Simple phenolic compounds in plants. Physical and chemical properties of simple phenolic compounds. Phenolic compounds with one aromatic ring

Depending on the additional carbon atoms, they are divided:

• - for compounds of the C 6 series (without additional carbon atoms);
• - compounds With 6 -Cj-series (one additional carbon atom);
• - compounds of the C 6 -C 2 series (two additional carbon atoms);
• - compounds of the C 6 -C 3 series (three additional carbon atoms);
• - compounds of the C 6 -C 4 series (four additional carbon atoms).

Compounds C (-series. These include simple phenols. This group of substances is sometimes referred to benzoquinones, although their aromatic ring is almost always connected to a long isoprenoid chain. Simple phenols are not widely distributed. Phenol is found in small amounts in pine needles, as part of the essential oils of currant, tobacco and rue. Pyrocatechin (7) is found in poplar and ephedra leaves, onion scales. Guaiacol, pyrocatechol monomethyl ester, is found in significant amounts in beech resin [see: 6, p. 108].

Connections From 6 - C ^ series. These include derivatives of hydroxybenzoic acid, which are often called phenolic acids, or phenolic acids. Phenolic acids, especially such as vanillic, n-hydroxybenzoic (8), protocatechuic, and gallic acids, were found in practically all studied angiosperms. More often they are in the tissues in a bound state and are released during isolation and hydrolysis. For example, salicylic acid, which is found in oak roots, is released into the environment as an allelopathic substance.

Connections C 6 -C 2 rows. This series of compounds includes phenol alcohols, phenylacetic acids, acetophenone. Unlike phenolic acids, they are not as common in plants. Willow bark contains salicylic alcohol. But vanillin (vanilla aldehyde) is especially known, which is found in the fruits and branches of the vanilla tree in the form of a glycoside.

Connections From 6 - C^-series. This most numerous and important group of substances is often also called phenylpropanoids. It includes hydroxycinnamic acids (according to the international nomenclature, it is recommended to call them hydroxycinnamic acids), hydroxycinnamic (hydroxycinnamic) alcohols, phenylpropenes, as well as coumarins, isocoumarins and chromones - compounds in which additional carbon atoms are closed in a condensed lactone ring.

Hydroxycinnamic acids include: l-hydroxycinnamic or l-coumaric (9), caffeic, ferulic and synapic. As a rule, in plants they are in a bound state (except for coffee). They are characterized cis-trans- isomerism. It has been shown that mis-isomers of hydroxycinnamic acids are activators of growth processes [see: 4, p. 157].

In addition to the widespread p-hydroxycinnamic acid, o-hydroxycinnamic acid has been found in some plants. Her trance- form is stable, but the rs-form (called coumaric acid) cyclizes in an acidic environment to form a stable coumarin lactone (10).

Coumarin is a colorless crystalline substance with a pleasant odor reminiscent of hay [see: 3, p. 319]. In plants, coumarin is usually found in the form of glycosides. During haymaking, plant tissues are damaged, and glycosides from cell sap come into contact with cytoplasmic enzymes. After cleavage of sugar, coumaric acid, after isomerization, closes into lactone - while withering grass acquires the smell of hay.

Hydroxycinnamic alcohols are derivatives of the corresponding acids. In some cases, phenylpropanoids can combine with each other and form dimers, i.e., compounds of the (C 6 -C 3) 2 type. Such substances are called lignans. However, they are usually classified as dimeric phenolic compounds.

Connections From 6 - From the 4th row. This series of compounds includes naphthoquinones. Naphthoquinone is vitamin K (phylloquinone).

Phenols are compounds whose molecules contain an aromatic (benzene) ring associated with one or more -OH groups. A high content of phenols is characteristic of a plant cell.

In the animal body, benzene rings are not synthesized, but can only be transformed, so they must constantly be ingested with food. At the same time, many phenolic compounds in animal tissues perform important functions (ubiquinone, adrenaline, thyroxine, serotonin, etc.).

Today, several thousand various phenolic compounds have already been found in plants. They are classified according to the structure of the carbon skeleton:

1. C 6 -phenols

2. C 6 -C 1 -phenolic acids

3. C 6 -C 3 -hydroxycinnamic acids and coumarins

4. C 6 -C 3 -C 6 -flavonoids

5. Oligomeric phenolic compounds.

6. Polymeric phenolic compounds.

C 6 -Phenols. Compounds whose benzene ring is linked to several hydroxyl groups are called polyphenols.

Free phenols in plants are rare and in small quantities. Thus, phenol was found in pine needles and cones, in the essential oil of blackcurrant, pyrocatechin - in onion scales, in bergenia leaves, hydroquinone - in pear bark and leaves, in bergenia leaves. More common are derivatives of phenols, where they are associated with any carbon chain or cycle. For example, urushiol and tetrahydrocannabinol.

Urushiol is a toxic substance from sumac leaves. Tetrahydrocannabinol is the hallucinogenic ingredient in cannabis.

During the oxidation of phenols, quinones (benzoquinones) are formed. In the free state, quinones are not found in plants, but their derivatives are common. For example, benzoquinone derivatives are electron carriers in the ETC of photosynthesis and respiration - plastoquinone and ubiquinone. Benzoquinone derivatives also include the burning substance of primrose - primin and the red pigment of fly agaric - muscarufin.

C 6 -C 1 -phenolic acids. Phenolic acids are common in plants. More often they are in the tissues in a bound state and are released during isolation and hydrolysis.

Salicylic acid is released as an allelopathic agent into the environment. At the same time, its regulatory effect on a number of physiological and biochemical processes in the plant (the formation of ethylene, the reduction of nitrates, etc.) has now been discovered.

Protocatechuic acid is found in onion scales.

Vanilla and gallic acids are found in wood. The latter is part of some tannins and can form dimers - digallic acid, in the molecule of which 2 residues of gallic acid are connected by an ester bond.

Found in plants derivatives of phenolic acids - aldehydes and alcohols. For example, salicylic alcohol is present in willow bark. But vanillin is especially famous - vanilla aldehyde. It has a very pleasant smell and in the form of a glycoside - glucovanillin is found in the fruits and branches of the vanilla tree. Glycoside and vanillin itself are widely used in the confectionery, soap and perfume industries.

Phenolic acids can be linked by ester bonds with sugars, more often with glucose. From a number of plants (rhubarb, eucalyptus), glycogallin was isolated, in which the carboxyl group of gallic acid is linked to the glycosidic hydroxyl of glucose.

C 6 -C 3 -hydroxycinnamic acids and coumarins. Hydroxycinnamic acids are widely distributed in plants. Usually they are in a bound state, and in a free state, except for coffee, they are rare.

It has been shown that cis-isomers of hydroxycinnamic acids are activators of plant growth processes, while trans-isomers do not possess such properties.

Hydroxycinnamic alcohols are found in plants - derivatives of the corresponding acids: coumaric - coumaric alcohol, ferulic - co-niferyl alcohol, synapic - synapic alcohol. Alcohols usually do not accumulate, but are obviously used to form lignin, of which they are monomers.

Hydroxycinnamic acids can form esters with aliphatic organic acids. So, caffeic acid forms esters with malic and tartaric acids. The first ester is called phaseolinic acid. It is present in bean leaves. The second is chicoric acid. It is found in chicory leaves.

Esters of hydroxycinnamic acids and sugars are common in plants, more often glucose. Thus, esters of caffeic, coumaric, and ferulic acids were found in petunia and snapdragon flowers, and in cereals, in general, most hydroxycinnamic acids are esters. At the same time, hydroxycinnamic acids are part of polysaccharides and proteins. For example, ferulic acid is found in wheat flour xylans and pineapple polysaccharides.

Coumarins are lactones that are formed by closing the ring between the hydroxyl and carboxyl groups in the hydroxycinnamic acid molecule.

Coumarin is a colorless crystalline substance with a pleasant smell of freshly cut hay. Coumarin is not found in free form in plants. It is usually found in the form of glycosides (flowers and leaves of sweet clover). In herbaceous plants, a glycoside containing ortho-coumaric acid is present in the cell sap. During haymaking, plant tissues are damaged, membrane permeability is impaired. Glycosides from cell sap come into contact with cytoplasmic enzymes. Sugars are split off from glycosides, and coumaric acid, after trans-cis isomerization, is closed into lactone-coumarin. At the same time, withering grass acquires the smell of hay.

Plants often contain hydroxylated coumarins as glycosides. For example, esculetin from the pericarp of horse chestnut and scopoletin from the roots of Japanese scopolia. Both of these coumarins have P-vitamin activity and are used in medicine as capillary strengthening agents.

Dicoumarin was found in white sweet clover, which prevents blood clotting. This and other dicoumarins are used as drugs to prevent blood clots.

C 6 -C 3 -C 6 -flavonoids. This is one of the most diverse and widespread groups of phenolic compounds. At the root of the structure of flavonoid molecules lies the structure of flavan, which consists of two benzene rings and one heterocyclic (pyran) ring.

Flavonoids are divided into several groups.

1. Catechins.

2. Anthocyanins.

3. Chalcones.

Catechins- the most restored flavonoids. Οʜᴎ do not form glycosides. Catechin was first isolated from the wood of Acacia catechu, hence its name. Catechins are found in over 200 plant species. Among the catechins, the best known are catechin and gallocatechin.

Οʜᴎ can form esters with gallic acid - catechin gallates and gallocatechin gallates. Catechins are found in many fruits (apples, pears, quince, cherries, plums, apricots, strawberries, blackberries, currants, lingonberries, grapes), in cocoa beans, coffee beans, in the bark and wood of many trees (willow, oak, pine , fir͵ cedar, cypress, acacia, eucalyptus). Especially a lot of catechins in the leaves and young shoots of tea (up to 30%). Oxidative transformations of catechins play an important role in tea production and winemaking. Oxidation products, and these are mainly dimers of catechins, have a pleasant slightly astringent taste and a golden brown color. This determines the color and taste of the final product. At the same time, catechins have a high P-vitamin activity, strengthen capillaries and normalize the permeability of vessel walls. Dimers of catechins in tea have the same activity. Catechins as monomers are part of condensed tannins.

Anthocyanins are the most important plant pigments. Οʜᴎ color petals of flowers, fruits, sometimes leaves in blue, blue, pink, red, purple colors with different shades and transitions. All anthocyanins are glycosides. Their aglycones are anthocyanidins. Anthocyanins are water soluble and found in cell sap.

Today, more than 20 anthocyanidins are known, but the most widely distributed are 4: pelargonidin, cyanidin, delphinidin, and malvidin (a methylated derivative of delphinidin).

As monosaccharides in anthocyanins, glucose, galactose, rhamnose, xylose, less often arabinose are found, and as disaccharides, most often rutinose, sophorose, sambubiose are found. Sometimes anthocyanins contain trisaccharides, usually branched. For example, anthocyanin was found in currants and raspberries, in which a branched trisaccharide is associated with cyanidin.

The color of anthocyanins depends on a number of factors:

1. concentration of anthocyanins in cell sap;

2. pH of cell sap;

3. complex formation of anthocyanins with cations;

4. co-pigmentation - a mixture of anthocyanins and the presence of other substances of a phenolic nature in the cell sap;

5. combinations with coloring of plastid pigments.

Let's consider these factors in more detail.

1. The concentration of anthocyanins in cell sap can vary in a wide range - from 0.01 to 15%. For example, an ordinary blue cornflower contains 0.05% anthocyanin cyanine, and its dark purple 13-14%.

2. Due to the fact that there is a free valency in anthocyanin molecules, the color can change based on the pH value. Usually, in an acidic environment, anthocyanins have a red color of various intensities and shades, and in an alkaline environment, they are blue. Such changes in the color of anthocyanins can be observed by adding acid or alkali to the colored juice of currants, cherries, red beets or red cabbage. In nature, there are no sharp changes in the pH of cell sap, and this factor does not play a big role in the color of anthocyanins. One can only notice that some pink and red flowers turn blue when they wither. This indicates a change in pH in dying cells.

3. Of great importance in the color of flowers and fruits is the ability of anthocyanins to chelate with metal ions. This is clearly seen in the example of a cornflower and a rose. Their petals contain the same anthocyanin - cyanine. In the petals of the blue cornflower, cyanine forms a complex with Fe ions (4 cyanine molecules are bonded to one Fe atom). Red rose petals contain free cyanine. Another example.
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If an ordinary hydrangea with pink flowers is grown on a mineral medium containing aluminum and molybdenum, then the flowers become blue in color.

4. Usually, in the cell sap of many flowers and fruits, there is not one, but several pigments. In this case, the color depends on their mixture, and it is called co-pigmentation. Thus, the color of blueberries is due to the co-pigmentation of delphin and malvin. There are 10 different anthocyanins found in purple potato flowers.

The color pattern of the petals of many flowers is determined either by a local increase in the concentration of one pigment (digitalis), or by the imposition of an additional pigment on the main one (a high concentration of cyanine is superimposed in the center of poppy flowers against the general background of pelargonin).

The coloration is also influenced by the co-pigmentation of anthocyanins with other substances, for example, with tannins. So, purple and dark red roses contain the same cyanine, but in dark reds it is pigmented with a large amount of tannin.

5. The combination of blue anthocyanins of cell sap and yellow-orange carotenoids of chromoplasts results in the brown color of the petals of some flowers.

Tab. Some plant anthocyanins

Anthocyanin	Aglicon	Sugar	Plants
Pelargonin	Pelargonidin	2 glucose	Pelargonium, asters
cyanine	Cyanidin	2 glucose	Roses, cornflowers
Keracyanin	Cyanidin	Glucose, rhamnose	Cherries
Prunicyanin	Cyanidin	Rhamnose, glucose	plums
Idain	Cyanidin	Galactose	Cowberry
Chrysanthemum	Cyanidin	Glucose	Asters, blueberries, elderberry
Malvin	Malvidin	2 glucose	Mallow
Enin	Malvidin	Glucose	Grape
Dolphin	Delphinidin	Rhamnose, glucose	Spurnik
Viglanin	Delphinidin	Glucose, rhamnose	Coltsfoot

Chalkons, or anthochlores, are flavonoids with an open heterocycle. Οʜᴎ give the flower petals a yellow color. Their distribution is limited to nine families. They are found in the form of glycosides. Chalcones, for example, are isosalipurposide from yellow carnation flowers, phloridzin from the bark and leaves of the apple tree. Floridzin is an apple growth inhibitor. When ingested by a person, it causes a one-time intensive release of glucose into the blood - ʼʼphloridzin diabetesʼʼ.

Oligomeric phenolic compounds. This includes lichen acids. Οʜᴎ are formed in lichens from two or more orsellic acid residues. Lecanoric and evernic acids consist of two residues of orsellic acid. Evernic acid is the main component of the evernia acid complex (ʼʼoakmossʼʼ), which is used in perfumery as a fragrant substance and at the same time as a fixative in the manufacture of the best varieties of perfumes.

Among lichen acids there are colored ones. Οʜᴎ give a variety of colors to lichens - yellow, orange, red, purple. Usnea lichen contains usnic acid, which is an effective bactericidal agent.

Dimers of hydroxycinnamic alcohols are found in the bark, wood, fruits and leaves of many plants. They form oligomers and flavonoids, especially catechins. Dimers of catechin are found in apples, chestnuts, hawthorn, cocoa beans, and eucalyptus wood.

Polymeric phenolic compounds. Polymeric phenolic compounds include tannins, or tannins, lignins and melanins.

Tannins, or tannins. They got their name due to the ability to tan the skin of animals, turning it into leather. Tanning is based on the interaction of tannins with skin protein - collagen. In this case, numerous hydrogen bonds are formed between the protein and tannin.

Natural tannins are a complex mixture of compounds with similar composition with a molecular weight of 500-5000.

A lot of tannins are found in the bark and wood of oak, eucalyptus, chestnut wood, in the rhizome of sorrel, rhubarb, and sumac leaves. There are many of them in the bark and wood of legumes, myrtle, pink. Especially high content of tannins are distinguished by galls, which are formed on the leaves when they are damaged by the nut washer (up to 50-70%).

Tannins (more often food tannins) are also called lower molecular weight substances that have a pleasant astringent taste, but are not capable of real tanning. Οʜᴎ are present in many fruits (quince, apples, persimmons, grapes), in tea leaves.

Tannins are widely used not only in the leather industry. They are used in the production of plastics, binders in the manufacture of plywood and boards from sawdust, as a mordant in dyeing. Οʜᴎ are used in water boiling plants as colloid stabilizers, to control the viscosity of solutions during well drilling.

The use of tannins in winemaking is associated with their inhibitory effect on enzymes and microorganisms, which prevents clouding of wines and improves their quality. With the help of tea tannin, betacyanin, a food red dye obtained from table beet, is stabilized.

In medicine, tannins are used as astringent, bactericidal, anti-radiation and antitumor agents.

lignin is part of the cell membranes of wood tissues. It is deposited between cellulose microfibrils, which gives the cell membranes hardness and strength. In this case, the connection between cells is disrupted, which leads to the death of living contents, in connection with this, lignification is the final stage of cell ontogenesis.

Lignin is an amorphous substance, insoluble in water, organic solvents, and even in concentrated acid.

Lignin has another important property: it is resistant to microorganisms. Only a few microorganisms, and then very slowly, decompose it.

Lignin is a three-dimensional polymer whose monomers are hydroxycinnamic alcohols. So, in conifers, co-niferyl alcohol predominates in lignin, in cereals - cumar, in many deciduous trees - synapic.

In the pulp and paper industry and in hydrolysis plants, a large amount of lignin accumulates as waste. It is used to produce activated carbon, plastics, synthetic resins.

Melanins- polymers of phenolic nature, which are the product of the oxidation of tyrosine. Their structure has not yet been fully elucidated.

Melanins are black or brown-black in color. Their formation explains the rapid darkening of the surface of a cut apple, potato tuber, and some mushrooms. Melanins are also present in animal organisms, causing the color of wool and hair. At the same time, plant and animal melanins differ in the composition of monomers. Plant melanins upon hydrolysis form pyrocatechin, and animals - dihydroxyindole. In other words, plant melanins, unlike animals, are nitrogen-free substances.

Functions of phenolic compounds in a plant. 1. Phenols are involved in redox processes: phenols are converted to quinones and vice versa with the participation of the polyphenol oxidase enzyme. At the same time, various compounds (amino acids, organic acids, phenols, cytochromes, etc.) can be oxidized in a non-enzymatic way.

2. Some phenolic compounds are electron and proton carriers in the ETC of photosynthesis and respiration (plastoquinone, ubiquinone).

3. A number of phenols have an effect on the growth processes of plants, sometimes activating, more often inhibiting. This effect is mediated by the action on phytohormones. So, it is known that some phenolic compounds are necessary for the synthesis of auxin, others - for its decay. The presence of a coumaric acid ester is extremely important for the formation of ethylene. It has been established that under stress, plants accumulate a large amount of phenols, which leads to inhibition of growth processes and an increase in their resistance to adverse conditions.

4. Phenols perform a protective function in plants: Phenolic compounds give plants resistance to diseases. For example, resistance to a number of diseases of onions with colored husks is associated with the presence of protocatechuic acid in it. With mechanical damage to plant tissues, phenols accumulate in the cells and, condensing, form a protective layer. Some plants, in response to damage by pathogenic fungi, form protective substances - phytoalexins, many of which are of a phenolic nature.

5. Many phenols are antioxidants and protect membrane lipids from oxidative degradation. Some of them are used in the food industry to protect fats from rancidity (gallic acid esters, flavonoids, etc.).

6. The role of phenolic compounds in the process of plant reproduction is very important. This is not only associated with the color of flowers and fruits, but also with the direct participation of phenols in fertilization. So, in the process of fertilization of the chlamydomonas algae and the higher forsythia plant, flavonoids take part.

7. Phenols can act as allelopathic substances in some plants. For example, salicylic acid should be such a substance in oak.

8. Some phenols act as activators or inhibitors of certain processes and enzymes (cell division, protein synthesis, oxidative phosphorylation, etc.).

Phenolic compounds - concept and types. Classification and features of the category "Phenolic compounds" 2017, 2018.

Introduction

Pharmacognosy is one of the pharmaceutical sciences that studies medicinal plants, medicinal raw materials of plant and animal (some groups) origin, and some products of primary processing of plants and animals.

Plants, including medicinal plants containing phenolic compounds, have acquired particular importance.

It has now been proven that all phenolic compounds, with a few exceptions, are active metabolites of cell metabolism and play an important role in various physiological processes - photosynthesis, respiration, growth, plant resistance to infectious diseases. The important biological role of polyphenols is evidenced by the nature of their distribution in the plant. Most of them are found in actively functioning organs - leaves, flowers (give them color and aroma), fruits, sprouts, as well as in integumentary tissues that perform protective functions. Different organs and tissues differ not only in the amount of polyphenols, but also in their qualitative composition.

There are several representatives of this class in our region. This is thyme and oregano.

Objective.

The aim of the work is to study medicinal plants containing phenolic compounds.

To study the main classes of phenolic compounds.

To study the pharmacological effect of medicinal plants and raw materials containing phenolic bases.

Consider in more detail the plants belonging to this class and growing in our region.

Classification of phenolic compounds

Phenolic compounds are a large number of substances containing aromatic rings with a hydroxyl group, as well as their functional derivatives. Phenolic compounds containing more than one hydroxyl group on the aromatic ring are called polyphenols.

The number of natural phenolic compounds of plant origin is very large.

According to the chemical structure, all phenolic compounds can be divided into three main groups:

1) with one aromatic ring,

2) with two aromatic rings

3) polymer compounds.

Phenolic compounds with one aromatic ring

This group of natural compounds includes:

I. Compounds with the basic structure C6-dioxy- and trihydroxybenzenes and their derivatives (simple phenols).

II. Compounds with basic structures C6--C2 -phenolic acids, C6--C2 - phenol alcohols acetophenones and phenylacetic acids.

III. Compounds with the main structure C6-C3, i.e. hydroxycinnamic acids and their derivatives.

Simple phenols

Simple phenols are not often found in plants and their distribution is random in terms of taxonomy.

Phenol itself was found in the needles and cones of Pinus silvestris, the essential oils of the leaves of Nicotiana tabacum L., Ribes nigrum L., and the lichen Evernia prunastri Ash. and etc.

Pyrocatechin (1,2-dioxybenzene) is found in ephedra leaves, onion scales, grapefruit fruits. There is no information about the content of resorcinol in plants.

Hydroquinone (1,4-dioxibenzene) is also common. Its glycoside arbutin is present in representatives of the genera of the following families: Ericaceae (Arctostaphylos, Rhododendron); Vacciniaceae (Vaccinium); Rosaceae (Pyrus, Docynia); Saxifragaceae (Bergenia); Compositae (Xanthium).

In some plants, arbutin accumulates in large quantities.

Methyl and ethyl esters of hydroquinone are found in the families Rugo-laceae-Pyrola, Liliaceae-Hyacinthus; Magnoliaceae-Illicinum.

Of trioxybenzenes, phloroglucinol (1,3,5-trioxybenzene) is found in plants. In its free form, it is found in the cones of Sequoia sempervirens and the scales of Allium cepa L., and in the amount of florin glycochid in the peel of the fruits of rye species of Citrus.

A special place is occupied by real ferns. Insignificant amounts of phloroglucinol derivatives accumulate in the plants of this family. These derivatives are very peculiar in their substituents (they are methylated and connected to the butyric acid residue) and, apparently, thanks to them, in the pharmacological sense, fern phloroglucides are an ancient antihelminthic.

Bearberry leaf (Folium Uvac ursi)

Plant. Bearberry, or bear's eye Arctostaphylos uva - ursi (L.) Spreng: heather family - Ericaceae.

Bearberry is an evergreen, strongly branched, creeping shrub. The leaves are small, dark green, leathery. The flowers are pinkish, drooping, collected in short apical racemes. Calyx and corolla are five-toothed; The fruits are red, berry-like drupes with a calyx remaining below, with 5 seeds in a mealy, inedible pulp. Blossoms in May, berries ripen by August.

Bearberry has a wide apeal. It is common in the forest zone of the European part of the CIS and the Baltic States, in Western Siberia and less often in the Far East (found in the mountains among the dwarf pine). It grows mainly in dry pine forests with lichen cover (white mosses), it also occurs on open sandy places, coastal dunes and stone placers.

Chemical composition. The leaves contain up to 8 - 16% arbutin glycosides and much less methylarbutin, as well as a lot of free hydroquinone. Bearberry leaves also contain phenolic acid-gallic acid and its dimeric condensation product ellagic acid and flavonoids, among them hyperoside. Bearberry leaves with tannins of the pyrogallic group (up to 20%). Ursolic acid is present (0.4 -0.7%).

Medicinal raw materials - leaves. They are harvested during flowering. Collect short branches (shoots); after drying, the leaves are peeled or threshed.

The bearberry leaves are inversely ovoid, narrowed towards the base, short-petiolate, entire, shiny on top, bare or (if young) but with small spikelets visible through a magnifying glass. Leaf surface with a network of depressed veins. The length of the leaves is about 2 cm, the width is about 2 cm, the width is about 1 cm. The color is dark green (yellow blackened leaves are a sign of oxidation and other consequences of the destruction of arbutin, methylarbutin such as tannins and other substances).

As impurities within the permissible amount (no more than 0.5%), leaves of lingonberries, blueberries, blueberries can be found in raw materials). All of them are easily recognizable by external signs. Bearberry leaves are very distinctive under a microscope. On the transverse section of the leaf, a thick cuticle reddening from the Sudan is visible on both sides. Under the upper epidermis are 3-4 rows of polysaccharide cells, above the lower - spongy tissue. In tissue cells, more along the veins, there are single prismatic crystals. Surface preparations show that the cells of the epidermis are straight-walled, and the stomata are very wide with 8 (rarely 4) peristomatal cells.

Application. Bearberry leaves are used in the form of decoctions for diseases of the urogenital bladder. The therapeutic (antiseptic) effect is due to hydroquinone, released in the body during the hydrolysis of arbutin and methylarbutin. The therapeutic effect is enhanced by the specific action of tannins and their hydrolysis products.

Lingonberry leaves (Folium vitis idaci)

Plant. Lingonberry -- Vaccinium vitis idaea L.; lingonberry family Vaceiniaceae

Small shrub with creeping rhizome and erect stems. The leaves are evergreen; flowers with a pale pink, bell-shaped corolla are collected in drooping brushes. Different from bearberry, the perianth is four-dimensional, the ovary is superior. The fruits are red juicy berries. Blooms in May - June.

Widely distributed throughout the forest zone.

Chemical composition. Lingonberry leaves contain 6-9% arbutin, tannins (up to 9%), flavonoids, ursolic acid.

Medicinal raw materials - leaves that are harvested before flowering. When harvested later, the green color of the leaves cannot be preserved during drying, they usually turn black (the reason is not clear). The leaves are elliptical in shape, entire, the edges are slightly wrapped towards the underside, glabrous, smooth, dark green above, the lower surface is light green, covered with multicellular glandular black dots. The smell is absent, the taste is astringent, bitter.

Application. Water decoctions are used as a diuretic, especially for urolithiasis, rheumatism and gout.

Badan leaves are very rich in arbutin. For this reason, they are an industrial raw material for the production of total drugs for the treatment of the urinary tract, as well as for the production of pure arbutin.

Rhizome of the male fern (Rhizoma Filicis maris)

Plant. Male fern, or male shield - Dryopteris filix mas Schott; family of centipedes - Polypodiaceae.

The plant has two generations - sexual and asexual. An asexual diploid sporophyte is a perennial herbaceous plant with an overwintering rhizome. The rhizome is oblique, powerful, with numerous cord-like roots. The upper growing end of the rhizome bears a bunch of large leaves up to 1 m long, 20–25 cm wide. Unblown leaves are snail-like folded. The petiole of a leaf up to 25 cm long is densely covered with rusty-brown scales, at its base it is very juicy and expanded; when the leaf dies, this part of the petiole remains on the rhizome.

The leaf blade is dark green, oblong-elliptical in outline, bipinnately dissected, segments of the 2nd order bear denticles - they are blunt, not needle-shaped. Brown vessels develop on the lower surface of the leaf, covered with a kidney-shaped veil, under which oval sporangia containing brown spores sit on long legs. Spores, germinating, give a sexual generation - a haploid gametophyte (with a simple number of chromosomes in the nuclei) in the form of a small, green, lamellar, heart-shaped outgrowth, forming archegonium and antheridium. After fertilization, an asexual generation grows from the egg, the plant described above, and the cycle begins anew.

The male fern grows in damp shady forests, under the cover of spruce or in spruce-deciduous plantations - in the European part of the CIS, under the cover of beech, hornbeam and oak - in the Caucasus, under the Schrenk spruce - in the Tien Shan, under spruce and fir in the Siberian taiga. The range of the male fern is thus broken. The huge resources of the male fern are used in a small proportion - the need for a rhizome is covered by harvesting in the Baltic states, the Moscow region and in the Transcaucasus.

Chemical composition. The quality of the rhizome is primarily judged by the content of "raw filicin", meaning by it the amount of phloroglucides, and the composition of raw filicin includes phloroglucides of varying structural complexity. The simplest compound is aspidinol containing one phloroglucinol ring. All other components of filicin are di- or trimeric phloroglucides, in which the monomers are compounds close to aspidinol. Also, the dimer is flavaspidic acid and the trimer is filixic acid; the more rings, the stronger the pharmacological action. The rhizomes of the male fern, in addition to phloroglucides, contain starch, sugar, tannins, fatty oil (up to 6%) and volatile fatty acids and their esters (butyric acid, etc.).

Medicinal raw materials - rhizomes covered with numerous bases of leaf petioles, with the lower part of the rhizome removed and without adventitious cord-like roots. Rhizome up to 25 cm long, up to 7 cm in the thickest part, bases of petioles 3-6 cm long, 6-11 mm thick, cylindrical, tiled obliquely upwards. At the upper end of the rhizome are cochlear-shaped folded leaf buds. The bases of petioles, especially leaf buds, are densely covered with rusty-brown membranous scales. The rhizomes and bases of the petioles are dark brown on the outside, and light green in the break. The smell is weak, peculiar. The taste is initially sweetish-astringent, then sharp, nauseating. No more than five percent of the male fern is not of standard condition - brown inside and not completely peeled. The content of raw filicin in the rhizomes of the male fern depends on the variety of the fern, the region of its harvest, and the vegetation phase. Harvested late summer and autumn. At this time, the rhizomes give the greatest raw mass. The content of crude filicin must be at least 1.8% (GF X). For medical purposes, raw materials are suitable that have retained the light green color of rhizomes and petioles (in a break). Shelf life is not more than 1 year in dry, dark rooms.

Active substances - phloroglucides are contained in the glands, called Mine cells. The glands are unicellular, mushroom-shaped, located in the intercellular spaces, going into them with their heads.

Inadmissible impurities are the rhizomes of the female fern and ostrich. The female fern (Athyrium filix femina Roth.) has delicate leaves, tripartitely dissected, with small segments. The sori are oblong or crescent-shaped (in the male fern, the sori are reniform-round). The rhizome and leaf petioles are almost black on the outside, the petioles are trihedral in shape with two large pillars, there are no shaft cells, the scales are entire.

Ferns of the genus Dryopteris contain more or less phloroglucides. This circumstance prompted us to investigate some of them, which have large rhizomes. The most promising of them are the following.

Podalpine fern (Dryopteris oreados Fom.). An endemic species, widespread in the mountain forests of the Western and Central Caucasus at an altitude of 1200-2700 m above sea level. The leaves are oblong-lanceolate or narrow-lanceolate, doubly pinnate, up to 60 cm long, with very short petioles - up to 5 cm (in the male fern, the leaf blade begins at a height of 20-25 cm from the rhizome). Segments of the 2nd order are oblong, contiguous, obtuse, finely dentate, with hairlike films. The rhizomes are as large as those of the male fern (up to 25 cm long, up to 7 cm thick, dry weight up to 160 g). They are also indistinguishable by the number of pillars in the petioles and along the edge of the films, which have the same double teeth. Needle fern (Dryopteris spinulosa O. Kuntze). Differs in the triangular outline of the leaf blade. The dissection is doubly-triple-pinnate, segments of the 1st order are unequal-sided, the denticles of the latter are elongated into a soft needle (a very characteristic sign). Rhizomes are small - from 2 to 10 cm long, dry weight no more than 15 g. Films are also a diagnostic sign. They are small, monochromatic (light brown), along the edge there are small capitate glands. polymorphic look.

Austrian fern (Dryopteris austriaca Woy). Polymorphic appearance, with triangular-shaped leaves and pronounced unequal-sideness of leaf lobes of the 2nd order. Rhizomes are large; the content of crude filicin, according to some authors, approaches its content in the male fern. Scales with a wide longitudinal black stripe are very characteristic.

Application. From the rhizomes of the male fern, freshly picked and dried, a thick extract is prepared, obtained by extraction with ether. The drug is an effective antihelminthic agent for tapeworms (storage - list B).

phenolic compound pharmacological plant

PHENOLIC COMPOUNDS - substances of an aromatic nature that contain one or more hydroxyl groups associated with carbon atoms of the aromatic nucleus. Among secondary products

Phenolic compounds are the most common and characteristic of every plant and even every plant cell. According to the number of OH groups, monoatomic (for example, phenol itself), diatomic (pyrocatechin, resorcinol, hydroquinone) and polyatomic (pyrogallol, phloroglucinum, etc.) phenolic compounds are distinguished.

Phenolic compounds can be in the form of monomers, dimers, oligomers and polymers; the classification of natural phenols is based on the biogenetic principle. In accordance with modern ideas about biosynthesis, they can be divided into several main groups:

• compounds of the C 6 -series - simple phenols;
• compounds C 6 - C 1 -series - derivatives of benzoic acid (phenolic acids);
• compounds C 6 - C 2 -series - phenol alcohols and phenylacetic acids;
• compounds C 6 - C 3 -series - derivatives of phenylpropane (hydroxycinnamic acids and alcohols, coumarins);
• compounds C 6 - C 3 - C 6 -series - flavonoids and isoflavonoids;
• compounds C 6 - C 3 - C 3 - C 6 -series - lignans;
• anthracene derivatives;
• polymeric phenolic compounds - lignin, tannins, melanins.

Phenolic compounds are colorless or colored crystals or amorphous substances with a characteristic odor, less often liquids, readily soluble in organic solvents (alcohol, ether, chloroform, ethyl acetate) or in water. Possessing acid properties, they form with alkalis salt-like products - phenolates. The most important property of phenolic compounds is their ability to oxidize with the formation of quinone forms. Polyphenols are especially easily oxidized in an alkaline environment under the action of atmospheric oxygen. Phenols are capable of producing colored complexes with heavy metal ions, which is typical for o-dioxy derivatives. Phenolic compounds enter into coupling reactions with diazonium compounds. In this case, products with a variety of colors are formed, which is often used in analytical practice. In addition to the qualitative reactions common to all phenols, there are specific group reactions.

In plants, phenolic compounds play an important role in some intermediate steps in the respiration process. Participating in redox reactions, they serve as a link between the hydrogen of the respiratory substrate and atmospheric oxygen. It has been established that some phenolic compounds play an important role in photosynthesis as cofactors. They are used by plants as an energy material for various life processes, they are regulators of growth, development and reproduction, while providing both stimulating and inhibitory effects. Known antioxidant activity of many phenols, they are increasingly used in the food industry to stabilize fats.

Preparations based on phenolic compounds are used as antimicrobial, anti-inflammatory, choleretic, diuretic, hypotensive, tonic, astringent and laxative agents.

Other definitions for the letter "F":

16. The concept of simple phenolic compounds (glycosides), their classification. Physical and chemical properties. Features of harvesting, drying, storage of raw materials. Assessment of the quality of raw materials, methods of analysis. Ways of using raw materials, medical applications.

Phenolic compounds

Natural phenolic compounds- substances of plant origin containing one or more aromatic rings with one or more free or bound hydroxyl groups.

Phenolic compounds have a universal distribution in the plant kingdom. They are characteristic of every plant and even every plant cell. Currently, more than two thousand natural phenolic compounds are known. The share of substances of this group accounts for up to 2-3% of the mass of organic matter of plants, and in some cases - up to 10% or more. Phenolic compounds are also found in fungi, lichens, and algae. Animals consume phenolic compounds in finished form and can only convert them.

Phenolic compounds play a very important role in plants. They are obligatory participants in all metabolic processes: respiration, photosynthesis, glycolysis, phosphorylation.

1. Research by the Russian biochemist V.I. Palladin (1912, St. Petersburg) established and confirmed by modern research that phenolic compounds are involved in the process of cellular respiration. Phenolic compounds act as hydrogen acceptors (carriers) at the final stages of the respiration process, and then are re-oxidized by specific oxidase enzymes.

2. Phenolic compounds are regulators of plant growth, development and reproduction. At the same time, they have both a stimulating and an inhibitory (slowing down) effect.

3. Phenolic compounds are used by plants as an energy material, perform structural, supporting and protective functions (increase plant resistance to fungal diseases, have antibiotic and antiviral effects).

Classification of phenolic compounds

The classification of natural phenolic compounds is based on the biogenetic principle. In accordance with modern concepts of biosynthesis and based on the structural features of the carbon skeleton, the following classes of plant phenols can be distinguished.

Physical and chemical properties of simple phenolic compounds

physical properties.

Simple phenolic compounds are colorless, rarely slightly colored, crystalline substances with a certain melting point, optically active. They have a specific smell, sometimes fragrant (thymol, carvacrol). In plants, they are more often found in the form of glycosides, which are readily soluble in water, alcohol, and acetone; insoluble in ether, chloroform. Aglycones are slightly soluble in water, but readily soluble in ether, benzene, chloroform, and ethyl acetate. Simple phenols have characteristic absorption spectra in the UV and visible regions of the spectrum.

Phenolic acids are crystalline substances, soluble in alcohol, ethyl acetate, ether, aqueous solutions of sodium bicarbonate and acetate.

Gossypol is a fine-crystalline powder from light yellow to dark yellow with a greenish tint, practically insoluble in water, slightly soluble in alcohol, and readily soluble in lipid phases.

Chemical properties.

The chemical properties of simple phenolic compounds are due to the presence of:

• aromatic ring, phenolic hydroxyl, carboxyl group;
• glycosidic bond.

Phenolic compounds are characterized by chemical reactions:

1. hydrolysis reaction(due to the glycosidic bond). Phenolic glycosides are easily hydrolyzed by acids, alkalis or enzymes to aglycone and sugars.

2. Oxidation reaction. Phenolic glycosides are easily oxidized, especially in an alkaline environment (even with atmospheric oxygen), forming quinoid compounds.

3. Salt reaction. Phenolic compounds, having acidic properties, form water-soluble phenolates with alkalis.

4. Complex formation reactions. Phenolic compounds form with metal ions (iron, lead, magnesium, aluminum, molybdenum, copper, nickel) complexes painted in various colors.

5. Azo coupling reaction with diazonium salts. Phenolic compounds with diazonium salts form orange to cherry red azo dyes.

6. The reaction of the formation of esters (depsides). Depsides form phenolic acids (digallic and trigallic acids).

Features of collection, drying and storage of raw materials containing simple phenolic compounds

The harvesting of raw lingonberries and bearberries is carried out in two terms - in early spring before flowering and in autumn from the beginning of fruit ripening until the appearance of snow cover. Drying air-shadow or artificial at a temperature not exceeding 50-60 ° C in a thin layer. Repeated harvesting on the same thickets is possible in 5-6 years.

Raw materials of Rhodiola rosea (golden root) are harvested in the phases of the end of flowering and fruiting. Dry at a temperature of 50-60 °C. Repeated harvesting on the same thickets is possible in 10-15 years.

The raw material of the male thyroid gland (Rhizomata Filicismaris) is harvested in autumn, not washed, dried in the shade or in dryers at a temperature not exceeding 40 °C. Repeated harvesting on the same thickets is possible after 20 years.

The raw material of cotton - root bark (Cortex radicum Gossypii) - is harvested after the cotton harvest.

Store raw materials according to the general list in a dry, well-ventilated area. Shelf life - 3 years. The rhizomes of the male fern are stored for 1 year.

Assessment of the quality of raw materials containing simple phenolic compounds. Analysis Methods

Qualitative and quantitative analysis of raw materials is based on physical and chemical properties.

Qualitative analysis.

Phenolic compounds are extracted from plant materials with water. Aqueous extracts are purified from accompanying substances by precipitating them with a solution of lead acetate. Qualitative reactions are performed with the purified extract.

Phenolic glycosides, having a free phenolic hydroxyl, give all the reactions characteristic of phenols (with salts of iron, aluminum, molybdenum, etc.).

Specific reactions (GF XI):

1. for arbutin (raw lingonberry and bearberry):

a) with crystalline iron ferrous sulfate. The reaction is based on obtaining a complex that changes color from lilac to dark purple, with the further formation of a dark purple precipitate.

b) with a 10% solution of sodium phosphomolybdic acid in hydrochloric acid. The reaction is based on the formation of a blue complex compound.

1. on salidroside (Rhodiola rosea raw material):

a) azo coupling reaction with diazotized sodium sulfacyl to form a cherry red azo dye

Chromatographic study:

Various types of chromatography are used (paper, thin-layer, etc.). In chromatographic analysis, solvent systems are usually used:

• n-butanol-acetic acid-water (BUV 4:1:2; 4:1:5);
• chloroform-methanol-water (26:14:3);
• 15% acetic acid.

Chromatographic study of alcohol extract from raw materials of Rhodiola rosea.

Thin layer chromatography is used. The test is based on the separation in a thin layer of silica gel (Silufol plates) of methanol extract from the raw material in the solvent system chloroform-methanol-water (26:14:3) followed by the development of the chromatogram with diazotized sodium sulfacyl. Spot salidroside with Rf=0.42 turns reddish.

Quantitation.

For the quantitative determination of phenol glycosides in medicinal plant materials, various methods are used: gravimetric, titrimetric, and physicochemical.

1. gravimetric method determine the content of phloroglucides in the rhizomes of the male fern. The method is based on the extraction of phloroglucides from raw materials with diethyl ether in a Soxhlet apparatus. The extract is purified, the ether is distilled off, the resulting dry residue is dried and brought to constant weight. In terms of absolutely dry raw materials, the content of phloroglucides should be at least 1.8%.

2. Titrimetric iodometric method used to determine the content of arbutin in raw lingonberries and bearberries. The method is based on the oxidation of hydroquinone aglycone to quinone with a 0.1 M iodine solution in an acid medium and in the presence of sodium bicarbonate after obtaining a purified aqueous extract and acid hydrolysis of arbutin. Hydrolysis is carried out with concentrated sulfuric acid in the presence of zinc dust, so that the released free hydrogen prevents its own oxidation of hydroquinone. A starch solution is used as an indicator.

3. Spectrophotometric method used to determine the content of salidroside in the raw materials of Rhodiola rosea. The method is based on the ability of colored azo dyes to absorb monochromatic light at a wavelength of 486 nm. Determine the optical density of the colored solution obtained by the reaction of salidroside with diazotized sodium sulfacyl, using a spectrophotometer. The content of salidroside is calculated taking into account the specific absorption rate of GSO salidroside E 1% 1 cm = 253.

Ways to use raw materials containing simple phenolic compounds

Raw lingonberries, bearberries, Rhodiola rosea are dispensed from a pharmacy without a doctor's prescription - order of the Ministry of Health and Social Development of the Russian Federation No. 578 dated September 13, 2005 - as medicines. The rhizomes of the male fern, rhizomes and roots of Rhodiola rosea, the bark of cotton roots are used as raw materials for the preparation of finished medicines.

From medicinal plant materials containing phenol glycosides, get:

1. Extemporaneous dosage forms:

• decoctions (raw lingonberries, bearberry, Rhodiola rosea);
• fees (raw lingonberry, bearberry, Rhodiola rosea).

2. Extraction (galenic) preparations:

Extracts:

• liquid extract (rhizomes and roots of Rhodiola rosea);
• thick ethereal extract (male fern rhizomes).

3. Novogalenic preparations:

• "Rodascon" from the raw materials of Rhodiola rosea.

4. Preparations of individual substances:

3% gossypol liniment and eye drops - 0.1% solution of gossypol in 0.07% solution of sodium tetraborate (cotton root bark).

Medical use of raw materials and preparations containing simple phenolic compounds

1. Antimicrobial, anti-inflammatory, diuretic (diuretic) the action is typical for raw lingonberries and bearberries. It is due to the presence of arbutin in the raw material, which, under the influence of enzymes of the gastrointestinal tract, is broken down into hydroquinone and glucose. Hydroquinone, excreted in the urine, has an antimicrobial and irritant effect on the kidneys, which causes a diuretic effect and anti-inflammatory effect. The anti-inflammatory effect is also due to the presence of tannins.

Apply dosage forms from the raw materials of cranberries and bearberries for the treatment of inflammatory diseases of the kidneys, bladder (cystitis, urethritis, pyelitis) and urinary tract. Decoctions of lingonberry leaves are used to treat diseases associated with impaired mineral metabolism: urolithiasis, rheumatism, gout, osteochondrosis.

Side effect: when taking large doses, an exacerbation of inflammatory processes, nausea, vomiting, diarrhea is possible. In this regard, the intake of dosage forms from the raw materials of lingonberry and bearberry is recommended to be carried out in combination with other plants.

2. Antiviral the action is characteristic of phenolic compounds in the bark of cotton roots. "Gossypol" is used in the treatment of herpes zoster, herpes simplex, psoriasis (liniment); with herpetic keratitis (eye drops).

3. adaptogenic, stimulating and tonic the action is exerted by preparations of rhizomes and roots of Rhodiola rosea. The drugs increase efficiency in case of fatigue, performing hard physical work, have an activating effect on the cerebral cortex. Phenolic compounds of Rhodiola are able to inhibit lipid peroxidation, increasing the body's resistance to extreme stress, thereby exhibiting an adaptogenic effect. Used to treat patients with neurosis, hypotension, vegetative-vascular dystonia, schizophrenia.

Contraindications Key words: hypertension, fever, agitation. Do not prescribe in the summer in hot weather and in the afternoon.

Contraindications: disorders of the circulatory system, diseases of the gastrointestinal tract, liver, kidneys, pregnancy, do not prescribe to children under the age of two years.