A process for preparing wogonin and baicalein from the waste liquid of baicalin extraction

Abstract

The present invention relates to the technical field of plant extraction, and particularly to a process for preparing wogonin and baicalein flavone from the waste liquid of baicalin extraction, which comprises the following steps: (1) taking the waste liquid after baicalin extraction, adjusting the pH, and controlling the temperature for standby; (2) the waste liquid enters the resin column, and is first eluted with purified water and then eluted with an organic solvent; (3) the collected effluent is concentrated, the pH is adjusted, it is allowed to stand, and after filtration treatment, a crude wogonin filter cake is obtained. Then, adding purified water or an organic solvent can effectively remove the impurities in the crude filter cake, and a high-purity wogonin product is obtained; (4) the filtrate after concentration and filtration is dried to obtain a baicalein flavone product. The above process has no raw material cost input, avoids waste of resources, and at the same time can obtain two high-value-added products, increasing the economic benefits for the enterprise.

Description

Technical Field

[0001] The present invention relates to the technical field of plant extraction, and particularly relates to a process method for preparing wogonin and baicalein from the waste liquid of baicalin extraction. Background Art

[0002] Scutellaria baicalensis Georgi is bitter in taste and cold in nature, and belongs to the lung, gallbladder, spleen, small intestine, and large intestine meridians. It has the effects of clearing away heat and dampness, purging fire and detoxifying, stopping bleeding, and preventing miscarriage, and has a long history of medication. It is currently commonly used in clinical practice for treating damp-warm syndrome, summer dampness, chest distress and nausea, and lung heat cough. Scutellaria baicalensis Georgi contains a variety of active chemical components and is one of the most commonly used traditional Chinese medicines in traditional Chinese medicine clinics and Chinese patent medicines. The existing process method for extracting baicalin is as follows: The roots of Scutellaria baicalensis Georgi are crushed and sieved, and then extracted with boiling water, and the crude filtrate is heated to adjust the pH, stirred, settled, and filtered to collect the first sediment and the first supernatant respectively; then the first sediment is filtered while it is hot to collect the filter cake and the first filtrate respectively; then the filter cake is slurried with water, the pH is adjusted, ethanol is added, the pH is adjusted and stirred, and after settling, it is filtered to collect the second sediment and the second supernatant respectively; then the collected second sediment is filtered while it is hot to collect the second filtrate and the filter cake respectively, and the collected filter cake is dried to obtain baicalin; in the above extraction process, the first supernatant, the first filtrate, the second supernatant, and the second filtrate after filtration are directly discharged as waste liquid; however, the supernatant and the filtrate contain baicalein and wogonin, and direct discharge will cause waste of resources. Therefore, in view of the above problems, a process method for preparing wogonin and baicalein from the waste liquid of baicalin extraction is explored and studied. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: aiming at the deficiencies existing in the prior art, to provide a process method for preparing wogonin and baicalein from the waste liquid of baicalin extraction, which can extract the effective components in the waste liquid and avoid waste of resources.

[0004] To solve the above technical problem, the technical solution of the present invention is:

[0005] A process method for preparing wogonin and baicalein from the waste liquid of baicalin extraction, the process method comprising the following steps:

[0006] (1) Collect the waste liquid after baicalin extraction, adjust the pH to be acidic, and control the temperature for standby;

[0007] (2) Let the waste liquid in step (1) flow into the resin column in a positive direction, and collect the first effluent; first rinse the resin column with purified water, and collect the second effluent; then rinse the resin column with an organic solvent in a positive direction, and collect the third effluent;

[0008] (3) Take the third effluent in step (2), concentrate it, adjust the pH, let it stand, and filter, and reserve the collected filtrate and the wogonin crude product filter cake respectively;

[0009] (4) Take the crude wogonin filter cake obtained in step (3), add an organic solvent or purified water at 90 - 100 °C, stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate obtained in step (3) and dry to obtain the baicalein flavone product.

[0010] As an improved technical solution, the waste liquid in step (1) is adjusted to a pH of 1.5 - 4 and the temperature is controlled at 30 - 80 °C.

[0011] As an improved technical solution, the waste liquid in step (2) enters the resin column in the positive flow at a flow rate of 0.5 - 5 BV / h; the purified water flushes the resin column in the positive flow at a flow rate of 0.5 - 5 BV / h; the organic solvent is ethanol or methanol with a volume fraction of 50 - 80 v / v%; the organic solvent flushes the resin column in the positive flow at a flow rate of 0.5 - 3 BV / h.

[0012] As an improved technical solution, the resin filled inside the resin column in step (2) is polyamide resin LX - 8, polystyrene resin LSA - 7, polystyrene resin DM18, or polyacrylic acid resin LX - 18.

[0013] As an improved technical solution, when the third effluent in step (3) is concentrated to a solid content of 20 - 50 wt%, the pH is adjusted to 4 - 7.

[0014] As an improved technical solution, the organic solvent in step (4) is ethanol, methanol, propanol, or acetone, and the concentration of the organic solvent is less than 80 v / v%.

[0015] As an improved technical solution, the concentration of the organic solvent is 30 - 70 v / v%.

[0016] After adopting the above technical solution, the beneficial effects of the present invention are:

[0017] The present invention uses the waste liquid after baicalin extraction as raw material. First, after adjusting the pH and controlling the temperature, it enters the resin column, where the wogonin and baicalein flavone components in the waste liquid can be adsorbed. Then, after elution with purified water, the impurities that were not adsorbed after the feeding is completed can be pushed out. After elution with an organic solvent, the wogonin and baicalein flavone components adsorbed by the resin can be desorbed. After concentration, pH adjustment, standing, and filtration, a crude wogonin filter cake is obtained. Adding purified water or an organic solvent can effectively remove the impurities in the crude filter cake, obtaining a high - purity wogonin product; at the same time, the filtrate after concentration and filtration is dried to obtain the baicalein flavone product. The above process method has no raw material cost input, avoids resource waste, and can obtain two high - value - added products, increasing the economic benefits for the enterprise. Description of the Drawings

[0018] Figure 1 It is the liquid-phase detection chromatogram of wogonin in Example 3;

[0019] Figure 2 It is the liquid-phase detection chromatogram of baicalein in Example 3;

[0020] Among them, a - wogonin, b - baicalin, c - wogonoside, d - baicalein. Detailed implementation manners

[0021] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the following embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0022] Example 1

[0023] A process method for preparing wogonin and baicalein from the waste liquid after baicalin extraction, comprising the following steps:

[0024] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 4, control the temperature at 30 °C, and set aside;

[0025] (2) Feed 20 L of the waste liquid in step (1) into a 1 L resin column (the resin is polyamide resin LX-8) at a flow rate of 0.5 BV / h in the forward flow direction, and collect the first effluent; first flush the resin column with 2 L of purified water at a flow rate of 0.5 BV / h in the forward flow direction, and collect the second effluent; then flush the resin column with 4 L of 50 v / v% ethanol at a flow rate of 0.5 BV / h in the forward flow direction, and collect the third effluent; among them, the first effluent and the second effluent are discharged or reserved for other uses;

[0026] (3) Take the third effluent in step (2), concentrate it to a solid content of 20 wt%, adjust the pH to 4, let it stand, filter, and reserve the collected filtrate of 431 ml and the crude wogonin filter cake of 9.8 g respectively;

[0027] (4) Take the crude wogonin filter cake in step (3), add 270 ml of purified water at 90 - 100 °C, stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate in step (3) and dry it to obtain the baicalein product.

[0028] Example 2

[0029] A process method for preparing wogonin and baicalein from the waste liquid after baicalin extraction, comprising the following steps:

[0030] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 3.5, control the temperature at 45 °C, and set aside;

[0031] (2) Feed 20 L of the waste liquid in step (1) into a 1-L resin column (the resin is polystyrene resin LSA-7) at a positive flow rate of 1.5 BV / h, and collect the first effluent; first flush the resin column with 1 L of purified water at a positive flow rate of 1.5 BV / h, and collect the second effluent; then flush the resin column with 6 L of 60 v / v% ethanol at a positive flow rate of 1 BV / h, and collect the third effluent; among them, the first effluent and the second effluent are discharged or reserved for other uses;

[0032] (3) Take the third effluent in step (2), concentrate it to a solid content of 25 wt%, adjust the pH to 4.8, let it stand, filter, and reserve 342 ml of the collected filtrate and 10.2 g of the crude wogonin filter cake respectively;

[0033] (4) Take the crude wogonin filter cake in step (3), add 70 ml of organic solvent (70 v / v% ethanol), stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate in step (3), and dry to obtain the baicalein flavone product.

[0034] Example 3

[0035] A process for preparing wogonin and baicalein flavone from the waste liquid after baicalin extraction, comprising the following steps:

[0036] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 1.5, and control the temperature at 65 °C for standby;

[0037] (2) Feed 20 L of the waste liquid in step (1) into a 1-L resin column (the resin is polystyrene resin DM18) at a positive flow rate of 2.5 BV / h, and collect the first effluent; first flush the resin column with 1.5 L of purified water at a positive flow rate of 2.5 BV / h, and collect the second effluent; then flush the resin column with 3 L of 80 v / v% ethanol at a positive flow rate of 1.5 BV / h, and collect the third effluent; among them, the first effluent and the second effluent are discharged or reserved for other uses;

[0038] (3) Take the third effluent in step (2), concentrate it to a solid content of 30 wt%, adjust the pH to 6.0, let it stand, filter, and reserve 286 ml of the collected filtrate and 10.6 g of the crude wogonin filter cake respectively;

[0039] (4) Take the crude wogonin filter cake in step (3), add 120 ml of organic solvent (65 v / v% ethanol), stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate in step (3), and dry to obtain the baicalein flavone product.

[0040] Example 4

[0041] A process for preparing wogonin and baicalein from the waste liquid of baicalin extraction, comprising the following steps:

[0042] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 3, and control the temperature at 60 °C for standby;

[0043] (2) Feed 20 L of the waste liquid in step (1) into a 1 L resin column (the resin is polyacrylic acid resin LX-18) at a flow rate of 3.5 BV / h in the forward flow direction, and collect the first effluent; first, rinse the resin column with 0.5 L of purified water at a flow rate of 3.5 BV / h in the forward flow direction, and collect the second effluent; then, rinse the resin column with 4 L of 65 v / v% ethanol at a flow rate of 2 BV / h in the forward flow direction, and collect the third effluent; among them, the first effluent and the second effluent are discharged or reserved for other uses;

[0044] (3) Take the third effluent in step (2), concentrate it to a solid content of 35 wt%, adjust the pH to 6, let it stand, filter, and reserve 233 ml of the collected filtrate and 10.4 g of the crude wogonin filter cake respectively;

[0045] (4) Take the crude wogonin filter cake in step (3), add 150 ml of an organic solvent (55 v / v% ethanol), stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate in step (3) and dry it to obtain the baicalein product.

[0046] Example 5

[0047] A process for preparing wogonin and baicalein from the waste liquid of baicalin extraction, comprising the following steps:

[0048] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 2.5, and control the temperature at 70 °C for standby;

[0049] (2) Feed 20 L of the waste liquid in step (1) into a 1 L resin column (polystyrene resin LSA-7) at a flow rate of 4.5 BV / h in the forward flow direction, and collect the first effluent; first, rinse the resin column with 2 L of purified water at a flow rate of 4.5 BV / h in the forward flow direction, and collect the second effluent; then, rinse the resin column with 3 L of 75 v / v% methanol at a flow rate of 2.5 BV / h in the forward flow direction, and collect the third effluent; among them, the first effluent and the second effluent are discharged or reserved for other uses;

[0050] (3) Take the third effluent in step (2), concentrate it to a solid content of 43 wt%, adjust the pH to 6.5, let it stand, filter, and reserve 197 ml of the collected filtrate and 9.7 g of the crude wogonin filter cake respectively;

[0051] (4) Take the crude wogonin filter cake from step (3), add 180 ml of an organic solvent (45 v / v% propanol), stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate from step (3) and dry to obtain the baicalein flavone product.

[0052] Example 6

[0053] A process for preparing wogonin and baicalein flavone from the waste liquid of baicalin extraction, comprising the following steps:

[0054] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 2, and control the temperature at 80 °C for standby.

[0055] (2) Feed 20 L of the waste liquid from step (1) into a 1 L resin column (the resin is polyamide resin LX-8) at a flow rate of 5 BV / h in the forward flow direction, and collect the first effluent; first wash the resin column with 3 L of purified water at a flow rate of 5 BV / h in the forward flow direction, and collect the second effluent; then wash the resin column with 2 L of 80 v / v% methanol at a flow rate of 3 BV / h in the forward flow direction, and collect the third effluent; among them, the first effluent and the second effluent are discharged or used for other purposes.

[0056] (3) Take the third effluent from step (2), concentrate it to a solid content of 50 wt%, adjust the pH to 7, let it stand, filter, and reserve 179 ml of the collected filtrate and 9.8 g of the crude wogonin filter cake separately.

[0057] (4) Take the crude wogonin filter cake from step (3), add 200 ml of an organic solvent (30 v / v% acetone), stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate from step (3) and dry to obtain the baicalein flavone product.

[0058] Example 7

[0059] A process for preparing wogonin and baicalein flavone from the waste liquid of baicalin extraction, comprising the following steps:

[0060] (1) Collect the waste liquid after baicalin extraction, adjust the pH to 1.5, and control the temperature at 72 °C for standby.

[0061] (2) Feed 20 L of the waste liquid from step (1) into a 1 L resin column (the resin is polyamide resin LX-8) at a flow rate of 2.5 BV / h in the forward flow direction, and collect the first effluent; first wash the resin column with 1 L of purified water at a flow rate of 3 BV / h in the forward flow direction, and collect the second effluent; then wash the resin column with 4 L of 60 v / v% ethanol at a flow rate of 2.5 BV / h in the forward flow direction, and collect the third effluent; among them, the first effluent and the second effluent are discharged or used for other purposes.

[0062] (3) Take the third effluent in step (2), concentrate it until the solid content is 50 wt%, adjust the pH to 5.3, let it stand, and filter. Reserve 178 ml of the collected filtrate and 10.4 g of the crude wogonin filter cake separately;

[0063] (4) Take the crude wogonin filter cake in step (3), add 110 ml of organic solvent (35 v / v% methanol), stir, heat under reflux, filter, and dry to obtain the wogonin product; Take the filtrate in step (3) and dry it to obtain the baicalein flavone product.

[0064] To better demonstrate that the process method of the present invention can obtain wogonin products and baicalein flavone products with high yield, high recovery rate, and high purity, three comparative examples are given with reference to Example 3. The yields, recovery rates, and purities of wogonin and baicalein flavone in Examples 1-6 and Comparative Examples 1-3 are shown in Table 1.

[0065] Comparative Example 1

[0066] Differing from Example 3, the temperature in step (1) was controlled at 95 °C, and the rest of the operations were the same;

[0067] Comparative Example 2

[0068] Differing from Example 3, the pH in step (1) was adjusted to 6, and the rest of the operations were the same;

[0069] Comparative Example 3

[0070] Differing from Example 3, the resin in step (2) was the cation exchange resin D331, and the rest of the operations were the same;

[0071] Comparative Example 4

[0072] Differing from Example 3, 30 v / v% ethanol was used to wash the resin column in step (2), and the rest of the operations were the same;

[0073] Comparative Example 5

[0074] Differing from Example 3, the pH in step (3) was adjusted to 8.0, and the rest of the operations were the same;

[0075] Comparative Example 6

[0076] Differing from Example 3, the pH in step (3) was adjusted to 3.5, and the rest of the operations were the same;

[0077] Table 1

[0078]

[0079]

[0080] It can be concluded from the data in Table 1 that the process method of the present invention is significantly superior to Comparative Examples 1-7. By adopting the process method of the present invention, the yields, recovery rates and purities of wogonin and baicalein can be greatly improved, thus increasing the economic benefits for enterprises. It should be noted that the total flavonoid content given in Table 1 refers to the total content of baicalin, wogonin and baicalein in astragalus flavonoids.

[0081] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A process for preparing wogonin and baicalein from the waste liquid of baicalin extraction, characterized in that The process method includes the following steps: (1) Collect the waste liquid after baicalin extraction, adjust the pH to 1.5 - 4, control the temperature at 30 - 80 °C for standby; (2) Let the waste liquid in step (1) flow into the resin column in the forward direction, and collect the first effluent; first rinse the resin column with purified water and collect the second effluent; then rinse the resin column with an organic solvent in the forward direction and collect the third effluent; the resin filled inside the resin column is polyamide resin, polystyrene resin or polyacrylic acid resin; the waste liquid flows into the resin column in the forward direction at a flow rate of 0.5 - 5 BV / h; the purified water rinses the resin column in the forward direction at a flow rate of 0.5 - 5 BV / h; the organic solvent is ethanol or methanol with a volume fraction of 50 - 80 v / v%; the organic solvent rinses the resin column in the forward direction at a flow rate of 0.5 - 3 BV / h; (3) Take the third effluent in step (2), concentrate it, adjust the pH, let it stand, and filter. Keep the collected filtrate and the crude wogonin filter cake separately for standby; when the third effluent is concentrated to a solid content of 20 - 50 wt%, adjust the pH to 4 - 7; (4) Take the crude wogonin filter cake in step (3), add an organic solvent or purified water at 90 - 100 °C, stir, heat under reflux, filter, and dry to obtain the wogonin product; take the filtrate in step (3) and dry to obtain the baicalein flavone product.

2. The process for preparing wogonin and baicalein from the waste liquid of baicalin extraction according to claim 1, characterized in that: In step (4), the organic solvent is ethanol, methanol, propanol or acetone, and the concentration of the organic solvent is less than 80 v / v%.

3. A process for preparing wogonin and baicalein from the waste liquid of baicalin extraction according to claim 2, characterized in that: The concentration of the organic solvent is 30 - 70 v / v%.

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