Lecture topic

Lecture No. 11

1. The concept of tannins.

2. Distribution of tannins in the plant kingdom.

3. The role of tannins for plant life.

4. Classification of tannins.

5. Biosynthesis, localization and accumulation of tannins in plants.

6. Features of the collection, drying and storage of raw materials containing tannins.

7. Physical and chemical properties of tannins.

8. Assessment of the quality of raw materials containing tannins. Analysis methods.

9. Raw material base of medicinal plants containing tannins.

10. Ways of using raw materials containing tannins.

11..Medical use and preparations containing tannins.

12. Medicinal plants and raw materials containing tannins

The concept of tannins

Tannins DV(tannins) are complex mixtures of plant high-molecular polymers of phenolic compounds with a molecular weight of 500 to 3000, with an astringent taste, capable of forming strong bonds with proteins, turning raw animal skin into tanned leather.

The essence of the tanning process is the formation of strong hydrogen bonds between the phenolic hydroxyls of the DV and the hydrogen and nitrogen atoms of the collagen protein molecules. The result is a strong cross-linked structure - skin, resistant to heat, moisture, microorganisms, enzymes, i.e. non-rotten.

Polyphenolic compounds with lower M.m. (less than 500) are only adsorbed on proteins, but are not able to form stable complexes, and are not used as tanning agents. High molecular weight polyphenols (with MM over 3000) are also not tanning agents, since their molecules are too large and do not penetrate between collagen fibrils.

Thus, the main difference between DV and other polyphenolic compounds is the ability to form strong hydrogen bonds with proteins.

The term "tannins" was first used by the French scientist Seguin in 1796 to refer to substances present in the extracts of certain plants that can carry out the tanning process. Another name for DV - "tannids" - comes from the Latinized form of the Celtic name for oak - "tan", the bark of which has long been used to process leather.

The first scientific research in the field of chemistry of the Far East dates back to the second half of the 18th century. They were caused by the practical needs of the leather industry. The first published work is the work of Gledich in 1754 "On the use of blueberries as a raw material for the production of tannins." The first monograph was Dekker's monograph in 1913, which summarized all the accumulated material on tannins. Russian scientists L. F. Ilyin, A. L. Kursanov, M. N. Zaprometov, F. M. Flavitsky, G. Povarnin A. I. Oparin and others were engaged in the search, isolation and establishment of the structure of DW; foreign scientists G. Procter, K. Freudenberg, E. Fischer, P. Karrer and others.

Distribution of tannins in the plant world

DV are widely distributed in the plant kingdom. They are found mainly in higher plants, most common in representatives of dicots, where they accumulate in maximum quantities. Monocotyledons usually do not contain DV, DV is found in ferns, and in horsetails, mosses, and club mosses they are almost absent, or they are in minimal quantities. The following families are distinguished by the highest content of DV: sumac - Anacardiaceae (tannic sumac, tanning skumpia), rosaceous - Rosaceae (officinalis burnet, erection cinquefoil), beech - Fagaceae (petal and rocky oak), buckwheat - Polygonaceae (snake mountaineer and meat-red, heather - Ericaceae (bearberry, lingonberry), birch - Betulaceae (grey and sticky alder), etc.

The role of tannins for plant life

The biological role for plant life has not been fully elucidated. There are several hypotheses:

one). DV perform a protective function, because. when plants are damaged, they form complexes with proteins that create a protective film that prevents the penetration of phytopathogenic organisms. They have bactericidal and fungicidal properties;

2). DV are involved in redox processes, are oxygen carriers in plants;

3). DV is one form of reserve nutrients. This is indicated by their localization in the underground organs and the cortex;

4). DV - waste products of vital activity of plant organisms.

Classification of tannins

Since AI is a mixture of various polyphenols, classification is difficult due to the diversity of their chemical composition.

The classification by G. Povarnin (1911) and K. Freidenberg (1920) based on the chemical nature of active substances and their relationship to hydrolyzing agents has received the greatest recognition. According to this classification, DV are divided into 2 large groups:

1) hydrolysable active ingredients;

2) condensed DW.

1. Hydrolysable active ingredients

Hydrolysable active ingredients - These are mixtures of esters of phenolcarboxylic acids with sugars and nonsaccharides. In aqueous solutions, under the action of acids, alkalis and enzymes, they are able to hydrolyze into constituent fragments of a phenolic and non-phenolic nature. Hydrolyzable active substances can be divided into 3 groups.

1.1. Gallotannins- esters of gallic, digallic acids and its other polymers with cyclic forms of sugars.

m-digallic acid (depsid - D)

The most important sources of gallotannins used in medicine are Turkish galls, formed on Lusitanian oak and Chinese galls, formed on semi-winged sumac, leaves of tanning sumac and tannery tannery.

Tannin is a heterogeneous mixture of substances of various structures. There are mono-, da-, tri-, tetra-, penta- and polygalloyl ethers.

According to L.F. Ilyin, E. Fischer and K. Freidenberg, Chinese tannin is penta-M-digalloyl-β-D-glucose, i.e. β-D-glucose, the hydroxyl groups of which are esterified with M-digallic acid .

According to P. Carrera, Chinese tannin is a heterogeneous mixture of substances of various structures, hydroxyl groups of glucose can be esterified with gallic, digallic and trigallic acids.

K. Freudenberg suggested that on average one of the five hydroxyl groups of glucose in Turkish tannin is free, the other is esterified with M-digallic acid, and the rest with gallic acid.

This group contains and predominates in the rhizomes and roots of burnet, the rhizomes of the serpentine, bergenia, alder seedlings, oak bark, witch hazel leaves.

1.2. Ellagotapnins- esters of ellagic and other acids having a neubiogenetic relationship, with cyclic forms of sugars. Contained in the peel of pomegranate fruits, eucalyptus bark, walnut peel, leaves and inflorescences of fireweed (willow-herb).

1.3. Nonsaccharide esters of phenolcarboxylic acids- esters of gallic acid with quinic, chlorogenic, caffeic, hydroxycinnamic acids and with flavans.

Example: theogallin found in Chinese tea leaves, which is an ester of quinic and gallic acids (3-O-galloylquinic acid ).

2. Condensed DW

Condensed active substances do not have an ether character, the polymer chain of these compounds is formed by carbon-carbon bonds (-C-C-), which determines their resistance to acids, alkalis and enzymes. Under the action of mineral acids, they do not break down, but increase the M.m. with the formation of products of oxidative condensation - flobafen or red-brown red.

Condensed DV - these are condensation products of catechins (flavan-3-ols), leucoanthocyanidins (flavan-3,4-diols), less often oxystilbenes (phenylethylenes).

The formation of condensed DWs can proceed in two ways. According to K. Freudenberg, it is accompanied by a rupture of the pyran ring of catechins, and the C2 atom of one molecule is connected by a carbon-carbon bond to the C6 or C8 atom of another molecule.

According to D. E. Hathway, condensed DWs are formed as a result of enzymatic oxidative condensation of molecules in the “head to tail” type (ring A to ring B) or “tail to tail” (ring B to ring B) at positions 6 "-8 ; 6 -2`, etc.

Condensed active substances are contained and predominate in the bark of viburnum, rhizomes of cinquefoil, blueberries, bird cherry, St. John's wort, tea leaves.

DV mixtures also include simple phenols (resorcinol, pyrocatechin, pyrogallol, phloroglucinol, etc.) and free phenolcarboxylic acids (gallic, ellagic, protocatechuic, etc.).

Most often in plants there is a mixture of hydrolysable and condensed active substances with a predominance of one or another group, therefore it is quite difficult to classify them according to the type of active substances. In some types of raw materials, the content of both groups of active substances is almost the same (for example, serpentine rhizomes).

Biosynthesis, localization and accumulation of tannins in plants

The biosynthesis of hydrolysable active substances proceeds along the shikimate pathway, while condensed active substances are formed along a mixed path (shikimate and acetate-malonate). DV are in a dissolved state in the vacuoles of plant cells and are separated from the cytoplasm by a protein-lipoid membrane - tanoplast; during cell aging they are adsorbed on cell walls.

They are localized in the cells of the epidermis, parietal cells surrounding the vascular fibrous bundles (leaf veins), in the parenchymal cells of the core rays, bark, wood and phloem.

DV accumulate mainly in the underground organs of perennial herbaceous plants (rhizomes of bergenia, serpentine, cinquefoil, rhizomes and roots of burnet), in the root wood of trees and shrubs (bark of oak, viburnum), in fruits (fruits of bird cherry, blueberry, alder seedlings) , less often in leaves (leaves of skumpia, sumac, tea).

The accumulation of tannins depends on genetic factors, climatic and environmental conditions. In herbaceous plants, as a rule, the minimum amount of active substances is noted in the spring during the period of regrowth, then their content increases and reaches a maximum during the period of budding and flowering (for example, cinquefoil rhizomes). By the end of the growing season, the amount of DV gradually decreases. In burnet, the maximum AD accumulates in the phase of development of rosette leaves, in the flowering phase their content decreases, and in autumn it increases again. The vegetation phase affects not only the quantity, but also the qualitative composition of the AI. In the spring, during the period of sap flow, in the bark of trees and shrubs and in the regrowth phase of herbaceous plants, hydrolyzable DVs mainly accumulate, and in the fall, in the phase of plant death, condensed DVs and their polymerization products, flobaphenes (reds).

The most favorable conditions for the accumulation of tannins are the conditions of a temperate climate (forest zone and high-mountain alpine belt).

The highest content of DV was noted in plants growing on dense calcareous soils; on loose chernozem and sandy soils, their content is lower. Phosphorus-rich soils contribute to the accumulation of DV, soils rich in nitrogen reduce the content of tannins.

Features of collection, drying and storage of raw materials containing tannins

Harvesting of raw materials is carried out during the period of maximum accumulation of DV.

The collected raw materials are dried in air in the shade or in dryers at a temperature of 50-60 degrees. Underground organs and oak bark can be dried in the sun.

Store in dry, well-ventilated areas without access to direct sunlight according to the general list for 2-6 years.

Physical and chemical properties of tannins

DV are isolated from plant materials in the form of a mixture of polymers and are amorphous substances of yellow or yellow-brown color, odorless, astringent taste, very hygroscopic. They dissolve well in water (especially in hot water) with the formation of colloidal solutions; they are also soluble in ethyl and methyl alcohol, acetone, ethyl acetate, butanol, pyridine. Insoluble in chloroform, benzene, diethyl ether and other non-polar solvents, optically active.

Easily oxidized in air. Able to form strong intermolecular bonds with proteins and other polymers (pectic substances, cellulose, etc.). Under the action of the tanase enzyme and acids, hydrolysable active substances decompose into their constituent parts, condensed active substances become larger.

From aqueous solutions precipitated by gelatin, alkaloids, basic lead acetate, potassium dichromate, cardiac glycosides.

As substances of a phenolic nature, DIs are easily oxidized by potassium permanganate in an acidic environment and other oxidizing agents; they form colored complexes with salts of heavy metals, ferric iron, and bromine water.

Able to be easily adsorbed on skin powder, cellulose, fiber, cotton wool.

Assessment of the quality of raw materials containing tannins,

Analysis Methods

To obtain the amount of AI, the plant material is extracted with hot water in the ratio 1:30 or 1:10.

Qualitative Analysis

Qualitative reactions (precipitation and color) and chromatographic examination are used.

1. A specific reaction is a gelatin precipitation reaction, using a 1% gelatin solution in a 10% sodium chloride solution. A flocculent precipitate or turbidity appears, soluble in excess gelatin. A negative reaction with gelatin indicates the absence of AD.

2. Reaction with salts of alkaloids, use 1% solution of quinine hydrochloric acid. An amorphous precipitate appears due to the formation of hydrogen bonds between the hydroxyl groups of the active ingredient and the nitrogen atoms of the alkaloid.

These reactions give the same effect regardless of the DV group. A number of reactions make it possible to determine the DV group.

Qualitative reactions to DV

The reaction with a 1% alcoholic solution of iron ammonium alum - this reaction is pharmacopoeial, is carried out both with a decoction of raw materials (GF-XI - oak bark, serpentine rhizome, alder seedlings, blueberries), and to open the active ingredient directly in dry raw materials (GF -XI - oak bark, viburnum bark, bergenia rhizomes).

quantitation

There are about 100 different methods for the quantitative determination of AI, which can be divided into the following main groups.

1. Gravimetric or weight - based on the quantitative precipitation of active substances by gelatin, heavy metal ions or adsorption by skin (naked) powder.

For technical purposes, the gravimetric method with the use of holly powder - the uniform weight method (BEM) is standard throughout the world.

The aqueous extract of DV is divided into two equal parts. One part of the extract is evaporated and dried to constant weight. Another part of the extract is treated with skin powder and filtered. AIs are adsorbed on the skin powder and remain on the filter. The filtrate and washings are evaporated and dried to constant weight. The content of AI is calculated from the difference in the mass of dry residues.

The method is inaccurate, because skin powder also adsorbs low molecular weight phenolic compounds, which is rather laborious and expensive.

2. titrimetric methods. These include:

a) Gelatin method - based on the ability of DI to form insoluble complexes with proteins. Aqueous extracts from raw materials are titrated with 1% gelatin solution; at the equivalence point, the gelatin-tannate complexes are dissolved in an excess of the reagent. The titer is determined by pure tannin. The equivalence point is determined by selecting the smallest volume of the titrated solution that causes complete precipitation of active substances.

The method is the most accurate, because allows you to determine the number of true DV. Disadvantages: the length of the definition and the difficulty of establishing the equivalence point.

b) Permanganometric method ( Leventhal method modified by A.P. Kursanov). This pharmacopoeial method is based on the easy oxidizability of DI with potassium permanganate in an acidic medium in the presence of an indicator and a catalyst of indigo sulfonic acid, which at the equivalence point turns into isatin, and the color of the solution changes from blue to golden yellow.

Features of the determination that allow titrating only DV macromolecules: titration is carried out in highly diluted solutions (the extraction is diluted 20 times) at room temperature in an acidic medium, potassium permanganate is added slowly, drop by drop, with vigorous stirring.

The method is economical, fast, easy to perform, but not accurate enough, because potassium permanganate partially oxidizes low molecular weight phenolic compounds.

Collection output:

METHODS FOR THE QUANTITATIVE DETERMINATION OF TANNIES IN MEDICINAL PLANT RAW MATERIALS

Mikhailova Elena Vladimirovna

cand. biol. Sci., Assistant, VSMA named after V.I. N.N. Burdenko,

Voronezh

Email: milenok[email protected] rambler.en

Vasilyeva Anna Petrovna

Martynova Daria Mikhailovna

student of VGMA them. N.N. Burdenko, Voronezh

Email: darjamartynova[email protected] rambler.en

Tannins (DV) are a very common group of biologically active substances (BAS) of plants, which have various pharmacological properties, which is the reason for their widespread use in medicine. Therefore, the problem of determining the good quality of drugs and medicinal plant raw materials (MPR) containing this group of biologically active substances is very relevant. One of the main methods for establishing the good quality of MPS is a quantitative phytochemical analysis. Currently, there are several methods that allow this type of analysis of MPC containing DV, but the literature data are scattered. In connection with the foregoing, it is necessary to systematize the methods of quantitative analysis of DVvLRS.

The classical methods for determining the content of active substances are gravimetric (weight) and titrimetric methods. The gravimetric method is based on the property of active substances to be precipitated by gelatin, heavy metal ions, and skin (naked) powder. The first step is to determine the mass of dry residue in the aqueous extract from the MPC. The extract is then dried to constant weight. The next stage is the release of the extract from the active ingredient by processing with a holly powder. In this case, a precipitate precipitates, which is then removed by filtration, the amount of dry residue is again determined, and the amount of AI is determined by the difference in the indicated masses of the dry residue.

Titrimetric methods include:

1. Titration with gelatin solution. This method is also based on the property of active substances to be precipitated by proteins (gelatin). Aqueous extracts from raw materials are titrated with 1% gelatin solution. The titer is determined by pure tannin. The equivalence point is set by selecting the smallest volume of titrant that causes complete precipitation of active substances. This method is highly specific and allows you to establish the content of true DV, but rather long in execution, and the establishment of the equivalence point depends on the human factor.

2. Permanganatometric titration. This method is presented in the General Pharmacopoeia Monograph and is based on the easy oxidizability of DV by potassium permanganate in an acidic medium in the presence of indigo sulfonic acid. At the end point of the titration, the color of the solution changes from blue to golden yellow. Despite the economy, speed, ease of implementation, the method is not accurate enough, due to the difficulty of establishing the equivalence point, as well as the overestimation of the measurement results due to the strong oxidizing ability of the titrant.

3. Complexometric titration with Trilon B with preliminary precipitation of DV zinc sulfate. The method is used for the quantitative determination of tannin in the raw materials of tanning sumac and tanning sumac. Xylenol orange is used as an indicator.

The physicochemical methods for the quantitative determination of DV in medicinal plant materials include the photoelectrocolorimetric, spectrophotometric, amperometric method and the method of potentiometric and coulometric titration.

1. Photoelectrocolorimetric method. It is based on the ability of DI to form colored chemical compounds with iron (III) salts, phosphotungstic acid, Folin-Denis reagent and other substances. One of the reagents is added to the studied extract from MPC, after the appearance of a stable color, the optical density is measured on a photocolorimeter. The percentage of AI is determined from a calibration curve constructed using a series of tannin solutions of known concentration.

2. Spectrophotometric determination. After obtaining an aqueous extract, part of it is centrifuged for 5 minutes at 3000 rpm. A 2% aqueous solution of ammonium molybdate is added to the centrifuge, after which it is diluted with water and left for 15 minutes. The intensity of the resulting color is measured on a spectrophotometer at a wavelength of 420 nm in a cuvette with a layer thickness of 10 mm. The calculation of tanides is carried out according to a standard sample. GSO of tannin is used as a standard sample.

3. Chromatographic determination. To identify condensed tannins, alcohol (95% ethyl alcohol) and water extracts are obtained and paper and thin layer chromatography is carried out. GSO of catechin is used as a standard sample. Separation is carried out in solvent systems butanol - acetic acid - water (BUW) (40: 12: 28), (4: 1: 2), 5% acetic acid on Filtrak paper and Silufol plates. Detection of zones of substances on the chromatogram is carried out in UV light, followed by treatment with a 1% solution of iron ammonium alum or a 1% solution of vanillin, concentrated hydrochloric acid. In the future, it is possible to carry out a quantitative analysis by elution from the DV plate with ethyl alcohol and conducting a spectophotometric analysis, taking the absorption spectrum in the range of 250-420 nm.

4. Amperometric method. The essence of the method is to measure the electric current that occurs during the oxidation of –OH groups of natural phenolic antioxidants on the surface of the working electrode at a certain potential. Preliminarily, a graphical dependence of the signal of the reference sample (quercetin) on its concentration is built and, using the resulting calibration, the content of phenols in the samples under study is calculated in units of quercetin concentration.

5. Potentiometric titration. This type of titration of aqueous extract (in particular, decoctions of oak bark) was carried out with a solution of potassium permanganate (0.02 M), the results were recorded using a pH meter (pH-410). The determination of the end point of the titration was carried out according to the Gran method using the computer program "GRAN v.0.5". The potentiometric type of titration gives more accurate results, since the equivalence point is clearly fixed in this case, which eliminates the bias of the results due to the human factor. Potentiometric titration is especially important compared to indicator titration in the study of colored solutions, such as aqueous extracts containing AD.

6. Coulometric titration. The method of quantitative determination of the content of active ingredients in PM in terms of tannin by coulometric titration is that the studied extract from the raw material reacts with the coulometric titrant - hypoiodite ions, which are formed during the disproportionation of electrogenerated iodine in an alkaline medium. Electrogeneration of hypoiodite ions is carried out from a 0.1 M solution of potassium iodide in a phosphate buffer solution (pH 9.8) on a platinum electrode at a constant current strength of 5.0 mA.

Thus, for the quantitative determination of DV in MHM, such methods for the quantitative determination of DV in MHM are used, such as titrimetric methods (including titration with gelatin, potassium permanganate, complexometric titration with Trilon B, potentiometric and coulometric titration), gravimetric, photoelectrocolorimetric, spectrophotometric, and amperometric methods.

Bibliography:

1. Vasilyeva A.P. The study of the dynamics of the content of tannins in the decoction of oak bark during storage // Youth innovation bulletin. - 2012. - V. 1, No. 1. - S. 199-200.
2. State Pharmacopoeia of the USSR, XI edition, no. 1. - M.: Medicine, 1987. - 336 p.
3. Grinkevich N.I., L.N. Safronych Chemical analysis of medicinal plants. - M., 1983. - 176 p.
4. Ermakov A.I., Arasimovich V.V. Determination of the total content of tannins. Methods of biological research of plants: Uch. Benefit. Leningrad: Agropromizdat. 1987. - 456 p.
5. Islambekov Sh.Yu. Karimdzhanov S.M., Mavlyanov A.K. Vegetable tannins // Chemistry of natural compounds. - 1990. - No. 3. - C. 293-307.
6. Kemertelidze E.P., Yavich P.A., Sarabunovich A.G. Quantitative determination of tannin // Pharmacy. - 1984. No. 4. - S. 34-37.
7. Pat. Russian Federation No. 2436084 Method for the coulometric determination of the content of tannins in vegetable raw materials; dec. 04/06/2010, publ. 12/10/2011. [Electronic resource]. Access mode. URL: http://www.freepatent.ru/patents/2436084 (date of access: 02.12.2012).
8. Ryabinina E.I. Comparison of chemical-analytical methods for determining tannins and antioxidant activity of vegetable raw materials // Analytics and control. - 2011. - V. 15, No. 2. - S. 202-204.
9. Fedoseeva L.M. The study of tannins of underground and aboveground vegetative organs of badan thick-leaved, growing in Altai. // Chemistry of plant raw materials. - 2005. No. 3. S. 45-50.

Ministry of Education and Science of the Russian Federation

FSBEI HPE Krasnoyarsk State Pedagogical University

them. V.P. Astafiev"

Faculty of Biology, Geography and Chemistry

Department of Chemistry

Tannins

course work

in physical and colloidal chemistry

Performed:

2nd year student

direction "Pedagogical education"

profile "Biology and Chemistry"

Zueva Ekaterina Vasilievna

Scientific adviser:

Candidate of Chemical Sciences, Associate Professor Bulgakova. ON THE.

Krasnoyarsk 2014

Content

Introduction……………………………………………………………………….....3

Chapter 1. Tannins. General characteristics………………………..4

1.1. The general concept of tannins and their distribution………………4.

1.2. Classification and properties of tannins………………………………5

1.3. Factors affecting the accumulation of tannins……………….8

1.4. The biological role of tannins…………………………………….9

Chapter 2. Quantitative determination of the content of tannins…..9

2.1. Isolation, research methods of tannins and their application in medicine………………………………………………………. ................................................. ..9

2.2. Medicinal plants containing tannins……………11

2.3. Quantitative calculation of the content of tannins in medicinal raw materials……………………………………………………………………………….13

Conclusion………………………………………………………………………….17

Bibliography used…………………………………………………..18

Introduction

The term "tannins" was first used in 1796 by the French researcher Seguin to refer to the substances present in the extracts of some plants that can carry out the tanning process. The practical issues of the leather industry laid the foundation for the study of the chemistry of tannins. Another name for tannins - "tannins" - comes from the Latinized form of the Celtic name for oak - "tan", the bark of which has long been used to process skins. The first scientific research in the field of tannin chemistry dates back to the second half of the 18th century. The first published work is the work of Gledich in 1754 "On the use of blueberries as a raw material for the production of tannins." The first monograph was Dekker's monograph in 1913, which summarized all the accumulated material on tannins. Domestic scientists L.F. Ilyin, A.L. Kursanov, M.N. Zaprometov, F.M. Flavitsky, A.I. Oparin and others were engaged in the search, isolation and establishment of the structure of tannins. The names of the largest foreign chemists are associated with the study of the structure of tannins: G. Procter, E. Fischer, K. Freidenberg, P. Carrera. Tannins are derivatives of pyrogallol, pyrocatechol, phloroglucinum. Simple phenols do not have a tanning effect, but together with phenolcarboxylic acids they accompany tannins.

Based on the theme of the work, one can distinguishpurpose: to study the characteristics of tannins. To achieve this goal, tasks will be required: 1. On the basis of literature data, give a general description of tannins. 2. To study how tannins are quantified in plants. 3. Study the classification of tannins.

Chapter 1. Tannins. General characteristics.

1.1. General concept of tannins and their distribution.

Tannins (tannins) are plant polyphenolic compounds with a molecular weight of 500 to 3000, capable of forming strong bonds with proteins and alkaloids and having tanning properties. They are named for their ability to tan raw animal skin, turning it into a durable skin that is resistant to moisture and microorganisms, enzymes, that is, not susceptible to decay. This ability of tannins is based on their interaction with collagen (skin protein), leading to the formation of a stable cross-linked structure - skin due to the occurrence of hydrogen bonds between collagen molecules and phenolic hydroxyls of tannins.

But these bonds can form when the molecules are large enough to attach adjacent collagen chains and have enough phenolic groups to cross-link. Polyphenolic compounds with a lower molecular weight (less than 500) are only adsorbed on proteins and are not able to form stable complexes; they are not used as tanning agents. High molecular weight polyphenols (with a molecular weight of more than 3000) are also not tanning agents, since their molecules are too large and do not penetrate between collagen fibrils. The degree of tanning depends on the nature of the bridges between the aromatic nuclei, i.e. on the structure of the tannin itself and on the orientation of the tannin molecule with respect to the polypeptide chains of the protein. With a flat arrangement of the tannide, stable hydrogen bonds appear on the protein molecule. The strength of the connection of tannins with protein depends on the number of hydrogen bonds and on the molecular weight. The most reliable indicators of the presence of tannins in plant extracts are the irreversible adsorption of tannins on the skin (naked) powder and the precipitation of gelatin from aqueous solutions.

1.2. Classification and properties of tannins.

Tannins are mixtures of various polyphenols, and due to the diversity of their chemical composition, classification is difficult.

According to Procter's (1894) classification, tannins, depending on the nature of their decomposition products, at a temperature of 180-200

0C (without air access) divided into two main groups: 1) pyrogallic (given pyrogallol when decomposed); 2) pyrocatechin (pyrocatechin is formed).

Table 1. Procter's classification.

stands out

pyrogallol

Black and blue staining

Pyrocatechin group

stands out

pyrocatechin

black and green

staining

According to the existing classification, which is based on the research of foreign and domestic scientists, all natural tannins are divided into two large groups:

1.Condensed

2. Hydrolysable

condensed tannins . These substances are mainly represented by polymers of catechins (flavanol -3) or leucocyanidins (flavandiol -3,4) or copolymers of these two types of flavonoid compounds. The process of polymerization of catechins and leukoanthocyanids has been studied to date, but there is still no consensus on the chemistry of this process. According to some studies, condensation is accompanied by rupture of the heterocycle (-C 3 -) and leads to the formation of linear polymers (or copolymers) of the type "heterocycle ring - ring A" with a large molecular weight. In this case, condensation is considered not as an enzymatic process, but as a result of the influence of heat and an acidic environment. Other studies suggest that polymers are formed as a result of oxidative enzymatic concentration, which can proceed in both head-to-tail (A-ring-B-ring) and tail-to-tail (B-ring-B ring) patterns. It is believed that this condensation occurs during the aerobic oxidation of catechins and flavandiols - 3,4, by polyphenol oxidases, followed by the polymerization of the resulting o-quinones.

hydrolysable tannins. This group includes substances that, when treated with dilute acids, decompose to form simpler compounds of a phenolic (and non-phenolic) nature. This sharply distinguishes them from condensed tannins, which, under the influence of acids, are even more compacted and form insoluble, amorphous compounds. Depending on the structure of the primary phenolic compounds formed during complete hydrolysis, gallic and ellagic hydrolysable tannins are distinguished. In both groups of substances, the non-phenolic component is always a monosaccharide. This is usually glucose, but there may be other monosaccharides. Unlike hydrolysable tannins, condensed tannins contain few carbohydrates.

gall tannins , otherwise called gallotannins, are esters of gallic or digallic acids with glucose, and a different number (up to 5) of gallic (or digallic) acid molecules can be attached to the glucose molecule. Digallic acid is a depside of gallic acid, i.e. an aromatic acid ester type compound. Depsides can be composed of 3 molecules of gallic acid (trigallic acid).

Ellag tannins , or ellagitannins, during hydrolysis cleave off ellagic acid as phenolic residues. Glucose is also the most common sugar residue in ellag tannins. On the division of plants according to this classification, one can speak only with some approximation, since only very few plants contain one group of tannins. Much more often, the same object contains condensed and hydrolysable tannins together, usually with a predominance of one or another group. Often the ratio of hydrolysable and condensed tannins changes greatly during the vegetation of the plant and with age.

1.3 Factors affecting the accumulation of tannins

The content of tannins in a plant depends on the age and phase of development, place of growth, climatic, genetic factors and soil conditions. The content of tannins varies depending on the growing season of the plant. It has been established that the amount of tannins increases with the growth of the plant. According to Chevrenidi, the minimum amount of tannins in the underground organs is observed in spring, during the period of plant growth, then it gradually increases, reaching the largest amount in the budding phase - the beginning of flowering. The vegetation phase affects not only the quantity, but also the qualitative composition of tannins. The altitude factor has a greater influence on the accumulation of tannins. Plants growing high above sea level (bergenia, skumpia, sumac) contain more tannins. Plants growing in the sun accumulate more tannins than those growing in the shade. Tropical plants contain much more tannins. Plants growing in damp places contain more tannins than those growing in dry places. There are more tannins in young plants than in old ones. In the morning (from 7 to 10), the content of tannins reaches a maximum, in the middle of the day it reaches a minimum, and in the evening it rises again. The most favorable conditions for the accumulation of tannins are the conditions of a temperate climate (forest zone and high-mountain alpine belt). The highest content of DV was noted in plants growing in dense calcareous soils, on loose chernozem and sandy soils - the content is less. Phosphorus-rich soils contribute to the accumulation of AI, while soils rich in nitrogen reduce the content of tannins. Revealing regularities in the accumulation of tannins in plants is of great practical importance for the correct organization of the procurement of raw materials. The biosynthesis of hydrolysable tannins proceeds along the shikimate pathway, condensed tannins are formed along a mixed path (shikimate and acetate).

1. . The biological role of tannins

The role of tannins for plants has not been fully elucidated. There are several hypotheses. They are assumed to be:

1. Spare substances (accumulate in the underground parts of many plants).

2. Possessing bactericidal and fungicidal properties as phenolic derivatives, they prevent wood decay, that is, they perform a protective function for the plant against pests and pathogens.

3. They are waste of vital activity of organisms.

4. Participate in redox processes, are oxygen carriers in plants.

Chapter 2. Quantification of the content of tannins

2.1. Isolation, research methods of tannins and their use in medicine

Tannins are easily extracted with water and water-alcohol mixtures: by extraction they are isolated from plant materials, then purer products are obtained from the obtained extracts and they are separated. To prove the presence of tannins in plants, the following reactions are used: the formation of precipitates with solutions of gelatin, alkaloids, salts of heavy metals and formaldehyde (with the latter in the presence of hydrochloric acid); binding to skin powder;staining (black - blue or black - green) with iron salts 3. Catechins give red staining with vanillin and concentrated hydrochloric acid. Since hydrolyzable tannins are based on gallic and ellagic acids, which are derivatives of pyrogallol, extracts from plants containing hydrolyzable tannins with a solution of iron-ammonium kvass give a black-blue color or precipitation. In condensed tannins, the primary units have the functions of catechol; therefore, with the specified reagent, a dark green color or precipitate is obtained.The most reliable reaction for distinguishing pyrogallic tanides from pyrocatechol phenomena is reactions with nitrosomethylurethane. When solutions of tannins are boiled with nitrosomethylurethane, pyrocatechol tanides are completely precipitated; the presence of pyrogallic tanides can be detected in the filtrate by adding iron ammonia kvass and sodium acetate - the filtrate stains purple. Many methods have been proposed for the quantitative determination of tannins. The official method in the tanning and extract industry is the unified weight method (BEM): in aqueous extracts from plant material, the total amount of soluble substances (dry residue) is first determined by drying a certain volume of the extract to constant weight; then tannins are removed from the extract by treating it with fat-free skin powder; after separating the precipitate in the filtrate, the amount of dry residue is again determined. The difference in the mass of dry residue before and after treatment of the extract with skin powder shows the amount of genuine tannins. The most widely used permanganometric method is Leventhal (GFXI) . According to this method, tanides are determined by oxidizing them with potassium permanganate in highly dilute solutions in the presence of indigo sulfonic acid. The Yakimov and Kurnitskova method was also used, based on the precipitation of tannins with a gelatin solution of a certain concentration. Under industrial conditions, tannins are extracted from raw materials by leaching with hot water (50 - C and above) in a battery of diffusers (percolators) according to the counterflow principle.

Tannin preparations are used as astringents and anti-inflammatory agents. The astringent action of tannins is based on their ability to bind to proteins to form dense albuminates. When applied to mucous membranes or a wound surface, tannins cause partial coagulation of mucus proteins or wound exudate and lead to the formation of a film that protects the sensitive nerve endings of the underlying tissues from irritation. The decrease in pain, local vasoconstriction, restriction of secretion, as well as direct compaction of cell membranes lead to a decrease in the inflammatory response. Tannins, due to their ability to form precipitates with alkaloids, glycosides and salts of heavy metals, are used as antidotes for oral poisoning with these substances.

2.2. Medicinal plants containing tannins.

Chinese galls - callaechinebses

Plant. Chinese sumac (semi-winged) -RhuschinensisMill. (= Rh. SemialataMurr); sumac family -Anacardiaceae. Shrub or low tree growing in China, Japan and India (slopes of the Himalayas). The causative agent is one of the types of aphids. Aphid females stick to young twigs and leaf petioles of sumac, laying numerous testicles in punctures. The formation of galls begins with vesicles that grow rapidly and soon reach large sizes.

Chemical composition. Chinese galls (ink nuts) contain 50-80% gallotannin. The main component of Chinese gallotannin is glucose, which is esterified with 2 molecules of gallic, 1 molecule of digallic and 1 molecule of trigallic acids. Accompanying substances include free gallic acid, starch (8%), sugar, resin.

Medicinal raw materials. Chinese Gauls are the formation of the most bizarre outlines with a thin wall, light. Their length can reach 6 cm with a maximum width of 20-25 mm and a wall thickness of only 1-2 mm; galls are hollow inside. Outside, they are gray-brown, rough, inside light brown with a smooth surface that shines like smeared with a layer of gum arabic.

Application. Industrial raw materials for the production of tannin and its preparations; comes by import

.

Leaves sumac – Folia Rhois coriariae

Plant. Sumac tannic -RhuscoriariaL.sumach family -Anacardiaceae. Shrub 1-3.5 m high, rarely a tree. The leaves are alternate, non-porous, compound, having 3-10 pairs of leaflets with a winged petiole; leaflets ovate with coarsely serrated margin. The flowers are small, greenish-white, collected in large cone-shaped paniculate inflorescences. The fruits are small koas drupes, densely covered with red-brown glandular hairs. It grows in the mountains of the Crimea, the Caucasus and Turkmenistan on dry rocky slopes. Cultivated.

Chemical composition . Contains 15-2% tannin, which is accompanied by free gallic acid and its methyl ester. The leaves contain a significant amount of flavonoids. The composition of sumac tannin is dominated by a component in which of the 6 galloyl residues 2 are dihalloy and 2 are monohalloy.

Medicinal raw materials. The leaves are cut off entirely, dried in the open air.

Application. Domestic industrial raw materials for the production of tannin and its preparations.

2.3. Quantitative calculation of the content of tannins in medicinal raw materials.

There are three methods for quantitative calculation of the content of tannins in medicinal raw materials.

1 . Gravimetric or weight methods - based on the quantitative precipitation of tannins by gelatin, heavy metal ions or adsorption by skin (naked) powder. The official method in the tanning and extract industry is the unified weight method (BEM). In aqueous extracts from plant material, the total amount of soluble substances (dry residue) is first determined by drying a certain volume of the extract to constant weight; then tannins are removed from the extract by treating it with fat-free skin powder; after separating the precipitate in the filtrate, the amount of dry residue is again established. The difference in the mass of the dry residue before and after the treatment of the extract with skin powder shows the amount of genuine tannins.

2 . Titrimetric methods . These include:

1) Gelatin method - The method of Yakimov and Kurnitskaya - is based on the ability of tannins to form insoluble complexes with proteins. Aqueous extracts from raw materials are titrated with 1% gelatin solution; at the equivalence point, the gelatin-tannate complexes are dissolved in an excess of the reagent. The titer is determined by pure tannin. The valence point is determined by sampling the smallest volume of titrated solution that causes complete precipitation of tannins. The method is the most accurate, because allows you to determine the amount of true tannins. Disadvantages: duration of determination and difficulty in establishing the equivalence point.

2) Permanganatometric method (Leventhal method modified by Kursanov). This pharmacopoeial method is based on easy oxidizability with potassium permanganate in an acidic medium in the presence of an indicator and a catalyst of indigo sulfonic acid, which changes from blue to golden yellow at the equivalence point of the solution. Features of the determination that allow titrating only macromolecules of tannins: titration is carried out in highly diluted solutions (the extraction is diluted 20 times) at room temperature in an acidic medium, permanganate is added slowly, drop by drop, with vigorous stirring. The method is economical, fast, easy to perform, but not accurate enough, since potassium permanganate partially oxidizes low molecular weight phenolic compounds. 3) For the quantitative determination of tannin in sumac and skumpia leaves, the method of precipitation of tannins with zinc sulfate is used, followed by complexometric titration with Trilon B in the presence of xylenol orange.

3 . Physical and chemical methods . 1) Photoelectrocolorimetric - based on the ability of DV to form colored compounds with ferric salts, phosphotungstic acid, Folin-Denis reagent, etc. 2) Chromatospectrophotometric and nephelometric methods are used in scientific research.

blank. Harvesting of raw materials is carried out during the period of maximum accumulation of DV. In herbaceous plants, as a rule, the minimum content of tannins is noted in the spring during the period of regrowth, then their content increases and reaches a maximum during the period of budding and flowering (for example, Potentilla rhizomes). By the end of the growing season, the amount of DV gradually decreases. In burnet, the maximum AD accumulates in the phase of development of razvetochnye leaves, in the flowering phase their content decreases, and in autumn it increases. The vegetation phase affects not only the quantity, but also the qualitative composition of the AI. In the spring, during the period of sap flow, in the bark of trees and shrubs and in the regrowth phase of herbaceous plants, hydrolyzable DVs mainly accumulate, and in the autumn, in the phase of plant death, condensed DVs and their polymerization products, flobaphenes (reds). It is produced during the period of the highest content of tannins in plants, to exclude water from entering the raw materials.

drying conditions. After harvesting, the raw materials must be dried quickly, since under the influence of enzymes, oxidation and hydrolysis of tannins occur. The collected raw materials are dried in air in the shade or in dryers at a temperature of 50-60 degrees. Underground organs and oak bark can be dried in the sun.

Storage conditions . They are stored in a dry, well-ventilated area without access to direct sunlight according to the general list for 2-6 years, in tight packaging, preferably in its entirety, since in the crushed state the raw material undergoes rapid oxidation due to an increase in the contact surface with atmospheric oxygen.

Ways of using raw materials containing tannins. In addition to the sources of tannin, all the studied objects are included in the order of July 19, 1999, which allows the non-prescription sale of raw materials from pharmacies. At home, raw materials are used in the form of decoctions and as part of fees. Tannin and combined preparations "Tanalbin" (a complex of tannin with casein protein) and "Tansal" (a complex of tanalbin with phenyl salicylate) are obtained from the leaves of skumpia leather, tanning sumac, Chinese tea, Chinese and Turkish galls. From the seedlings of alder, the drug "Altan" is obtained.

Medical use of raw materials and preparations containing tannins. Raw materials and preparations containing DV are used externally and internally as astringent, anti-inflammatory, bactericidal and hemostatic agents. The action is based on the ability of DV to bind to proteins with the formation of dense albuminates. Upon contact with an inflamed mucous membrane or wound surface, a thin surface film is formed that protects sensitive nerve endings from irritation. There is a sealing of cell membranes, narrowing of blood vessels, the release of exudates decreases, which leads to a decrease in the inflammatory process. Due to the ability of DV to form precipitates with alkaloids, cardiac glycosides, salts of heavy metals, they are used as antidotes for poisoning with these substances. Outwardly, for diseases of the oral cavity, pharynx, larynx (stomatitis, gingivitis, pharyngitis, tonsillitis), as well as for burns, decoctions of oak bark, bergenia rhizomes, serpentine, cinquefoil, rhizomes and roots of burnet, and the drug "Altan" are used. Inside, for gastrointestinal diseases (colitis, enterocolitis, diarrhea, dysentery), tannin preparations are used (Tanalbin, Tansal, Altan, decoctions of blueberries, bird cherry (especially in pediatric practice), alder seedlings, bergenia rhizomes, serpentine, cinquefoil, rhizomes and roots of burnet.As hemostatic agents for uterine, gastric and hemorrhoidal bleeding, decoctions of the bark of viburnum, rhizomes and roots of burnet, rhizomes of cinquefoil, alder seedlings are used.Decoctions are prepared in a ratio of 1:5 or 1:10.Do not apply strongly concentrated decoctions, since in this case, the film of albuminates dries up, cracks appear, and a secondary inflammatory process occurs.The antitumor effect of tannins of the aqueous extract of pomegranate fruit exocarp (for lymphosarcoma, sarcoma and other diseases) and the preparation "Hanerol", obtained on the basis of ellagitannins, has been experimentally established and polysaccharides of inflorescences of common fireweed (willow-tea) for cancer of the stomach and lungs their.

Conclusion

1. Tannins (tannins) are plant polyphenolic compounds with a molecular weight of 500 to 3000, capable of forming strong bonds with proteins and alkaloids and having tanning properties.

2. There are several classifications of tannins, they were described in detail in the work and supplemented with examples.

3. The task set by me was implemented, this indicates that the characteristics of tannins have been studied, methods for the quantitative determination of tannins in medicinal raw materials have also been considered.

Used bibliography

1. Muravieva D.A. Pharmacognosy: textbook for students of pharmaceutical universities / D.A. Muravyova, I.A. Samylina, G.P. Yakovlev.-M.: Medicine, 2002. - 656p.

2. Hydrolysable tannins - biologically active compounds of medicinal plants Access mode: http://www.webkursovik.ru/kartgotrab.asp?id=-132308

3. Kazantseva N. S. Merchandising of food products. - M.: 2007.-163s.

4. Tannins, general characteristics Access mode: http://www.fito.nnov.ru/special/glycozides/dube/

5. New approaches to the quantitative determination of tannins Access mode: http://otherreferats.allbest.ru/medicine/00173256_0.html

6. Petrov K.P.//Methods of biochemistry of plant products, 2009.-204p.

Isolation from VRS . Tannins are a mixture of various polyphenols with a complex structure and very labile, so the isolation and analysis of individual components of tannins is very difficult. To obtain the amount of tannins, the herbal raw materials are extracted with hot water, cooled, and then the extract is processed sequentially:

Petroleum ether (purification of chlorophyll, terpenoids, lipids);

Diethyl ether extracting catechins, hydroxycinnamic acids and other phenols

Ethyl acetate, into which leukoanthocyanidins, esters of hydroxycinnamic acid, etc. pass. The remaining aqueous extract with tannins and other phenolic compounds and fractions 2 and 3 (diethyl ether and ethyl acetate) is separated into individual components using various types of chromatography. Use:

a) adsorption chromatography on cellulose columns,

b) partition chromatography on silica gel columns;

c) ion exchange chromatography;

d) gel filtration on Sephadex columns, etc.

Identification of individual tannins is based on comparison RF in chromatographic methods (on paper, in a thin layer of sorbent), spectral studies, qualitative reactions and the study of cleavage products (for hydrolyzable tannins).

Quantification of tannins . can be divided into gravimetric, titrimetric and physico-chemical.

Gravimetric Methods are based on the quantitative precipitation of tannins by salts of heavy metals, gelatin, or adsorption by naked powder. Weighted Unified Method (BEM) widely used in the leather industry. The method is based on the ability of tannins to form strong bonds with skin collagen. To do this, the resulting water extract from the MPC is divided into two equal parts. One part is evaporated, dried and weighed. The second part is treated with skin (naked) powder, filtered. The filtrate is evaporated, dried and weighed. The difference between the dry residues of parts 1 and 2 (i.e., control and experience) determines the content of tannins in the solution.

Titrimetric method, included in GF-XI, referred to as the Leventhal-Neubauer method, is based on the oxidation of phenolic OH groups with potassium permanganate (KMnO 4) in the presence of indigo sulfonic acid, which is a regulator and indicator of the reaction. After complete oxidation of tannins, indigo sulfonic acid begins to oxidize to isatin, as a result of which the color of the solution changes from blue to golden yellow. Another titrimetric method for the determination of tannins, the method of precipitation of tannin with zinc sulfate, followed by complexometric titration with Trilon B in the presence of xylene orange, is used to determine tannin in the leaves of tannic sumac and tannery tannery.

Physical and chemical methods for the determination of tannins:

1) colorimetric- DV give colored compounds with phos-molib or phosph-tungsten to-mi in the presence of Na 2 CO 3 or with the Folin-Denis reagent (for phenols).

2) chromato-spectrophotometric and nephelometric methods that are used mainly in scientific research.

Distribution in the plant world, conditions of formation and the role of plants. The low content of tannins was noted in cereals. In dicotyledons, some families - for example, rosaceae, buckwheat, legumes, willows, sumac, beech, heather - include many genera and species, where the content of tannins reaches 20-30% or more. The highest content of tannins was found in pathological formations - galls (up to 60-80%). Woody forms are richer in tannins than herbaceous ones. Tannins are unevenly distributed over the organs and tissues of plants. They accumulate mainly in the bark and wood of trees and shrubs, as well as in the underground parts of herbaceous perennials; green parts of plants are much poorer in tannins.

Tannins accumulate in vacuoles, and during cell aging they are adsorbed on cell walls. Most often in plants there is a mixture of hydrolysable and condensed tannins with a predominance of compounds of one group or another.

With the age of plants, the amount of tannins in them decreases. Plants growing in the sun accumulate more tannins than those growing in the shade. In tropical plants, much more tannins are formed than in plants of temperate latitudes.

Bio-medical action and use of tannins . Tannins and LR containing them are mainly used as astringent, anti-inflammatory and hemostatic agents.

A. Predominantly hydrolysable:

Rhizomata Bistortae – serpentine rhizomes.

Highlander snake (snake root, coil) (Polygonumbistorta) - sem. Buckwheat, Polygonaceae

Chemical composition: 15-25% tannins, predominantly hydrolysable, gallic, ellagic, ascorbic, phenolcarboxylic and organic acids, flavonoids (quercetin)

The main action of the LRS: astringent, antiseptic.

Nature of application. Infusion and decoction is used as an astringent, hemostatic, anti-inflammatory for minor bleeding in the gastrointestinal tract, acute and chronic inflammation of the stomach, food poisoning, dermatosis, burns, inflammation of the oral cavity, vagina, hemorrhoids.

FoliaCotinus coggygriae – Leaves of skumpia leather.

Skumpia tannery (Cotinuscoggygria) - sem. Sumac, Anacardiaceae- branchy shrub

Chemical composition. 0.2% essential oil (myrcene predominates), ~25% tannin, flavonoids.

The main action of the LRS: astringent, disinfectant.

Nature of application. are used for the industrial production of tannin and its preparations, as well as the preparation Flacumin, which is the sum of flavonol aglycones from skumpia leaves and has a choleretic effect.

FoliaRhuscoriariae – tannic sumac leaves.

Sumac tannin (Rhuscoriariae) - sem. Sumac, Anacardiaceae– shrub

Chemical composition. tannins (25%, tannin predominates), flavonoids (2.5% - derivatives of quercetin, myricetin, kaempferol), gallic and ellagic acids.

The main action of the LRS: astringent, disinfectant.

Nature of application. are used for the industrial production of tannin and its preparations used in the treatment of inflammatory processes of the oronasal cavity by rinsing with a 2% aqueous or water-glycerin solution, ulcers, wounds and burns by lubricating with 3-10% solutions and ointments.

Rhizomata Bergeniaecrassifoliae - rhizomes of Badan thick-leaved.

Badan thick-leaved (Bergenia crassifolia) - sem. saxifrage, Saxifragaceae- perennial herbaceous plant

Chemical composition: tannins (~27%, of which tannin - 8-10%), gallic acid, arbutin (up to 22%), free hydroquinone (2-4%), coumarins, resins, vitamin C, sugar,

Nature of application. Infusion and decoction of the roots and rhizomes of bergenia are used in gynecology, dentistry to stop bleeding and as an anti-inflammatory, antiseptic, for the treatment of gastritis and gastric and duodenal ulcers, in folk medicine - for the treatment of pulmonary tuberculosis.

Rhizomataetradices Sanguisorbae -rhizomes and roots of the burnet.

Burnet officinalis (Sangusorba officinalis) - sem. Rosaceae, Rosaceae- perennial herbaceous plant

Chemical composition of LR: tannins, predominantly hydrolysable (12-20%), ellagic, gallic acids, flavonoids, anthocyanins, catechins, saponins.

The main action of the LRS: astringent, hemostatic.

Nature of application. Rhizomes and roots of burnet are used in the form of a decoction and liquid extract as an astringent for gastrointestinal diseases, enterocolitis, diarrhea; as a hemostatic agent for uterine and hemorrhoidal bleeding, hemoptysis.

FructusAlni – seedlings (cones) Alder.

FoliaAlniincanae – gray alder leaves.

Folia Alniglutinosa– black alder leaves.

Black alder(sticky) (Alnusglutinosa), O. gray (Alnusincana) - sem. birch, Betulaceae trees or large shrubs.

Chemical composition: alder seeds contain tannins, gallic acid (up to 4%), flavonoids. In the leaves of gray and about. black contains flavonoids.

The main action of the LRS: astringent, disinfectant, anti-inflammatory.

Nature of application. Decoction and infusion are used orally for acute and chronic enteritis, colitis, disinteria; externally - for gargling, mouth cavity.

B. Predominantly condensed:

CorticesQuerqus–Oak bark.

Common oak(Querqusrobur) - sem. beech, Fagaceae- mighty tree

Chemical composition: tannins (10-20%, hydrolysable and condensed), gallic, ellagic acids, flavonoids

The main action of the LRS: astringent, antibacterial.

Nature of application. in the form of a decoction and infusion as an external astringent and anti-inflammatory agent for the treatment of stomatitis, gingivitis, inflammation of the oral cavity, female genital organs, skin burns, sweating.

Rhizomata Tormentillae – rhizomes of Potentilla erectus.

Potentilla erectus– Potentilla erecta- seven. Rosaceae, Rosaceae- perennial herbaceous plant

Chemical composition. tannins (15-30%: condensed tannins predominate), anthocyanins, catechins.

The main action of the LRS

Nature of application. A decoction and infusion are used internally as an astringent and anti-inflammatory agent for inflammatory conditions of the mouth and larynx, gastrointestinal disorders, and externally for eczema.

Fructus Vaccinium myrtilli blueberries.

Cormi Vaccinii mytilli shooters.

blueberry (Vaccinium myrtillus L.) - Heather, Ericaceae- small shrub

Chemical composition. tannins (18-20%), including condensed (5-12%), flavonoids (hyperin, rutin), anthocyanins.

The main action of the LRS: astringent, anti-inflammatory.

Nature of application. more often in the form of infusion, decoction, jelly in connection with fermentation and putrefactive processes in the intestines, colitis. Blueberries have been shown to improve blood supply to the eyes, stabilize the structure of the retina, and improve night vision.

FructusPadi-bird cherry fruit.

Common bird cherry (padusavium), h. Asian (P. asiatica) - sem. Rosaceae, Rosaceae– tree up to 10 m tall

Chemical composition: tannins (15%: predominantly condensed), phenolcarboxylic and organic acids, vitamin C, sugars, terpenoid glycosides

The main action of the LRS: astringent, disinfectant.

Nature of application. Decoction and infusion are used as an astringent and disinfectant of the gastrointestinal tract: for dysentery, diarrhea. Bird cherry fruits are a component of gastric preparations.

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What are tannins?

Tannins are natural high-molecular phenolic compounds widely distributed in the plant world. In simpler terms, these are substances that give various fruits an astringent and tart taste. Depending on what their concentration is in a particular plant, it will have more or less pronounced astringency. Turn, persimmon, pear, - recall the characteristic taste of these and berries? It's all about the presence of tannins.

What are the properties of tannins? You can say big. Phenolic compounds affect the organic environment and eliminate the influence of microorganisms. Tannins of plants are characterized by a special astringent taste and are divided into organic and mineral. Organic are of plant and animal origin.

What plants contain the most tannins?

• serpentine rhizomes
• Potentilla rhizomes
• Rhizomes and roots of burnet
• Fruit
• Bird cherry fruits
• Alder fruit
• Badan rhizomes
• Skumpia leaf
• sumac leaf
• Black
• Dogwood
• Persimmon
• Black

Tannins in tea have proven effectiveness. They are much more in tea leaves than even in fruits. By the way, in green tea, its concentration reaches 10-30%, in black - 5-17% . It is known that due to the presence drink works like and an active disinfectant, as well as helps to neutralize radioactive strontium in the body.

Tannins are also found in natural which give it a bitter taste and a tart aftertaste. A lot of tannins in red wine, which give the body and . They are also found in cognac, thanks to which the absorption of vitamin C improves.

The effect of tannins on the human body

Tannins have a rather noticeable effect on the human body. First of all, their astringent property is noted. It manifests itself in many different areas. Tannins when used correctly, successfully achieve and help to cope with his disorders, , diarrhea.

Tannins, when interacting with proteins, cause their partial coagulation, and create a waterproof protective albuminate film (tanning), on which their bactericidal and anti-inflammatory effect on mucous membranes and wound surfaces is based.

Benefits for digestion

Tannins have a positive effect on the functioning of the gastrointestinal tract as a whole. In particular, they suppress the activity of pathogenic microorganisms, promote the removal of harmful deposits, and help the best absorption of beneficial compounds.

The active substances of tannin also contribute to the general cleansing of the body. They remove from it a variety of types of toxins and toxins. These compounds can help even with radiation exposure.

Hemostatic properties

The hemostatic property of tannins is especially distinguished. It is actively used in a variety of cases. Tannins help stop both extrinsic and intrinsic . Therefore, they are used for abundant , hemorrhoids, bleeding gums and damage to the skin - cuts and other wounds.

Anti-inflammatory action

They have tannins and anti-inflammatory properties. They protect tissues from infections, destroy pathogens stop the inflammatory process. Thus, they are widely used in medicine in the treatment of a variety of ailments. Tannins are especially effective against inflammation in the mouth and throat, since in this case there is a direct effect by . When treatment of intestinal or gastric diseases is required, it is necessary to drink medicinal decoctions on an empty stomach and between meals so that the active compounds can freely reach one or another organ. Of course, tannins effectively cope with inflammatory processes on the skin. In particular, they help eliminate acne and some dermatological diseases. In these cases, special ointments and lotions with tannins are used.

In addition, tannins have the following beneficial properties:

• Eliminate .
• Make blood more elastic.
• containing tannins, used for diseases of the nose and eyes (in the form of drops).
• Food products with these substances have a beneficial effect in preventing the deposition of salts of heavy metals, with diarrhea, and radioactive damage.
• They are used to rinse the mouth and throat with such painful inflammatory diseases as stomatitis, , etc.
• Due to the fact that tannins are able to effectively disinfect and block the influence of pathogenic microflora, solutions with these substances used as compresses for abrasions, cuts, .
• If developed body, accompanied by serious , they will help to bind and remove harmful substances. With alkaloids and salts of heavy metals, tannins create insoluble compounds, so that they cease to have a negative effect. Tannins - an effective antidote for poisoning , such raw materials at a temperature of 50-60°C. and store in a dry place in dense packaging, preferably in its entirety, since in the crushed state the raw material undergoes rapid oxidation due to an increase in the contact surface with air.

  Conclusion

  Tannins play an important role in the formation of good health. They are found in some products that are often present on almost every table. To get only the benefit from them, remember that everything is good in moderation. When using tannins for medicinal purposes, follow the rules for taking medications and monitor your well-being.