Method for simultaneously preparing baicalin, wogonoside, scutellaria baicalensis flavone and scutellaria baicalensis polysaccharide

Abstract

The invention discloses a method for simultaneously preparing baicalin, wogonoside, baical skullcap root flavone and baical skullcap root polysaccharide, which specifically comprises the following steps: adjusting the pH value of baical skullcap root acid precipitation waste liquid, cooling, and concentrating by using a ceramic membrane to obtain permeate liquid I; carrying out electrodialysis-ultrafiltration coupling separation on the permeate 1, and collecting an ion phase 1, an ion phase 2 and an ion phase 3; adjusting the pH value of the ion phase 1, and concentrating to obtain permeate II and trapped fluid II; heating the trapped fluid II, adjusting the pH value, stirring and crystallizing, and filtering to obtain filtrate I and a filter cake I; purifying the filter cake I to obtain wogonoside; crystallizing the filtrate I to obtain a baicalin product, and combining the filtrate III with the ion phase 2 to recover scutellaria flavone; and recovering the desalinated solution to obtain the scutellaria baicalensis polysaccharide. According to the method, effective components in the scutellaria baicalensis acid precipitation waste liquid are recycled, the waste liquid in the whole process is fully utilized, environmental pollution is avoided, the economic value of the scutellaria baicalensis acid precipitation waste liquid is improved, and good benefits are brought to enterprises.

Description

Technical Field

[0001] The invention relates to the technical field of resource recycling, and in particular to a method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide. Background Art

[0002] Scutellaria baicalensis, a plant of the Lamiaceae family, is often used as a traditional Chinese medicine. Its dried roots are one of the commonly used traditional Chinese medicines. Scutellaria baicalensis is widely used in the field of traditional Chinese medicine and modern medicine. The main active ingredients of Scutellaria baicalensis are flavonoids such as baicalin, wogonin, baicalein, and wogonin. At present, most pharmaceutical companies use Scutellaria baicalensis medicinal materials to produce monomer baicalin, and a large amount of baicalic acid precipitate is directly discarded, causing environmental pollution.

[0003] Patent application number 201510086688.4 provides a method for simultaneously extracting baicalin, baicalein and wogonin from Scutellaria baicalensis, comprising: extracting Scutellaria baicalensis with water and concentrating it to obtain a concentrated solution; applying the concentrated solution to a macroporous adsorption resin column, washing with water until colorless, and then eluting with 60-70% ethanol and 75-80% ethanol by volume, respectively, and collecting the eluates; concentrating the eluate containing baicalin under reduced pressure, adjusting the pH, keeping warm, standing, and filtering to obtain pure baicalin; evaporating the eluate containing baicalein and wogonin to dryness, applying it to a gel column, eluting with methanol, collecting baicalein fractions and wogonin fractions, removing methanol from the fractions, and obtaining pure baicalein and pure wogonin. The above method can effectively extract the active ingredients in Scutellaria baicalensis, but a large amount of waste liquid will be generated in the process. This part of the waste liquid still has certain active ingredients remaining. If it is directly discarded, it will not only pollute the environment, but also cause great waste of resources and economic loss. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in view of the shortcomings of the existing technology, a method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharides is provided. The method not only recovers the effective components in the baicalin acid-precipitated waste liquid, but also makes full use of the waste liquid in the whole process, which not only avoids environmental pollution, but also improves the economic value of the baicalin acid-precipitated waste liquid, bringing good benefits to the enterprise.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide comprises the following steps:

[0007] S1: adjusting the pH value of the scutellaria acid precipitation waste liquid to 5.5-6.0, then cooling it to 40-50°C, and then filtering and concentrating it with a ceramic membrane to obtain a permeate 1;

[0008] S2: Perform electrodialysis-ultrafiltration coupling separation on the permeate 1. When the conductivity of the solution in the desalination chamber is less than 500 μs / cm, stop the operation, and collect the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II, and the ion phase 3 in the cation chamber;

[0009] S3: adjusting the pH of ionic phase 1 to 4.5-5.0, and then filtering and concentrating with a nanofiltration membrane to obtain a permeate 2 and a retentate 2; heating the retentate 2, adjusting its pH to 2.5-3.0, stirring and crystallizing, and then filtering to collect a filtrate 1 and a filter cake 1; mixing the filter cake 1 and the ethanol solution for reflux reaction, filtering, and obtaining a filtrate 2 and a filter cake 2; drying the filter cake 2 to obtain a baicalin product, and the filtrate 2 is dealcoholized and then combined with the ionic phase 1;

[0010] S4: heating the filtrate 1, adjusting its pH to 1.8-2.2, stirring for crystallization, filtering to obtain filter cake 3 and filtrate 3; drying the filter cake 3 to obtain the baicalin product, combining the filtrate 3 with the ionic phase 2, and concentrating using a nanofiltration membrane to obtain permeate 3 and retentate 3; the retentate 3 is thermally concentrated and then spray-dried to obtain the scutellaria flavonoid product;

[0011] S5: the permeate 2, the permeate 3 and the ion phase 3 are mixed and concentrated by a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, and the permeate 4 is recovered and used in step (2) as water for the initial ion chamber of the electrodialysis-ultrafiltration; the retentate 4 is thermally concentrated and filtered to obtain a filter cake 4 and a filtrate 4; the filtrate 4 is further concentrated and filtered to obtain a filter cake 5 and a filtrate 5, and the filter cake 5 is combined with the filter cake 4 and dried to obtain the sodium salt;

[0012] S6: The desalinated liquid is concentrated by reverse osmosis membrane to obtain retentate five and permeate five. The retentate five is thermally concentrated and then spray-dried to obtain the Scutellaria polysaccharide product.

[0013] Preferably, in step S1, an alkali solution with a concentration of 10-30wt% is used to adjust the pH of the baicalin acid precipitation waste liquid, and the alkali solution is a mixture of one or more of NaOH, NaHCO3, and Na2CO3.

[0014] Preferably, in step S1, the pore size of the ceramic membrane is 5-10 nm, the membrane pressure during filtration and concentration is 0.4-0.8 MPa, and the filtration and concentration is stopped when the volume is 2-3% of the original volume.

[0015] Preferably, in step S2, during electrodialysis-ultrafiltration coupling separation, ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are stacked in sequence between the anion exchange membrane and the cation exchange membrane in the electrodialysis system, and the effective membrane areas of ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are all 300-400 cm 2The molecular weight cutoff of ultrafiltration membrane I is 1000-2000Da, the molecular weight cutoff of ultrafiltration membrane II and ultrafiltration membrane III is the same, both are 5000-10000Da, the desalination chamber is between ultrafiltration membrane II and ultrafiltration membrane III, the anion chamber I is between ultrafiltration membrane I and ultrafiltration membrane II, the anion chamber II is between ultrafiltration membrane I and the anion exchange membrane, and the cation chamber is between ultrafiltration membrane III and the cation exchange membrane. After separation, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II, the desalinated liquid in the desalination chamber, and the ion phase 3 in the cation chamber are collected respectively.

[0016] Preferably, during the separation process, hydrochloric acid solution is used to adjust the pH of the solution in anion chamber I to 4.5-5.0, and the feed solution in the cation chamber is used to adjust the pH of the solution in anion chamber II to 5.0-5.5; and / or the polar liquid during separation is a sodium chloride solution with a concentration of 5wt%; and / or water is first added to the anion chamber I, anion chamber II and cation chamber at the initial stage of separation, and the amount of water added to each chamber is 1 / 8-1 / 5 of the volume of the permeate I; and / or the flow rate of the permeate I is 200-400ml / min; and / or the electric field strength during separation is 18-25V / cm.

[0017] Preferably, in step S3, the molecular weight cutoff of the nanofiltration membrane is 150-300 Da, the membrane pressure during filtration and concentration is 3.0-5.0 MPa, and the solid content of the retentate second is 5-10 wt%.

[0018] Preferably, in step S3, the temperature of the stirred crystallization is 50-70° C. and the time is 6-12 h.

[0019] Preferably, in step S3, the concentration of the ethanol solution is 40-60 v / v%; the mass ratio of filter cake 1 to the ethanol solution is 1:(5-10); the temperature of the reflux reaction is 70-80° C., and the reflux reaction time is >2 h.

[0020] Preferably, in steps S3 and S4, when adjusting the pH, a hydrochloric acid solution with a concentration of 10-35wt% is used for adjustment; in step S4, the temperature of the stirred crystallization is above 90°C, and the stirring crystallization time is 0.5-1.5h.

[0021] Preferably, in step S4, the molecular weight cutoff of the nanofiltration membrane is 150-300Da, the membrane pressure during concentration is 3.0-5.0MPa, the solid content of the retentate three is 10-15wt%; and / or the retentate three is thermally concentrated to a solid content of 40-55wt%.

[0022] Preferably, in step S5, a reverse osmosis membrane is used to concentrate the solution to a solid content of 5-10 wt%, the retentate is thermally concentrated to a solid content of 60-65 wt%, and the filtrate is further concentrated to a solid content of 65-70 wt%.

[0023] Preferably, in step S6, the solid content of the retentate five is 10-20wt%; the retentate five is thermally concentrated to a solid content of 45-60wt%; and the permeate five is used for Scutellaria baicalensis extraction.

[0024] Due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0025] 1. The present invention uses baicalin acid-precipitated waste liquid as raw material, firstly adopts electrodialysis-ultrafiltration coupling technology to preliminarily separate the effective components in the baicalin acid-precipitated waste liquid, then adopts membrane concentration, acid precipitation, crystallization purification and other technologies, reasonably adjusts the conditions, and simultaneously obtains high content of baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide, and obtains sodium salt, which reduces resource waste and increases economic benefits.

[0026] 2. The present invention effectively adjusts the pH of the scutellaria acidification waste liquid before the electrodialysis-ultrafiltration coupling treatment, and effectively controls the pH of the solution in the anion chamber I and the anion chamber II during the separation process, thereby preventing the damage of scutellaria substances and greatly improving the yield of the target product.

[0027] 3. During the electrodialysis-ultrafiltration coupling treatment, the present invention effectively adjusts the flow rate, electric field strength and other conditions of the permeate, and effectively separates the components in the scutellaria acid precipitate waste liquid, which is convenient for the next step of treatment. The process is simple to operate, has a good separation effect, and the conditions are easy to control.

[0028] 4. When separating wogonin and baicalin, the present invention effectively adjusts the crystallization temperature and the pH value during crystallization, and preliminarily obtains and separates crude wogonin and crude baicalin without damaging the effective ingredients. The obtained crude wogonin is purified under certain conditions using an ethanol solution of a certain concentration to obtain a high content of baicalin. The crude baicalin is crystallized and purified under certain conditions to obtain a high content of baicalin.

[0029] 5. The present invention also recovers scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharides in the scutellaria baicalensis acid precipitation waste liquid, and obtains the by-product sodium salt, which further improves the economic value of the scutellaria baicalensis acid precipitation waste liquid. The whole process is simple to operate, the conditions are easy to control, and it is suitable for large-scale production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0031] Figure 1Schematic diagram of electrodialysis-ultrafiltration coupling system;

[0032] In the figure, 1, anode plate; 2, cathode plate; 3, anion exchange membrane; 4, ultrafiltration membrane I; 5, ultrafiltration membrane II; 6, ultrafiltration membrane III; 7, cation exchange membrane; 8, anion chamber I; 9, anion chamber II; 10, cation chamber; 11, desalination chamber; 12, anode chamber; 13, cathode chamber. DETAILED DESCRIPTION

[0033] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0034] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0035] The electrodialysis-ultrafiltration coupling system used in the following embodiments and comparative examples is as follows: Figure 1 As shown, it includes an anode plate 1 and a cathode plate 2, wherein an anion exchange membrane 3, an ultrafiltration membrane I 4, an ultrafiltration membrane II 5, an ultrafiltration membrane III 6, and a cation exchange membrane 7 are sequentially stacked between the anode plate 1 and the cathode plate 2, an anion chamber I 8 is provided between the ultrafiltration membrane I 4 and the ultrafiltration membrane II 5, an anion chamber II 9 is provided between the ultrafiltration membrane I 4 and the anion exchange membrane 3, a cation chamber 10 is provided between the ultrafiltration membrane III 6 and the cation exchange membrane 7, and a desalination chamber 11 is provided between the ultrafiltration membrane II5 and the ultrafiltration membrane III 6.

[0036] In the separation chamber, the permeate is pumped into the desalination chamber 11 at a certain flow rate, water is pumped into the anion chamber I8, the anion chamber II 9, and the cation chamber 10, and the polar liquid is pumped into the anode chamber 12 and the cathode chamber 13, and separation is performed under a certain electric field strength.

[0037] Specifically, in order to better solve the problems pointed out in the background technology, the present invention provides a method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide, which specifically comprises the following steps:

[0038] (1) adjusting the pH value of the scutellaria acid precipitation waste liquid to 5.5-6.0, then cooling it to 40-50° C., and then filtering and concentrating it using a ceramic membrane to obtain a permeate solution;

[0039] (2) performing electrodialysis-ultrafiltration coupled separation on the permeate, and stopping the operation when the conductivity of the solution in the desalination chamber is less than 500 us / cm, collecting the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber 1, the ion phase 2 in the anion chamber 2, and the ion phase 3 in the cation chamber;

[0040] (3) adjusting the pH of the ionic phase 1 to 4.5-5.0, and then filtering and concentrating with a nanofiltration membrane to obtain a permeate 2 and a retentate 2; heating the retentate 2 to adjust its pH to 2.5-3.0, stirring and crystallizing, and then filtering to collect a filtrate 1 and a filter cake 1; mixing the filter cake 1 and the ethanol solution for reflux reaction, filtering, and obtaining a filtrate 2 and a filter cake 2; drying the filter cake 2 to obtain a baicalin product, and the filtrate 2 is dealcoholized and then combined with the ionic phase 1;

[0041] (4) heating the filtrate 1, adjusting its pH value to 1.8-2.2, stirring for crystallization, filtering to obtain filter cake 3 and filtrate 3; drying the filter cake 3 to obtain the baicalin product, combining the filtrate 3 with the ionic phase 2, and concentrating the mixture using a nanofiltration membrane to obtain permeate 3 and retentate 3; and thermally concentrating the retentate 3 and then spray drying the mixture to obtain the scutellaria flavonoid product.

[0042] (5) the permeate 2, the permeate 3 and the ion phase 3 are mixed and concentrated by a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, and the permeate 4 is recovered and used in step (2) as water for the initial ion chamber of the electrodialysis-ultrafiltration; the retentate 4 is thermally concentrated and filtered to obtain a filter cake 4 and a filtrate 4; the filtrate 4 is further concentrated and filtered to obtain a filter cake 5 and a filtrate 5, and the filter cake 5 is combined with the filter cake 4 and dried to obtain the sodium salt;

[0043] (6) The desalinated liquid is concentrated by a reverse osmosis membrane to obtain a retentate solution 5 and a permeate solution 5. The retentate solution 5 is thermally concentrated and then spray-dried to obtain a Scutellaria polysaccharide product.

[0044] Regarding step (1):

[0045] In order to facilitate the subsequent ceramic membrane and nanofiltration membrane treatment, the baicalin acid precipitation waste liquid needs to be pretreated, including reasonably adjusting the pH and temperature of the baicalin acid precipitation waste liquid.

[0046] In some embodiments of the present invention, an alkaline solution with a concentration of 10-30wt% is used to adjust the pH of the baicalin acid precipitation waste liquid, and the alkaline solution is a mixture of one or more of NaOH, NaHCO3, and Na2CO3. Specifically, the concentration of the alkaline solution is preferably 10wt%, 15wt%, 20wt%, 25wt%, and 30wt%, but is not limited thereto.

[0047] The pH of the baicalin acid waste liquid has a certain influence on the subsequent separation. If the pH is too high, the flavonoids will come into contact with the air during the subsequent membrane concentration process, and some of the effective ingredients will be destroyed, thereby affecting the yield of the effective product; while if the pH is too low, some flavonoids will precipitate during the cooling process, resulting in the loss of effective ingredients. Therefore, in order to ensure the efficient recovery of effective ingredients, the pH of the baicalin acid waste liquid is reasonably adjusted to 5.5-6.0; specifically, preferably 5.5, 5.6, 5.7, 5.8, 5.9, 6.0, but not limited thereto.

[0048] In some embodiments of the present invention, the pore size of the ceramic membrane is 5-10 nm, the membrane pressure during filtration and concentration is 0.4-0.8 MPa, and the filtration and concentration is stopped when the volume is 2-3% of the original volume. The ceramic membrane is used for preliminary concentration treatment to remove some solids, polysaccharides and proteins in the baicalin acid precipitation waste liquid, which is convenient for subsequent treatment.

[0049] Regarding step (2):

[0050] When the electrodialysis-ultrafiltration coupling technology is used for separation, ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are stacked in sequence between the anion exchange membrane and the cation exchange membrane, and the retention molecular weights of the three ultrafiltration membranes are controlled respectively. Under a certain electric field strength, ultrafiltration membrane II and ultrafiltration membrane III can allow flavonoids and chloride ions to pass through, thereby being enriched in the anion chamber I; ultrafiltration membrane I can allow baicalein, wogonin and chloride ions to pass through, thereby being enriched in the anion chamber II; thereby the effective components in the baicalein acid-precipitated waste liquid are preliminarily separated.

[0051] In some embodiments of the present invention, during electrodialysis-ultrafiltration coupling separation, ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are stacked in sequence between the anion exchange membrane and the cation exchange membrane in the electrodialysis system, and the effective membrane areas of ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are all 300-400 cm 2 The molecular weight cutoff of ultrafiltration membrane I is 1000-2000Da, the molecular weight cutoff of ultrafiltration membrane II and ultrafiltration membrane III is the same, both are 5000-10000Da, the desalination chamber is between ultrafiltration membrane II and ultrafiltration membrane III, the anion chamber I is between ultrafiltration membrane I and ultrafiltration membrane II, the anion chamber II is between ultrafiltration membrane I and the anion exchange membrane, and the cation chamber is between ultrafiltration membrane III and the cation exchange membrane. After separation, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II, the desalinated liquid in the desalination chamber, and the ion phase 3 in the cation chamber are collected respectively.

[0052] In some embodiments of the present invention, during the separation process, hydrochloric acid solution is used to adjust the pH of the solution in anion chamber I to 4.5-5.0, and the solution in the cation chamber is used to adjust the pH of the solution in anion chamber II to 5.0-5.5; and / or the polar liquid during separation is a sodium chloride solution with a concentration of 5wt%; and / or water is first added to anion chamber I, anion chamber II and cation chamber at the initial stage of separation, and the amount of water added to each chamber is 1 / 8-1 / 5 of the volume of permeate one; and / or the flow rate of permeate one is 200-400ml / min; and / or the electric field strength during separation is 18-25V / cm. In the above process, during separation, the pH of the solution in anion chamber I and the solution in anion chamber II need to be adjusted in real time to ensure the stability of the active ingredients. If the pH is too low, the active ingredients will precipitate, and if the pH is too high, the active ingredients will be destroyed.

[0053] Regarding step (3):

[0054] In some embodiments of the present invention, the molecular weight cutoff of the nanofiltration membrane is 150-300Da, the membrane pressure during filtration and concentration is 3.0-5.0MPa, and the solid content of the retentate II is 5-10wt%. By effectively controlling the solid content of the concentrated solution, subsequent precipitation and recovery of wogonin are facilitated.

[0055] In some embodiments of the present invention, the temperature of the stirred crystallization is 50-70°C, and the time is 6-12h. Specifically, the temperature of the stirred crystallization is preferably 50°C, 55°C, 60°C, 65°C, 70°C, and the time of the stirred crystallization is preferably 6h, 7h, 8h, 9h, 10h, 11h, 12h, but not limited thereto.

[0056] In the above process, the pH of the solution also affects the purity and yield of the product. If the pH is too low, other flavonoid components of Scutellaria baicalensis will precipitate, affecting the content of wogonin, while if the pH is too high, wogonin will not be completely precipitated, affecting the product yield. Therefore, in order to ensure the high purity and high yield of wogonin, the pH of the solution is controlled to be 2.5-3.0 during the stirring crystallization. Specifically, it can be preferably 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, but not limited thereto.

[0057] In order to remove impurities in wogonin, a solution of a certain concentration is used for purification. During purification, the concentration of the ethanol solution, the reflux temperature, the reflux time and other conditions need to be reasonably controlled. If the concentration of the ethanol solution is too low, the alcohol-soluble impurities are not completely dissolved, while if the concentration of the ethanol solution is too high, the water-soluble impurities are not completely dissolved; if the reflux temperature is too low, the impurities are not completely dissolved; if the reflux time is short, the impurities are not completely dissolved, and the product content is low. In order to ensure the high purity and high yield of the product, the concentration of the ethanol solution is 40-60v / v%, which can dissolve both alcohol-soluble impurities and water-soluble impurities; specifically, the concentration of the ethanol solution is preferably 40v / v%, 45v / v%, 50v / v%, 55v / v%, 60v / v%, but not limited thereto. During reflux, the mass ratio of filter cake 1 to the ethanol solution is 1:(5-10), preferably 1:5, 1:6, 1:7, 1:8, 1:9, 1:10, but not limited thereto; the temperature of the reflux reaction is 70-80°C, preferably 70°C, 75°C, 80°C, and the reflux reaction time is >2h.

[0058] Regarding step (4):

[0059] In some embodiments of the present invention, in steps S3 and S4, when adjusting the pH, a hydrochloric acid solution with a concentration of 10-35wt% is used for adjustment; specifically, the concentration of the hydrochloric acid solution is preferably 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, but not limited thereto.

[0060] In some embodiments of the present invention, the temperature of the stirred crystallization is above 90°C, and the time of the stirred crystallization is 0.5-1.5h. Specifically, the stirring solution time is preferably 0.5h, 1.0h, 1.5h, but not limited thereto. The pH of the solution also needs to be reasonably adjusted during the stirred crystallization process; if the pH is too high, the effective components are not completely precipitated, and the product yield is low; if the pH is too low, impurities are precipitated, affecting the product content. Therefore, the pH of the solution needs to be adjusted to 1.8-2.2, specifically, preferably 1.8, 1.9, 2.0, 2.1, 2.2, but not limited thereto.

[0061] In some embodiments of the present invention, the molecular weight cutoff of the nanofiltration membrane is 150-300Da, the membrane pressure during concentration is 3.0-5.0MPa, the solid content of the retentate three is 10-15wt%; and / or the retentate three is thermally concentrated to a solid content of 40-55wt%.

[0062] Regarding step (5):

[0063] In some embodiments of the present invention, reverse osmosis membrane is used for concentration to a solid content of 5-10wt%, the retentate is thermally concentrated to a solid content of 60-65wt%, and the filtrate is further concentrated to a solid content of 65-70wt%.

[0064] Regarding step (6):

[0065] In some embodiments of the present invention, the retentate 5 has a solid content of 10-20 wt %; the retentate 5 is thermally concentrated to a solid content of 45-60 wt %. The permeate 5 is used in the extraction of Scutellaria baicalensis.

[0066] In the following examples and comparative examples, the raw materials are commercially available unless otherwise specified, and the conditions are conventional conditions in the art unless otherwise specified.

[0067] In the following examples, the yield of each product is calculated as follows:

[0068] Wogonin yield (%) = [(wogonin product mass × wogonin product content) / (baicalin acid precipitation waste liquid mass × baicalin acid precipitation waste liquid dry matter concentration × wogonin content in the dry matter)] × 100%.

[0069] Baicalin yield (%) = [(baicalin product mass × baicalin product content) / (baicalin acid precipitation waste liquid mass × baicalin acid precipitation waste liquid dry matter concentration × baicalin content in the dry matter)] × 100%.

[0070] Total flavonoid yield (%) = {[(mass of scutellaria baicalensis flavonoids product × content of scutellaria baicalensis flavonoids product) + (mass of wogonin product × content of wogonin product) + (mass of baicalin product × content of baicalin product)] / (mass of baicalin acid precipitation waste liquid × dry matter concentration of baicalin acid precipitation waste liquid × content of scutellaria baicalensis flavonoids in the dry matter)} × 100%.

[0071] Example 1

[0072] A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide comprises the following steps:

[0073] (1) Using 10 wt % NaOH to adjust the pH of 100 kg of baicalin acid precipitation waste liquid (the dry matter concentration in the baicalin acid precipitation waste liquid is 4.5 wt %, and the total baicalin content in the dry matter is 6.4 wt %, baicalin content is 1.6 wt %, and wogonin content is 3.3 wt %) to 6.0, then cooling to 40° C., using a ceramic membrane with a filtration pore size of 5 nm under a membrane pressure of 0.8 MPa to concentrate to 2.0% of the original volume, stopping the filtration, and collecting the permeate;

[0074] (2) The permeate was pumped into an electrodialysis-ultrafiltration coupling device at a flow rate of 200 ml / min for separation. The molecular weight cutoff of ultrafiltration membrane I in the electrodialysis-ultrafiltration coupling system was 1000 Da, and the molecular weight cutoffs of ultrafiltration membranes II and III were the same, both 5000 Da. The effective areas of ultrafiltration membranes I, II and III were 300 cm 2 , the polar liquid is 5wt% NaCl, at the initial stage of separation, the volume of water in each ion chamber is 1 / 5 of the volume of the permeate; during the separation process, the pH of the solution in the anion chamber II is adjusted to 5.0 with the feed liquid in the cation chamber, and the pH of the solution in the anion chamber I is adjusted to 4.5 with 10wt% hydrochloric acid, the electric field strength is 25V / cm, when the conductivity of the solution in the desalination chamber is less than 500μs / cm, the operation is stopped, and the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II and the ion phase 3 in the cation chamber are collected;

[0075] (3) The ion phase 1 was concentrated to a solid content of 5 wt % using a nanofiltration membrane with a molecular weight cutoff of 150 Da at a membrane pressure of 5.0 MPa, and the filtration was stopped to obtain a permeate 2 and a retentate 2;

[0076] (4) The retentate II was heated to 50° C., the pH value was adjusted to 2.5 with a 10 wt % hydrochloric acid solution, and the mixture was stirred for crystallization for 12 h and then filtered to obtain a filter cake I and a filtrate I. The filter cake I and a 40% v / v ethanol solution were mixed in a mass ratio of 1:10, and refluxed at 70° C. for more than 2 h, and filtered to obtain a filter cake II and a filtrate II. The filter cake II was dried to obtain 142.5 g of a baicalin product, the baicalin content of which was 98.9 wt % and the yield was 94.9%. The filtrate II was dealcoholized and then applied to step (3) and combined with the next batch of ionic phase 1 for further treatment;

[0077] (5) heating the filtrate 1 to above 90° C., adding a 35 wt % hydrochloric acid solution to adjust the pH to 1.8, stirring and crystallizing for 1 h, filtering after the stirring to obtain a filter cake 3 and a filtrate 3, and drying the filter cake 3 to obtain 75.5 g of a baicalin product, with a baicalin content of 88.4 wt % and a yield of 92.7%;

[0078] (6) The filtrate 3 and the ionic phase 2 were mixed and filtered through a nanofiltration membrane with a molecular weight cutoff of 150 Da. The mixture was concentrated to a solid content of 15 wt % under a membrane pressure of 3.0 MPa. The filtration was stopped to obtain a permeate 3 and a retentate 3. The retentate 3 was thermally concentrated to a solid content of 55 wt %, and spray dried to obtain 196.1 g of a scutellaria flavonoid product with a scutellaria flavonoid content of 37.3 wt % and a total flavonoid yield of 97.5%. The permeate 3 was combined with the permeate 2.

[0079] (7) the ion phase 3, the permeate 2 and the permeate 3 are mixed and concentrated to a solid content of 5 wt % by using a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, the permeate 4 is recycled and used in step (2) as water for the initial ion chamber of the next batch of electrodialysis-ultrafiltration, the retentate 4 is thermally concentrated to a solid content of 65 wt %, filtered to obtain a filter cake 4 and a filtrate 4, the filtrate 4 is further concentrated to a solid content of 70 wt %, filtered to obtain a filter cake 5, the filter cake 5 and the filter cake 4 are dried to obtain a NaCl product having a content of > 90 wt %;

[0080] (8) The desalinated liquid was concentrated to a solid content of 20 wt% by using a reverse osmosis membrane to obtain a retentate solution 5 and a permeate solution 5. The retentate solution 5 was thermally concentrated to a solid content of 60 wt% and then spray-dried to obtain 2152 g of a Scutellaria baicalensis polysaccharide product with a Scutellaria baicalensis polysaccharide content of 24.2 wt%; the permeate solution 5 was used for Scutellaria baicalensis extraction.

[0081] Example 2

[0082] A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide comprises the following steps:

[0083] (1) 100 kg of baicalin acid precipitation waste liquid (the dry matter concentration in the baicalin acid precipitation waste liquid is 4.5 wt %, and the total baicalin content, baicalin content, and wogonin content in the dry matter are 6.4 wt %, 1.6 wt %, and 3.3 wt %) are adjusted to pH 5.5 using 30 wt % NaHCO 3, and then the temperature is lowered to 50° C., and the filtration is concentrated to 3.0 % of the original volume using a ceramic membrane with a pore size of 10 nm under a membrane pressure of 0.4 MPa, and the filtration is stopped to collect the permeate;

[0084] (2) The permeate was pumped into an electrodialysis-ultrafiltration coupling device at a flow rate of 400 ml / min for separation. The molecular weight cutoff of ultrafiltration membrane I in the electrodialysis-ultrafiltration coupling system was 2000 Da, and the molecular weight cutoffs of ultrafiltration membranes II and III were the same, both 10000 Da. The effective areas of ultrafiltration membranes I, II and III were 400 cm 2 , the polar liquid is 5wt% NaCl, at the initial stage of separation, the volume of water in each ion chamber is 1 / 5 of the volume of the permeate; during the separation process, the pH of the solution in the anion chamber II is adjusted to 5.5 with the feed liquid of the cation chamber, and the pH of the solution in the anion chamber I is adjusted to 5.0 with a 35wt% hydrochloric acid solution, the electric field strength is 18V / cm, when the solution conductivity of the desalination chamber is less than 500μs / cm, the operation is stopped, and the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II and the ion phase 3 in the cation chamber are collected;

[0085] (3) The ion phase 1 was concentrated to a solid content of 10 wt % using a nanofiltration membrane with a molecular weight cutoff of 300 Da at a membrane pressure of 3.0 MPa, and the filtration was stopped to obtain a permeate 2 and a retentate 2;

[0086] (4) The retentate II was heated to 70° C., the pH value was adjusted to 3.0 with a 35 wt % hydrochloric acid solution, and the mixture was stirred for crystallization for 6 h and then filtered to obtain a filter cake I and a filtrate I. The filter cake I and a 60% v / v ethanol solution were mixed in a mass ratio of 1:5, and refluxed at 80° C. for more than 2 h, and filtered to obtain a filter cake II and a filtrate II. The filter cake II was dried to obtain 143.2 g of a baicalin product, with a baicalin content of 98.5 wt % and a yield of 95.0%. The filtrate II was dealcoholized and then applied to step (3) and combined with the next batch of ionic phase 1 for treatment;

[0087] (5) heating the filtrate 1 to above 90° C., adding a 10 wt % hydrochloric acid solution to adjust the pH to 2.2, stirring and crystallizing for 1 h, filtering after the stirring to obtain a filter cake 3 and a filtrate 3, and drying the filter cake 3 to obtain 74.8 g of a baicalin product, with a baicalin content of 88.6 wt % and a yield of 92.0%;

[0088] (6) The filtrate 3 and the ionic phase 2 were mixed and filtered through a nanofiltration membrane with a molecular weight cutoff of 300 Da. Under a membrane pressure of 5.0 MPa, the mixture was concentrated to a solid content of 10 wt%, and the filtration was stopped to obtain a permeate 3 and a retentate 3. The retentate 3 was thermally concentrated to a solid content of 40 wt%, and spray-dried to obtain 194.3 g of a scutellaria flavonoid product, with a scutellaria flavonoid content of 38.5 wt% and a total flavonoid yield of 98.0%. The permeate 3 was combined with the permeate 2.

[0089] (7) the ion phase 3, the permeate 2 and the permeate 3 are mixed and concentrated to a solid content of 10 wt % by using a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, the permeate 4 is recovered and used in step (2) as water for the initial ion chamber of the next batch of electrodialysis-ultrafiltration, the retentate 4 is thermally concentrated to a solid content of 60 wt %, filtered to obtain a filter cake 4 and a filtrate 4, the filtrate 4 is further concentrated to a solid content of 65 wt %, filtered to obtain a filter cake 5, the filter cake 5 and the filter cake 4 are dried to obtain a NaCl product having a content of > 90 wt %;

[0090] (8) The desalinated liquid was concentrated to a solid content of 10 wt% by using a reverse osmosis membrane to obtain a retentate five and a permeate five. The retentate five was thermally concentrated to a solid content of 45 wt% and then spray-dried to obtain 2105 g of a Scutellaria baicalensis polysaccharide product with a Scutellaria baicalensis polysaccharide content of 25.1 wt%; the permeate five was used for Scutellaria baicalensis extraction.

[0091] Example 3

[0092] A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide comprises the following steps:

[0093] (1) Using 20 wt % Na2CO3, the pH of 100 kg of baicalin acid precipitation waste liquid (the dry matter concentration in the baicalin acid precipitation waste liquid is 4.5 wt %, and the total baicalin content, 6.4 wt %, baicalin content, and wogonin content, 3.3 wt %) was adjusted to 5.6, and then the temperature was lowered to 42° C., and concentrated to 2.7% of the original volume using a ceramic membrane with a filtration pore size of 10 nm under a membrane pressure of 0.6 MPa, and the filtration was stopped to collect the permeate;

[0094] (2) The permeate was pumped into an electrodialysis-ultrafiltration coupling device at a flow rate of 350 ml / min for separation. The molecular weight cutoff of ultrafiltration membrane I in the electrodialysis-ultrafiltration coupling system was 1700 Da, and the molecular weight cutoffs of ultrafiltration membranes II and III were the same, both 8000 Da. The effective areas of ultrafiltration membranes I, II and III were 330 cm 2 , the polar liquid is 5wt% NaCl, at the initial stage of separation, the volume of water in each ion chamber is 1 / 5 of the volume of the permeate; during the separation process, the pH of the solution in the anion chamber II is adjusted to 5.2 with the feed liquid of the cation chamber, and the pH of the solution in the anion chamber I is adjusted to 4.8 with 15wt% hydrochloric acid, the electric field strength is 20V / cm, when the conductivity of the desalination chamber is less than 500μs / cm, the operation is stopped, and the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II and the ion phase 3 in the cation chamber are collected;

[0095] (3) The ion phase 1 is concentrated to a solid content of 7 wt % using a nanofiltration membrane with a molecular weight cutoff of 200 Da at a membrane pressure of 3.5 MPa, and the filtration is stopped to obtain a permeate 2 and a retentate 2;

[0096] (4) The retentate solution 2 was heated to 65° C., and the pH value was adjusted to 2.8 with a 15 wt % hydrochloric acid solution. The solution was stirred for crystallization for 8 h and then filtered to obtain a filter cake 1 and a filtrate 1. The filter cake 1 and a 55% v / v ethanol solution were mixed in a mass ratio of 1:6, and refluxed at 73° C. for more than 2 h. The filter cake 2 was filtered to obtain a filter cake 2 and a filtrate 2. The filter cake 2 was dried to obtain 141.1 g of a baicalin product, with a baicalin content of 99.1 wt % and a yield of 94.2%. The filtrate was dealcoholized and then applied to step (3) and combined with the next batch of ionic phase 1 for treatment;

[0097] (5) heating the filtrate 1 to above 90° C., adding a 15 wt % hydrochloric acid solution to adjust the pH to 2.0, stirring and crystallizing for 1 h, filtering after the stirring to obtain a filter cake 3 and a filtrate 3, and drying the filter cake 3 to obtain 76.1 g of baicalin product, with a baicalin content of 88.9 wt % and a yield of 94.0%;

[0098] (6) The filtrate 3 and the ionic phase 2 were mixed and filtered through a nanofiltration membrane with a molecular weight cutoff of 200 Da. Under a membrane pressure of 4.5 MPa, the mixture was concentrated to a solid content of 13 wt %, and the filtration was stopped to obtain a permeate 3 and a retentate 3. The retentate 3 was thermally concentrated to a solid content of 48 wt %, and spray-dried to obtain 192.0 g of a scutellaria flavonoid product, with a scutellaria flavonoid content of 38.6 wt % and a total flavonoid yield of 97.8%. The permeate 3 was combined with the permeate 2.

[0099] (7) the ion phase 3, the permeate 2 and the permeate 3 are mixed and concentrated to a solid content of 8 wt % by using a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, the permeate 4 is recycled and used in step (2) as water for the initial ion chamber of the next batch of electrodialysis-ultrafiltration, the retentate 4 is thermally concentrated to a solid content of 62 wt %, filtered to obtain a filter cake 4 and a filtrate 4, the filtrate 4 is further concentrated to a solid content of 68 wt %, filtered to obtain a filter cake 5, the filter cake 5 and the filter cake 4 are dried to obtain a NaCl product having a content of >90 wt %;

[0100] (8) The desalinated liquid was concentrated to a solid content of 18 wt % by using a reverse osmosis membrane to obtain a retentate five and a permeate five. The retentate five was thermally concentrated to a solid content of 56 wt %, and then spray-dried to obtain 2126 g of a Scutellaria baicalensis polysaccharide product with a Scutellaria baicalensis polysaccharide content of 25.0 wt %. The permeate five was used for Scutellaria baicalensis extraction.

[0101] Example 4

[0102] A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide comprises the following steps:

[0103] (1) Using 15 wt % NaHCO3, the pH of 100 kg of baicalin acid precipitation waste liquid (the dry matter concentration in the baicalin acid precipitation waste liquid is 4.5 wt %, and the total baicalin content in the dry matter is 6.4 wt %, baicalin content is 1.6 wt %, and wogonin content is 3.3 wt %) is adjusted to 5.8, then cooled to 47° C., concentrated to 2.2% of the original volume using a ceramic membrane with a filtration pore size of 8 nm under a membrane pressure of 0.5 MPa, and the filtration is stopped to collect the permeate;

[0104] (2) The permeate was pumped into an electrodialysis-ultrafiltration coupling device at a flow rate of 270 ml / min for separation. The molecular weight cutoff of ultrafiltration membrane I in the electrodialysis-ultrafiltration coupling system was 1500 Da, and the molecular weight cutoffs of ultrafiltration membranes II and III were the same, both 7000 Da. The effective areas of ultrafiltration membranes I, II and III were 360 ​​cm 2, the polar liquid is 5wt% NaCl, at the initial stage of separation, the volume of water in each ion chamber is 1 / 5 of the volume of the permeate; during the separation process, the pH of the solution in the anion chamber II is adjusted to 5.3 with the feed liquid of the cation chamber, and the pH of the solution in the anion chamber I is adjusted to 4.7 with 25wt% hydrochloric acid, the electric field strength is 22V / cm, when the conductivity of the desalination chamber is less than 500μs / cm, the operation is stopped, and the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II and the ion phase 3 in the cation chamber are collected;

[0105] (3) The ion phase 1 was concentrated to a solid content of 8 wt % using a nanofiltration membrane with a molecular weight cutoff of 200 Da at a membrane pressure of 4.0 MPa, and the filtration was stopped to obtain a permeate 2 and a retentate 2;

[0106] (4) The retentate II was heated to 60°C, the pH value was adjusted to 2.7 with a 25 wt% hydrochloric acid solution, the mixture was stirred for crystallization for 9 hours, and then filtered to obtain a filter cake I and a filtrate I. The filter cake I and a 48% v / v ethanol solution were mixed in a mass ratio of 1:8, refluxed at 77°C for more than 2 hours, and filtered to obtain a filter cake II and a filtrate II. The filter cake II was dried to obtain 142.7 g of wogonin product, the content of wogonin was 99.3 wt% and the yield was 95.4%. The filtrate II was dealcoholized and then applied to step (3) and combined with the next batch of ionic phase 1 for treatment;

[0107] (5) heating the filtrate 1 to above 90° C., adding a 25 wt % hydrochloric acid solution to adjust the pH to 2.0, stirring and crystallizing for 1 h, filtering after the stirring to obtain a filter cake 3 and a filtrate 3, and drying the filter cake 3 to obtain 75.8 g of a baicalin product, with a baicalin content of 89.5 wt % and a yield of 94.2%;

[0108] (6) The filtrate 3 and the ionic phase 2 were mixed and filtered through a nanofiltration membrane with a molecular weight cutoff of 200 Da. Under a membrane pressure of 3.5 MPa, the mixture was concentrated to a solid content of 12 wt%, and the filtration was stopped to obtain a permeate 3 and a retentate 3. The retentate 3 was thermally concentrated to a solid content of 52 wt%, and spray-dried to obtain 190.1 g of a scutellaria flavonoid product, with a scutellaria flavonoid content of 38.8 wt% and a total flavonoid yield of 98.4%. The permeate 3 was combined with the permeate 2.

[0109] (7) the ion phase 3, the permeate 2 and the permeate 3 are mixed and concentrated to a solid content of 7 wt % by using a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, the permeate 4 is recovered and used in step (2) as water for the initial ion chamber of the next batch of electrodialysis-ultrafiltration, the retentate 4 is thermally concentrated to a solid content of 63 wt %, filtered to obtain a filter cake 4 and a filtrate 4, the filtrate 4 is further concentrated to a solid content of 67 wt %, filtered to obtain a filter cake 5, the filter cake 5 and the filter cake 4 are dried to obtain a NaCl product having a content of > 90 wt %;

[0110] (8) The desalinated liquid was concentrated to a solid content of 13 wt % by using a reverse osmosis membrane to obtain a retentate five and a permeate five. The retentate five was thermally concentrated to a solid content of 51 wt %, and then spray-dried to obtain 2132 g of a Scutellaria baicalensis polysaccharide product with a Scutellaria baicalensis polysaccharide content of 25.1 wt %. The permeate five was used for Scutellaria baicalensis extraction.

[0111] Comparative Example 1

[0112] Compared with Example 4, the difference is that: in step (1), the pH of the baicalin acid-precipitated waste liquid is adjusted to 4.5, and the other conditions are the same as those in Example 4, to obtain 47.6 g of baicalin product, the baicalin content is 93.9wt%, and the yield is 30.1%; 26.0 g of baicalin product, the baicalin content is 81.7wt%, and the yield is 29.5%; 112.7 g of scutellaria flavonoids product, the scutellaria flavonoids content is 29.5wt%, and the total flavonoids yield is 34.4%; 2685 g of scutellaria polysaccharide product, the scutellaria polysaccharide content is 19.7wt%.

[0113] Comparative Example 2

[0114] Compared with Example 4, the difference is that: in step (1), the pH of the baicalin waste liquid is adjusted to 7.5, and the other conditions are the same as those in Example 4, to obtain 52.8g of baicalin product, the content of baicalin is 94.3wt%, and the yield is 33.5%; 33.7g of baicalin product, the content of baicalin is 82.6wt%, and the yield is 38.7%; 338.4g of scutellaria flavonoid product, the content of scutellaria flavonoid is 25.6wt%, and the total flavonoid yield is 57.0%; 2085g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.7wt%.

[0115] Comparative Example 3

[0116] Compared with Example 4, the difference is that in step (2), the flow rate of permeation one is 100 ml / min, and the other conditions are the same as those in Example 4, and 133.1 g of baicalin product is obtained, the content of baicalin is 95.8wt%, and the yield is 85.9%; 75.6 g of baicalin product, the content of baicalin is 84.5wt%, and the yield is 88.7%; 233.7 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 38.5wt%, and the total flavonoid yield is 97.7%; 2069 g of scutellaria baicalensis polysaccharide product, the content of scutellaria baicalensis polysaccharide is 25.0wt%.

[0117] Comparative Example 4

[0118] Compared with Example 4, the difference is that in step (2), the flow rate of permeate one is 500 ml / min, and the other conditions are the same as those in Example 4, and 118.2 g of baicalin product is obtained, the content of baicalin is 98.0 wt%, and the yield is 78.0%; 72.1 g of baicalin product, the content of baicalin is 85.5 wt%, and the yield is 85.6%; 206.9 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 37.7 wt%, and the total flavonoid yield is 88.7%; 2173 g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.5 wt%.

[0119] Comparative Example 5

[0120] Compared with Example 4, the difference is that in step (2), the electric field strength is 10 V / cm, and the other conditions are the same as those in Example 4, and 115.0 g of baicalin product is obtained, the content of baicalin is 97.5 wt%, and the yield is 75.5%; 69.4 g of baicalin product, the content of baicalin is 85.2 wt%, and the yield is 82.1%; 221.4 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 37.2 wt%, and the total flavonoid yield is 88.1%; 2170 g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.4 wt%.

[0121] Comparative Example 6

[0122] Compared with Example 4, the difference is that in step (2), the electric field strength is 35 V / cm, and the other conditions are the same as those in Example 4, and 132.4 g of baicalin product is obtained, the content of baicalin is 96.0 wt%, and the yield is 85.6%; 74.4 g of baicalin product, the content of baicalin is 84.6 wt%, and the yield is 87.4%; 237.8 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 38.1 wt%, and the total flavonoid yield is 97.4%; 2034 g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 25.1 wt%.

[0123] Comparative Example 7

[0124] Compared with Example 4, the difference is that: in step (2), the pH of the solution in the anion chamber I is adjusted to 6.5, and the other conditions are the same as those in Example 4, and 75.8g of baicalin product is obtained, the content of baicalin is 91.6wt%, and the yield is 46.8%; 32.4g of baicalin product, the content of baicalin is 78.9wt%, and the yield is 35.5%; 308.7g of scutellaria flavonoid product, the content of scutellaria flavonoid is 21.9wt%, and the total flavonoid yield is 56.5%; 2130g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.9wt%.

[0125] Comparative Example 8

[0126] Compared with Example 4, the difference is that: in step (2), the pH of the solution in the anion chamber II is adjusted to 7.0, and the other conditions are the same as those in Example 4, and 142.8g of baicalin product is obtained, the content of baicalin is 98.9wt%, and the yield is 95.1%; 75.6g of baicalin product, the content of baicalin is 89.1wt%, and the yield is 93.6%; 204.2g of scutellaria flavonoid product, the content of scutellaria flavonoid is 27.1wt%, and the total flavonoid yield is 91.6%; 2128g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.6wt%.

[0127] Comparative Example 9

[0128] Compared with Example 4, the difference is that in step (4), the temperature of the stirred crystallization is 40°C, and the other conditions are the same as those in Example 4, and 142.7g of baicalin product is obtained, the content of baicalin is 93.6wt%, and the yield is 89.9%; 68.9g of baicalin product, the content of baicalin is 86.8wt%, and the yield is 83.1%; 202.4g of scutellaria flavonoid product, the content of scutellaria flavonoid is 36.0wt%, and the total flavonoid yield is 92.4%; 2128g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.9wt%.

[0129] Comparative Example 10

[0130] Compared with Example 4, the difference is that in step (4), the temperature of the stirred crystallization is 80°C, and the other conditions are the same as those in Example 4, and 106.1g of baicalin product is obtained, the content of baicalin is 98.8wt%, and the yield is 70.6%; 80.2g of baicalin product, the content of baicalin is 75.4wt%, and the yield is 84.0%; 228.6g of scutellaria flavonoid product, the content of scutellaria flavonoid is 42.2wt%, and the total flavonoid yield is 90.9%; 2135g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.8wt%.

[0131] Comparative Example 11

[0132] Compared with Example 4, the difference is that: in step (4), the pH of the solution is adjusted to 1.5 during the stirring crystallization, and the other conditions are the same as those in Example 4, and 148.3g of baicalin product is obtained, the content of baicalin is 90.1wt%, and the yield is 90.0%; 68.8g of baicalin product, the content of baicalin is 86.6wt%, and the yield is 82.8%; 195.2g of scutellaria flavonoid product, the content of scutellaria flavonoid is 35.7wt%, and the total flavonoid yield is 91.3%; 2146g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.9wt%.

[0133] Comparative Example 12

[0134] Compared with Example 4, the difference is that: in step (4), the pH of the solution is adjusted to 4.0 during the stirring crystallization, and the other conditions are the same as those in Example 4, and 58.9g of baicalin product is obtained, the content of baicalin is 98.9wt%, and the yield is 39.2%; 79.8g of baicalin product, the content of baicalin is 75.7wt%, and the yield is 83.9%; 274.3g of scutellaria flavonoid product, the content of scutellaria flavonoid is 49.6wt%, and the total flavonoid yield is 88.4%; 2137g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.9wt%.

[0135] Comparative Example 13

[0136] Compared with Example 4, the difference is that: in step (4), the concentration of the ethanol solution is 30 v / v%, and the other conditions are the same as those in Example 4, and 150.3 g of baicalin product is obtained, the content of baicalin is 91.6 wt%, and the yield is 92.7%; 69.5 g of baicalin product, the content of baicalin is 86.1 wt%, and the yield is 83.1%; 193.0 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 34.8 wt%, and the total flavonoid yield is 91.9%; 2132 g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.6 wt%.

[0137] Comparative Example 14

[0138] Compared with Example 4, the difference is that: in step (4), the concentration of the ethanol solution is 70 v / v%, and the other conditions are the same as those in Example 4, and 123.1 g of baicalin product is obtained, the content of baicalin is 99.1 wt%, and the yield is 82.1%; 82.4 g of baicalin product, the content of baicalin is 77.5 wt%, and the yield is 88.7%; 206.4 g of scutellaria flavonoid product, the content of scutellaria flavonoid is 37.7 wt%, and the total flavonoid yield is 91.6%; 2124 g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 25.0 wt%.

[0139] Comparative Example 15

[0140] Compared with Example 4, the difference is that in step (4), the reflux reaction temperature is 60°C, and the other conditions are the same as those in Example 4, to obtain 153.5g of baicalin product, with a baicalin content of 93.2wt% and a yield of 96.3%; 75.2g of baicalin product, with a baicalin content of 87.2wt% and a yield of 91.1%; 190.8g of scutellaria flavonoid product, with a scutellaria flavonoid content of 31.3wt% and a total flavonoid yield of 93.2%; 2125g of scutellaria polysaccharide product, with a scutellaria polysaccharide content of 25.1wt%.

[0141] Comparative Example 16

[0142] Compared with Example 4, the difference is that: in step (5), the pH of the solution is adjusted to 1.0 during the stirring crystallization, and the other conditions are the same as those in Example 4, and 141.3g of baicalin product is obtained, the content of baicalin is 99.0wt%, and the yield is 94.2%; 89.6g of baicalin product, the content of baicalin is 76.5wt%, and the yield is 95.2%; 168.6g of scutellaria flavonoid product, the content of scutellaria flavonoid is 35.1wt%, and the total flavonoid yield is 92.9%; 2140g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 24.7wt%.

[0143] Comparative Example 17

[0144] Compared with Example 4, the difference is that: in step (5), the pH of the solution is adjusted to 3.0 during the stirring crystallization, and the other conditions are the same as those in Example 4, and 142.9g of baicalin product is obtained, the content of baicalin is 98.8wt%, and the yield is 95.1%; 23.6g of baicalin product, the content of baicalin is 88.7wt%, and the yield is 29.1%; 255.1g of scutellaria flavonoid product, the content of scutellaria flavonoid is 47.6wt%, and the total flavonoid yield is 98.5%; 2128g of scutellaria polysaccharide product, the content of scutellaria polysaccharide is 25.1wt%.

[0145] In summary, the present invention treats baicalin acid precipitation waste liquid by combining electrodialysis-ultrafiltration coupling technology, acid precipitation, etc. During electrodialysis-ultrafiltration coupling, baicalin and wogonin in the baicalin acid precipitation waste liquid are separated by sequentially stacking ultrafiltration membranes with different molecular weight cutoffs between anion exchange membranes and cation exchange membranes, and then high-content baicalin and wogonin are obtained through subsequent treatment, and at the same time, baicalin flavonoids and baicalin polysaccharides of a certain purity are recovered, thereby greatly improving the economic value of the baicalin acid precipitation waste liquid.

[0146] Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core ideas, including the best mode, and also enable any technician in the field to practice the present invention, including making and using any device or system, and implementing any combined method. It should be pointed out that for ordinary technicians in this technical field, without departing from the principle of the present invention, the present invention can also be improved and modified, and these improvements and modifications also fall within the scope of protection of the claims of the present invention. The scope of patent protection of the present invention is defined by the claims and may include other embodiments that can be thought of by those skilled in the art. If these other embodiments have structural elements similar to the literal expression of the claims, or if they include equivalent structural elements that are not substantially different from the literal expression of the claims, then these other embodiments should also be included in the scope of the claims.

Claims

1. A method for simultaneously preparing baicalin, wogonin, scutellaria baicalensis flavonoids and scutellaria baicalensis polysaccharide, characterized in that: The following steps are involved: S1: adjusting the pH of the baicalin acid precipitation waste liquid to 5.5-6.0, then cooling it to 40-50°C, and then filtering and concentrating it with a ceramic membrane to obtain a permeate 1; S2: Perform electrodialysis-ultrafiltration coupling separation on the permeate 1. When the conductivity of the solution in the desalination chamber is less than 500 μs / cm, stop the operation, and collect the desalinated liquid in the desalination chamber, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II, and the ion phase 3 in the cation chamber; S3: adjusting the pH of ionic phase 1 to 4.5-5.0, filtering and concentrating by nanofiltration membrane to obtain permeate 2 and retentate 2; heating the retentate 2 to adjust its pH to 2.5-3.0, stirring and crystallizing, filtering, collecting filtrate 1 and filter cake 1; mixing filter cake 1 and ethanol solution for reflux reaction, filtering, obtaining filtrate 2 and filter cake 2; drying filter cake 2 to obtain wogonin product, and combining filtrate 2 with ionic phase 1 after dealcoholization; S4: heating the filtrate 1, adjusting its pH to 1.8-2.2, stirring for crystallization, filtering to obtain filter cake 3 and filtrate 3; drying the filter cake 3 to obtain the baicalin product, combining the filtrate 3 with the ionic phase 2, and concentrating using a nanofiltration membrane to obtain permeate 3 and retentate 3; the retentate 3 is thermally concentrated and then spray-dried to obtain the scutellaria flavonoid product; S5: the permeate 2, the permeate 3 and the ion phase 3 are mixed and concentrated by a reverse osmosis membrane to obtain a retentate 4 and a permeate 4, and the permeate 4 is recovered and used in step (2) as water for the initial ion chamber of the electrodialysis-ultrafiltration; the retentate 4 is thermally concentrated and filtered to obtain a filter cake 4 and a filtrate 4; the filtrate 4 is further concentrated and filtered to obtain a filter cake 5 and a filtrate 5, and the filter cake 5 is combined with the filter cake 4 and dried to obtain the sodium salt; S6: The desalinated liquid is concentrated by reverse osmosis membrane to obtain retentate five and permeate five. The retentate five is thermally concentrated and then spray-dried to obtain the Scutellaria polysaccharide product.

2. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S1, an alkaline solution with a concentration of 10-30wt% is used to adjust the pH of the baicalin acid precipitation waste liquid, wherein the alkaline solution is a mixture of one or more of NaOH, NaHCO3, and Na2CO3; and / or the pore size of the ceramic membrane is 5-10nm, and the membrane pressure during filtration and concentration is 0.4-0.8MPa. The filtration and concentration is stopped when the volume is 2-3% of the original volume.

3. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S2, during electrodialysis-ultrafiltration coupling separation, ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are stacked in sequence between the anion exchange membrane and the cation exchange membrane in the electrodialysis system, and the effective membrane areas of ultrafiltration membrane I, ultrafiltration membrane II, and ultrafiltration membrane III are all 300-400 cm 2 The molecular weight cutoff of ultrafiltration membrane I is 1000-2000Da, the molecular weight cutoff of ultrafiltration membrane II and ultrafiltration membrane III is the same, both are 5000-10000Da, the desalination chamber is between ultrafiltration membrane II and ultrafiltration membrane III, the anion chamber I is between ultrafiltration membrane I and ultrafiltration membrane II, the anion chamber II is between ultrafiltration membrane I and the anion exchange membrane, and the cation chamber is between ultrafiltration membrane III and the cation exchange membrane. After separation, the ion phase 1 in the anion chamber I, the ion phase 2 in the anion chamber II, the desalinated liquid in the desalination chamber, and the ion phase 3 in the cation chamber are collected respectively.

4. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 3, characterized in that: During the separation process, hydrochloric acid solution is used to adjust the pH of the solution in the anion chamber I to 4.5-5.0, and the feed solution in the cation chamber is used to adjust the pH of the solution in the anion chamber II to 5.0-5.5; and / or the polar liquid during separation is a sodium chloride solution with a concentration of 5wt%; and / or water is first added to the anion chamber I, the anion chamber II and the cation chamber at the initial stage of separation, and the amount of water added to each ion chamber is 1 / 8-1 / 5 of the volume of the permeate I; and / or the flow rate of the permeate I is 200-400ml / min; and / or the electric field strength during separation is 18-25V / cm.

5. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S3, the molecular weight cutoff of the nanofiltration membrane is 150-300Da, the membrane pressure during filtration and concentration is 3.0-5.0MPa, the solid content of the retentate II is 5-10wt%; and / or the temperature of the stirred crystallization is 50-70°C, and the time is 6-12h.

6. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S3, the concentration of the ethanol solution is 40-60 v / v%; the mass ratio of the filter cake 1 to the ethanol solution is 1:(5-10); the temperature of the reflux reaction is 70-80° C., and the reflux reaction time is >2h.

7. A method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In steps S3 and S4, when adjusting the pH, a hydrochloric acid solution with a concentration of 10-35wt% is used for adjustment; in step S4, the temperature of the stirred crystallization is above 90°C, and the stirring crystallization time is 0.5-1.5h.

8. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S4, the molecular weight cutoff of the nanofiltration membrane is 150-300Da, the membrane pressure during concentration is 3.0-5.0MPa, the solid content of the retentate three is 10-15wt%; and / or the retentate three is thermally concentrated to a solid content of 40-55wt%.

9. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and scutellaria baicalensis polysaccharide according to claim 1, characterized in that: Step S5, using a reverse osmosis membrane to concentrate to a solid content of 5-10wt%, the retentate four is thermally concentrated to a solid content of 60-65wt%, and the filtrate four is further concentrated to a solid content of 65-70wt%.

10. The method for simultaneously preparing baicalin, wogonin, baicalin flavonoids and baicalin polysaccharide according to claim 1, characterized in that: In step S6, the solid content of the retentate five is 10-20wt%; the retentate five is thermally concentrated to a solid content of 45-60wt%; and the permeate five is used in the extraction of Scutellaria baicalensis.

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