A process for the combined preparation of baicalein and wogonin

Abstract

The present application relates to the technical field of plant extraction, and particularly relates to a process method for jointly preparing baicalein and wogonin, comprising the following steps: (1) crushing the roots of Scutellaria baicalensis Georgi, adding boiling water to extract, and combining the extract; (2) concentrating the extract and adjusting the pH; (3) heating, cooling and adjusting the pH of the concentrated solution to obtain a lysis solution; (4) introducing the lysis solution into a resin column, eluting with purified water and an organic solvent, and concentrating the collected desorption solution; (5) adjusting the pH of the concentrated solution, filtering, drying and crushing the collected first filter cake to obtain a baicalein product; (6) adjusting the pH of the first filtrate and concentrating; (7) cooling, filtering and eluting the concentrated solution, and collecting the second filtrate and second filter cake; (8) adding purified water to the second filter cake to make a pulp, filtering, drying and collecting the third filter cake to obtain a wogonin product; and (9) spray drying the second filtrate to obtain a Scutellaria baicalensis Georgi flavone product. The above process method can simultaneously obtain high-yield baicalein, wogonin and Scutellaria baicalensis Georgi flavone products.

Description

Technical Field

[0001] This invention relates to the field of plant extraction technology, and in particular to a process for the combined preparation of baicalin and wogonin. Background Technology

[0002] Scutellaria baicalensis, a traditional Chinese medicine, is the dried root of the plant *Scutellaria baicalensis* (Lamiaceae family). It is widely used in traditional Chinese medicine for its bitter and cold properties, clearing heat and dampness. Scutellaria baicalensis primarily enters the lung, gallbladder, spleen, large intestine, and small intestine meridians. It is mainly used to treat febrile diseases, upper respiratory tract infections, cough due to lung heat, damp-heat jaundice, pneumonia, dysentery, conjunctivitis, threatened abortion, hypertension, and carbuncles. In addition, Scutellaria baicalensis has multiple medicinal effects, including antipyretic, antibacterial, antiviral, anti-aging, liver-protective, antitumor, diuretic, and hypoglycemic effects. Scutellaria baicalensis contains various active chemical components, the main active components being flavonoids. Currently, more than 40 flavonoids have been identified, such as baicalin, wogonin, baicalin glycoside, and wogonin glycoside.

[0003] Baicalein possesses antioxidant, antiviral, antibacterial, anti-inflammatory, and anti-allergic therapeutic effects. It also reduces cerebrovascular resistance, improves cerebral blood circulation, increases cerebral blood flow, and inhibits platelet aggregation. Baicalein exhibits broad-spectrum antibacterial activity, inhibiting most types of bacteria. Furthermore, it possesses anti-inflammatory and anti-tumor effects, inhibiting the release of various inflammatory mediators, thereby effectively alleviating inflammatory symptoms.

[0004] Chinese patent CN105906599A describes a method for preparing baicalein in high yield using 2,6-dimethoxy-p-benzoquinone as a starting material, through reduction, Friedel-Crafts acetylation, Claisen condensation, dehydrogenation cyclization, and demethylation reactions. This method involves numerous steps, is complex, and has high costs, making it unsuitable for large-scale production. Chinese patent CN113621530A describes a method for introducing exogenous genes into engineered yeast strains using gene recombination technology to obtain yeast strains capable of producing wogonin, using guar gum as a precursor. This patent uses engineered yeast strains and can only produce gram-level products, making it unsuitable for industrial production. Therefore, to address the above problems, it is necessary to establish a process for the combined preparation of baicalein and wogonin. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a process for the joint preparation of baicalin and wogonin, which can simultaneously obtain high-content baicalin and wogonin products, as well as scutellaria flavonoid products, thereby increasing the economic benefits for enterprises.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A process for the combined preparation of baicalin and wogonin, the process comprising the following steps:

[0008] (1) Take Scutellaria baicalensis root, crush it, add boiling water to extract it multiple times, and combine the filtered extracts for later use.

[0009] (2) Take the extract from step (1), concentrate it and adjust the pH to acidic, and use the concentrated solution for later use;

[0010] (3) Take the concentrated solution described in step (2), heat it and react it for a period of time, then cool it down and adjust the pH to acidic. The resulting lysate is ready for use.

[0011] (4) Take the pyrolysis solution described in step (3) and feed it into the resin column. After the feeding is completed, use purified water to top the feed and then use an organic solvent to elute the resin column. The collected desorbed solution is heated and concentrated to obtain the concentrated solution for later use.

[0012] (5) Take the concentrated liquid from step (4), control the temperature, adjust the pH to acidic, keep it warm and crystallize for a period of time, filter, rinse, and collect the first filtrate and the first filter cake respectively; wherein the first filter cake is dried and crushed to obtain a baicalin product with a content ≥95wt%;

[0013] (6) Take the first filtrate from step (5), adjust the pH to acidic, and use the concentrated solution obtained after concentration.

[0014] (7) Take the concentrated liquid described in step (6), cool it down and keep it warm for a period of time, then filter and rinse it to collect the second filtrate and the second filter cake respectively.

[0015] (8) Take the second filter cake from step (7), add purified water to slurry, control the temperature, keep warm, filter and rinse, and collect the third filtrate and the third filter cake respectively; wherein the third filter cake is dried and crushed to obtain a baicalin product with a content ≥98wt%;

[0016] (9) Take the second filtrate from step (7) and spray dry it to obtain a Scutellaria baicalensis flavonoid product with a content of 8-15wt%.

[0017] As an improved technical solution, in step (1), the particle size of the Scutellaria baicalensis root is 18-20 mesh, the number of times of boiling water extraction is 2-3, the extraction time is 0.5-2h each time, and the Scutellaria baicalensis root and boiling water are added at a ratio of 1:7-15 during each extraction.

[0018] As an improved technical solution, the solid content of the concentrate in step (2) is 10-15 wt%, and the pH is adjusted to 5-6 using 5-20 wt% NaOH, KOH or NH4OH solution.

[0019] As an improved technical solution, the concentrated solution in step (3) is heated to 120-140℃, reacted for 3-6 hours, and then cooled to 20-50℃. The pH is adjusted to 3-4.5 using 20-35wt% HCl, H2SO4 or HNO3.

[0020] As an improved technical solution, the packing material in the resin column in step (4) is a macroporous adsorption resin, and the resin type is D101, AB-8 or DM30; the lysis solution enters the resin column at a flow rate of 1-3 BV / h, the purified water is fed at a flow rate of 1-3 BV / h, the organic solvent is eluted from the resin column at a flow rate of 1-3 BV / h, and the organic solvent is 60-85 v / v% methanol or ethanol.

[0021] As an improved technical solution, the solid content of the concentrate in step (4) is 10-20 wt%, and the organic solvent content in the concentrate is 20-30 v / v.

[0022] As an improved technical solution, the temperature of the concentrate in step (5) is controlled at 50-70℃, and the pH is adjusted to 2-3 using 20-35wt% HCl, H2SO4 or HNO3, and the solution is kept at this temperature for 4-8 hours for crystallization.

[0023] As an improved technical solution, in step (6), the pH of the first filtrate is adjusted to 4-5 using 5-20wt% NaOH, KOH or NH4OH solution, and the solid content of the concentrate is 25-40wt%, and the content of organic solvent in the concentrate is less than 5v / v.

[0024] As an improved technical solution, the concentrated liquid in step (7) is cooled to 35-45℃ and kept at that temperature for crystallization for 1-3 hours.

[0025] As an improved technical solution, in step (8), the second filter cake and purified water are added at a ratio of 1:10-20, the temperature is controlled at 80-100℃, and the filter is filtered after keeping warm for 0.5-2h.

[0026] After adopting the above technical solution, the beneficial effects of the present invention are:

[0027] This invention uses Scutellaria baicalensis root as raw material. The process involves crushing, extraction, and filtration. The combined extract is then subjected to high-temperature pyrolysis. The resulting pyrolysis solution enters a resin column, where, after impurity removal, an organic solvent is used as an eluent for elution. The collected eluent is concentrated, acid-precipitated, crystallized, and filtered. The first filter cake is dried and crushed to obtain baicalein. The first filtrate is then pH-adjusted, concentrated, cooled, and filtered again. The second filter cake is mixed with purified water, slurried, and filtered under controlled temperature. The third filter cake is dried and crushed to obtain baicalein. The second filtrate is concentrated and spray-dried to obtain baicalein flavonoids. This process is simple and efficient, yielding high-purity, high-yield baicalein, baicalein flavonoids, and baicalein flavonoids, thus increasing the economic benefits for enterprises. Attached Figure Description

[0028] Figure 1 The liquid chromatography chromatogram of baicalin in Example 4;

[0029] Figure 2 The liquid chromatography chromatogram of baicalin in Example 4;

[0030] Figure 3 The image shows the liquid chromatography chromatogram of scutellaria baicalensis flavonoids in Example 4. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0032] Example 1

[0033] A process for the combined preparation of baicalin and wogonin includes the following steps:

[0034] (1) Take 10 kg of Scutellaria baicalensis root that has been crushed to 18 mesh, add boiling water and extract twice (each extraction time is 0.5 h, and the amount of boiling water used each time is 70 L), and combine the filtered extracts to obtain 132 L for later use.

[0035] (2) Take 132L of the extract from step (1), concentrate it to obtain a concentrate with a solid content of 10wt%, adjust the pH to 5 with 5wt% NaOH solution and set it aside.

[0036] (3) Take 51.0 L of the concentrated solution from step (2), heat it to 120°C and react for 3 h, then cool it down to 20°C and adjust the pH to 3 with 20 wt% HCl to obtain 51.3 L of lysis solution for later use.

[0037] (4) Take 51.3L of the lysis solution from step (3) and feed it into a 17.0L resin column (macroporous adsorption resin, and the resin type is D101) at a flow rate of 1BV / h. After the feed is finished, use 51.0L of purified water to push the feed at a flow rate of 1BV / h, and then use 68.0L of organic solvent (60v / v% methanol) to elute the resin column at a flow rate of 1BV / h. Collect 65.9L of desorption solution and heat it to concentrate it to obtain 21.9L of concentrate (solid content is 10wt%, organic solvent content is 20v / v%) for later use.

[0038] (5) Take 21.9L of the concentrated solution in step (4), control the temperature at 50℃, adjust the pH to 2 with 20wt% HCl, keep it warm for 4h for crystallization, filter, rinse, and collect 20.6L of the first filtrate and 1.5kg of the first filter cake respectively; the first filter cake is dried and crushed to obtain baicalin product;

[0039] (6) Take 20.6L of the first filtrate from step (5), adjust the pH to 4 with 5wt% NaOH solution, and concentrate it to obtain 5.8L of concentrate (solid content is 25wt%, organic solvent content is 4v / v%) for later use.

[0040] (7) Take 5.8L of the concentrated liquid from step (6), cool it to 35℃, keep it warm for 1 hour, filter and rinse it, and collect 5.6L of the second filtrate and 0.45kg of the second filter cake respectively.

[0041] (8) Take 0.45 kg of the second filter cake from step (7), add 4.5 L of purified water to make a pulp, control the temperature at 80℃, keep warm for 0.5 h, filter and rinse, and collect the third filtrate (used in the first filtrate) and the third filter cake 0.29 kg respectively; the third filter cake is dried and crushed to obtain the scutellaria baicalensis product;

[0042] (9) Take 5.6L of the second filtrate from step (7) and spray dry it at an inlet temperature of 160℃ and an outlet temperature of 70℃ to obtain the Scutellaria baicalensis flavonoid product.

[0043] Example 2

[0044] A process for the combined preparation of baicalin and wogonin includes the following steps:

[0045] (1) Take 10 kg of Scutellaria baicalensis root that has been crushed to 18 mesh, add boiling water to extract twice (each extraction time is 0.8 h, and the amount of boiling water used each time is 90 L), and combine the filtered extracts to obtain 169 L for later use.

[0046] (2) Take 169L of the extract from step (1), concentrate it to obtain a concentrate with a solid content of 12wt%, adjust the pH to 5.3 with 10wt% NaOH solution and set it aside.

[0047] (3) Take 169L of the concentrated solution from step (2), heat it to 125℃ and react for 3.5h, then cool it down to 30℃ and adjust the pH to 3.5 with 25wt% HCl to obtain 43.2L of lysis solution for later use.

[0048] (4) Take 43.2L of the lysis solution from step (3) and feed it into a 20.8L resin column (macroporous adsorption resin, model AB-8) at a flow rate of 1.5BV / h. After the feed is finished, use 20.8L of purified water to top the feed at a flow rate of 1.5BV / h, and then use 41.6L of organic solvent (65v / v% methanol) to elute the resin column at a flow rate of 1.5BV / h. Collect 41.3L of desorption solution and heat it to concentrate it to obtain 17.7L of concentrate (solid content is 12wt%, organic solvent content is 23v / v%) for later use.

[0049] (5) Take 17.7L of the concentrated solution in step (4), control the temperature at 55℃, adjust the pH to 2.3 with 25wt% HCl, keep it warm for 5h for crystallization, filter, rinse, and collect 16.9L of the first filtrate and 1.6kg of the first filter cake respectively; the first filter cake is dried and crushed to obtain baicalin product;

[0050] (6) Take 16.9L of the first filtrate from step (5), adjust the pH to 4.3 with 10wt% NaOH solution, and after concentration, obtain 4.8L of concentrate (solid content is 30wt%, organic solvent content is 3.5v / v%) for later use.

[0051] (7) Take 4.8L of the concentrated liquid from step (6), cool it to 38℃, keep it warm for 1.5h, filter and rinse it, and collect 4.7L of the second filtrate and 0.42kg of the second filter cake respectively;

[0052] (8) Take 0.42 kg of the second filter cake from step (7), add 5.0 L of purified water to make a slurry, control the temperature at 85℃, keep warm for 0.8 h, filter and rinse, and collect the third filtrate (used in the first filtrate) and 0.31 kg of the third filter cake respectively; the third filter cake is dried and crushed to obtain the baicalin product;

[0053] (9) Take 4.7L of the second filtrate from step (7) and spray dry it at an inlet temperature of 165℃ and an outlet temperature of 75℃ to obtain the Scutellaria baicalensis flavonoid product.

[0054] Example 3

[0055] A process for the combined preparation of baicalin and wogonin includes the following steps:

[0056] (1) Take 10 kg of Scutellaria baicalensis root that has been crushed to 18 mesh, add boiling water to extract 3 times (each extraction time is 3 hours, and the amount of boiling water used each time is 100 L), and combine the filtered extracts to obtain 289 L for later use.

[0057] (2) Take 289L of the extract from step (1), concentrate it to obtain a concentrate with a solid content of 13wt%, adjust the pH to 5.8 with 12wt% NH4OH solution and set it aside.

[0058] (3) Take 42.1L of the concentrated solution from step (2), heat it to 130℃ and react for 5h, then cool it down to 30℃ and adjust the pH to 4 with 30wt% H2SO4 to obtain 42.5L of lysis solution for later use.

[0059] (4) Take 42.5L of the lysis solution from step (3) and feed it into a 20.0L resin column (macroporous adsorption resin, resin type DM30) at a flow rate of 2BV / h. After the feed is finished, use 30.0L of purified water to top the feed at a flow rate of 2BV / h, and then use 40L of organic solvent (70v / v% ethanol) to elute the resin column at a flow rate of 2BV / h. Collect 38.5L of desorption solution and heat it to concentrate it to obtain 13.9L of concentrate (solid content is 15wt%, organic solvent content is 25v / v%) for later use.

[0060] (5) Take 13.9L of the concentrated solution in step (4), control the temperature at 60℃, adjust the pH to 2.8 with 30wt% HCl, keep it warm for 6h for crystallization, filter, rinse, and collect 13.9L of the first filtrate and 1.4kg of the first filter cake respectively; the first filter cake is dried and crushed to obtain baicalin product;

[0061] (6) Take 13.9L of the first filtrate from step (5), adjust the pH to 4.8 with 12wt% KOH solution, and after concentration, obtain 4.4L of concentrate (solid content is 32wt%, organic solvent content is 3v / v%) for later use.

[0062] (7) Take 4.4L of the concentrated liquid from step (6), cool it to 38℃, keep it warm for 2 hours, filter and rinse it, and collect 4.3L of the second filtrate and 0.46kg of the second filter cake respectively;

[0063] (8) Take 0.46g of the second filter cake from step (7), add 6.9L of purified water to make a pulp, control the temperature at 90℃, keep it warm for 1h, filter and rinse, and collect the third filtrate (used in the first filtrate) and 0.30kg of the third filter cake respectively; the third filter cake is dried and crushed to obtain the baicalin product;

[0064] (9) Take 4.3L of the second filtrate from step (7) and spray dry it at an inlet temperature of 178℃ and an outlet temperature of 82℃ to obtain the Scutellaria baicalensis flavonoid product.

[0065] Example 4

[0066] A process for the combined preparation of baicalin and wogonin includes the following steps:

[0067] (1) Take 10 kg of Scutellaria baicalensis root that has been crushed to 20 mesh, add boiling water and extract 3 times (each extraction time is 3 hours, and the amount of boiling water used each time is 120 L), and combine the filtered extracts to obtain 351 L for later use.

[0068] (2) Take 351L of the extract from step (1), concentrate it to obtain a concentrate with a solid content of 12wt%, adjust the pH to 5.5 with 15wt% NH4OH solution and set it aside.

[0069] (3) Take 45.3L of the concentrated solution from step (2), heat it to 135℃ and react for 5h, then cool it down to 45℃ and adjust the pH to 4.2 with 32wt% HCl to obtain 45.6L of lysis solution for later use.

[0070] (4) Take 45.6L of the lysis solution from step (3) and feed it into a 23.0L resin column (macroporous adsorption resin, resin type AB-8) at a flow rate of 2.0BV / h. After the feed is finished, use 46.0L of purified water to top the feed at a flow rate of 2.2BV / h, and then use 57.5L of organic solvent (80v / v% ethanol) to elute the resin column at a flow rate of 2.0BV / h. Collect 54.5L of desorption solution and heat it to concentrate it to obtain 11.9L of concentrate (solid content is 18wt%, organic solvent content is 25v / v%) for later use.

[0071] (5) Take 11.9L of the concentrated solution from step (4), control the temperature at 65℃, adjust the pH to 2.5 with 32wt% HCl, keep it warm for crystallization for 7h, filter, rinse, and collect 12.2L of the first filtrate and 1.5kg of the first filter cake respectively; the first filter cake is dried and crushed to obtain baicalin product;

[0072] (6) Take 12.2L of the first filtrate from step (5), adjust the pH to 4.5 with 20wt% NaOH solution, and concentrate it to obtain 4.2L of concentrate (solid content is 35wt%, organic solvent content is 2.8v / v%) for later use.

[0073] (7) Take 4.2L of the concentrated liquid from step (6), cool it to 42℃, keep it warm for 2.5h, filter and rinse it, and collect 4.3L of the second filtrate and 0.48kg of the second filter cake respectively;

[0074] (8) Take 0.48 kg of the second filter cake from step (7), add 7.7 L of purified water to make a slurry, control the temperature at 95℃, keep warm for 1.8 h, filter and rinse, and collect the third filtrate (used in the first filtrate) and 0.32 kg of the third filter cake respectively; the third filter cake is dried and crushed to obtain the baicalin product;

[0075] (9) Take 4.3L of the second filtrate from step (7) and spray dry it at an inlet temperature of 185℃ and an outlet temperature of 92℃ to obtain the Scutellaria baicalensis flavonoid product.

[0076] Example 5

[0077] A process for the combined preparation of baicalin and wogonin includes the following steps:

[0078] (1) Take 10 kg of Scutellaria baicalensis root that has been crushed to 20 mesh, add boiling water and extract 3 times (each extraction time is 3 hours, and the amount of boiling water used each time is 150 L), and combine the filtered extracts to obtain 439 L for later use.

[0079] (2) Take 439L of the extract from step (1), concentrate it to obtain a concentrate with a solid content of 15wt%, adjust the pH to 6 with 20wt% NH4OH solution and set it aside.

[0080] (3) Take 36.5L of the concentrated solution from step (2), heat it to 140℃ and react for 6 hours, then cool it down to 50℃ and adjust the pH to 4.5 with 35wt% HCl to obtain 37.1L of lysis solution for later use.

[0081] (4) Take 37.1L of the lysis solution from step (3) and feed it into a 27.0L resin column (macroporous adsorption resin, and the resin type is DM30) at a flow rate of 3BV / h. After the feed is finished, use 27.0L of purified water to push the feed at a flow rate of 2.5BV / h, and then use 54.0L of organic solvent (85v / v% ethanol) to elute the resin column at a flow rate of 3BV / h. Collect 52.5L of desorption solution and heat it to concentrate it to obtain 12.1L of concentrate (solid content is 20wt%, organic solvent content is 30v / v%) for later use.

[0082] (5) Take 12.1L of the concentrated solution in step (4), control the temperature at 70℃, adjust the pH to 3 with 35wt% HCl, keep it at the temperature for 8h for crystallization, filter, rinse, and collect 11.8L of the first filtrate and 1.4kg of the first filter cake respectively; the first filter cake is dried and crushed to obtain baicalin product.

[0083] (6) Take 11.8L of the first filtrate from step (5), adjust the pH to 5 with 20wt% NH4OH solution, and after concentration, obtain 4.4L of concentrate (solid content is 40wt%, organic solvent content is 2.5v / v%) for later use.

[0084] (7) Take 4.4L of the concentrated liquid from step (6), cool it to 45℃, keep it warm for 3 hours, filter and rinse it, and collect 4.3L of the second filtrate and 0.36kg of the second filter cake respectively;

[0085] (8) Take 0.36 kg of the second filter cake from step (7), add 7.2 L of purified water to make a slurry, control the temperature at 100℃, keep warm for 2 hours, filter and rinse, and collect the third filtrate (used in the first filtrate) and 0.32 kg of the third filter cake respectively; wherein the third filter cake is dried and crushed to obtain the baicalin product;

[0086] (9) Take 4.3L of the second filtrate from step (7) and spray dry it at an inlet temperature of 190℃ and an outlet temperature of 95℃ to obtain the Scutellaria baicalensis flavonoid product.

[0087] To better demonstrate the superior technical effectiveness of the process method of the present invention, 15 comparative examples are provided with reference to Example 4. The yield, purity, and production of baicalein, wogonin, and baicalein flavonoids in Examples 1-5 and Comparative Examples 1-15 are shown in Table 1.

[0088] Comparative Example 1

[0089] Unlike Example 4, in step (2), the extract was concentrated and the pH was adjusted to 4, while the rest of the operation was the same.

[0090] Comparative Example 2

[0091] Unlike Example 4, in step (2), the extract was concentrated and the pH was adjusted to 6.5, while the rest of the operation was the same.

[0092] Comparative Example 3

[0093] Unlike Example 4, the concentrate in step (3) is heated to 110°C, while the rest of the operation is the same.

[0094] Comparative Example 4

[0095] Unlike Example 4, the concentrate in step (3) is heated to 150°C, while the rest of the operation is the same.

[0096] Comparative Example 5

[0097] Unlike Example 4, the concentration of the organic solvent in step (4) is 50% v / v, and the rest of the operation is the same.

[0098] Comparative Example 6

[0099] Unlike Example 4, the filler in the resin column in step (4) is a weakly basic anion exchange resin LX-600J, and the rest of the operation is the same.

[0100] Comparative Example 7

[0101] Unlike Example 4, the organic solvent content in the concentrate in step (4) is 15 v / v%, and the rest of the operation is the same.

[0102] Comparative Example 8

[0103] Unlike Example 4, the temperature is controlled at 45°C in step (5), while the rest of the operation is the same.

[0104] Comparative Example 9

[0105] Unlike Example 4, the temperature is controlled at 80°C in step (5), while the rest of the operation is the same.

[0106] Comparative Example 10

[0107] Unlike Example 4, in step (5), the pH is adjusted to 1.5, while the rest of the operation is the same.

[0108] Comparative Example 11

[0109] Unlike Example 4, in step (5), the pH is adjusted to 4, while the rest of the operation is the same.

[0110] Comparative Example 12

[0111] Unlike Example 4, in step (6), the pH is adjusted to 3, while the rest of the operation is the same.

[0112] Comparative Example 13

[0113] Unlike Example 4, in step (6), the pH is adjusted to 6, while the rest of the operation is the same.

[0114] Comparative Example 14

[0115] Unlike Example 4, the concentrate in step (7) is cooled to 50°C, while the rest of the operation is the same.

[0116] Comparative Example 15

[0117] Unlike Example 4, in step (8), purified water was added and the mixture was stirred at a temperature of 75°C. The rest of the operation was the same.

[0118] Table 1

[0119]

[0120] The data in Table 1 shows that the yield, purity, and overall quality of baicalin, wogonin, and baicalein flavonoids in Examples 1-5 using the process of this invention are significantly better than those in Comparative Examples 1-15.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for the combined preparation of baicalin and wogonin, characterized in that, The process includes the following steps: (1) Take Scutellaria baicalensis root, crush it, add boiling water to extract it multiple times, and combine the filtered extracts for later use; (2) Take the extract from step (1), concentrate it, and adjust the pH to 5-6. The resulting concentrate is ready for use. (3) Take the concentrated solution described in step (2), heat it to 120-140℃ and react for a period of time, then cool it down and adjust the pH to acidic. The resulting lysis solution is ready for use. (4) Take the pyrolysis solution described in step (3) and feed it into the resin column. After the feed is completed, use purified water to top the column and then use an organic solvent to elute the resin column. The collected desorbed solution is concentrated by heating and the concentrated solution is used for later use. The packing material in the resin column is macroporous adsorption resin, and the resin type is D101, AB-8 or DM30. The organic solvent is 60-85 v / v% methanol or ethanol. (5) Take the concentrated liquid described in step (4), control the temperature at 50-70℃, adjust the pH to 2-3 with 20-35wt% HCl, H2SO4 or HNO3, keep it warm and crystallize for a period of time, filter, rinse, and collect the first filtrate and the first filter cake respectively; wherein the first filter cake is dried and crushed to obtain a baicalin product with a content ≥95wt%; (6) Take the first filtrate from step (5), adjust the pH to acidic, and concentrate it for later use; (7) Take the concentrated liquid described in step (6), cool it down and keep it warm for a period of time, then filter and rinse it, and collect the second filtrate and the second filter cake respectively; (8) Take the second filter cake from step (7), add purified water to slurry, control the temperature, keep warm, filter and rinse, and collect the third filtrate and the third filter cake respectively; wherein the third filter cake is dried and crushed to obtain a baicalin product with a content ≥98wt%; (9) Take the second filtrate from step (7) and spray dry it to obtain a Scutellaria baicalensis flavonoid product with a content of 8-15wt%.

2. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, In step (1), the particle size of the Scutellaria baicalensis root is 18-20 mesh, the boiling water extraction is performed 2-3 times, and the extraction time is 0.5-2h each time. The Scutellaria baicalensis root and boiling water are added at a ratio of 1:7-15 during each extraction.

3. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, The solid content of the concentrate in step (2) is 10-15 wt%, and the pH is adjusted by using 5-20 wt% NaOH, KOH or NH4OH solution.

4. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, After reacting for 3-6 hours in step (3), the temperature is lowered to 20-50℃, and the pH is adjusted to 3-4.5 using 20-35wt% HCl, H2SO4 or HNO3.

5. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, In step (4), the lysis buffer is fed into the resin column at a flow rate of 1-3 BV / h, the purified water is fed at a flow rate of 1-3 BV / h, and the organic solvent is eluted from the resin column at a flow rate of 1-3 BV / h.

6. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, The solid content of the concentrate in step (4) is 10-20 wt%, and the organic solvent content in the concentrate is 20-30 v / v.

7. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, In step (5), the crystallization process is carried out at a constant temperature for 4-8 hours.

8. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, In step (6), the pH of the first filtrate is adjusted to 4-5 using 5-20wt% NaOH, KOH or NH4OH solution, and the solid content of the concentrate is 25-40wt%, and the content of organic solvent in the concentrate is less than 5v / v.

9. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, The concentrated solution in step (7) is cooled to 35-45℃ and kept at that temperature for 1-3 hours for crystallization.

10. The process for jointly preparing baicalin and wogonin according to claim 1, characterized in that, In step (8), the second filter cake and purified water are added at a ratio of 1:10-20, the temperature is controlled at 80-100℃, and the filter is filtered after keeping it warm for 0.5-2 hours.

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