Saponins - what is it? Description, description

Saponin chemicals (also glycosides, saponizides or heterozides) are derivatives of triterpenoids and steroids. They have surface and hemolytic activity, and are also toxic to cold-blooded animal species. Saponins are divided into triterpene and steroid. They are contained in stems, leaves, flowers, roots and fruits of plants. These substances consist of carbohydrates and aglycons.

Description and characteristics

Any saponin, whose properties have several characteristic features, has a marked effect on biological organisms. This substance causes hemolysis of erythrocytes and forms cholesterol (because of this the erythrocyte membrane loses its semipermeability). The action of saponins leads to the entry of hemoglobin into the blood. As a result of this effect, the work of the gills is disrupted in cold-blooded animals.

Many organisms perish from the poison, which secrete saponins. What it is? These compounds are amorphous or crystalline hygroscopic substances of a yellowish hue (or colorless). Saponins are characterized by high melting and decomposition temperatures. They are able to lower the surface tension, due to which, when shaken, their aqueous solutions form an abundant stable foam. In chloroform, benzene and diethyl ether, siponins are insoluble. Otherwise, the situation is with water, ethanol and methanol. In these hydrophilic solvents, saponins are soluble in the case of a high content of monosaccharides in their molecules.

Examples of saponin in nature

Not a single family of plants contains saponins. In total, scientists have about 40 similar species groups. Cells of such plants contain dissolved saponins. What it is? Most often this is part of the chemical composition of underground plants. Triterpene saponins are characteristic of clove, aral, legume, blue-eyed, sedimentary, conchascant, rosaceous, etc. These are such common plants as licorice, ginseng or, for example, aralia.

Steroid saponins are part of plants belonging to the families of lily, nymph, agave, dioscoreal, etc. This group includes sarsaparilla, digitalis and dioscorea.

It is interesting that representatives of the plant world allocate saponins for their own protection against pathogens. So, glycosides stimulate the rate of their growth, resistance to stress and improve germination. By means of saponin, the composition of carotenoid pigments participating in photosynthesis changes. The substance can be produced in leaves, from where it is transported through the rest of the plant. A useful compound is stored in special cells of stems and epidermis. In the end, it falls into the rhizome responsible for vegetative reproduction. Saponins are produced with increased speed in case of damage to plant tissues.

Hydrolysis and monosaccharide content

Biological saponins in plants are hydrolyzed by acids. They can form molecular complexes with lipids, sterols, proteins and phenolic compounds. Saponins (more precisely, their carbohydrate moiety) contain from 1 to 11 monosaccharides. Depending on this amount, the substance belongs to a certain type: oligosides, pentosides, triosides, biosides, monosides.

Most often they contain substances such as D-xylose, D-glucose, D-galactose, L-arabinose, L-rhamnose, etc. Such elements include saponins. What it is? Monosaccharides are organic compounds that form carbon chains that can be branched or linear. Steroidal saponin species consist of 1-5 such elements, while triterpenes can number 10 or even more.

Extraction of saponins

The production of saponins from the original natural raw material is carried out in several stages. First, extraction takes place (transferring components from a solid to a liquid with a solvent). Then the obtained substance is purified and separated.

For extraction, polar solvents - ethanol and methanol with different concentrations are used. A solution of sodium chloride is also used. In some cases, before extraction, the raw material is treated with ether and carbon. Without this procedure, it is impossible to destroy complex soluble complexes including saponins, proteins, sterols and phenolic compounds.

Cleaning

The method for purifying the saponins obtained depends on their structure. For example, polar species are poorly soluble in methyl and ethyl alcohol, and upon cooling or addition of ethanol they form a characteristic precipitate. Otherwise, the situation is with glycosides. They precipitate after dilution with water of alcohol extracts, and also dissolve poorly in the water itself. It is necessary to alkali to purify triterpene saponins. Also on them acts acetone, diethyl ether, ethyl acetate, isoamyl and butyl alcohols.

Other purification methods are based on the property of saponins to create salt-insoluble salts together with lead acetate or barium hydroxide. After the preparation of such complexes, they are decomposed. Such methods are necessary in order to form the purest saponins. What it is? These are the most qualitative and impurity-free components with a homogeneous composition.

Chromatographic separation

Any plant substances (eg flavonoids, saponins, etc.) require careful treatment. When they are cleaned, in addition to the methods already described, chromatographic separation is often used today. In this case, solvents such as acetic acid, n-butanol, chloroform, aqueous ammonia, n-propyl alcohol, methanol, etc. are used.

Following the preliminary chromatographic separation, treatment with acidic reagents-phosphoric-molybdic acid, antimony pentachloride, etc., begins. As a result, saponins form polyenes-conjugated unsaturated compounds. They can be painted red-violet or pink (depending on the structure of the substance).

Application

Saponins are used for a variety of purposes. For example, they are added to the foaming agent in fire extinguishers (due to the fact that these substances form a copious foam). Saponins are also included in the composition of suspensions and emulsions, thereby stabilizing these disperse systems. Substances of this group differ in emulsifying properties, which makes them a useful component of soap.

Saponins are used in the preparation of certain beverages (for example, beer), as well as confectionery (halva). They are produced as dietary and nutritional supplements. They are also used in medical devices (sedatives, tonic, expectorants, vaccines, etc.). Despite the therapeutic benefits, saponins due to their toxicity require caution when used.

Use in pharmacology

Saponins of licorice have long been known for their anti-allergic and anti-inflammatory effects. Preparations based on them can be a powder, a syrup or an extract. The licorice root is the basis of pills. It is added to improve the taste of medicines and preparations. Licorice is used in the case of viral infections of the skin and genitals, as well as in lichen.

The most useful part of saponins from the point of view of pharmacology is glycyrrhetin and glycyrrhizic acid. On their basis, drugs are produced that help in the fight against bronchial asthma. Another useful component is flavonoid. These compounds are part of flacarbine and lyciritone, which have antiulcer, antisecretory, antispasmodic and anti-inflammatory effects. These drugs are used in cases of gastric ulcer and duodenal ulcers or gastritis.

The beneficial effect of ginseng has been known in the East for several millennia, where this plant has become a popular medicinal product and is symbolically called the "root of life". In China and Korea it is used in cooking. The roots of ginseng have a tonic and stimulating effect, they are used as an adaptogen. The agents based on these reagents are used in the treatment of the adrenal glands. The concentration of saponins in ginseng reaches a maximum when the plant reaches the age of six.

Influence on the human body

Like alkaloids, saponins have an impact on human health. When ingested in the oral cavity or on the mucous membranes of the nose and eyes, they cause irritation. An intensive secretion of the glands begins, which helps to get rid of sputum and helps the bronchi. However, the concentration of saponins for the human body may be excessive. In this case, irritation of the intestine and stomach occurs. The toxic effects of these substances lead to vomiting, nausea, dizziness and diarrhea.

Saponins are useful as substances, due to which other drugs are quickly absorbed into the human body. Their action depends on the particular plant. In addition to the already mentioned effects, they can have antiulcer, mild laxative, adaptogenic, corticotropic and diuretic effect.

Raw materials

One of the most frequent sources of raw materials for isolating saponins is the Manchu aralia. It is a small and fast-growing tree with a height of 3 to 6 meters. It is distinguished by a superficial root system and looks like a palm tree. The plant is distributed in the Far East of Russia, including Khabarovsk Territory, Primorsky Krai and the Amur Region.

Saponins are found in the roots of aralia. When they are harvested, plants aged 5 to 15 years are used. Roots are harvested in autumn or spring before opening the leaves. They dig them out with crowbars and shovels. Then, drying is required, most often it is carried out in special dryers, the temperature in which reaches 60 ° C. The shelf life of such raw materials is three years.