Method for extracting baicalin from scutellaria baicalensis
By controlling the alcohol precipitation temperature and alcohol content, combined with stirring or static treatment, the problem of low baicalin transfer rate was solved, efficient and stable baicalin extraction was achieved, and production costs were reduced.
Patent Information
- Application Number
- CN202510849454.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-24
- Publication Date
- 2025-09-26
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the existing industrial production methods of baicalin, the baicalin transfer rate is low and the process is unstable, resulting in large losses of active ingredients and high production costs.
After water decoction extraction, the alcohol precipitation temperature is controlled at 40-60 DEG C, the alcohol content of the concentrated solution is adjusted to 50-70%, and the solution is subjected to alcohol precipitation treatment in combination with stirring or standing. The supernatant is separated and ethanol is recovered under reduced pressure to obtain the scutellaria baicalensis extract.
The transfer rate of baicalin was significantly increased to more than 70%, the process stability and production efficiency were improved, the unit product raw material cost was reduced, and it was suitable for stable industrial production.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of traditional Chinese medicine extraction, and particularly relates to a method for extracting baicalin from scutellaria baicalensis. Background Art
[0002] Scutellaria baicalensis, the dried root of the Lamiaceae plant Scutellaria baicalensis Georgi, is a commonly used traditional Chinese medicine with benefits such as clearing heat and dampness, purging fire and detoxifying, stopping bleeding, and stabilizing pregnancy. It is used to treat damp-heat, summer heat, chest tightness and nausea, damp-heat fullness and distension, diarrhea, jaundice, lung-heat cough, high fever and thirst, vomiting and epistaxis due to blood heat, carbuncles, sores, and fetal restlessness.
[0003] Baicalin, a flavonoid extracted from Scutellaria baicalensis, possesses significant biological activity, including antibacterial, diuretic, anti-inflammatory, anti-allergic, and antispasmodic properties, and possesses strong anti-cancer properties. Baicalin also absorbs ultraviolet light, scavenges oxygen free radicals, and inhibits melanin production, making it suitable for both medical and cosmetic applications.
[0004] Patent document CN104873573A discloses a method for extracting crude baicalin from Scutellaria baicalensis, which is suitable for industrial production. The method comprises the following steps: washing the Scutellaria baicalensis medicinal material and cutting it into small segments of 0.5 to 1 cm, adding a 50% to 80% low-carbon alcohol at a solid-liquid ratio of 1:4 to 8, performing reflux extraction three times, each time for 0.5 to 2 hours, combining the extracts, cooling to room temperature, and filtering. The filtrate is concentrated under reduced pressure to 5 times the amount of the Scutellaria baicalensis medicinal material, adjusting the pH to 1 to 2 with hydrochloric acid at room temperature, keeping the temperature at 80 to 85°C for 30 to 60 minutes, and discarding the supernatant; adding an equal volume of 90% to 95% low-carbon alcohol to the precipitate, keeping the temperature at 50 to 80°C for 30 to 60 minutes, cooling to room temperature, removing the alcohol, and drying the precipitate at 55 to 60°C. The yield of baicalin in the crude baicalin product of this process is above 35%, and the extraction rate is above 6.5%, which is relatively low. In addition, hydrochloric acid is required to adjust the pH value, which easily consumes acid and causes acid pollution problems.
[0005] At present, the existing industrial production generally uses the water extraction and alcohol precipitation process to extract baicalin, but there are problems such as low transfer rate, unstable process (large fluctuations in the loss of active ingredients, significant differences in the purity and yield of the dry paste between batches, and poor process reproducibility), which affect production efficiency and production costs. Therefore, it is of great application value to develop a method that can significantly improve the transfer rate of baicalin and ensure process stability. Summary of the Invention
[0006] The purpose of the present invention is to provide a method for extracting baicalin from Scutellaria baicalensis, so as to overcome the technical problems of the prior art such as low baicalin transfer rate and unstable process.
[0007] In order to overcome the defects of the prior art, the present invention provides a method for extracting baicalin from Scutellaria baicalensis. The method comprises the following steps:
[0008] a. Adding water to the Radix Scutellariae and boiling it for extraction, combining the extracts, and concentrating under reduced pressure to obtain a concentrate;
[0009] b. Add ethanol solution to the concentrate to adjust the alcohol content of the concentrate, and perform alcohol precipitation at 40-60°C;
[0010] c. After the alcohol precipitation is completed, separate the supernatant, filter, and recover the ethanol under reduced pressure until there is no alcohol taste, to obtain the Scutellaria baicalensis extract.
[0011] Furthermore, in step a, the amount of water added to the scutellaria baicalensis medicinal material is 10 to 12 times the weight of the scutellaria baicalensis medicinal material.
[0012] Furthermore, in step a, the decocting is performed 2 to 3 times, each time for 1 to 1.5 hours.
[0013] Furthermore, in step a, the reduced pressure concentration is performed until the relative density of the concentrated liquid at 60° C. is 1.05 to 1.15.
[0014] During their research, the inventors discovered that when the relative density of the concentrate is greater than 1.15, the concentrate becomes very viscous. When the ethanol solution is added, the viscous liquid is difficult to mix quickly and evenly with the ethanol solution, resulting in localized areas where the ethanol concentration is too high or too low. When the local ethanol concentration is too high, baicalin can reach local supersaturation and precipitate prematurely. At this time, impurities have not yet fully precipitated, and small baicalin particles are easily encapsulated, adsorbed, or co-precipitated by subsequent large impurity particles, resulting in losses. When the local ethanol concentration is too low, impurity precipitation is incomplete, affecting the subsequent separation effect and the purity of the final product.
[0015] When the relative density of the concentrate is less than 1.05, the solids content is low, requiring the addition of more ethanol to reach the target alcohol content. This not only increases costs but also increases the volume and difficulty of subsequent processing. Furthermore, the precipitate formed by the concentrate at low concentrations is finer and looser, making it difficult to settle and filter, increasing the risk of baicalin being encapsulated or adsorbed on the filter residue.
[0016] Through extensive experimental research, the inventors found that controlling the alcohol precipitation temperature at 40-60°C increases the solubility of baicalin in ethanol solution. This makes it less likely that baicalin will co-precipitate or be encapsulated with impurities due to oversaturation during the precipitation process.
[0017] If the alcohol precipitation temperature is too low, the viscosity is high, and the risk of uneven mixing is high; the solubility of baicalin is reduced, making it more likely to co-precipitate with impurities; the precipitate may be finer and more viscous, making it difficult to handle, resulting in a decreased transfer rate. If the alcohol precipitation temperature is too high, the ethanol is easily volatile, increasing losses and safety risks, and may also change the actual alcohol content. Therefore, the present invention controls the alcohol precipitation temperature between 40 and 60°C. By increasing the solubility of baicalin and significantly reducing the viscosity of the system, the risk of baicalin being lost during the impurity precipitation stage is effectively reduced, and the physical properties and separation efficiency of the precipitate are improved, thereby increasing the transfer rate.
[0018] Keeping warm can greatly increase the transfer rate of baicalin.
[0019] Furthermore, in step b, the volume concentration of the ethanol solution is 90%.
[0020] Furthermore, in step b, the alcohol content of the concentrated solution is adjusted to 50% to 70%.
[0021] Furthermore, in step b, the alcohol precipitation time is 8 to 14 hours.
[0022] Preferably, in step b, the alcohol precipitation time is 12 hours.
[0023] Furthermore, in step b, stirring is performed within the first 30 minutes of the alcohol precipitation.
[0024] Furthermore, in step b, the stirring speed is 30 to 50 rpm.
[0025] The beneficial effects of the present invention are:
[0026] The present invention increases the transfer rate of baicalin from medicinal materials to the extract to over 70% by controlling the relative density of the concentrate before alcohol precipitation (1.05-1.1560°C), the alcohol content of the alcohol precipitation (50-70%), and the alcohol precipitation temperature (40-60°C), combined with heat preservation and static stabilization. This significantly improves the transfer rate of baicalin. The method of the present invention has a stable process, clear and controllable process parameters, and is suitable for stable and efficient industrial production. The method of the present invention can reduce the loss of active ingredients during the alcohol precipitation process, and the high transfer rate can reduce the raw material cost per unit product, thereby improving economic benefits. DETAILED DESCRIPTION
[0027] The present invention will be further described in detail below through specific examples. The drugs and reagents involved in the specific embodiments are all commercially available.
[0028] Example 1
[0029] Weigh 100 kg of Radix Scutellariae baicalensis and add 1000 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0030] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 70%, and performing alcohol precipitation at 55° C. for 10 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 30 rpm was used;
[0031] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0032] Example 2
[0033] Weigh 100 kg of Radix Scutellariae baicalensis and add 1100 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0034] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 50%, and performing alcohol precipitation at 55° C. for 9 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 40 rpm was used;
[0035] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0036] Example 3
[0037] Weigh 100 kg of Scutellaria baicalensis and add 1200 kg of water to decoct for 3 times. Decoction for 1 hour each for the first and second times and for 1 hour for the third time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.10.
[0038] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 60%, and performing alcohol precipitation at 55° C. for 12 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 50 rpm was used;
[0039] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0040] Example 4
[0041] Weigh 100 kg of Radix Scutellariae baicalensis and add 1100 kg of water to decoct the extract twice. Decoction the extracts for 1 hour each for the first and second times and for 1 hour for the third time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.10.
[0042] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 50%, and performing alcohol precipitation at 55° C. for 13 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 50 rpm was used;
[0043] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0044] Example 5
[0045] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1.5 hours the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0046] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 60%, and performing alcohol precipitation at 55° C. for 12 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 40 rpm was used;
[0047] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0048] Comparative Example 1
[0049] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1 hour each time for the first time and for the second time for 1 hour each time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.15.
[0050] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 70%, and performing alcohol precipitation at 10° C. for 12 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring is used at a speed of 50 rpm.
[0051] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0052] Comparative Example 2
[0053] Weigh 100 kg of Scutellaria baicalensis medicinal material, add 1200 kg of water and boil and extract twice, each time for 1.5 hours, combine the extracts, and concentrate under reduced pressure until the relative density of the concentrate at 80°C is 1.18. Cool, add ethanol to make the alcohol content reach 60%, let it stand for more than 12 hours, take the supernatant, filter, and recover the ethanol under reduced pressure until there is no alcohol taste, to obtain Scutellaria baicalensis extract.
[0054] Comparative Example 3
[0055] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0056] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 45%, and performing alcohol precipitation at 55° C. for 10 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 30 rpm was used;
[0057] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0058] Comparative Example 4
[0059] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0060] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 80%, and performing alcohol precipitation at 55° C. for 10 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 30 rpm was used;
[0061] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0062] Comparative Example 5
[0063] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0064] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 70%, and performing alcohol precipitation at 30° C. for 10 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 30 rpm was used;
[0065] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0066] Comparative Example 6
[0067] Weigh 100 kg of Radix Scutellariae baicalensis and add 1200 kg of water to decoct the extract twice, decocting for 1 hour the first time and 1 hour the second time. Combine the extracts and concentrate under reduced pressure until the relative density of the concentrate at 60°C is 1.05.
[0068] Adding 90% ethanol solution by volume to the concentrate to adjust the alcohol content of the concentrate to 70%, and performing alcohol precipitation at 65° C. for 10 hours. During the first 30 minutes of the alcohol precipitation process, low-speed stirring at a speed of 30 rpm was used;
[0069] After the alcohol precipitation is completed, the supernatant is separated, filtered, and the ethanol is recovered under reduced pressure until there is no alcohol taste, thereby obtaining the Scutellaria baicalensis extract.
[0070] The extracts obtained in the Examples and Comparative Examples were measured according to the Chinese Pharmacopoeia High Performance Liquid Chromatography (General Rule 0512). The results are shown in Table 1.
[0071] Table 1 Transfer rate results of examples and comparative examples
[0072]
[0073] In summary, the method of the present invention greatly improves the transfer rate of baicalin, and can increase the transfer rate of baicalin from medicinal materials to extract to more than 70%. The method of the present invention has a stable process, clear and controllable process parameters, and is suitable for stable and efficient industrial production.
Claims
1. A method for extracting baicalin from Scutellaria baicalensis, characterized in that: The steps include: a. Adding water to the Radix Scutellariae and boiling it for extraction, combining the extracts, and concentrating under reduced pressure to obtain a concentrate; b. Add ethanol solution to the concentrate to adjust the alcohol content of the concentrate, and perform alcohol precipitation at 40-60°C; c. After the alcohol precipitation is completed, separate the supernatant, filter, and recover the ethanol under reduced pressure until there is no alcohol taste, to obtain the Scutellaria baicalensis extract.
2. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step a, the amount of water added to the scutellaria baicalensis medicinal material is 10 to 12 times the weight of the scutellaria baicalensis medicinal material.
3. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step a, the decocting is performed 2 to 3 times, each time for 1 to 1.5 hours.
4. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step a, the reduced pressure concentration is performed until the relative density of the concentrated solution at 60° C. is 1.05 to 1.
15.
5. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step b, the volume concentration of the ethanol solution is 90%.
6. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step b, the alcohol content of the concentrated solution is adjusted to 50% to 70%.
7. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step b, the alcohol precipitation time is 8 to 14 hours.
8. The method for extracting baicalin from Scutellaria baicalensis according to claim 7, wherein: In step b, the alcohol precipitation time is 12 hours.
9. The method for extracting baicalin from Scutellaria baicalensis according to claim 1, wherein: In step b, stirring is performed within the first 30 minutes of the alcohol precipitation.
10. The method for extracting baicalin from Scutellaria baicalensis according to claim 9, wherein: In step b, the stirring speed is 30 to 50 rpm.
Citation Information
Patent Citations
Method for being suitable for industrial production and extracting crude baicalin from scutellaria baicalensis
CN104873573A