Processing method of indigo naturalis mixed with lampwick

Abstract

The invention provides a processing method of mixed indigo naturalis and medulla junci, which comprises the following steps: taking cleaned and segmented medulla junci, spraying a small amount of clear water, adding indigo naturalis powder, and mixing until the surface of the medulla junci is uniformly adhered with indigo naturalis. Wherein the extraction process of the indigo naturalis powder is improved, and the indigo naturalis powder is subjected to hydrophilic modification to obtain a high-quality indigo naturalis product.

Description

Technical Field

[0001] The invention belongs to the field of traditional Chinese medicine, and particularly relates to a method for preparing indigo naturalis mixed with rush. Background Art

[0002] Indigo powder is the dried pigment from the leaves of the dicotyledonous plant Acanthaceae plant Indigofera tinctoria, the dicotyledonous plant Fabaceae plant Indigofera tinctoria, the dicotyledonous plant Cruciferae plant Isatis indigotica, Indigofera glutinosa, or the Polygonum tinctorium leaf of the Polygonaceae family.

[0003] Rush enters the heart meridian, can reduce heart fire, has the effect of stopping bleeding, ventilating, dispersing swelling and relieving cough. Clinically, it can be used to treat heart fire inflammation caused by various fevers, and can eliminate irritability, irritability, and mouth sores.

[0004] The fresh rush products usually picked after harvesting have a lot of dirt or dust on the surface, so they need to be cleaned before subsequent operations can be carried out. If the machine is cleaned with clean water less frequently, there will be residual stains, which require backwashing. If the cleaning frequency is too high, not only the cleaning efficiency is low, but also the effective water-soluble components of the rush will be lost to a certain extent. Therefore, improving the cleaning solution and reducing the cleaning frequency are one of the key directions of the present invention.

[0005] Indigo mixed with rush, often used with cirsium, cirsium, Imperata root, etc., can clear away heat and promote diuresis, cool blood and stop bleeding, and can treat blood in urine and even hematuria caused by damp heat in the lower part of the body damaging the blood vessels of the bladder. The traditional processing technology of indigo powder usually introduces lime, and the complexity and uncontrollability of the processing technology lead to uneven quality of indigo, affecting the efficacy.

[0006] Among them, the indigo carmine in Indigo has good effects in treating common diseases and leukemia. Therefore, in order to reduce the impact of lime introduced in the traditional processing technology, as well as the odor caused by soaking and other problems, and how to increase the indigo carmine content in Indigo, an improved Indigo extraction process is provided to address this problem, which is the research focus of the present invention.

[0007] Indigo is light and loose in texture, and has unique hydrophobicity. Traditionally, Yiren Pills are used for loose-mouthed use. When it is made into powder and mixed with rush, it has poor adhesion, so how to improve the hydrophilicity of Indigo is one of the key directions of the present invention. Summary of the invention

[0008] The present invention discloses a method for preparing Indigo Naturalis mixed with rush, so as to solve the above and any potential problems in the prior art. In order to solve the above technical problems, the method for preparing the present invention is as follows:

[0009] Take the cleaned and dried rush, cut it into 4-6cm segments, spray 0.5%-1% clean water on its surface, add indigo powder, and stir until the surface of the rush is evenly covered with indigo. For every 100kg of rush, use 50kg of indigo powder.

[0010] The rush also includes the following cleaning step: placing the picked rush in a cleaning solution with a mass fraction of 0.5-1.0%, soaking it at room temperature for 5-10 minutes, turning it over every 2 minutes during the soaking process, rinsing it with clean water for 3 times, drying it naturally, and cutting it into sections for later use.

[0011] The cleaning solution is higenamine hydrochloride solution.

[0012] The indigo powder also includes the following extraction steps: taking 15-20 parts of fresh indigo leaves cut into 1-2 cm, extracting with hot water for 20-30 minutes at a solid-liquid ratio of 1:1, and the temperature is 80-100°C, filtering to remove leaf residue to obtain a filtrate, adding 50-60 parts of an extracting agent solution to the filtrate for hydrolysis for 2 hours, and after the hydrolysis is completed, adding sodium hydroxide solution to adjust the solution pH to 6-8, letting it stand and discarding the supernatant, taking the precipitate, washing it to neutrality, drying it, and crushing it to obtain the indigo powder.

[0013] The extracting agent is a 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution with a mass fraction of 20-30%.

[0014] The obtained indigo powder also includes a modification process: the indigo powder obtained by the above crushing is dissolved in a 5-10% modified ethanol solution at a material ratio of 1:3, ultrasonically treated at 360w for 10 minutes to dissolve, and then placed in a grinder with the indigo powder and ground for 5-10 minutes. After taking out, rinse with clean water 2-3 times, and place in a 60°C oven to dry for 10-20 minutes.

[0015] The modified ethanol solution is a diether fluorene acrylate ethanol solution.

[0016] The advantages and beneficial effects of the present invention are:

[0017] 1. The present invention provides a method for preparing indigo mixed with rush, comprising taking cleaned and cut rush, spraying a little water, adding indigo powder, and mixing until the surface of the rush is evenly coated with indigo. The extraction process of indigo powder is improved, and the indigo powder is hydrophilically modified to obtain a high-quality indigo product.

[0018] 2. The present invention provides an indigo natural extraction process. By adding 2-hydroxypropyltrimethylisooctanoic acid ammonium salt, which is a quaternary ammonium salt substance, as an extraction promoter, on the one hand, the surface tension of water can be reduced, which is helpful to improve the solubility and dispersibility of the substance; on the other hand, the structure of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt is relatively stable and not easy to decompose, and can provide a lasting oxidizing environment, so that the precursor substance is generated in the direction of indigo red, so that the indigo red content and yield are greatly increased accordingly, the quality of indigo natural is qualitatively improved, and the application value of indigo natural in treatment is improved.

[0019] 3. The new processing technology of Indigo provided by the present invention can avoid the influence of CaCO3 caused by the introduction of lime milk in the traditional processing technology, and does not require water-flying refining and other links, and the production process is simple. The labor intensity of Indigo production is greatly reduced, the production cycle is shortened, efficient production is achieved, and the stench generated by traditional soaking can be eliminated, which is more friendly to the environment.

[0020] 4. Ordinary indigo has several spherical protrusions, and the surface is rich in small particles. This surface irregularity will lead to its poor dispersibility in the solution. The present invention adopts a solid-liquid grinding modification method to modify it with diether fluorene acrylate. After the modification, the surface of the indigo is smoother. The reason may be that the diether fluorene acrylate has modified its surface to a certain extent, which can effectively fill and cover the uneven parts of the surface of the indigo. It contains hydrophilic functional groups, such as ether bonds and carboxyl groups. These functional groups can interact with the surface of the indigo, thereby increasing the hydrophilicity of the surface of the indigo. Through chemical reaction or physical adsorption, its surface becomes smooth. Ordinary indigo has poor hydrophilicity, which is not conducive to subsequent mixing, and adheres to the surface of the wick. The modified indigo has better hydrophilicity. The indigo modified by diether fluorene acrylate has better dispersibility and stability. The better hydrophilicity allows the indigo to be evenly distributed in the subsequent mixing process, and it is easier to adhere to the surface of the wick, and the dissolution is more uniform.

[0021] 5. The hydrophilicity of the indigo modified with bisether fluorene acrylate was significantly improved, the polar component and total amount of surface free energy were significantly increased, the actual utilization rate was significantly increased, the dissolution amount of indigo and indirubin increased, and the dissolution was more stable and uniform. The antipyretic efficacy and safety of the modified indigo were not affected, and it was even better than ordinary indigo, and it was conducive to subsequent adhesion to the surface of rush, resulting in a better quality product.

[0022] 6. If the machine is not cleaned with water frequently enough, there will be residual stains, which require backwashing. If the cleaning frequency is too high, not only will the cleaning efficiency be low, but also the effective water-soluble components of rush will be lost to a certain extent. Due to its strong alkalinity and chemical activity, higenamine hydrochloride solution can quickly dissolve slightly acidic or neutral clay loam with high organic matter content and decompose organic matter, making the cleaning process quick and effective. It has a strong cleaning ability and can quickly dissolve and remove the dirt and floating dust on the surface of rush, so the time required for cleaning is shorter, which can reduce the duration of each cleaning, thereby improving the overall cleaning efficiency.

[0023] 7. In addition to its strong cleaning ability, higenamine hydrochloride has a mild effect, which can reduce the damage to the structure of rush itself and retain its active ingredients to the greatest extent, thus not affecting the subsequent efficacy. DETAILED DESCRIPTION

[0024] The present invention will be further described in detail below in conjunction with the embodiments.

[0025] Example 1

[0026] Indigo extraction: Take 18 parts of fresh Indigo leaves cut into 1.5 cm, use a solid-liquid ratio of 1:1 for hot water extraction for 25 minutes at 90°C, filter out the leaf residue to obtain a filtrate, add 55 parts of 25% by mass 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution to the filtrate and hydrolyze for 2 hours. After the hydrolysis is completed, add sodium hydroxide solution to adjust the solution pH to 7, let it stand and discard the supernatant, take the precipitate, wash it to neutrality, dry it, and grind it to obtain Indigo powder.

[0027] Example 2

[0028] Indigo extraction: Take 15 parts of fresh Indigo leaves cut into 2 cm, use a solid-liquid ratio of 1:1 for hot water extraction for 30 minutes at 80°C, filter out the leaf residue to obtain a filtrate, add 60 parts of 30% by mass 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution to the filtrate and hydrolyze for 2 hours. After the hydrolysis is completed, add sodium hydroxide solution to adjust the solution pH to 8, let it stand and discard the supernatant, take the precipitate, wash it until neutral, dry it, and grind it to obtain Indigo powder.

[0029] Example 3

[0030] Indigo extraction: Take 20 parts of fresh Indigo leaves cut into 1 cm, extract with hot water for 20 minutes at a solid-liquid ratio of 1:1 at a temperature of 100°C, filter out the leaf residue to obtain a filtrate, add 50 parts of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution with a mass fraction of 20 to the filtrate and hydrolyze for 2 hours. After the hydrolysis is completed, add sodium hydroxide solution to adjust the solution pH to 6, let it stand and discard the supernatant, take the precipitate, wash it to neutrality, dry it, and grind it to obtain Indigo powder.

[0031] Comparative Example 1

[0032] The difference between this comparative example and Example 1 is that in this comparative example, a traditional extraction process is performed on Indigo naturalis, specifically: the preparation process of Indigo naturalis for directed generation of indigo red is as follows: fresh Indigo leaves cut into 1-2 cm are placed in 60°C tap water with a pH of about 7, wherein the water volume is 15: the mass of fresh leaves. After soaking for 48 hours, the leaf residue is filtered out, the filtrate is aerated for 30 minutes, ammonia water is added to adjust the pH of the filtrate to 10.5, and then aerated for 180 minutes, and 10% freshly prepared lime milk is added (take 10% of the mass of fresh leaves, add 10 times the amount of quicklime, add to 10 times the amount of boiling water, and stir continuously to form a suspension), stir evenly and let stand for 24 hours, filter out the precipitate, and grind to obtain Indigo naturalis powder.

[0033] Comparative Example 2

[0034] The difference between this comparative example and Example 1 is that the 2-hydroxypropyltrimethylisooctanoate ammonium salt solution is hexadecyltrimethylammonium bromide, and the rest is the same as Example 1.

[0035] Comparative Example 3

[0036] The difference between this comparative example and Example 1 is that the amount of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution added in this comparative example is different, and the specific process is as follows: take 18 parts of fresh Indigo leaves cut to 1.5 cm, and extract them with hot water for 25 minutes at a solid-liquid ratio of 1:1 at a temperature of 90°C, filter out the leaf residue to obtain a filtrate, add 55 parts of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution with a mass fraction of 50% to the filtrate, and hydrolyze for 2 hours. After the hydrolysis is completed, add sodium hydroxide solution to adjust the solution pH to 7, let it stand and discard the supernatant, take the precipitate, wash it to neutrality, dry it, and grind it to obtain Indigo powder.

[0037] Comparative Example 4

[0038] The difference between this comparative example and Example 1 is that the amount of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution added in this comparative example is different, and the specific process is as follows: take 18 parts of fresh Indigo leaves cut to 1.5 cm, and extract them with hot water for 25 minutes at a solid-liquid ratio of 1:1 at a temperature of 90°C, filter out the leaf residue to obtain a filtrate, add 55 parts of 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution with a mass fraction of 10% to the filtrate, and hydrolyze for 2 hours. After the hydrolysis is completed, add sodium hydroxide solution to adjust the solution pH to 7, let it stand and discard the supernatant, take the precipitate, wash it to neutrality, dry it, and grind it to obtain Indigo powder.

[0039] Test 1: Determination of indirubin content

[0040] Preparation of reference solution: accurately weigh 2.50 mg of indigo red reference substance, place it in a 100 mL volumetric flask, add about 80 mL of DMF, sonicate to dissolve it, and dilute to the mark with DMF to serve as the indigo red stock solution;

[0041] Preparation of the test solution: Accurately weigh 1.00 mg of the sample of Example 1-3 and Comparative Example 1-4, place it in a 10 mL volumetric flask, add about 8 mL of DMF, sonicate for 30 min to dissolve it, and dilute to the mark with DMF to serve as the test solution.

[0042] Chromatographic column: Yilite YWGC18 (4.6*200mm); mobile phase: methanol: water (7:3); flow rate: 1mL / min; detection wavelength: 292nm.

[0043] Content determination: According to the above chromatographic conditions, 10 μL of 25 μg / mL indigo red reference solution and 100 μg / mL indigo naturalis test solution were injected into the high performance liquid chromatograph to determine the indigo red content in the test solution. The results are shown in Table 1.

[0044] Table 1 Indigo red content

[0045] Group Indirubin measured amount / μg Example 1 106.52 Example 2 104.21 Example 3 103.74 Comparative Example 1 65.35 Comparative Example 2 83.84 Comparative Example 3 98.36 Comparative Example 4 90.57

[0046] Example 4

[0047] Modification of Indigo powder: The Indigo powder obtained by crushing Example 1 is dissolved in 8% diether fluorene acrylate ethanol solution at a material ratio of 1:3, and ultrasonically treated at 360w for 10 minutes to dissolve, and then placed in a grinder with the Indigo powder and ground for 8 minutes. After taking out, rinse with clean water twice, and place in a 60°C oven to dry for 15 minutes.

[0048] Example 5

[0049] Modification of Indigo powder: The Indigo powder obtained by crushing Example 1 is dissolved in 5% diether fluorene acrylate ethanol solution at a material ratio of 1:3, and ultrasonically treated at 360w for 10 minutes to dissolve, and then placed in a grinder with the Indigo powder and ground for 10 minutes. After taking out, rinse with clean water twice, and place in a 60°C oven to dry for 20 minutes.

[0050] Example 6

[0051] Modification of Indigo powder: The Indigo powder obtained by crushing Example 1 is dissolved in 10% diether fluorene acrylate ethanol solution at a material ratio of 1:3, and ultrasonically treated at 360w for 10 minutes to dissolve, and then placed in a grinder with the Indigo powder and ground for 5 minutes. After taking out, rinse with clean water 3 times, and place in a 60°C oven to dry for 10 minutes.

[0052] Comparative Example 5

[0053] The difference between this comparative example and Example 4 is that the ethanol solution of diether fluorene acrylate is an ethanol solution; the rest is the same as Example 4.

[0054] Comparative Example 6

[0055] The difference between this comparative example and Example 4 is that the ethanol solution of diether fluorene acrylate is a PEG6000 solution; the rest is the same as Example 4.

[0056] Comparative Example 7

[0057] The difference between this comparative example and Example 1 is that the amount of diether fluorene acrylate ethanol solution added is different, specifically: Indigo powder modification: The indigo powder obtained by crushing Example 1 is dissolved in 15% diether fluorene acrylate ethanol solution at a material ratio of 1:3, and after ultrasonic treatment at 360w for 10 minutes to dissolve, it is placed in a grinder with the indigo powder and ground for 8 minutes. After taking out, rinse with clean water twice, and place in a 60°C oven to dry for 15 minutes.

[0058] Comparative Example 8

[0059] The difference between this comparative example and Example 1 is that the amount of diether fluorene acrylate ethanol solution added is different, specifically: Indigo powder modification: The indigo powder obtained by crushing Example 1 is dissolved in 3% diether fluorene acrylate ethanol solution at a material ratio of 1:3, and after ultrasonic treatment at 360w for 10 minutes to dissolve, it is placed in a grinder with the indigo powder and ground for 8 minutes. After taking out, rinse with clean water twice, and place in a 60°C oven to dry for 15 minutes.

[0060] Comparative Example 9

[0061] The difference between this comparative example and Example 1 is that the modified indigo powder raw material is the indigo powder prepared in Comparative Example 1, and the remaining steps are the same as Example 4.

[0062] Test 2: Contact angle test

[0063] The contact angles of the ground samples of Examples 4-6 and Comparative Examples 5-9 were tested, and the results are shown in Table 2.

[0064] Table 2 Contact angle test results

[0065] Group Contact angle (°) Example 4 26.51 Example 5 27.36 Example 6 29.58 Comparative Example 5 45.65 Comparative Example 6 39.72 Comparative Example 7 32.59 Comparative Example 8 36.93 Comparative Example 9 33.37

[0066] Example 7

[0067] Rush cleaning: place the picked rush in a 0.8% by mass higenamine hydrochloride solution, soak at room temperature for 8 minutes, turn it over every 2 minutes during the soaking process, rinse it with clean water 3 times, dry it naturally, and cut it into sections for later use.

[0068] Take the cleaned and dried rush, cut it into 5 cm segments, spray 0.8% clean water on its surface, add indigo powder, and stir until the surface of the rush is evenly covered with indigo. For every 100 kg of rush, use 50 kg of indigo powder.

[0069] Example 8

[0070] Rush cleaning: place the picked rush in a 1.0% by mass higenamine hydrochloride solution, soak for 5 minutes at room temperature, turn it over every 2 minutes during the soaking process, rinse it with clean water 3 times, dry it naturally, and cut it into sections for later use.

[0071] Take the cleaned and dried rush, cut it into 6 cm segments, spray 1% clean water on its surface, add indigo powder, and mix until the surface of the rush is evenly covered with indigo. For every 100 kg of rush, use 50 kg of indigo powder.

[0072] Example 9

[0073] Rush cleaning: place the picked rush in a 0.5% by mass higenamine hydrochloride solution, soak for 10 minutes at room temperature, turn it over every 2 minutes during the soaking process, rinse it with clean water 3 times, dry it naturally, and cut it into sections for later use.

[0074] Take the cleaned and dried rush, cut it into 4 cm segments, spray 0.5% clean water on its surface, add indigo powder, and stir until the surface of the rush is evenly covered with indigo. For every 100 kg of rush, use 50 kg of indigo powder.

[0075] Comparative Example 10

[0076] The difference between this comparative example and Example 7 is that in this comparative example, clean water is used to clean the rush. Specifically, the picked rush is placed in clean water, and the cleaning is swung back and forth for 15 minutes, and the cleaning is repeated 4 times in total; the rest is the same as Example 7.

[0077] Comparative Example 11

[0078] The difference between this comparative example and Example 7 is that the higenamine hydrochloride solution is a sodium bicarbonate solution, and the rest is the same as Example 7.

[0079] Comparative Example 12

[0080] The difference between this comparative example and Example 7 is that the content of the higenamine hydrochloride solution in this comparative example is different, specifically: the picked Juncus effusus is placed in a 1.5% by mass higenamine hydrochloride solution, soaked at room temperature for 8 minutes, turned over every 2 minutes during the soaking process, rinsed with clean water 3 times, dried naturally, and cut into sections for later use; the rest is the same as Example 7.

[0081] Comparative Example 13

[0082] The difference between this comparative example and Example 7 is that the content of higenamine hydrochloride solution in this comparative example is different, specifically: the picked Juncus effusus is placed in a higenamine hydrochloride solution with a mass fraction of 0.2%, soaked at room temperature for 8 minutes, turned over every 2 minutes during the soaking process, rinsed with clean water 3 times, dried naturally, and cut into sections for later use; the rest is the same as Example 7.

[0083] Test 3: Determination of Juncus effusus Phenanthrene Components

[0084] The reference substances desaminoephrol (batch number: MBI3634), ephrol (batch number: MBI3633), and juncophenol (batch number: MBI3637) were all purchased from Dalian Meilun Biotechnology Co., Ltd., with a purity greater than 98%; methanol was chromatographically pure; anhydrous ethanol was analytically pure; and water was ultrapure water.

[0085] Chromatographic conditions: chromatographic column: ACQUITY UHPLC HSS-T3 chromatographic column (100 mm x 2.1 mm; 1.7 mm), mobile phase: methanol (A) - water (B), gradient elution (0-5 min, 3% -30% A: 5-6 min, 30% -35% A; 6-7 min, 35% -40% A: 7-20 min, 40% ~ 100% A); column temperature is 27 ° C; detection wavelength is 265 nm; flow rate is 0.2 mL'min-; sample room temperature is 10 ° C; analysis time is 20 min: injection volume is 1.0 μL, and the number of theoretical plates calculated based on juncophenol should not be less than 30009.

[0086] Preparation of reference solution: Accurately weigh dehydroephagenol, ephagenol, and rushol reference substances, add methanol to completely dissolve them, and prepare mixed reference solution with mass concentrations of dehydroephagenol, ephagenol, and rushol of 68.35, 81.60, and 82.41 μg / mL, respectively.

[0087] Preparation of test solution: Grind the rush of Examples 7-9 and Comparative Examples 10-13, take about 0.1 g of powder, accurately weigh it, put it in a stoppered conical flask, accurately add 25 mL of 95% ethanol, stopper it, weigh it, treat it with ultrasound (250 W, 40 kHz) for 30 min, take it out, cool it, weigh it again, make up for the loss with 95% ethanol if there is any loss, shake it well, filter it through quantitative filter paper, take the filtrate, filter it into a sample vial with a 0.22 mm microfiltration membrane, and obtain it.

[0088] The results are shown in Table 3.

[0089] Table 3 Determination of Juncus effusus phenanthroline components

[0090] Group Desaminoglycan(mg / g) Ephedrine(mg / g) Juncophenol(mg / g) Example 7 1.89 0.91 0.76 Example 8 1.87 0.87 0.75 Example 9 1.85 0.88 0.72 Comparative Example 10 0.67 0.45 0.28 Comparative Example 11 1.12 0.55 0.35 Comparative Example 12 1.67 0.77 0.67 Comparative Example 13 1.49 0.68 0.59

[0091] To 100kg of Poria cocos slices, add 1kg of cinnabar powder and stir until the surface of the Poria cocos is evenly coated with red.

[0092] Experiment 3: Disintegration performance of Zhu Fuling tablets

[0093] Six Zhu Fuling tablets were taken from each group, and the average disintegration time was determined according to the pharmacopoeia method. The results are shown in Table 3.

[0094] Group Disintegration time / min Example 7 5.65 Example 8 6.84 Example 9 6.93

Claims

1. A method for preparing Indigo Naturalis mixed with rush, characterized in that: The processing method specifically comprises the following steps: Take the cleaned and dried rush, cut it into 4-6cm segments, spray 0.5%-1% clean water on its surface, add indigo powder, and mix until the surface of the rush is evenly covered with indigo. For every 100kg of rush, use 50kg of indigo powder.

2. The method for preparing Indigo Naturalis mixed with rush according to claim 1, characterized in that: The rush also includes the following cleaning step: placing the picked rush in a cleaning solution with a mass fraction of 0.5-1.0%, soaking it at room temperature for 5-10 minutes, turning it over every 2 minutes during the soaking process, rinsing it with clean water for 3 times, drying it naturally, and cutting it into sections for later use.

3. A method for preparing Indigo Naturalis mixed with rush according to claim 2, characterized in that: The cleaning solution is higenamine hydrochloride solution.

4. The method for preparing Indigo Naturalis mixed with rush according to claim 1, characterized in that: The indigo powder also includes the following extraction steps: taking 15-20 parts of fresh indigo leaves cut into 1-2 cm, extracting with hot water for 20-30 minutes at a solid-liquid ratio of 1:1, and the temperature is 80-100°C, filtering to remove leaf residue to obtain a filtrate, adding 50-60 parts of an extracting agent solution to the filtrate for hydrolysis for 2 hours, and after the hydrolysis is completed, adding sodium hydroxide solution to adjust the solution pH to 6-8, letting it stand and discarding the supernatant, taking the precipitate, washing it to neutrality, drying it, and crushing it to obtain the indigo powder.

5. The method for preparing Indigo Naturalis mixed with rush according to claim 4, characterized in that: The extracting agent is a 2-hydroxypropyltrimethylisooctanoic acid ammonium salt solution with a mass fraction of 20-30%.

6. The method for preparing Indigo Naturalis mixed with rush according to claim 4, characterized in that: The obtained indigo powder also includes a modification process: the indigo powder obtained by the above crushing is dissolved in a 5-10% modified ethanol solution at a material ratio of 1:3, ultrasonically treated at 360w for 10 minutes to dissolve, and then placed in a grinder with the indigo powder and ground for 5-10 minutes. After taking out, rinse with clean water 2-3 times, and place in a 60°C oven to dry for 10-20 minutes.

7. The method for preparing Indigo Naturalis mixed with rush according to claim 6, characterized in that: The modified ethanol solution is a diether fluorene acrylate ethanol solution.