, t. 3, page 151, M., 1980.
H. G. Budkovskaya; D. N. Samoylov (pharm.).