RU2346941C2 - Method of dihydroquercetin extraction from larch wood, and device for method implementation - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention concerns organic chemistry, particularly method of dihydroquercetin extraction from larch wood, and can be applied in chemical and pharmaceutical industry, medicine, food industry. Invention claims method of dihydroquercetin extraction from milled larch wood by extraction with organic solvent. Wood is milled into chips, extraction is performed gradually in several stages in at least two extractors, maintaining continuous circulation of one minimal extraction solvent volume required for chip submersion in liquid medium at each stage, simultaneously generating low-frequency oscillating field at temperature close to boiling point of solvent, with further hot extract transport after completion of process at one stage in one extractor volume to the next extraction stage, each time adding new extraction solvent in amount equal to solvent outflow with extracted chips. Then each extracted chip portion is flushed with one minimal solvent volume required, extracts from the last n extraction and flushing stages are combined into one volume, solvent is separated from it, remains are concentrated, and dihydroquercetin is extracted. Invention also claims aggregate for dihydroquercetin extraction from larch wood, including feeding tank, heater, extraction solvent collector and at least one extraction solvent processing lines with further dihydroquercetin extraction from it, each line including inlet and outlet valves, extraction reactor and pulp pump and carrying solvent vapour condenser, heater for solvent heating and low-frequency oscillator in the form of diaphragm pump mounted on pipeline. Each extractor is active periodically and is connected to feeder tank outlet by one of inlets, to extract feed unit by the other inlet over first inlet valve, to condenser inlet by one of outlets. Condenser outlet is connected over second inlet valves to another inlet of each extractor, the other extractor outlet connected to third inlet of each extractor over a sequence of heater, pump, oscillator and third inlet valve. Third extractor inlets are connected to extraction solvent collector over third pump and fourth valve.

EFFECT: reduced extraction agent expenditure.

5 cl, 2 dwg, 3 tbl, 2 ex

Description

The invention relates to organic chemistry, and in particular to a method for the isolation of dihydroquercetin from larch wood, and can be used in the pharmaceutical industry, in medicine, in the food industry.

Larch wood Larix sibirica and L. dahurica, growing in Siberia and the Far East, is a rich source of flavonoids - flavanonol dihydroquercetin 3,5,7,3 ', 4'-pentaoxiflavanone (taxifolin) and its concomitant dihydrocampferol and naringenin.

Flavonoid compounds, in particular dihydroquercetin (DHQ), have a wide range of biological properties - antihistamine, antioxidant, antiplatelet, gastro- and hepatoprotective, capillary-protective, anti-atherosclerotic, anti-inflammatory and radioprotective effects and are increasingly used in pharmaceuticals, cosmetics.

Most known methods for the isolation of dihydroquercetin from larch wood are based on extraction with various solvents. Depending on the solvent-extractant used, all known methods can be divided into three groups:

1) extraction with water and aqueous-organic mixtures;

2) extraction with water-organic mixed solvents;

3) extraction with organic monocomponent solvents.

When extraction with water due to the low solubility of DHQ in it, a very large volume of solvent is required - 8-10 parts per 1 weight part of wood. As a result, after the isolation of DHQ, a large volume of wastewater with a high content of arabinogalactan is formed, requiring neutralization or disposal. From water extracts, DHQ is extracted either by sorption on a polyamide sorbent followed by desorption with organic solvents (RF patent No. 2000797), or by extraction with organic solvents, in particular methyl tertiary butyl ether (RF patents No. 2180566 and 2233858). The disadvantages of the first method are the need to use relatively expensive polyamide sorbents not produced by the domestic industry and the presence of a large volume of wastewater. The same group includes the method of extraction of DHQ with aqueous acetone after preliminary washing of wood material with a large (tenfold) volume of water (RF patent No. 2038094) and the method of extraction with aqueous acetone without preliminary washing of the material, but with a large ratio of solvent volume to wood weight equal to 10: 1 (RF patent No. 2184561). These include the method according to the patent of the Russian Federation No. 21114331 with preliminary treatment of wood with boiling water and subsequent extraction of DHQ with acetone. They have the same disadvantages mentioned above - a large amount of wastewater and high energy consumption for the regeneration of the extractant. The second group of methods for the isolation of DHQ from larch wood include methods in which several solvents are used in the process of isolating DHQ as a stage of complex processing of wood, not counting the stages of purification of raw DHQ.

- 2 solvents (hexane and ethyl acetate, RF patent No. 2034559); hexane and ethanol, RF patent No. 2252220),

- 3 solvents (hexane, ethanol and diethyl ether, RF patents №2135510, RF №2165416, RF №2211836 and international application number WO 003779),

- and finally, 4 solvents (hexane, ethanol, ethyl acetate and diethyl ether, (RF patent No. 2164416).

The solvents are in contact with each other, and their regeneration will require enormous energy costs. In addition, their boiling points are close, they form azeotropic mixtures with water and with each other, this applies to ethanol-hexane, ethanol-ethyl acetate and others.

The last group includes methods in which monocomponent organic solvents are used and small volumes of process water are used in the process or water is not used at all. As solvents, both miscible with water (ethanol according to RF patent No. 2279284) and non-miscible substances with it (ethyl acetate according to RF patent No. 2158598) are proposed. Due to the simplicity of technical equipment and technological implementation, small volumes of used monocomponent (which is very important) solvent, these methods of extraction of DHQ reduce energy consumption and do not produce large volumes of wastewater; for these reasons, the methods of the latter group are preferable to those of the 1st and 2nd groups . That is why the prototype is taken as a means of isolating DKV according to the patents of the Russian Federation No. 2158598 and the Russian Federation No. 2279284. As previously mentioned methods, they have a common significant disadvantage in that the extractant is used once to extract one portion of wood material, and then regenerated. At the same time, due to the low mass of chopped wood per unit volume (about 300 g / l), a significant amount of the latter is required for complete immersion of wood in a solvent - 400-500 cm ³ is used for every 100 g of chopped wood.

With a low content of DHQ in larch wood (an average of 1.0-2.5%), very dilute extracts are obtained that are far from saturation with DHQ solutions. Such low-concentrated extracts, in principle, can be used for further extraction in order to obtain more concentrated solutions and thereby reduce the energy consumption for the regeneration of the solvent.

More specifically, the following should be noted.

A known method of producing dihydroquercetin described in the patent of the Russian Federation No. 2158598, class. A61K 35/78, C07D 311/32, application 04/21/1998, publ. November 10, 2000

The known method consists in the extraction of wet chopped larch wood with an organic solvent-ethyl acetate, followed by evaporation of the extract, processing it with hot water, filtering the aqueous solution from impurities and crystallizing dihydroquercetin from it, and chopped wood is saturated with water immediately before extraction, the evaporated extract is degreased with hexane or gasoline, and an aqueous solution of dihydroquercetin is filtered from impurities before crystallization.

The disadvantage of this method is the difficulty of preparing raw materials, as well as the high consumption of extractant.

For the prototype, a well-known method for the isolation of dihydroquercetin, described in the patent of the Russian Federation No. 2279284, class. A61K 36/15, application 04.03.2005, publ. 07/10/2006.

The known method consists in the fact that larch wood is crushed in the presence of an extractant - ethyl alcohol - to a particle size of not more than 0.1 mm, the resulting crushed pulp is extracted with ethyl alcohol at an extractant: raw material ratio of 3-10: 1 for 5-10 minutes at at a temperature of 22-25 ° C, then the solid and liquid phases are separated mechanically, ethanol with dihydroquercetin dissolved in it is separated mechanically, and the liquid phase is filtered, then evaporated, and a mixture of ethereal mixtures is isolated from the resulting concentrate villages and fatty organic acids for use in the cosmetic industry, and dihydroquercetin is extracted from the remaining organic phase, while the entire wood processing process is carried out at a temperature not exceeding 36 ° C.

The disadvantage of this method is that the extractant is used once to extract one portion of wood material, and then regenerated. Moreover, due to the low mass of chopped wood per unit volume (about 300 g / l), a significant amount of the latter is required for complete immersion of wood in a solvent, 400-500 cm ^{3 is} needed for every 100 g of chopped wood. In addition, the preparation of raw materials is rather complicated - grinding to 0.1 mm.

Known installations for the isolation of dihydroquercetin.

A known installation for the isolation of dihydroquercetin described in the patent of the Russian Federation No. 2211836 "Method for processing larch wood with the release of dihydroquercetin and a device for its implementation", cl. C07D 311/40, 311/32, application 04.24.02, publ. 09/10/03 and selected as a prototype.

The known installation is very complex and contains, in particular, including a line for the preparation of raw materials, including a device for chopping wood to a state of crumb size from 0 to 5 and more mm, a sieve, and a hopper feeder, a deionized water supply unit with a heater, an employee for soaking wood, an extractant-solvent supply unit and two lines for the production of water-alcohol extracts and the separation of dihydroquercetin, each of which includes a reactor-extractor of water-alcohol solutions, a pulp pump, a reaction device avitatsionnogo type flow filtration centrifuge, a collection of water-alcoholic extract, cleaning units and shut-off valves. A disadvantage of the known installation is its complexity and high consumption of extractant, in particular, due to too fine crushing of wood (see page 8 of the description of the well-known patent, paragraph 5 above).

The objective of the proposed method is to reduce the consumption of extractant and increase the efficiency of the method, and the installation task is to simplify the design while reducing the consumption of extractant and increase its efficiency. The tasks are solved in that:

- in the method for the isolation of dihydroquercetin from crushed larch wood by extraction with a monocomponent organic solvent, according to the invention, the wood is crushed to wood chips, the extraction process is carried out sequentially and multistage in at least two extractors, ensuring at each individual step continuous circulation of one minimum necessary for immersion chips in a liquid medium the volume of the solvent extract in the extractor simultaneously with the creation of a low-frequency pulsating field in it at a temperature close to the boiling point of the solvent, and transferring the hot extract after the completion of the process in one step in a separate extractor to the next extraction step, adding each time a fresh solvent extract in an amount equal to the volume of its outflow with the extracted chips, then each washed from the portions of the extracted wood chips with one minimum necessary volume of solvent, then the extracts from the last n-th extraction and washing steps are combined into one volume from which the solutions are distilled off spruce, concentrated and the residue is isolated therefrom dihydroquercetin. In this case, an azeotropic mixture of isopropyl alcohol with water or flooded ethyl acetate can be used as a monocomponent solvent;

- in the installation for the production of dihydroquercetin from crushed wood containing a hopper feeder, a heater, a solvent supply unit, a solvent extract collector and at least two solvent extract extract lines with subsequent separation of dihydroquercetin from it, each of which contains inlet and outlet valves , reactor-extractor, and pulp pump, according to the invention, a vapor condenser of the solvent extract is introduced into it, and a heater and a low-frequency pulsator are installed in each of the lines in the form a diaphragm pump installed on the pipeline, wherein each of the extractors is connected by an input through the first supply valve to the extract supply unit, one of the outputs is connected to a condenser input, the output of which through the second supply valves is also connected to the other input of each of the extractors, the output of each of which through a series-connected heater, pump, pulsator and a third supply valve connected to the third input of each of the extractors, the outputs of which through the third pump and the fourth valve are connected with a collection of extract.

The use of one and the same minimum portion of extractant for immersion of crushed wood in the liquid phase of the solvent during the extraction of two, three, and generally n servings of crushed wood in combination with the transfer of weak extracts after the first, second, and further stages as extractant to subsequent extraction stages allows as a result, to obtain more concentrated extracts, for the regeneration of the solvent from which lower total energy consumption is required, which, together with the subsequent bedineniem extracts latest stages of extraction and washing in one volume of washing, distilling off the solvent therefrom, and the concentration residue and recovering therefrom dihydroquercetin achieves the desired result. The use of an extractant-solvent and a low-frequency pulsating field at each extraction stage increases the flow rate of chips of a solid porous solid body flowing around the extractant stream, which leads to the fact that the diffusion process on the surface of the solid body transfers to the convective diffusion region, accompanied by an increase in the extraction rate and in the aggregate of these techniques allows to reduce the solvent consumption for obtaining 1 g of DHQ by about half, all other things being equal (under the same conditions Rye DHQ in wood), as well as intensify the extraction process makes it possible to reduce energy costs.

The use of larch as technological wood chips in the proposed method instead of wood crushed to particles smaller than 0.1 mm makes it possible to use commercially available equipment with a slight refinement at the extraction stage, simplify the technology for preparing raw materials and transfer the spent wood chips as a complete material to the production of wood chip fiberboards or cellulose, which also makes the process more economical.

An introduction to the installation for the separation of dihydroquercetin by the claimed method of a vapor condenser of an extract-solvent, and to each of the heater lines and a low-frequency pulsator in the form of a diaphragm pump installed on the pipeline, while each of the extractors is connected via an input through the first supply valve to the extract supply unit, one of the outputs are connected to the input of the capacitor, the output of which through the second supply valves is also connected to the input of each of the extractors, the output of each of which through series The combined heater, pump, pulsator and the third supply valve are connected to the inlet of each extractor, the outputs of which through the third pump and the fourth valve are connected to the extract collector, provides recycling of the extractant, saturating it with dihydroquercetin, intensifying the extraction process, reducing the consumption of extractant and accelerating the extraction process, which reduces energy costs with a very simple installation design.

The technical result is the intensification of the extraction process, lower consumption of extractant while reducing cost and energy costs and a very simple processing scheme.

The inventive method has a novelty in comparison with the prototype, differing from it by such essential features as chopping wood to wood chips, carrying out the extraction process sequentially and multistage in at least two extractors, ensuring at each individual step continuous circulation of one minimum necessary for immersion chips into the liquid medium of the volume of the solvent extract in the extractor simultaneously with the creation of a low-frequency pulsating field in it at a temperature close to the boiling point solvent, transferring the hot extract further at the end of the process in one step in a separate extractor to the next extraction step, adding fresh solvent extract each time in an amount equal to the outflow volume with the extracted chips, then washing each portion of the extracted chips with one minimally the required volume of solvent, combining the extracts from the last n-th extraction and washing steps into one volume, distilling off the solvent from this volume, the concentration of the residue and Highlighted therefrom dihydroquercetin providing collectively achieve the desired result.

The inventive installation has a novelty in comparison with the prototype, differing from it by such significant features as the presence of a vapor condenser of the extract-solvent, and in each of the lines - a heater and a low-frequency pulsator in the form of a diaphragm pump installed on the pipeline, the connection of each of the extractors with an input through the first supply valve with an extract supply unit, the connection of one of the outputs to the input of the capacitor, the output of which through the second supply valves is also connected to another input of each extract tori, the output of each of which through a series-connected heater, pump, pulsator and the third supply valve is connected to the third input of each of the extractors, the outputs of which through the third pump and the fourth valve are connected to the extract collector, which together ensure the achievement of a given result.

The applicant does not know the technical solutions possessing the totality of the indicated distinguishing features ensuring the achievement of the desired result, therefore, he believes that the claimed method for the isolation of digiroquercetin from larch wood and the installation for its implementation meet the criterion of "inventive step".

The inventive method and installation can be widely used in the chemical industry for the isolation of dihydroquercetin, and therefore meet the criterion of "industrial applicability".

The invention is illustrated by drawings, where:

- figure 1 is a functional diagram of an apparatus for implementing the method of isolation of digiroquercetin from larch wood;

- figure 2 - diagram of material flows during the extraction of dihydroquercetin.

The inventive method is as follows.

Larch wood is ground to wood chips. Then, the extraction process is carried out sequentially and multistage for n portions of wood, ensuring at each individual stage a continuous circulation of one minimum required volume of the solvent extract in the extractor. Simultaneously with the circulation in each extractor of one minimum necessary volume of extract, a low-frequency pulsating field is created at a temperature close to the boiling point of the solvent. Upon completion of the extraction process in one stage in a separate extractor, the hot extract is transferred further to the next stage of extraction, adding each time a fresh extract-solvent in a volume equal to the volume of its outflow with extracted wood chips. Then each portion of the extracted wood chips is washed with one minimum volume of solvent and then the extracts from the last n-th extraction and washing steps are combined into one volume from which the solvent is distilled off. The residue is then concentrated and dihydroquercetin is isolated from it.

In this case, an azeotropic mixture of isopropyl alcohol with water or flooded ethyl acetate can be used as a monocomponent solvent.

The inventive installation for the production of dihydroquercetin from larch wood (Fig. 1) contains a larch wood shredder to the state of wood chips (not shown in the drawings), a hopper feeder 1, a supply unit 2 for supplying fresh and regenerated extract-solvent, a collection of 3 extract-solvent, and at least two lines I and II of the extraction of the solvent extract and the allocation of dihydroquercetin. Each of the lines contains inlet and outlet valves 4-6 and 7 (4 ', 6' and 7 '), a reactor-extractor 8 (8') and a pulp pump 9 (9 '). Moreover, the device has a condenser 10 vapors of the solvent extract, and in each of the lines a heater 11 (11) and a pulsator 12 (12 ') are installed. Each of the extractors 8 and 8 'is connected by an input through the first supply valve 4 and 4' to the extract supply unit 2, one of the outputs is connected to the input of the capacitor 10. The output of the capacitor 10 through the second supply valves 5 and 5 'is also connected to the input of each of the extractors 8 and 8 ', the output of each of which through a series-connected heater 11 (11), pump 9 (9'), a pulsator 12 (12 ') and a third inlet valve 6 and 6' is connected to the input of each of the extractors 8 and 8 ', the outputs which through the third pump 13 and the fourth valve 7 (7 ') are connected to the collector 3 extract .

The extractors 8 and 8 'are periodically active, the condenser 10 serves to condense the solvent vapor on the overhead line, the pumps 9 and 13 are designed to provide internal circulation of the extractant in the extractors 8 and 8'. The heaters 11 and 11 'are used to heat the solvent after loading the extractors 8 and 8' and maintaining the desired temperature during the extraction process. On the extractant circulation line, low-frequency pulsators 12 and 12 'are installed, operating on the principle of a diaphragm pump.

The method of separation of dihydroquercetin is carried out using the installation as follows. The larch wood, crushed to a state of wood chips, is loaded into the extractor 8 from the hopper 1, poured with a fresh extract-solvent from node 2 and extracted at a temperature close to the boiling point of the solvent, pumping the solvent through the heater 11. At the end of the extraction process, the hot extract is transferred into the newly charged extractor 8 '. In the case of using a solvent immiscible with water, the aqueous layer is separated in the course of pumping. The required amount of fresh solvent is added to the extractor 8 'to replenish its selection with the extracted wood in the extractor 8. Then, an extraction process is carried out in the extractor 8'. At this time, the extractor 8 is washed with solvent in the extractor 8, the solvent is blown away from the spent chips, the latter is unloaded, and fresh chips are loaded.

In the extractor 8 prepared for operation, the hot extract is transferred from the extractor 8 ′ and the extraction process is performed in the extractor 8. Subsequently, the obtained extract is transferred to the extractor 8 ′; thus the process is repeated a total of n times. Diagram of material flows of the process of extraction of dihydroquercetin by the present method is shown in figure 2. At the end of the nth stage of the extraction process, the liquid streams from the extraction of chopped wood are combined and sent for processing to isolate dihydroquercetin. Spent shredded wood (wood chips) can be further used in the production of particle boards, fiberboards or cellulose.

The extraction process is carried out in batch mode using one minimum amount of solvent to extract two, three and, in general, n portions of chopped wood and then washing these n portions of extracted wood with the minimum required volume of solvent, combining the extracts from the last n stages of extraction and washing and using them to isolate dihydroquercetin.

From the combined extracts from the extraction of ground wood and washing of the extracted ground wood obtained with water-miscible solvents, the solvent is distilled off, the aqueous residue is concentrated and dihydroquercetin is isolated from it. From the combined extracts obtained with water-immiscible solvents, the solvent is distilled off and dihydroquercetin is isolated from the dry residue.

When using a solvent immiscible with water, water is separated from the extract in the next step. As an extractant, monocomponent or water-immiscible solvents with a boiling point of ≤80 ° C are used. It can be an azeotropic mixture of isopropyl alcohol with water or flooded ethyl acetate.

Examples of a specific implementation of the method using an isopropyl alcohol-water azeotropic mixture (IPA-azeotrope), a water-miscible solvent and water-saturated ethyl acetate, a water-immiscible solvent, inexpensive, affordable and low toxicity solvents are given below.

In the experiments, crushed larch wood of a fraction of 5-20 mm with a content of DHQ of 2.05% per a.s.d. and humidity 25-40% rel.

Examples of experiments.

100 g a.s. chips are loaded into the flask under reflux, pour 500 cm ^{3 of} solvent and boil for 6 hours. After this, the solvent is carefully decanted from the chips, its volume is measured, a portion of the solvent that is missing up to 500 cm ^{3 is} added to it, and the resulting amount is transferred to the processing of a new portion of 100 g of fresh wood. The extracted wood chips from the first stage are poured with 500 cm ^{3 of} fresh solvent, boiled for 1-2 hours and the washing extract is drained. Further, it is used to wash the extracted wood chips from the second, third extraction stages. The sequence of operations is visible from the scheme of material flows (figure 2). In the extracts of the main stream of extraction and washing after each stage, the content of DHQ is determined.

Example 1. The process of isolation of dihydroquercetin by extraction from larch wood, according to the method described above using IPA azeotrope as a solvent.

The results are presented below in table 1.

Table 1 Extraction stage The content of DHQ, g In the main stream extract In wash extracts Total one
2 1,546
2,341 0.234
1,039 1.78
3.38 3 3.67 1.25 4.92 four 4.64 1.68 6.32 5 5.22 2,30 7.52

Thus, the total content of DHQ in the combined extracts is 7.52 g or 73.4% of its content in wood. Isopropyl alcohol was distilled off from the combined extracts under vacuum, the aqueous solution was concentrated, and 5.64 g of DHQ was obtained from it with a basic substance content of 92%. The total yield of DHQ was 55% of its content in wood.

Example 2. The process of separation of DHQ by extraction from larch wood according to the method described above using water-diluted ethyl acetate as a solvent. The results are presented in table.2.

table 2 Extraction stage The content of DHQ, g In the main stream extract In wash extracts Total one
2 1,175
2,36 0.605
1.42 1.78
3.78 3 2.99 2.29 5.28 four 2.63 2.63 6.28 5 4.12 3.06 7.18

Thus, the total content of DHQ in the combined extracts is 7.18 g or 70% of its content in wood. Ethyl acetate was distilled off from the combined extracts, and 20.2 g of a dry residue was obtained with a DHQ content of 35.6%. 6.0 g of DHQ with a basic substance content of 92% were obtained from the dry residue by purification and recrystallization. The yield of DHQ was 53% of its content in wood.

Table 3 shows the comparative characteristics of the process of extracting DHQ by the proposed method and by well-known patents.

Table 3 Extraction method Solvent Indicator Solvent consumption for processing 1 kg a.s.d., l Solvent consumption for 1 g recovery
DKV from wood, l According to the patent of the Russian Federation No. 2158598
By the proposed method * Ethyl acetate
Water saturated ethyl acetate 4.0
2,8 0.48
0.195 According to the patent of the Russian Federation No. 2279284 Ethanol 5,0 0.35 By the proposed method * Isopropanol azeotrope 2,8 0.186 Note: * The data shown in table 3 do not take into account the increase in the yield of extractive substances due to the use of low-frequency vibrations and are given taking into account the adjustment for a 2% content of DHQ in the source wood.

From these data it can be seen that the solvent consumption for wood processing by the proposed method is reduced by about 1/3, and in the calculation of extracting the extract of DHQ (g) - more than half. Due to this, energy consumption will be significantly lower.

Another advantage of the method is that the production uses technological chips, which, after blowing off the solvent, can be used in another production, as well as the fact that no process water is added in the process, the volume of wastewater is small and is determined only by the moisture content of the technological chips. The process is tested in laboratory conditions and can be easily implemented in industrial production.

In comparison with the prototype of the inventive method and installation for the isolation of dihydroquercetin are more economical and easier to implement in industrial enterprises.

Claims (5)

1. The method of extraction of dihydroquercetin from crushed larch wood by extraction with a monocomponent organic solvent, characterized in that the wood is crushed to wood chips, the extraction process is carried out sequentially and multistage in at least two extractors, ensuring at each individual stage continuous circulation of one minimum necessary for immersion chips in a liquid medium the volume of the solvent extract in the extractor simultaneously with the creation of a low-frequency pulsating field in it at t at a temperature close to the boiling point of the solvent, and transferring the hot extract after the completion of the process in one step in a separate extractor to the next extraction step, adding each time a fresh solvent extract in an amount equal to the volume of its outflow with the extracted chips, then each washed from portions of extracted wood chips with one minimum necessary volume of solvent, then the extracts from the last n-th extraction and washing steps are combined into one volume, from which they dissolve v, concentrated and the residue is isolated therefrom dihydroquercetin. 2. The method according to claim 1, characterized in that a mixture of isopropyl alcohol with water is used as a monocomponent organic solvent. 3. The method according to claim 1, characterized in that as a monocomponent organic solvent, waterlogged ethyl acetate is used. 4. The method according to claim 3, characterized in that when transferring the extract to the next step, water is separated. 5. Installation for the separation of dihydroquercetin from larch wood, containing a hopper feeder, a solvent supply unit, a heater, a collection of solvent extract and at least two lines for producing an extract solvent, followed by separation of dihydroquercetin from it, each of which contains inlet and outlet valves , a reactor-extractor and a pulp pump, characterized in that a vapor condenser of the solvent extract is introduced into it, and in each of the lines a heater is installed to heat the solvent and low an oscillatory pulsator in the form of a diaphragm pump installed on the pipeline, with each of the extractors being periodically active and connected by one of the inputs to the output of the hopper - feeder, the other input through the first supply valve - to the extract supply unit, one of the outputs is connected to the input of the condenser, the output of which through the second supply valves is also connected to another input of each of the extractors, the other output of each of which through a series-connected heater, pump, pulsator and a third supply the th valve is connected to the third inlet of each of the extractors, the third outlets of which through the third pump and the fourth valve are connected to the collector of the solvent extract.

Images