Preparation process for luteolin

Abstract

The present invention relates to a preparation method for luteolin. A preparation process for luteolin comprises the steps of: pretreatment of raw material rutin, degreasing before extraction, preparation of modified cellulase, enzyme-assisted ultrasonic treatment, preparation of feed liquid, and purification to obtain luteolin. Compared with traditional extraction methods, the present invention overcomes the shortcomings in traditional organic solvent extraction technologies, integrates the advantages of an enzymatic technology and traditional extraction processes, optimizes process conditions in the extraction process, and improves the extraction yield of luteolin. A silica gel column chromatography method uses the steps of extraction and separation. Luteolin has a broad spectrum of biochemical and pharmacological activities.

Description

A preparation process of luteolin Technical Field

[0001] The invention belongs to an extraction method, and particularly relates to a preparation process of luteolin. Background Art

[0002] Luteolin, chemically known as 3',4',5,7-tetrahydroxyflavone, is a yellow needle-shaped crystal. It is a representative natural flavonoid that is widely distributed in the plant kingdom. However, due to the large number of flavonoid compounds with similar structures to luteolin, the purification of luteolin by macroporous adsorption resin method has certain limitations.

[0003] Luteolin has multiple pharmacological effects, including antibacterial, anti-inflammatory, and astringent properties, and also has the pharmacological functions of a vitamin. Furthermore, luteolin and its glycosides have pharmacological effects such as antispasmodic, antihypertensive, and enhanced coronary blood flow. Recent reports indicate that luteolin also has important antihypertensive and anticancer properties. Currently, luteolin is mainly extracted from rutin, chrysanthemum, and luteolin, both domestically and internationally, but the extraction rates are relatively low. Although my country is a major producer of Chinese herbal medicine, the content of luteolin is very low, and these plants contain a large number of other flavonoids, phenols, tannins, and other substances, resulting in a high level of impurities in the extracts. These impurities have a negative impact on the efficacy of luteolin.

[0004] By studying the effects of luteolin on human choroidal melanoma cells (C918 and OCM-1), it was found that luteolin may induce cell apoptosis by regulating the levels of apoptosis-related proteins in C918 and OCM-1 cells. Luteolin can induce cell cycle arrest and reduce the expression and secretion of vascular endothelial growth factor. Hu et al. found that luteolin pretreatment can improve the expression of SERCA2a by upregulating Sp1, thereby alleviating myocardial ischemia / reperfusion injury. The study found that luteolin can inhibit the production of cold-induced RNA-binding protein (CIRP) and alleviate lung injury in neonatal sepsis, which may be related to downregulating HIF-1a and The results indicate that luteolin has anti-inflammatory effects, and thus luteolin can be developed as an adjuvant therapy for neonatal sepsis. The study explored the role of luteolin in alleviating sevoflurane-induced neurotoxicity and found that luteolin inhibits sevoflurane-induced neuronal apoptosis and inflammatory response by activating autophagy caused by upregulation of heme oxygenase-1, thereby alleviating cognitive impairment in sevoflurane-induced mice. The study found that luteolin may change the polarity of bone marrow-derived macrophages (BMDM) through p-STAT1 / 6, thereby regulating the expression of inflammatory mediators and inhibiting inflammation. Naturally occurring luteolin is expected to be used as an anti-inflammatory and immunomodulatory agent.

[0005] There are relatively many analytical tests and clinical studies on luteolin at home and abroad, as well as its pharmacological properties. Luteolin has high medicinal value, and its development and application in clinical practice are of great research significance. Summary of the Invention

[0006] The present invention provides a preparation process of luteolin, which comprises the following steps: pretreatment of raw material rutin, defatting before extraction, preparation of modified cellulase, enzyme-assisted ultrasonic treatment, preparation of feed liquid, and purification to obtain luteolin.

[0007] As a preference, step (1) pretreatment of the raw material rutin

[0008] First, a certain amount of raw rutin is washed and dried, then crushed into coarse powder and stored for later use; finally, an appropriate amount of the coarse rutin powder is weighed and pre-treated, and then dissolved in a certain volume of a buffer solution of appropriate pH value;

[0009] Step (2) Degreasing before extraction

[0010] Take the crushed rutin powder and add petroleum ether to the liquid, and use ultrasonic degreasing;

[0011] Step (3) Preparation method of modified cellulase:

[0012] A citric acid-sodium citrate buffer solution is measured and added to a three-necked flask equipped with a thermometer, a rotor, and a condenser; the three-necked flask is placed in a constant temperature magnetic stirrer and the temperature is set to a certain time. After the temperature reaches an appropriate temperature, an appropriate amount of monomethoxy polyethylene glycol maleimide (mPEG-MAL5 K) is added and slowly stirred to dissolve it completely. Then, a certain amount of natural cellulase is added. After it is completely dissolved, the timing is started, the reaction is allowed to proceed for a period of time, and the reaction is stopped. Then, the modified cellulase (Cell-MAL 5 K) is finally obtained by dialyzing in a citric acid-sodium citrate solution with a certain value for a certain period of time using a dialysis bag.

[0013] Step (4) Enzyme-assisted ultrasonic treatment

[0014] First, dissolve it in alkaline solution and add several times of reducing agent; add appropriate amount of complex enzyme (cellulase, hemicellulase) and shake well, then place it in a specific ultrasonic cleaner and treat it at a specific temperature for a period of time, then take it out and kill the enzyme in a water bath at a suitable temperature and centrifuge it for a certain time, centrifuge it at a suitable temperature for a certain time, and repeat the operation; then heat the raw materials to a certain temperature and add cellulase.

[0015] Step (5) Preparation of liquid

[0016] After stirring the reaction solution for a period of time, filter press it while hot to obtain a filtrate; cool the filtrate to an appropriate temperature, slowly add hydrochloric acid and adjust the pH to a certain value; bubbles will be generated in this process, and when the pH value reaches a certain value, a large number of bubbles are likely to be generated, and attention should be paid to the acid addition rate; heat and stir for a period of time, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0017] Step (6) Purification to obtain luteolin

[0018] The content of 1G luteolin is low. 1G solid is added to ethanol, heated and stirred for a certain time, filtered to obtain 2M to obtain 2G, and then added to ethanol aqueous solution for pulping. The mixture is heated and stirred for a certain time and filtered to obtain 3M to obtain 3G. The mixture is precipitated and crystallized, and vacuum dried to obtain luteolin.

[0019] As a preference, step (1) pretreatment of the raw material rutin

[0020] First, 25-30 grams of raw rutin is washed and dried, then crushed into coarse powder and stored at 0-4°C for later use. Finally, 2.6-3.5 grams of the rutin coarse powder is weighed and pretreated, and then dissolved in a certain volume of a buffer solution with an appropriate pH value.

[0021] The present invention has the advantages of simultaneously completing the enrichment and purification of raw rutin, greatly improving the detection sensitivity, being faster than liquid-liquid extraction, saving more solvent, and being capable of automated batch processing, making the rutin extraction process faster and more convenient, while also making the extracted raw rutin purer.

[0022] As a preference, step (2) is to defatted before extraction.

[0023] Take the crushed rutin powder and add petroleum ether at a ratio of 1:10-2:10 of feed liquid, and degrease twice by ultrasonication, each time for about 1-3 minutes.

[0024] The advantage of the present invention is that since fresh rutin contains a certain amount of oil and chlorophyll, defatting before extraction can not only effectively reduce the content of fat-soluble impurities in the extract, but also promote the expansion of cell gaps, which is beneficial to the penetration of the extractant and promotes the rapid dissolution of effective ingredients during the extraction process.

[0025] Preferably, step (3) is to prepare modified cellulase

[0026] 30-40 mL of citric acid-sodium citrate buffer solution with a pH of 7-8 was measured and added to a 40-50 mL three-necked flask equipped with a thermometer, a rotor, and a condenser; the three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 30-40 ° C. After the temperature reached 30-40 ° C, 100-150 mg of monomethoxy polyethylene glycol maleimide (mPEG-MAL5 K) was added and slowly stirred to dissolve it completely. Then, 100-150 mg of natural cellulase was added. After it was completely dissolved, the timing was started. The reaction time was 1-3 hours. The reaction was stopped, and then dialyzed in a citric acid-sodium citrate solution with a pH of 4-5 using an 8000-12000 dialysis bag for 10-12 hours to finally obtain 2-4 mg / mL of modified cellulase (Cell-MAL 5 K);

[0027] The advantage of the present invention is that a macromolecular binding modification method is used to construct a cellulase with high stability in an alkaline system, which can enhance the stability and catalytic efficiency of the enzyme and is beneficial to the release or extraction of luteolin during the extraction or utilization process of luteolin.

[0028] Preferably, step (4) enzyme-assisted ultrasonic treatment

[0029] First, dissolve it in 20-30 times alkali solution and 2-4 times reducing agent; add appropriate amount of complex enzyme (cellulase, hemicellulase), shake well and place it in a specific ultrasonic cleaner for treatment at a specific temperature for 30-40 minutes, then take it out and kill the enzyme in 85-90℃ water bath for 10-12 minutes, centrifuge, and set the centrifugal filtration parameters to a speed of 5000-5200r / min and a temperature of 5-6℃ for 10-12 minutes, repeat 3-4 times; then heat the raw material to 50℃-55℃ and finally add cellulase, and finally, assist with ultrasonic treatment.

[0030] The invention has the advantages that cellulose hydrolase can be used to destroy the cell wall structure and the pectin connecting the cells, so that the cell wall is loose and broken, thereby reducing the mass transfer resistance of the extraction; finally, ultrasonic treatment is performed, wherein the enzyme-assisted ultrasonic treatment method is used to extract rutin to obtain luteolin; ultrasonic waves can produce comprehensive effects such as cavitation, vibration, crushing, and stirring, so when applied to the natural product component extraction process, the cell content can be extracted by destroying the cell wall; due to the shortcomings of traditional organic solvent extraction technology, enzyme-assisted ultrasonic treatment is required to improve the extraction rate of luteolin.

[0031] As a preference, step (5) of preparing the liquid:

[0032] After stirring the reaction solution for 2-3 hours, filter press it while hot to obtain a filtrate; cool the filtrate to below 30-40°C, slowly add hydrochloric acid and adjust the pH to 3-6; bubbles will be generated during this process, and a large number of bubbles are likely to be generated when the pH reaches 7-8, so pay attention to the acid addition rate; heat and stir for 2-3 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0033] As a preferred method, step (6) is to purify and obtain luteolin.

[0034] 1G luteolin content is low. Add ethanol to 1G solid and heat and stir for 2-3 hours, filter to obtain 2M to obtain 2G, add ethanol aqueous solution again to slurry, heat and stir for 2-4 hours, filter to obtain 3M to obtain 3G, precipitate and crystallize, and vacuum dry to obtain luteolin.

[0035] The present invention has the advantages of simple process, improved extraction rate of luteolin, and reduced residual amount of luteolin in rutin.

[0036] Preferably, step (7) of the present invention is to purify luteolin to obtain

[0037] A temperature-controllable pulping and purification device is adopted, comprising a tank body, a discharging mechanism is provided at the bottom end of the tank body, a support frame is provided on the tank body, a slot is provided at the top end of the tank body, a top cover is provided on the slot, a water inlet pipe, a heater and a stirring mechanism are provided on the top cover, an annular heating pipe is provided between the heater and the bottom end of the top cover, a vertical heating pipe is provided at the bottom end of the annular heating pipe, a lifting mechanism is provided between the support frame and the top cover, the lifting mechanism comprises a support plate and an electric telescopic rod, the support plate and the electric telescopic rod are both installed on the support frame, and the output end of the electric telescopic rod is provided between the top cover and the bottom end. A connecting box is provided, wherein an adjustment groove is provided inside the connecting box, an elastic component and a fastening plate are provided on the adjusting groove, an opening is provided between the adjusting groove and one side of the connecting box, a fastening inclined column is provided between the fastening plate and the opening, a fastening groove is provided on one side of the fastening plate, a through hole is provided between the fastening groove and the fastening plate, a fastening block is provided on the fastening groove, an adjusting column is provided between the fastening block and the through hole, a telescopic mechanism is provided on the other side of the connecting box, the telescopic mechanism is connected to the adjusting column, a docking groove is provided on the support plate, two docking grooves are provided, and two lifting mechanisms are provided and symmetrically arranged.

[0038] Furthermore, the stirring mechanism includes a stirring motor and a stirring shaft, the stirring motor is installed at the top end of the top cover, the output end of the stirring motor extends to the bottom end of the top cover, the stirring shaft is connected to the output end of the stirring motor, and the stirring shaft is provided with stirring blades;

[0039] The discharging mechanism includes a discharging pipe, which is installed at the bottom end of the tank body and is provided with a solenoid valve;

[0040] There are multiple vertical heating tubes arranged in a circular array.

[0041] In summary, the advantages of the present invention are:

[0042] 1. The addition of ethanol solvent can effectively reduce water-soluble impurities in the medicinal material extract; on the one hand, the increase in the amount of solvent increases the concentration difference of luteolin between rutin and the solvent, reduces the residual amount of luteolin in rutin, and thus increases the extraction yield; on the other hand, a significant increase in the dosage will lead to a longer time for reagent recovery, higher energy consumption, and waste of resources; the extraction yield of luteolin gradually increases with the extension of extraction time. If the extraction time is too long, ethanol will evaporate and the solvent content will decrease. In addition, long-term heating may also cause the active ingredients of luteolin flavonoids to be damaged and the stability to deteriorate, which also leads to a decrease in the extraction yield. Therefore, the extraction time should not be too long; the use of ultrasonic-assisted composite enzyme extraction can effectively shorten the extraction time and improve the extraction efficiency;

[0043] 2. A macromolecular binding modification method is used to construct a cellulase with high stability in an alkaline system, which can enhance the stability and catalytic efficiency of the enzyme and is beneficial to the release or extraction of luteolin during the extraction or utilization process.

[0044] 3. The temperature-controllable beating and purification device heats the annular heating tube by controlling the heater, so that the heat is transferred to the vertical heating tube through the annular heating tube, thereby heating the liquid inside the tank body, thereby achieving temperature control of the liquid inside the tank body, so that the liquid is in a temperature range suitable for solvent reaction, ensuring the purification effect and speed.

[0045] 4. The use of cellulose hydrolase can destroy the cell wall structure and the pectin connecting the cells, making the cell wall loose and broken, reducing the mass transfer resistance of the extraction; finally, it is assisted by ultrasonic treatment, in which enzyme-assisted ultrasonic treatment is used to extract rutin to obtain luteolin; ultrasound can produce cavitation, vibration, crushing, stirring and other comprehensive effects, so its application in the natural product ingredient extraction process can achieve the process of extracting cell contents by destroying the cell wall; due to the shortcomings of traditional organic solvent extraction technology, enzyme-assisted ultrasonic treatment is required to improve the extraction rate of luteolin. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] FIG1 is a schematic diagram of a preparation process of luteolin according to the present invention;

[0047] FIG2 is a schematic diagram of the crystallization process of luteolin in Example 1 of the present invention;

[0048] FIG3 is a schematic structural diagram of a temperature-controllable pulping and purification device according to the present invention;

[0049] FIG4 is a front view of a half-section of the structure of a temperature-controllable beating and purification device according to the present invention;

[0050] FIG5 is a left half-sectional view of the enlarged structure of the connection box in FIG2 of the temperature-controllable beating and purification device of the present invention.

[0051] In the figure: 1. Tank body; 2. Support frame; 3. Top cover; 4. Heater; 5. Annular heating tube; 6. Vertical heating tube; 7. Support plate; 8. Electric telescopic rod; 9. Connection box; 10. Elastic component; 11. Fastening plate; 12. Fastening inclined column; 13. Fastening block; 14. Adjusting column; 15. Telescopic mechanism; 16. Stirring motor; 17. Stirring shaft; 18. Discharge pipe; 19. Solenoid valve. DETAILED DESCRIPTION

[0052] Example 1

[0053] Step (1) Pretreatment of raw material rutin

[0054] First, 25 grams of raw rutin was washed and dried, then ground into coarse powder and stored at 4°C for later use. Finally, 2.6 grams of rutin coarse powder was weighed and dissolved in a certain volume of buffer solution with appropriate pH value after rutin pretreatment.

[0055] Step (2) Degreasing before extraction

[0056] Take the crushed rutin powder and add petroleum ether at a ratio of 1:10, and use ultrasonic degreasing twice, 2 minutes each time;

[0057] Step (3) Preparation of modified cellulase

[0058] 30 mL of pH = 7.0 citric acid-sodium citrate buffer solution was measured and added to a 50 mL three-necked flask equipped with a thermometer, rotor and condenser; the three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 35°C. After the temperature reached 35°C, 150 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K) was added and slowly stirred to dissolve it completely. Then 150 mg of natural cellulase was added. After it was completely dissolved, the timing was started. The reaction time was 3 h. The reaction was stopped and then dialyzed in a citric acid-sodium citrate solution with a pH = 4.8 using an 8000-12000 dialysis bag for 12 h to finally obtain 3 mg / mL of modified cellulase (Cell-MAL 5 K).

[0059] Step (4) Enzyme-assisted ultrasonic treatment

[0060] First, dissolve it in 25 times alkali solution and 3.5 times reducing agent (auxiliary materials: thiourea dioxide, potassium chloride, potassium carbonate); after heating to 50°C, add appropriate amount of complex enzyme (cellulase, hemicellulase), shake well and place it in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then take it out and inactivate the enzyme in an 85°C water bath for 10 minutes, and set the centrifugal filtration parameters to 5000r / min and 5°C for 10 minutes, repeat 3 times, then heat the raw material to 50°C and finally add cellulase, and finally, assist with ultrasonic treatment.

[0061] Step (5) Preparation of liquid

[0062] After stirring the reaction solution for 3 hours, filter press it while hot to obtain a filtrate. The filtrate was cooled to 38°C and slowly added with hydrochloric acid to adjust the pH to 3.7. This process will produce bubbles, and a large amount of bubbles will easily be generated when the pH is 7, so the acid addition rate should be paid attention to. Stir for 3 hours, heat, and finally filter press it while hot. After using plate and frame filter press, 1g of solid was obtained, and 1M was discarded.

[0063] Step (6) Purification to obtain luteolin

[0064] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 3 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 4 hours and filtered to obtain 3M to obtain 3G. Luteolin is obtained after precipitation and crystallization and vacuum drying.

[0065] Wherein, referring to Figures 3-5, the process of extracting luteolin in step (6) adopts a specific temperature-controllable pulping and purification device, which includes a tank body 1, a discharging mechanism is provided at the bottom end of the tank body 1, a support frame 2 is provided on the tank body 1, a slot is provided at the top end of the tank body 1, a top cover 3 is provided on the slot, a water inlet pipe, a heater 4 and a stirring mechanism are provided on the top cover 3, an annular heating pipe 5 is provided between the heater 4 and the bottom end of the top cover 3, a vertical heating pipe 6 is provided at the bottom end of the annular heating pipe 5, a lifting mechanism is provided between the support frame 2 and the top cover 3, the lifting mechanism includes a support plate 7 and an electric telescopic rod 8, the support plate 7 and the electric telescopic rod 8 are both installed on the support frame 2, a connecting box 9 is provided between the output end of the electric telescopic rod 8 and the top cover 3, and the internal opening of the connecting box 9 An adjusting groove is provided, an elastic component 10 and a fastening plate 11 are provided on the adjusting groove, an opening is provided between the adjusting groove and one side of the connecting box 9, a fastening oblique column 12 is provided between the fastening plate 11 and the opening, a fastening groove is provided on one side of the fastening plate 11, a through hole is provided between the fastening groove and the fastening plate 11, a fastening block 13 is provided on the fastening groove, an adjusting column 14 is provided between the fastening block 13 and the through hole, a telescopic mechanism 15 is provided on the other side of the connecting box 9, the telescopic mechanism 15 is connected to the adjusting column 14, a docking groove is provided on the support plate 7, two docking grooves are provided, and two lifting mechanisms are provided and symmetrically arranged. In this embodiment, personnel access the liquid and solvent through the water inlet pipe, and then facilitate the mixing of the solvent and the liquid by controlling the stirring mechanism, and then control the annular heating by controlling the heater 4 The heat pipe 5 is heated, and the heat is conducted to the vertical heating pipe 6 through the annular heating pipe 5, thereby heating the liquid inside the tank body 1, realizing temperature control of the liquid inside the tank body 1, so that the liquid is in a temperature range suitable for solvent reaction, ensuring the purification effect and speed, and facilitating the discharge of the purified liquid by using a discharging mechanism. The tank body 1 is a common pulping purification tank in existing life, and is not described in detail in this structure. After long-term use or before the next purification, impurities and residual solvents or liquids will remain inside the tank body 1, the annular heating pipe 5 and the vertical heating pipe 6. At this time, personnel need to clean them up, and the adjusting column 14 is driven to move by controlling the telescopic mechanism 15, so that the adjusting column 14 drives the fastening block 13 to move, and the fastening block 13 is fastened. Drive the fastening plate 11 to move, the elastic component 10 is squeezed and contracted to deform, so that one end of the fastening oblique column 12 leaves a docking groove, and then the output end of the electric telescopic rod 8 is controlled to move the connecting box 9 upward. The connecting box 9 in the two lifting mechanisms drives the top cover 3 to move upward stably, so that the top cover 3 leaves the slot opened at the top of the tank body 1, and the telescopic mechanism 15 is reset. When the fastening oblique column 12 on the connecting box 9 is aligned with the other docking groove, the fastening plate 11 is supported by the elastic component 10 so that the fastening oblique column 12 is inserted into the aligned docking groove. At this time, the connecting box 9 is fixed to the support plate 7, so that the height of the top cover 3 is fixed. At this time, the annular heating pipe 5 and the vertical heating pipe 6 are exposed to the outside, which is convenient for personnel to clean and inspect, and the slots are convenient for cleaning the inside of the tank body 1.At the same time, the stirring mechanism on the top cover 3 is convenient for personnel to inspect and maintain, thereby enabling more efficient cleaning and maintenance operations. When the top cover 3 needs to be assembled on the slot, the telescopic mechanism 15 is controlled to move the fastening block 13 through the adjustment column 14. The fastening block 13 drives the fastening plate 11 to move, and the elastic component 10 is squeezed and deformed, causing one end of the fastening oblique column 12 to leave the docking slot it abuts against. The output end of the electric telescopic rod 8 is controlled to reset, so that the top cover 3 abuts against the slot. The telescopic mechanism 15 is controlled to reset. At this time, the fastening oblique column 12 is aligned with and abuts the originally corresponding docking slot, thereby fixing the connection box 9 on the support plate 7 and the top cover 3.

[0066] In this solution, the stirring mechanism includes a stirring motor 16 and a stirring shaft 17. The stirring motor 16 is installed at the top of the top cover 3. The output end of the stirring motor 16 extends to the bottom end of the top cover 3. The stirring shaft 17 is connected to the output end of the stirring motor 16. The stirring shaft 17 is provided with stirring blades. The stirring shaft 17 is driven to rotate by controlling the output end of the stirring motor 16. The stirring shaft 17 rotates inside the tank body 1. The stirring shaft 17 drives the stirring blades to rotate, thereby stirring the liquid inside the tank body 1 and mixing the solvent in the liquid.

[0067] In this solution, the discharge mechanism includes a discharge pipe 18, which is installed at the bottom end of the tank body 1. A solenoid valve 19 is provided on the discharge pipe 18. By switching the solenoid valve 19, the liquid inside the tank body 1 can be easily controlled to be discharged from the discharge pipe 18.

[0068] In this solution, a plurality of vertical heating tubes 6 are provided and arranged in a circular array. By providing a plurality of vertical heating tubes 6 arranged in a circular array, the liquid inside the tank body 1 can be heated more efficiently.

[0069] In this embodiment, the stirring motor 16 is a servo motor. The servo motor has the characteristic of high rotation accuracy, thereby improving the rotation accuracy of the stirring motor 16.

[0070] In this solution, the docking groove is adapted to the fastening oblique column 12. By adapting the docking groove to the fastening oblique column 12, one end of the fastening oblique column 12 can be more stably pressed against the docking groove, thereby making the top cover 3 more firmly fixed.

[0071] In this solution, the telescopic mechanism 15 is a cylinder, which can facilitate the linear movement of the adjustment column 14. The cylinder has the characteristics of low power consumption and high precision.

[0072] In this solution, a rubber sealing ring is provided at the bottom end of the top cover 3 , and the rubber sealing ring at the bottom end of the top cover 3 can improve the sealing between the top cover 3 and the top groove of the tank body 1 .

[0073] Example 2

[0074] Step (1) Pretreatment of raw material rutin

[0075] First, 25.6 g of raw rutin was washed, dried, and then ground into coarse powder and stored at 2°C for later use. Finally, 1 g of the coarse rutin powder was weighed and pretreated, and then dissolved in a certain volume of buffer solution with an appropriate pH value.

[0076] Step (2) Degreasing before extraction

[0077] Since fresh rutin contains a certain amount of oil and chlorophyll, it must be defatted before extraction. This can promote the expansion of intercellular spaces, facilitate the penetration of the extractant, and promote the rapid dissolution of the active ingredients during the extraction process. Take the crushed rutin powder and add petroleum ether at a ratio of 1:20 to the liquid, and defatted twice with ultrasonic wave, each time for 2 minutes.

[0078] Step (3) Preparation of modified cellulase

[0079] 31 mL of pH 7.5 citric acid-sodium citrate buffer solution was measured and added to a 49 mL three-necked flask equipped with a thermometer, rotor, and condenser. The three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 35°C. After the temperature reached 35°C, 100 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K, 10 K, 20 K) was added and slowly stirred to dissolve it completely. Then, 100 mg of native cellulase was added. After it was completely dissolved, the reaction time was started. The reaction time was 10 h. The reaction was stopped and dialyzed in a citric acid-sodium citrate solution with an 8000-12000 dialysis bag for 11 h in a pH 4.5 solution to finally obtain 2 mg / mL of modified cellulase (Cell-MAL 5 K, 10 K, 20 K).

[0080] Step (4) Enzyme-assisted ultrasonic treatment

[0081] First, it was dissolved in 27 times alkali solution and 4.6 times reducing agent (auxiliary materials: thiourea dioxide: potassium chloride: potassium carbonate); enzyme pretreatment was performed, the pH value was first adjusted to 3.6, heated to 35°C, an appropriate amount of complex enzyme (cellulase, hemicellulase) was added, shaken well, and placed in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then taken out and inactivated in an 85°C water bath for 10 minutes, centrifuged, and the centrifugal filtration parameters were set to a speed of 5000 r / min and a temperature of 5°C for 10 minutes, repeated 3 times, then the raw material was heated to 55°C and cellulase was added, and finally, it was assisted with ultrasonic treatment.

[0082] Step (5) Preparation of liquid

[0083] After stirring the reaction solution for 3 hours, filter press it while hot to obtain a filtrate; cool the filtrate to 38, slowly add hydrochloric acid to adjust the pH to 3.7; bubbles will be generated during this process, and a large number of bubbles are likely to be generated when the pH reaches 7, so attention should be paid to the acid addition rate; heat and stir for 2 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0084] Step (6) Purification to obtain luteolin

[0085] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 3 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 2 hours and filtered to obtain 3M to obtain 3G. The solid is precipitated and crystallized, and vacuum dried to obtain luteolin.

[0086] Example 3

[0087] Step (1) Pretreatment of raw material rutin

[0088] First, 26.6 g of raw rutin was washed and dried, then ground into coarse powder and stored at 2°C for later use. Finally, 8.9 g of the pre-treated rutin powder was weighed and dissolved in a certain volume of buffer solution with an appropriate pH value by adding 20 mL of ethanol aqueous solution.

[0089] Step (2) Degreasing before extraction

[0090] Since fresh rutin contains a certain amount of oil and chlorophyll, defatting before extraction can not only effectively reduce the content of fat-soluble impurities in the extract, but also promote the expansion of cell gaps, which is beneficial to the penetration of the extractant and promotes the rapid dissolution of the active ingredients during the extraction process. Take the crushed rutin powder and add petroleum ether to the liquid at a ratio of 1:30, and use ultrasonic degreasing twice, each time for 2 minutes.

[0091] Step (3) Preparation of modified cellulase

[0092] 35 mL of pH 7.2 citric acid-sodium citrate buffer solution was measured and added to a 40 mL three-necked flask equipped with a thermometer, rotor, and condenser. The three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 33°C. After the temperature reached 33°C, 120 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K, 10 K, 20 K) was added and slowly stirred to dissolve it completely. Then, 120 mg of native cellulase was added. After it was completely dissolved, the reaction time was started. The reaction time was 2 h. The reaction was stopped and dialyzed in a citric acid-sodium citrate solution with an 8000-12000 dialysis bag for 10 h in a pH 4.8 solution to finally obtain 32 mg / mL of modified cellulase (Cell-MAL 5 K, 10 K, 20 K).

[0093] Step (4) Enzyme-assisted ultrasonic treatment

[0094] First, dissolve it in 29 times alkali solution and 4.6 times reducing agent (auxiliary materials: thiourea dioxide: potassium chloride: potassium carbonate); heat to 40°C, add appropriate amount of complex enzyme (cellulase, hemicellulase), shake well and place it in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then take it out and kill the enzyme in an 85°C water bath for 10 minutes, centrifuge, and set the centrifugal filtration parameters to a speed of 5000r / min and a temperature of 5°C for 10 minutes, repeat 3 times, then heat the raw material to 40°C and finally add cellulase, and finally, assist with ultrasonic treatment.

[0095] Step (5) Preparation of liquid

[0096] After stirring the reaction solution for 3 hours, filter press it while hot to obtain a filtrate; cool the filtrate to below 40°C, slowly add hydrochloric acid and adjust the pH to 3.6; bubbles will be generated during this process, and a large number of bubbles will easily be generated when the pH reaches 7, so attention should be paid to the acid addition rate; heat and stir for 3 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0097] Step (6) Purification to obtain luteolin

[0098] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 3 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 4 hours and filtered to obtain 3M to obtain 3G. Luteolin is obtained after precipitation and crystallization and vacuum drying.

[0099] Example 4

[0100] Step (1) Pretreatment of raw material rutin

[0101] First, 27 grams of raw rutin was crushed, washed, dried, and then crushed into coarse powder. After washing and drying, the powder was crushed into coarse powder and stored at 3°C ​​for later use. Finally, 8 grams of the rutin coarse powder was weighed and pretreated, and then dissolved in a certain volume of a buffer solution with an appropriate pH value.

[0102] Step (2) Degreasing before extraction

[0103] Since fresh rutin contains a certain amount of oil and chlorophyll, it must be defatted before extraction. This can promote the expansion of intercellular spaces, facilitate the penetration of the extractant, and promote the rapid dissolution of the active ingredients during the extraction process. Take the crushed rutin powder and add petroleum ether at a ratio of 1:0 to the liquid, and defatted twice with ultrasonic wave, each time for 2 minutes.

[0104] Step (3) Preparation of modified cellulase

[0105] 37 mL of pH = 7.6 citric acid-sodium citrate buffer solution was measured and added to a 44 mL three-necked flask equipped with a thermometer, rotor and condenser; the three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 35°C. After the temperature reached 35°C, 130 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K, 10 K, 20 K) was added and slowly stirred until it was completely dissolved. Then, 130 mg of native cellulase was added. After it was completely dissolved, the reaction time was started. The reaction time was 2 h. The reaction was stopped and dialyzed in a citric acid-sodium citrate solution with an 8000-12000 dialysis bag for 12 h in a pH = 4.2 citric acid-sodium citrate solution to finally obtain 3 mg / mL of modified cellulase (Cell-MAL 5 K, 10 K, 20 K).

[0106] Step (4) Enzyme-assisted ultrasonic treatment

[0107] First, it is dissolved in 26 times alkali solution and 5.6 times reducing agent; enzyme pretreatment is carried out, the pH value is first adjusted to 6.7, heated to 45℃, an appropriate amount of complex enzyme (cellulase, hemicellulase) is added, shaken well, and placed in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then taken out and inactivated in an 85℃ water bath for 10 minutes, centrifuged and filtered with the parameters set to a speed of 5000r / min and a temperature of 5℃ for 10 minutes, and repeated 3 times; then the raw material is heated to 45℃ and cellulase is added, and finally, it is assisted by ultrasonic treatment.

[0108] Step (5) Preparation of liquid

[0109] After stirring the reaction solution for 2 hours, filter press it while hot to obtain a filtrate; cool the filtrate to below 30°C, slowly add hydrochloric acid and adjust the pH to 3.6; bubbles will be generated during this process, and a large number of bubbles will easily be generated when the pH reaches 7, so attention should be paid to the acid addition rate; heat and stir for 3 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0110] Step (6) Purification to obtain luteolin

[0111] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 3 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 4 hours and filtered to obtain 3M to obtain 3G. Luteolin is obtained after precipitation and crystallization and vacuum drying.

[0112] Comparative Example 1

[0113] Step (1) Pretreatment of raw material rutin

[0114] First, 27 grams of raw rutin was crushed, washed, dried, and then crushed into coarse powder, which was then washed, dried, and then crushed into coarse powder and stored at 3° C. for future use; finally, 5 grams of the rutin coarse powder was weighed, pretreated, and dissolved in a certain volume of a buffer solution of appropriate pH value;

[0115] Step (2) Preparation of modified cellulase

[0116] 40 mL of pH 7.5 citric acid-sodium citrate buffer solution was measured and added to a 44 mL three-necked flask equipped with a thermometer, rotor and condenser. The three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 37°C. After the temperature reached 37°C, 130 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K, 10 K, 20 K) was added and slowly stirred to dissolve it completely. Then, 130 mg of native cellulase was added. After it was completely dissolved, the reaction time was started. The reaction time was 2 h. The reaction was stopped and dialyzed in a citric acid-sodium citrate solution with an 8000-12000 dialysis bag for 101 h in a pH 4.9 solution to finally obtain 4 mg / mL of modified cellulase (Cell-MAL 5 K, 10 K, 20 K).

[0117] Step (3) Enzyme-assisted ultrasonic treatment

[0118] First, it is dissolved in 25 times alkali solution and 4.6 times reducing agent (auxiliary materials: thiourea dioxide, potassium chloride, potassium carbonate); heated to 55 ° C, added with appropriate amount of complex enzyme (cellulase, hemicellulase), shaken and placed in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then taken out and inactivated in an 85 ° C water bath for 10 minutes, centrifuged and filtered with parameters set to 5000 r / min, temperature 5 ° C for 10 minutes, repeated 3 times; then the raw material is heated to 35 ° C and finally cellulase is added, and finally, it is assisted by ultrasonic treatment;

[0119] Step (4) Preparation of liquid

[0120] After stirring the reaction solution for 3 hours, filter press it while hot to obtain a filtrate; cool the filtrate to below 30°C, slowly add hydrochloric acid and adjust the pH to 3.6; bubbles will be generated during this process, and a large number of bubbles will easily be generated when the pH reaches 7, so attention should be paid to the acid addition rate; heat and stir for 2 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

[0121] Step (5) Purification to obtain luteolin

[0122] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 2 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 3 hours and filtered to obtain 3M to obtain 3G. Luteolin is obtained after precipitation and crystallization and vacuum drying.

[0123] Comparative Example 2

[0124] Step (1) Pretreatment of raw material rutin

[0125] First, 25 grams of raw rutin was washed and dried, then ground into coarse powder and stored at 2°C for later use. Finally, 8 grams of the rutin coarse powder was weighed and pretreated, and dissolved in a certain volume of buffer solution with an appropriate pH value.

[0126] Step (2) Preparation of modified cellulase

[0127] 40 mL of pH 8 citric acid-sodium citrate buffer solution was measured and added to a 45 mL three-necked flask equipped with a thermometer, rotor and condenser; the three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 40°C. After the temperature reached 39°C, 140 mg of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K, 10 K, 20 K) was added and slowly stirred to dissolve it completely. Then, 140 mg of natural cellulase was added. After it was completely dissolved, the timing was started. The reaction time was 3 h. The reaction was stopped and then dialyzed in a citric acid-sodium citrate solution with an 8000-12000 dialysis bag for 12 h in a pH 4.9 solution to finally obtain 33 mg / mL of modified cellulase (Cell-MAL 5 K, 10 K, 20 K).

[0128] Step (3) Enzyme-assisted ultrasonic treatment

[0129] First, it is dissolved in 27 times alkali solution and 3.5 times reducing agent (auxiliary materials: thiourea dioxide, potassium chloride, potassium carbonate); heated to 60 ° C, added with appropriate amount of complex enzyme (cellulase, hemicellulase), shaken and placed in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then taken out and inactivated in an 85 ° C water bath for 10 minutes, centrifuged and filtered with parameters set to 5000 r / min, temperature 5 ° C for 10 minutes, and repeated three times; then the raw material is heated to 60 ° C and cellulase is added, and finally, it is assisted by ultrasonic treatment;

[0130] Step (4) Preparation of liquid

[0131] After stirring the reaction solution for 2 hours, filter press it while hot to obtain a filtrate. The filtrate was cooled to 48°C and hydrochloric acid was slowly added to adjust the pH to 2.8. This process will produce bubbles, and a large amount of bubbles will easily be generated when the pH is 7, so the acid addition rate should be paid attention to. Stir for 3 hours, heat, and finally filter press it while hot. After using plate and frame filter press, 1g of solid was obtained, and 1M was discarded.

[0132] Step (5) Purification to obtain luteolin

[0133] 1G luteolin content is low. 1G solid is added to ethanol and heated with stirring for 2 hours, filtered to obtain 2M to obtain 2G, and then added with ethanol aqueous solution to make pulp, heated with stirring for 2 hours and filtered to obtain 3M to obtain 3G. The solid is precipitated and crystallized, and vacuum dried to obtain luteolin.

[0134] The luteolin obtained in Examples 1 to 4 and the comparative products 1 and 2 were tested. The specific testing method is as follows:

[0135] Enzymatic hydrolysis temperature test method

[0136] The enzymatic hydrolysis conditions were controlled as follows: pH 4.8, enzyme dosage 25U / g medicinal material, enzymatic hydrolysis time 4h, and the effect of enzymes at different temperatures on the extraction amount of luteolin; 5.00g of rutin was added to 100mL of buffer solution with a pH value of 5.4 and an enzyme dosage of 0.10%. The enzymatic hydrolysis was performed for 1h at different enzymatic hydrolysis temperatures. The filter residue was added with 50%mL of 60% ethanol solution and refluxed for 1h, and the filtrate was detected and analyzed.

[0137] Cellulase activity assay

[0138] Cellulase is a protein structure and can be determined using the method of Mandels et al.: add 2 mL of 1% CMC-Na-acetate buffer solution (pH 4.8) to a test tube, add 1 mL of enzyme solution, and keep it at 50°C for 30 minutes. Then remove it and add 3 mL of DNS reagent. Other steps are the same as the filter paper enzyme activity determination; the results of the cellulase activity determination provide a direct comparison of cellulase activity under different experimental conditions.

[0139] Ethanol quality test method

[0140] Six portions of rutin coarse and fine powder (1 g each) were weighed and pretreated. The ethanol solutions with different mass fractions were used at a solid-liquid ratio of 1:10 and extracted at 80°C for 3 h. The amount of luteolin extracted from the rutin shell extract was determined.

[0141] Table 1 Enzymatic hydrolysis temperature test results

[0142]

[0143] As shown in Table 1, Example 1 is the best and Comparative Example 1 is the worst. From the experimental results, it can be seen that when the enzymatic hydrolysis temperature is 50°C, the luteolin extraction amount reaches the maximum, the efficiency of the enzyme-catalyzed reaction is the highest, and the effective extraction of luteolin is promoted; the temperature of Comparative Example 1 is too low to meet the optimal standard for luteolin extraction, so it is the worst; in enzyme-catalyzed reactions, as the temperature increases, the energy of the reactants increases, which will accelerate the reaction rate. However, when it exceeds its optimal temperature, the enzyme protein will denature, which will weaken the enzyme activity until it completely loses its activity. The reaction rate will also decrease rapidly with increasing temperature.

[0144] Table 2 Cellulase activity determination results

[0145]

[0146] As shown in Figure 2, Example 1 is the best and Comparative Example 1 is the worst. In the examples, the cellulase activity values ​​measured under four different conditions were significantly lower in Comparative Example 1 than in Example 1. The enzyme activity in the examples was generally higher, indicating that the cellulase was able to effectively catalyze substrate degradation. Although cellulase modification with monomethoxypolyethylene glycol derivatives improves its temperature tolerance, the protein's active center is affected at lower temperatures, reducing its activity. Adding carboxymethyl cellulose solution significantly increases the activity, and the cellulase activity values ​​measured in the examples are higher, indicating that under these conditions, cellulase is able to more effectively catalyze cellulose degradation.

[0147] Table 3 Ethanol mass fraction test results

[0148]

[0149] Table 4 Test results of extraction amount and extraction rate

[0150]

[0151] As shown in Tables 3 and 4, Example 1 performed best, while Comparative Example 1 performed worst. The luteolin extraction yield gradually increased with increasing ethanol concentration, reaching its highest yield when the ethanol concentration reached 70%. However, the extraction yield of Comparative Example 1 decreased as the ethanol concentration increased to 90%. Therefore, the 70% ethanol in Example 1 was the best for extracting luteolin. The extraction yield decreased slightly from Examples 1 to 4, indicating that increasing the solvent concentration did not further increase the extraction yield or yield after reaching the maximum value. Comparative Example 1, with its too low extraction concentration and lowest yield, demonstrated that the solvent concentration was insufficient to achieve the desired extraction efficiency, resulting in the worst extraction result.

[0152] This specific embodiment is merely an explanation of the present invention and does not limit the present invention. After reading this specification, those skilled in the art can make non-creative modifications to this embodiment as needed, but as long as they are within the scope of the claims of the present invention, they are protected by patent law.

Claims

1. A process for preparing luteolin, characterized in that: The method includes pretreatment of raw material rutin, defatting before extraction, preparation of modified cellulase, enzyme-assisted ultrasonic treatment, preparation of feed solution, and purification to obtain luteolin.

2. A process for preparing luteolin according to claim 1, characterized in that: Step (1) Pretreatment of raw material rutin First, a certain amount of raw rutin is washed, dried, and then crushed into coarse powder for storage. Finally, an appropriate amount of the coarse powder is weighed and dissolved in a certain volume of a buffer solution with an appropriate pH value. Step (2) Degreasing before extraction Take the crushed rutin powder and add petroleum ether to the liquid, and use ultrasonic degreasing; Step (3) Preparation of modified cellulase: A citric acid-sodium citrate buffer solution is measured and added to a three-necked flask equipped with a thermometer, a rotor, and a condenser. The three-necked flask is placed in a constant-temperature magnetic stirrer and the temperature is set to a certain time. After the temperature reaches an appropriate temperature, an appropriate amount of monomethoxypolyethylene glycol maleimide (mPEG-MAL5 K) is added and slowly stirred to dissolve it completely. A certain amount of natural cellulase is then added. After it is completely dissolved, a timer is started, the reaction is allowed to proceed for a period of time, and then the reaction is stopped. The modified cellulase (Cell-MAL 5 K) is finally obtained by dialyzing the solution in a citric acid-sodium citrate solution with a dialysis bag for a certain period of time. Step (4) Enzyme-assisted ultrasonic treatment First, rutin coarse powder is weighed each time and dissolved in a certain amount of alkali solution, and a multiple reducing agent is added; after heating to a suitable temperature, a suitable amount of complex enzyme (modified cellulase, hemicellulase) is added, shaken well, and placed in a specific ultrasonic cleaner for treatment at a specific temperature for a period of time, then taken out and inactivated in a water bath at a suitable temperature, centrifuged, and centrifuged at a suitable temperature for a period of time, and the operation is repeated, and then the raw material is heated and finally cellulase is added, and finally, it is assisted by ultrasonic treatment; Step (5) Preparation of liquid The obtained treated liquid is stirred and filtered while hot to obtain a filtrate; the filtrate is cooled and hydrochloric acid is slowly added to adjust the pH; This process will produce bubbles. When the pH reaches a certain value, a large number of bubbles are likely to be generated. At this time, attention should be paid to the acid addition rate; heat and stir, and finally filter while hot. After using plate and frame filter press, 1G of solid is obtained and 1M is discarded; Step (6) Purification to obtain luteolin The content of 1G luteolin is low. 1G solid is added to ethanol, heated and stirred for a certain time, filtered to obtain 2M to obtain 2G, and then added to ethanol aqueous solution for pulping. The mixture is heated and stirred for a certain time and filtered to obtain 3M to obtain 3G. The mixture is precipitated and crystallized, and vacuum dried to obtain luteolin.

3. The preparation process of luteolin according to claim 2, characterized in that: Step (1) Pretreatment of raw material rutin First, 25-30 grams of raw rutin is taken and pre-treated by crushing, and finally an appropriate amount of coarse powder is weighed and dissolved in a certain volume of a buffer solution with an appropriate pH value.

4. The process for preparing luteolin according to claim 3, wherein: Step (2) Degreasing before extraction Take the crushed rutin powder and add petroleum ether at a ratio of 1:0~1:50 between the feed and liquid, and use ultrasonic degreasing for 2-3 times, each time for about 2-3 minutes.

5. The process for preparing luteolin according to claim 4, wherein: Step (3) Preparation method of modified cellulase: 30-40 mL of citric acid-sodium citrate buffer solution with a pH of 7-8 was measured and added to a 40-50 mL three-necked flask equipped with a thermometer, a rotor and a condenser; the three-necked flask was placed in a constant temperature magnetic stirrer and the temperature was set to 30-40 ° C. After the temperature reached 30-40 ° C, 100-150 mg of monomethoxy polyethylene glycol maleimide (mPEG-MAL5 K) was added and slowly stirred to dissolve it completely. Then, 100-150 mg of natural cellulase was added. After it was completely dissolved, the timing was started. The reaction time was 1-3 hours. The reaction was stopped, and then dialyzed using an 8000-12000 dialysis bag in a citric acid-sodium citrate solution with a pH of 4-5 for 10-12 hours to finally obtain 2-4 mg / mL of modified cellulase (Cell-MAL 5 K).

6. The process for preparing luteolin according to claim 5, characterized in that: Step (4) Enzyme-assisted ultrasonic treatment First, dissolve it in 20-30 times alkali solution and 2.5-3.5 times reducing agent; add appropriate amount of complex enzyme and shake well, then place it in a specific ultrasonic cleaner and treat it at a specific temperature for 30-40 minutes, then take it out and kill the enzyme in 85-90℃ water bath for 10-12 minutes, centrifuge, and set the centrifugal filtration parameters to a speed of 5000-5200r / min and a temperature of 5-6℃ for 10-12 minutes, repeat 3-4 times; then heat the raw material to 50-55℃ and finally add cellulase, and finally, assist with ultrasonic treatment.

7. The process for preparing luteolin according to claim 6, wherein: Step (5) Preparation of liquid After stirring the obtained treated liquid for 2-3 hours, filter press it while hot to obtain a filtrate; cool the filtrate to below 30-40°C, slowly add hydrochloric acid and adjust the pH to 3-6; bubbles will be generated during this process, and a large number of bubbles are likely to be generated when the pH reaches 7-8. At this time, attention should be paid to the acid addition rate; heat and stir for 2-3 hours, and finally filter press it while hot; after using plate and frame filter press, 1G of solid is obtained and 1M is discarded.

8. The process for preparing luteolin according to claim 7, characterized in that: Step (6) Purification to obtain luteolin 1G luteolin content is low. Add ethanol to 1G solid and heat and stir for 2-3 hours, filter to obtain 2M to obtain 2G, add ethanol aqueous solution again to slurry, heat and stir for 2-4 hours, filter to obtain 3M to obtain 3G, precipitate and crystallize, and vacuum dry to obtain luteolin.

9. The process for preparing luteolin according to any one of claims 1 to 8, characterized in that: The process of extracting luteolin in step (6) adopts a specific temperature-controllable pulping and purification device, comprising a tank body (1), a discharging mechanism provided at the bottom end of the tank body (1), a support frame (2) provided on the tank body (1), a slot provided at the top end of the tank body (1), a top cover (3) provided on the slot, a water inlet pipe, a heater (4) and a stirring mechanism provided on the top cover (3), an annular heating pipe (5) provided between the heater (4) and the bottom end of the top cover (3), a vertical heating pipe (6) provided at the bottom end of the annular heating pipe (5), a lifting mechanism provided between the support frame (2) and the top cover (3), the lifting mechanism comprising a support plate (7) and an electric telescopic rod (8), the support plate (7) and the electric telescopic rod (8) both being mounted on the support frame (2), the output of the electric telescopic rod (8) A connection box (9) is provided between the end and the top cover (3), an adjustment groove is provided inside the connection box (9), an elastic component (10) and a fastening plate (11) are provided on the adjustment groove, an opening is provided between the adjustment groove and one side of the connection box (9), a fastening inclined column (12) is provided between the fastening plate (11) and the opening, a fastening groove is provided on one side of the fastening plate (11), a through hole is provided between the fastening groove and the fastening plate (11), a fastening block (13) is provided on the fastening groove, an adjustment column (14) is provided between the fastening block (13) and the through hole, a telescopic mechanism (15) is provided on the other side of the connection box (9), the telescopic mechanism (15) is connected to the adjustment column (14), a docking groove is provided on the support plate (7), two docking grooves are provided, and two lifting mechanisms are provided and symmetrically arranged.

10. The process for preparing luteolin according to claim 9, characterized in that: The stirring mechanism includes a stirring motor (16) and a stirring shaft (17), wherein the stirring motor (16) is mounted on the top end of the top cover (3), the output end of the stirring motor (16) extends to the bottom end of the top cover (3), the stirring shaft (17) is connected to the output end of the stirring motor (16), and the stirring shaft (17) is provided with stirring blades; the discharging mechanism includes a discharging pipe (18), wherein the discharging pipe (18) is mounted on the bottom end of the tank body (1), and the discharging pipe (18) is provided with a solenoid valve (19); the vertical heating pipe (6) is provided with a plurality of and arranged in a ring array.

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