RU2473356C1 - Method for preparing aqueous extracts of crude drugs rich in active extractants - Google Patents

Abstract

FIELD: medicine, pharmaceutics.

SUBSTANCE: invention refers to cosmetic and pharmaceutical industry, particularly a method for preparing an aqueous extract of crude drugs. The method for preparing an aqueous extract of crude drugs rich in active extractants consisting in the fact that ground, dried or fresh crude drugs are placed in a vapour vessel provided in a thermostat oven; crud drugs are heated with temperature gradually increased, and the vapour vessel cooled in certain environment.

EFFECT: aqueous extracts prepared by the method described above are rich in active substances and have a long shelf life without loss of desired biological activity.

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Description

The invention relates to the cosmetic and pharmaceutical industries, for the extraction of active substances from plants, in particular medicinal plants, by obtaining aqueous extracts from plants.

Methods for the isolation of active (biologically active) substances from plant materials, in particular medicinal plants, by extraction of both aboveground and underground parts of these plants are widely known in the pharmaceutical, cosmetic, food, and medical industries.

Plants and plant organisms serve as an important source of active compositions and compounds used in medicine. New plants, new compounds from plants or even modifications of compounds found in plants are of great interest for phytocosmetics and phytomedicine.

The methods used in the extraction of components from plant organisms and plants are of great importance not only in terms of the yield of the obtained compounds, but also in the chemical nature of those compounds that can actually be obtained.

Conventional methods used in the phytochemical industry are based on extraction from crushed plants or plant organisms with water or steam, an organic solvent or a mixture of water and organic solvents such as water and alcohols. The inclusion of a maceration step is also well known in the art. Finally, the separation of the aqueous extract from the solid phase is carried out by conventional methods, such as decantation, centrifugation or filtration. Additional chemical treatments may also be used to modify the structure of compounds found in plants. Further information on this topic can be found in: Dr. Pio Font Quer, Medicinal Plants. The updated Discorides »Ed. Labor, SA, 12 ^fh Edition, 1990.

French patent FR 2733419, 10.31.1996, describes the preparation of extracts from a mixture of at least three different plants selected from the genera Geranium, Plantago and Calendula by soaking 300-400 g of fresh leaves of Geranium robertanium, 10-50 g of dry leaves Plantago lanceolata and 10-50 g of dry leaves of Calendula officinalis in 3 l of water at 15-30 ° C for 3-15 days. According to FR 2733419, the composition obtained in this way finds use in the treatment of cancer. The activity of these extracts was unsatisfactory.

European patent application EP 0934746 A, 08/11/1999, discloses a method for producing an aqueous extract from plants of the genera Geranium and Plantago, as well as from the species Calendula officinalis, in which these extracts are obtained from the following amounts of these plants in water: 10-60 g of Geranium sibiricum or fresh Geranium sibiricum, 10-60 g of dry Plantago lanceolata and 10-60 g of dry Calendula officinalis in 300 g of water. A method of obtaining these aqueous extracts involves soaking the crushed plants in water before press filtering the mixture and subsequent centrifugation. According to EP 0934746 A, this extract can be used in cancer practice as part of a cancer therapy program.

From RU 2265448, 12/10/2005, there is a known method for producing aqueous extracts from plants, consisting of the following stages:

a) removal of contaminants from plants;

b) crushing the plant;

c) laser treatment of the shredded plant;

d) suspending the mixture obtained in step c in water;

e) maceration of the suspension obtained in stage d; *

f) separating the resulting liquid.

* The suspension can withstand from 5 to 20 days at temperatures from 2 ° C to 10 ° C, while the mixture is macerated. The obtained extracts are used as immunostimulants in the treatment of hepatitis C, i.e. only in medicine, the method is quite complicated.

The method can be applied to any type of plant, either single or dicotyledonous. It can be applied to mixtures of various plants. The whole plant may undergo treatment by the method of the invention, although leaves and flowers are preferred.

Scientists of the St. Petersburg Forestry Engineering Academy have developed a new approach to the use of deciduous woody greenery (birch, aspen, alder) and created the basis for the production of biologically active substances. The extraction of biologically active substances is carried out simultaneously by gasoline and water, followed by separation into solutions of gasoline and water-soluble substances. After the wax is separated from the purified gasoline solution, an extract of polar lipids, a suspension of metalless chlorophyll analogues, an essential oil and a provitamin concentrate are obtained

(Yagodin V.I. Woody greens: universal waste-free technology // Tr. Scientists of the Faculty of Chemistry and Technology of St. Petersburg State Technical University. - St. Petersburg, 2001).

A known method of obtaining a decoction from the collection of diuretic No. 2, consisting of the leaves of bearberry ordinary 40 g, fruits of juniper ordinary 40 g, licorice roots Ural 20 g (radar, 2002, issue 4. S.876).

To prepare the broth, the crushed collection in a ratio of 1:20 is poured with room temperature water, taken into account the coefficient of water absorption, in an appropriate container and insisted on a boiling water bath with frequent stirring for 30 minutes. Filter and add water to the required volume of extraction (GF XI, issue 2. S.147-148).

A known method of obtaining the sum of extractive substances with diuretic activity, including extraction of plant materials with ethyl alcohol in the ratio of raw materials: extractant 1: (10-14) three times for 60 minutes, followed by evaporation of the combined extracts, separation and drying (RF patent No. 1737797, 30.11. 1994).

A disadvantage of known sources is the low yield of extractive and active substances.

In addition, the use of organic solvents during extraction, as a rule, involves the subsequent purification of the extract from the solvent; however, the cleaning process is quite complicated, and it is not always possible to completely remove the solvent from the extract.

Currently, alcoholic extracts from plants are widely distributed: tinctures, extracts. But they also have significant drawbacks. During extraction, ethyl alcohol is not only not extracted, but also precipitates many classes of natural compounds, including polysaccharides, polypeptides, proteins and oligopeptides. Alcohol well dissolves simple and organic compounds, for example polyphenolic, which may not be integral components.

Therefore, during extraction in alcohol, an insignificant part of the biologically active substances found in plants is ultimately used; therefore, the use of structured water as an extractant allows one to obtain more biologically active substances.

So, to increase the efficiency of water extraction, the use of ammonia is proposed, which increases the yield of aralia and ivy saponins by 10-20% (RF patent 2395515, RF patent 2395516).

It is known to use "structured water" for conducting water extraction (RF patent 2232026). It is proposed to use the juice of vegetables: cucumbers and tomatoes as structured water in this patent. This method does not seem effective, since the juice of these vegetables by itself has a certain biological activity, which can erode the cosmetic and pharmaceutical effects of the use of these extracts in cosmetic and pharmaceutical preparations. Also, this method seems to be ineffective from an economic point of view.

There is also known a method of increasing the efficiency of water extraction by exposure to the extraction mixture of high voltage electric pulses (2191520). However, this can lead to the destruction of a large number of active components, which are inherently unstable compounds.

RU 2216574, November 20, 2003 describe a method for intensifying the process of extraction of valuable active substances from plant materials. The method consists in the extraction of valuable substances from plant materials using microwave energy, while the extraction is carried out by steam of water, which is part of the raw materials and heated by microwave energy, the raw materials are loaded into a dielectric chamber in which it is not mixed, not crushed and retains its isotropy and integrity of the capillaries, while cylindrical dielectric containers pre-loaded with raw materials are placed horizontally in the dielectric chamber, and the chamber rotates at a speed of 2-10 rpm, at The radiation of raw materials is carried out using an antenna system with a radiation pattern of microwave radiation, in which the electric field is directed parallel to the axis of the camera.

Plants containing various essential oils, i.e. etheriferous plants, mainly plant leaves. The method has a limited change and is quite difficult to implement. From SU 1629019, 02.23.1991, a method is known for the extraction of plant materials in order to obtain liquid concentrates of non-alcoholic (food) drinks.

A liquid concentrate is obtained from rosehip leaves by extraction with hot water, filtration, concentration and sterilization of the concentrate. The extraction is carried out with hot water at 90-100 ° C for 35-50 minutes and a ratio of solid and liquid phases from 1: 8 to 1:10 of freshly collected raw materials dried at 30-90 ° C, followed by concentration of the extract to a solids content in the range of 15 -75%. 10-20% of the total sugar is added to the extract, and 1-3% of the total number of aromatic plants such as mint, linden flowers, rose hips and others are added to obtain a flavored concentrate.

The method has limited use, does not allow extraction of valuable active substances.

From SU 515518, 01/27/1977, a method is known for extracting liquid soluble products from plant materials used as herbal preparations from medicinal plants in the food industry.

Plant materials (according to this known method) are placed in a closed volume and solvent vapor (for example, water vapor) is pumped into it, while bleeding air from the volume. Thereby, the solid is placed in solvent vapor. Substitution in the pores of the solvent first occurs by heating the solid and air in its pores and capillaries with steam. The heated air in the solid and the solid itself expand, and, since the walls of plant materials are harder than the surrounding medium - steam, the air from the pores is partially forced out into the vapor medium surrounding the raw material, and a vaporous solvent enters into the pores and capillaries. However, the solvent vapor surrounding the raw material (solid) itself creates some pressure in the volume, therefore, with a simple placement of the raw material in the vapor, part of the air remains in the pores and capillaries of the raw material. For a more complete replacement of air in the pores and capillaries of the raw material, the pressure of the medium surrounding the raw material (solid - plant material) is lowered.

To do this, the steam is condensed, for example, by injecting a liquid agent (for example, cold sprayed water) into the vapor medium, and a vacuum of about 400 mm Hg is created.

For the almost complete extraction of the useful substance from the solid (until the solid is almost completely depleted), the pressure of the medium surrounding the raw material is increased and decreased repeatedly, approximately five times, i.e. bring the liquid solvent to boil in the pores and capillaries of the solid five times.

The method is technologically sophisticated and does not allow efficiently enough to provide extracts with a high content of active substances.

The technical task of the claimed invention is to increase the yield of biologically active substances from plant materials, increase the duration of storage of extracts, which increases the efficiency of their use while simplifying the process of extracting these active substances and expanding the arsenal of tools used to extract biologically active substances from plant materials.

The technical task is achieved by the claimed method of obtaining aqueous extracts from plant materials with a high content of active substances. The method consists in sequentially carrying out the following stages:

a) vegetable raw materials, possibly crushed, dried or fresh, are placed in a pressure vessel placed in a thermostat;

b) carry out heating of the raw materials with a gradual increase in temperature from 20 ° C to 40 ° C for 2 hours;

c) carry out subsequent heating with a gradual increase in temperature to 80-90 ° C for 4-8 hours;

g) cool the pressure vessel with plant material for 2-8 hours.

In this case, before or after carrying out stage (c), the extractable raw material is held in a pressure vessel for about 1 hour at a temperature to which the vegetable raw material is heated at the initial heating stage (b). Separation of the aqueous extract from the used plant material was carried out using a standard nuch filter.

In the present invention, the term “plant material” is understood to mean one or more plants of the same species, or several plants of different species, or any part or parts of plants, such as stems, leaves, flowers, fruits.

The following examples illustrate the invention, but do not limit it. The time indicated in the examples as “about” should be understood as “approximately”, for example about 2 hours — this is 1 hour 55 minutes, 1 hour 57 minutes; 2 h 3 min, 2 h 5 min, etc.

Example 1

The ascorbic acid was extracted from plant material - common viburnum. Raw materials were obtained from central Russia. In a pressure vessel 12 l capacity was loaded with 1 kg of fresh raw materials - the fruits of viburnum. Next, the pressure vessel was placed in a thermostat furnace and the process was carried out in the following temperature mode: during the hour, the temperature was raised from 20 to 40 ° C for 2 hours. Then, it was held at 40 ° C for 1 hour, and the temperature was raised to 80 ° C over 4 hours. Next, cooling was carried out to 20 ° C for 2 hours. Quantitative determination of vitamin C was carried out according to the method of Tilmans [Ermakov A.I., Arasimovich V.V., Smirnova-Ikonnikova M.I. and other Methods of biochemical studies of plants. L .: 1972. 283 p.]. The following vitamin C content was determined - 150.8 mg / 100 g of fresh fruits.

Example 2 (Control, comparative)

Conducted water extraction of fresh fruits of viburnum using the decoction method. In a container of 12 l was loaded 1 kg of raw materials. Boiled for 4 hours, then cooled to room temperature. The determination of vitamin C in the decoction was determined analogously to example 1. The content of vitamin C was 63.0 mg / 100 g of fresh raw materials. Thus, the yield of vitamin C was 2.4 times lower than in Example 1.

Example 3

Water extraction of dry raw materials of the aboveground part of the cornflower (Thalicfrum minus L) was carried out by the proposed method of steam. In a pressure vessel with a capacity of 12 l was loaded 1 kg of dry raw materials of the above plants. Next, the pressure vessel was placed in an oven-thermostat, the process was carried out in the following temperature regime: the temperature was increased from 20 ° C to 40 ° C for 2 hours. Then, within 1 hour, the temperature was increased to 85 ° C and kept for 1 hour, after which it was reduced to 20 ° C for 8 hours. The content of active substances in the obtained vapor was determined by HPLC on a STAYER liquid chromatograph on a Luna C18 reverse-phase column. The following results were obtained (all percentages are referred to as a.m.): easily hydrolyzable polysaccharides 21.1%, hard hydrolyzable polysaccharides 10.3%, lignin 8.1%, protein 1.0%. In the composition of poly- and monosaccharides found: glucose 6.2%, galactose 4.2%, arabinose 0.8%, xylose 4.2%. In addition, saponins 0.2%, flavonoids 0.05%, vitamin C 0.005%.

Example 4 (Control, comparative)

Water extraction of dry raw materials of the aboveground part of the cornflower (Thalicfrum minus L) was carried out by the proposed method of boiling. In a cooking vessel with a capacity of 12 l, 1 kg of dry raw material of the above plant was loaded. Next, boiling was carried out at the boiling temperature of the mixture for 8 hours. The content of active substances in the resulting broth was carried out by the method described in example 3. Received: easily hydrolyzable polysaccharides 10.5%, hard hydrolyzable polysaccharides 8.7%, lignin 10.7%, protein 0.5%. In the composition of poly- and monosaccharides found: glucose 5.8%, galactose 3.6%, arabinose 0.4%, xylose 4.1%. In addition, saponins 0.1%, flavonoids 0.04%, vitamin C 0.002%.

It can be seen from the above example that there is a noticeable drop in the concentration of all controlled components, with the exception of lignin, which does not exhibit biological activity that is useful to us.

Example 5

Water extraction of weeping birch leaves (Betula pendula Roth) was carried out using the steam method. Samples of raw materials for extraction were taken in the south of the Moscow region. The feed was dried to an air dry state at 20-15 ° C. In the extract, water-soluble phenolic compounds were determined, which are of interest for the manufacture of cosmetics. The loading of the steam vessel with crushed raw materials and the temperature regime of evaporation are similar to Example 3. The determination of water-soluble phenols was carried out by the Swain-Hillis method [Swain J., Hillis W.E. // The phenolic constituents of prunus domestica. The quantitative analysis of phenolic constituents. // J / Sci. Food and Ags. 1959. V. 10. N1. P.63-68]. The phenol content was 2.5 mg / 100 g of feed.

Example 6 (Control, comparative)

Water extraction of weeping birch leaves (Betula pendula Roth) was carried out by boiling. The raw materials were taken similarly, as described in example 5. The loading of the cooking vessel and the temperature mode of evaporation are similar to example 5. The phenol content was 1.5 mg / 100 g of raw material. Thus, the extraction by the method of steam allows you to get the concentration of phenols in the extract is 1.7 higher than in the similar process of obtaining the broth.

Thus, the above examples show the effectiveness of the claimed invention as a method, its simplicity and affordability. The method allows to obtain aqueous extracts with a high content of active substances, provides the maximum reduction in thermal degradation of active substances in the extraction process. It was found that the aqueous extracts obtained by the proposed method retained the necessary biological activity for 1-1.5 years from the moment of the extraction process.

The resulting aqueous extracts are used for the preparation of various cosmetics, such as shampoos, balms, lotions, foams, mousses, creams, gels, soaps, etc., as well as pharmaceuticals (ointments, balms, infusions, etc.).

Claims (1)

A method of obtaining aqueous extracts from plant materials with a high content of recoverable active substances, which consists in sequentially carrying out the following stages:
a) the plant material is crushed, dried or fresh is placed in a pressure vessel placed in a thermostat;
b) carry out the heating of plant materials with a gradual increase in temperature from 20 ° C to 40 ° C for about 2 hours;
c) carry out subsequent heating with a gradual increase in temperature to 80-90 ° C for 1-8 hours;
g) carry out the cooling of the pressure vessel for 2-8 hours;
d) and at the same time, before or after the implementation of stage (c), the raw materials are held in the pressure vessel for about 1 hour at a temperature to which the raw materials are heated at the initial stage (b) of heating.