Extraction method and application of chlorogenic acid in honeysuckle

Abstract

The invention relates to the technical field of separation and extraction, and provides an extraction method and application of chlorogenic acid in honeysuckle. The invention relates to a method for extracting chlorogenic acid from honeysuckle, which comprises the following steps: mixing honeysuckle powder with an ethanol solution, and carrying out ultrasonic enzymolysis; carrying out suction filtration to obtain a supernatant A containing chlorogenic acid and medicine residues I, and adding an ethanol solution into the medicine residues I to carry out microwave extraction; performing suction filtration to obtain a filtrate B and medicine residues II, mixing the medicine residues II with a citric acid-sodium citrate buffer solution, adding a Fe3O4-coated GO-coated MOFs nano-catalyst, performing hydrothermal reaction, performing suction filtration to obtain hydrolysate, and combining the hydrolysate with the supernate A and the filtrate B to obtain a total extraction solution; concentrating the total extracting solution under reduced pressure, and recovering ethanol until the volume of the concentrated solution is about 1 / 6-1 / 8 of the original volume; and concentrating under reduced pressure to thick paste, and drying to obtain the chlorogenic acid. The extraction efficiency and yield of chlorogenic acid are improved, and the utilization rate of raw materials and the product purity are improved.

Description

Technical Field

[0001] This invention relates to the field of separation and extraction technology, specifically to a method for extracting chlorogenic acid from honeysuckle and its application. Background Technology

[0002] Chlorogenic acid is a phenolic acid compound with various biological activities, abundant in plants such as honeysuckle, and widely used in medicine, food, and cosmetics. Traditional methods for extracting chlorogenic acid from honeysuckle suffer from low extraction efficiency, low yield, and compromised product purity. For example, single extraction methods are insufficient to fully disrupt the cell wall structure of honeysuckle, leading to incomplete dissolution of chlorogenic acid; insufficient recovery and utilization of residual chlorogenic acid precursor compounds in the residue results in raw material waste; and high temperatures during drying can easily degrade heat-sensitive chlorogenic acid, affecting product purity. Therefore, developing a highly efficient, high-yield chlorogenic acid extraction method that ensures product purity is of great significance. Based on this, this invention proposes a method for extracting chlorogenic acid from honeysuckle and its applications. Summary of the Invention

[0003] This invention proposes a method and application for extracting chlorogenic acid from honeysuckle, which improves the extraction efficiency and yield of chlorogenic acid, and addresses the problem of insufficient chlorogenic acid dissolution caused by the inability of a single extraction method to fully destroy the cell wall structure of honeysuckle. It also improves the utilization rate of raw materials, addressing the problem of insufficient recovery and utilization of residual chlorogenic acid precursor compounds in the residue, which leads to raw material waste. Furthermore, it improves product purity, addressing the problem of high temperature during drying causing degradation of heat-sensitive chlorogenic acid and affecting product purity.

[0004] The technical solution of the present invention is as follows: This invention proposes a method for extracting chlorogenic acid from honeysuckle, comprising the following steps: (1) Honeysuckle powder obtained by drying and pulverizing honeysuckle; honeysuckle powder is mixed with ethanol solution and a compound enzyme is added for ultrasonic enzymatic hydrolysis; (2) After the enzymatic hydrolysis, the supernatant A containing chlorogenic acid and the residue 1 were obtained by filtration. Ethanol solution was added to the residue 1 for microwave extraction. (3) After microwave extraction, filter to obtain filtrate B and residue II. Mix residue II with citrate-sodium citrate buffer, add Fe3O4@GO@MOFs nanocatalyst, recover the catalyst after hydrothermal reaction, filter to obtain hydrolysate containing chlorogenic acid precursor compound, combine with supernatant A and filtrate B to obtain total extract; (4) Concentrate the total extract under reduced pressure and recover ethanol until the volume of the concentrate is about 1 / 6 to 1 / 8 of the original volume. (5) The concentrate is further concentrated under reduced pressure to a thick paste, and then dried using supercritical fluid drying technology to obtain chlorogenic acid.

[0005] As a further technical solution, the ratio of honeysuckle powder to ethanol solution is 1g:35-50mL; the compound enzyme includes cellulase and pectinase in a weight ratio of 1:1.5-2.5, and the amount of enzyme added is 1.2wt%-2.2wt% of the dry weight of honeysuckle powder; the enzymatic hydrolysis is performed by ultrasonic enzymatic hydrolysis at 40-50℃ and 190-200W for 70-100min.

[0006] As a further technical solution, the ethanol solution in step (2) is an ethanol aqueous solution with a volume fraction of 40%-50%, and the solid-liquid ratio of the dry weight of the medicinal residue and the ethanol solution in step (2) is 1g:18-22mL.

[0007] As a further technical solution, the microwave extraction is performed by microwave processing for 15-25 minutes under the conditions of microwave power of 300-500W and microwave frequency of 2400-2500MHz.

[0008] As a further technical solution, the concentration of the citrate-sodium citrate buffer solution is 0.3-0.5 mol / L, pH=4.0-5.0, and the solid-liquid ratio of the drug residue to the citrate-sodium citrate buffer solution is 1g:18-22mL.

[0009] As a further technical solution, the preparation method of the Fe3O4@GO@MOFs nanocatalyst includes: resuspending Fe3O4 in an aqueous GO solution with a concentration of 0.5-1.5 mg / mL, ultrasonically dispersing for 30-60 min to uniformly coat the Fe3O4 magnetic core surface, then transferring the mixture to a hydrothermal reactor and reacting at 130-150℃ for 8-10 h, and obtaining Fe3O4@GO composite material after separation and drying; dispersing the Fe3O4@GO composite material in a methanol solution containing zinc nitrate and 2-methylimidazole, stirring and reacting at room temperature for 2-4 h to load MOFs on the Fe3O4@GO surface, and obtaining Fe3O4@GO@MOFs nanocatalyst after separation, washing and drying.

[0010] As a further technical solution, the weight ratio of Fe3O4 to GO is 1g:0.03-0.06g; the ratio of Fe3O4@GO composite material, zinc nitrate, 2-methylimidazole and methanol is 1g:0.45-0.55g:1.6-1.7g:100-120mL.

[0011] As a further technical solution, in step (3), the ratio of the amount of medicinal residue 2, citric acid-sodium citrate buffer and Fe3O4@GO@MOFs nanocatalyst is 1g:18-22mL:0.03-0.05g.

[0012] As a further technical solution, the temperature of the hydrothermal reaction in step (3) is 160-180℃ and the time is 1.5-2.5h.

[0013] As a further technical solution, in step (5), the drying process uses carbon dioxide as a supercritical fluid and is carried out under conditions of pressure of 15-25 MPa and temperature of 30-40℃.

[0014] On the other hand, the extraction method of chlorogenic acid from honeysuckle in this invention is applied in the preparation of antioxidant and anti-inflammatory agents.

[0015] The working principle and beneficial effects of this invention are as follows: This invention employs a multi-stage synergistic extraction process involving ultrasonic enzymatic hydrolysis, microwave extraction, and nanocatalytic hydrothermal extraction. In the ultrasonic enzymatic hydrolysis stage, the synergistic action of cellulase and pectinase specifically degrades cellulose and pectin components in the cell walls of honeysuckle, creating initial cell structure disruption and facilitating subsequent extraction. The microwave extraction stage utilizes the selective heating properties of microwaves to generate localized high temperature and pressure within the cells, achieving secondary cell structure disruption and promoting the diffusion of chlorogenic acid from the cytoplasm to the extraction solvent. The nanocatalytic hydrothermal stage utilizes the specific catalytic action of Fe3O4@GO@MOFs nanocatalysts to directionally hydrolyze residual chlorogenic acid precursor compounds in the residue into chlorogenic acid, achieving deep utilization of the raw material. The synergistic effect of these three stages forms a complete extraction chain from cell structure disruption to active ingredient release and precursor transformation, solving the problem of low extraction efficiency caused by single extraction methods due to their limited mechanisms of action.

[0016] In this invention, the Fe3O4 magnetic core in the Fe3O4@GO@MOFs nanocatalyst serves as the catalyst support, enabling convenient catalyst recovery through magnetic separation characteristics, while simultaneously providing stable support for the GO coating layer. The GO intermediate layer forms strong chemical bonds with MOFs through π-π conjugation, and its high specific surface area significantly increases the loading of MOFs, forming a three-dimensional porous structure that provides ample diffusion channels for reactants. The ZIF-8 type MOFs serve as active centers, and their regular pore structure is highly matched to the molecular size of chlorogenic acid precursors, achieving specific catalytic hydrolysis through spatial confinement effects.

[0017] In this invention, the ultrasonic enzymatic hydrolysis stage utilizes a temperature control of 40-50℃ to maintain enzyme activity while preventing thermal degradation of chlorogenic acid. The ultrasonic power selection of 190-200W balances cavitation effect intensity and energy input efficiency, achieving moderate cell wall disruption. The microwave extraction stage employs a microwave frequency of 2400-2500MHz, matched to the rotational frequency of water molecules, achieving efficient dielectric heating. Simultaneously, a power control of 300-500W prevents localized overheating and component destruction. The nanocatalytic hydrothermal stage, with a temperature control of 160-180℃, ensures the kinetic feasibility of the hydrolysis reaction while utilizing a citrate-sodium citrate buffer to maintain the catalytic activity of MOFs. The acidic environment of this buffer is close to the isoelectric point of the MOFs, enhancing substrate adsorption through electrostatic interactions and thus increasing the reaction rate.

[0018] In this invention, the CO2 in the supercritical fluid drying technology is in a supercritical state, possessing both the high diffusion coefficient of a gas and the high solubility of a liquid. It removes moisture uniformly through permeation, avoiding the surface tension caused by phase change. At the same time, the low temperature effectively inhibits the thermal decomposition reaction of chlorogenic acid, solving the quality deterioration problem in the drying process of heat-sensitive components. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. It should be noted that the cellulase and pectinase used in the present invention were purchased from Shandong Longket Enzyme Preparation Co., Ltd.

[0020] Example 1 This embodiment provides a method for extracting chlorogenic acid from honeysuckle, the steps of which include: (1) Honeysuckle powder obtained by drying honeysuckle at 55℃ to constant weight, pulverizing it and passing it through a 90-mesh sieve; (2) Mix honeysuckle powder with ethanol and water at a ratio of 1g:30mL:12mL, add a complex enzyme of cellulase and pectinase in a weight ratio of 1:2, and sonicate at 45℃ and 205W for 85min; the amount of enzyme added is 1.7wt% of the dry weight of honeysuckle powder; (3) After the enzymatic hydrolysis, the supernatant containing chlorogenic acid, A and residue 1 were obtained by suction filtration. A 45% ethanol aqueous solution was added to residue 1, and the solid-liquid ratio relative to dry residue 1 was adjusted to 1g:27mL. The mixture was transferred to a microwave reactor and microwaved for 20min under the conditions of microwave power of 400W and microwave frequency of 2450MHz. (4) After microwave extraction, the filtration device is used to filter the chlorogenic acid-containing alcohol extract filtrate and record it as filtrate B. The obtained residue II is mixed with citrate-sodium citrate buffer solution with a buffer concentration of 0.4 mol / L and pH=4.5. The solid-liquid ratio of residue II to buffer solution is 1 g: 20 mL. (5) Add Fe3O4@GO@MOFs nanocatalyst to the residue-buffer mixture system. The ratio of residue-buffer mixture, buffer and catalyst is 1g:20mL:0.04g. Transfer the mixture to a high-pressure reactor and carry out hydrothermal reaction at 170℃ for 2h. After the hydrothermal reaction is completed, the catalyst is magnetically separated and recovered. The hydrolysate containing chlorogenic acid precursor compound is obtained by filtration. The hydrolysate is combined with the supernatant A in step (3) and the filtrate B in step (4) to obtain the total extract. (6) The total extract was transferred to a rotary evaporator and concentrated under reduced pressure at a temperature of 45°C and a vacuum of 0.085 MPa to recover ethanol until the volume of the concentrate was about 1 / 7 of the original volume. The concentrate was further concentrated under reduced pressure to a thick paste and dried using supercritical fluid drying technology. Carbon dioxide was used as the supercritical fluid and dried at a pressure of 20 MPa and a temperature of 35°C to obtain chlorogenic acid. Preparation of Fe3O4@GO@MOFs nanocatalysts: GO (graphene oxide) modification: Fe3O4 was resuspended in an aqueous GO solution with a concentration of 1 mg / mL and a weight ratio of Fe3O4 to GO of 1 g: 0.045 g. The mixture was ultrasonically dispersed for 45 min to ensure that GO was uniformly coated on the surface of the Fe3O4 magnetic core. The mixture was then transferred to a hydrothermal reactor and reacted at 140 °C for 9 h. After separation and drying, Fe3O4@GO composite material was obtained. MOF (metal-organic framework) loading: Fe3O4@GO composite material was dispersed in a methanol solution containing zinc nitrate and 2-methylimidazole. The ratio of Fe3O4@GO composite material, zinc nitrate, 2-methylimidazole and methanol was 1g:0.5g:1.65g:110mL. The reaction was stirred at room temperature for 3h to load MOFs on the Fe3O4@GO surface. After separation, washing and drying, Fe3O4@GO@MOF nanocatalyst was obtained.

[0021] Example 2 This embodiment provides a method for extracting chlorogenic acid from honeysuckle, the steps of which include: (1) Honeysuckle powder is obtained by drying honeysuckle at 50°C to constant weight, pulverizing it and passing it through an 80-mesh sieve. (2) Mix honeysuckle powder with ethanol and water at a ratio of 1g:25mL:10mL, add a complex enzyme of cellulase and pectinase with a weight ratio of 1:1.5, and sonicate at 40℃ and 190W for 70min; the amount of enzyme added is 1.2wt% of the dry weight of honeysuckle powder; (3) After the enzymatic hydrolysis, the supernatant containing chlorogenic acid, A and residue 1 were obtained by suction filtration. A 40% ethanol aqueous solution was added to residue 1, and the solid-liquid ratio relative to dry residue 1 was adjusted to 1g:22mL. The mixture was transferred to a microwave reactor and microwaved for 15min under the conditions of microwave power of 300W and microwave frequency of 2400MHz. (4) After microwave extraction, the filtration device is used to filter the chlorogenic acid-containing alcohol extract filtrate and record it as filtrate B. The obtained residue II is mixed with citrate-sodium citrate buffer solution with a buffer concentration of 0.3 mol / L and pH=4.0. The solid-liquid ratio of residue II to buffer solution is 1 g: 18 mL. (5) Add Fe3O4@GO@MOFs nanocatalyst to the residue-buffer mixture system. The ratio of residue-buffer mixture, buffer and catalyst is 1g:18mL:0.03g. Transfer the mixture to a high-pressure reactor and carry out hydrothermal reaction at 160℃ for 1.5h. After the hydrothermal reaction is completed, the catalyst is magnetically separated and recovered. The hydrolysate containing chlorogenic acid precursor compound is obtained by filtration. The hydrolysate is combined with the supernatant A in step (3) and the filtrate B in step (4) to obtain the total extract. (6) The total extract was transferred to a rotary evaporator and concentrated under reduced pressure at a temperature of 40°C and a vacuum of 0.08 MPa to recover ethanol until the volume of the concentrate was about 1 / 6 of the original volume. The concentrate was further concentrated under reduced pressure to a thick paste and dried using supercritical fluid drying technology. Carbon dioxide was used as the supercritical fluid and dried at a pressure of 15 MPa and a temperature of 30°C to obtain chlorogenic acid. Preparation of Fe3O4@GO@MOFs nanocatalysts: GO (graphene oxide) modification: Fe3O4 was resuspended in an aqueous GO solution with a concentration of 0.5 mg / mL and a weight ratio of Fe3O4 to GO of 1 g: 0.03 g. The mixture was ultrasonically dispersed for 30 min to ensure that GO was uniformly coated on the surface of the Fe3O4 magnetic core. The mixture was then transferred to a hydrothermal reactor and reacted at 130 °C for 8 h. After separation and drying, Fe3O4@GO composite material was obtained. MOF (metal-organic framework) loading: Fe3O4@GO composite material was dispersed in a methanol solution containing zinc nitrate and 2-methylimidazole. The ratio of Fe3O4@GO composite material, zinc nitrate, 2-methylimidazole and methanol was 1g:0.45g:1.6g:100mL. The reaction was stirred at room temperature for 2h to load MOFs on the Fe3O4@GO surface. After separation, washing and drying, Fe3O4@GO@MOF nanocatalyst was obtained.

[0022] Example 3 This embodiment provides a method for extracting chlorogenic acid from honeysuckle, the steps of which include: (1) Honeysuckle powder obtained by drying honeysuckle at 60℃ to constant weight, pulverizing it and passing it through a 100-mesh sieve; (2) Mix honeysuckle powder with ethanol and water at a ratio of 1g:35mL:15mL, add a complex enzyme of cellulase and pectinase with a weight ratio of 1:2.5, and sonicate at 50℃ and 200W for 100min; the amount of enzyme added is 2.2wt% of the dry weight of honeysuckle powder; (3) After the enzymatic hydrolysis, the supernatant containing chlorogenic acid, A and residue 1 were obtained by suction filtration. A 50% ethanol aqueous solution was added to residue 1, and the solid-liquid ratio relative to dry residue 1 was adjusted to 1g:32mL. The mixture was transferred to a microwave reactor and microwaved for 25min under the conditions of microwave power of 500W and microwave frequency of 2500MHz. (4) After microwave extraction, the filtration device is used to filter the chlorogenic acid-containing alcohol extract filtrate and record it as filtrate B. The obtained residue II is mixed with citrate-sodium citrate buffer solution with a buffer concentration of 0.5 mol / L and pH=5.0. The solid-liquid ratio of residue II to buffer solution is 1g:22mL. (5) Add Fe3O4@GO@MOFs nanocatalyst to the residue-buffer mixture system. The ratio of residue-buffer mixture, buffer and catalyst is 1g:22mL:0.05g. Transfer the mixture to a high-pressure reactor and carry out hydrothermal reaction at 180℃ for 2.5h. After the hydrothermal reaction is completed, the catalyst is magnetically separated and recovered. The hydrolysate containing chlorogenic acid precursor compound is obtained by filtration. The hydrolysate is combined with the supernatant A in step (3) and the filtrate B in step (4) to obtain the total extract. (6) The total extract was transferred to a rotary evaporator and concentrated under reduced pressure at a temperature of 50°C and a vacuum of 0.09 MPa to recover ethanol until the volume of the concentrate was about 1 / 8 of the original volume. The concentrate was further concentrated under reduced pressure to a thick paste and dried using supercritical fluid drying technology. Carbon dioxide was used as the supercritical fluid and dried at a pressure of 25 MPa and a temperature of 40°C to obtain chlorogenic acid. Preparation of the Fe3O4@GO@MOFs nanocatalyst: GO (graphene oxide) modification: Fe3O4 was resuspended in an aqueous GO solution with a concentration of 1.5 mg / mL and a weight ratio of Fe3O4 to GO of 1 g: 0.06 g. The mixture was ultrasonically dispersed for 60 min to ensure that GO was uniformly coated on the surface of the Fe3O4 magnetic core. The mixture was then transferred to a hydrothermal reactor and reacted at 150 °C for 10 h. After separation and drying, Fe3O4@GO composite material was obtained. MOF (metal-organic framework) loading: Fe3O4@GO composite material was dispersed in a methanol solution containing zinc nitrate and 2-methylimidazole. The ratio of Fe3O4@GO composite material, zinc nitrate, 2-methylimidazole and methanol was 1g:0.55g:1.7g:120mL. The reaction was stirred at room temperature for 4h to load MOFs on the Fe3O4@GO surface. After separation, washing and drying, Fe3O4@GO@MOF nanocatalyst was obtained.

[0023] Comparative Example 1 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. In the preparation of Fe3O4@GO@MOFs, zinc nitrate and 2-methylimidazole are replaced with equimolar amounts of copper nitrate and trimesic acid to construct different MOFs. The rest is the same as in Example 1.

[0024] Comparative Example 2 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. In the preparation of Fe3O4@GO@MOFs, the GO modification step is skipped, and MOFs are directly loaded on Fe3O4. The rest is the same as in Example 1.

[0025] Comparative Example 3 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. Step (5) is omitted. The residue obtained in step (4) is directly refluxed at 95°C for 2 hours with a dilute sulfuric acid solution of pH=2.0 and concentration of 0.5M (solid-liquid ratio 1g:20mL) to replace the nano-catalytic hydrothermal reaction. The hydrolysate is combined with filtrate A and B, and the rest is the same as in Example 1.

[0026] Comparative Example 4 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. In step (3), "transfer the mixture to a microwave reactor and microwave it for 20 minutes at a microwave power of 400W and a microwave frequency of 2450MHz" is replaced with "sonicate the mixture at a temperature of 45℃ and 200W for 85 minutes". The rest is the same as in Example 1.

[0027] Comparative Example 5 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. In step (4), the citric acid-sodium citrate buffer solution is replaced with potassium dihydrogen phosphate aqueous solution, and the rest is the same as in Example 1.

[0028] Comparative Example 6 This comparative example provides a method for extracting chlorogenic acid from honeysuckle. In step (6), supercritical fluid drying is replaced by ordinary vacuum drying at 60°C. The rest is the same as in Example 1.

[0029] Experimental Example 1: The chlorogenic acid obtained from Examples 1-3 and Comparative Examples 1-6 was determined: Chlorogenic acid yield: HPLC method, chromatographic column: C18 reversed-phase column (4.6 mm × 250 mm, 5 μm); mobile phase: acetonitrile-0.1% phosphoric acid aqueous solution (12:88, v / v); flow rate: 1.0 mL / min, detection wavelength: 327 nm, column temperature: 30 ℃; Calculation formula: Yield (%) = (mass of chlorogenic acid / mass of raw honeysuckle) × 100%; Purity: The percentage of chlorogenic acid was calculated using the peak area normalization method of HPLC chromatograms from the same batch. Catalyst recovery rate: After magnetic separation, the catalyst is dried and weighed, and the recovery rate (%) is calculated. The test results are shown in Table 1 below: Table 1

[0030] Based on the above data, it can be seen that in Comparative Example 1, changing the MOF type resulted in a 17.2% decrease in yield and a 12.3% decrease in purity. The ZIF-8 type MOF constructed from zinc nitrate / 2-methylimidazole exhibits specific catalytic activity for the hydrolysis of chlorogenic acid precursors, while the catalytic efficiency of copper-based MOFs is significantly reduced. In Comparative Example 2, skipping the GO modification step resulted in a 13.5% decrease in yield and a 12.0% decrease in catalyst recovery. The GO intermediate layer significantly improves catalyst stability and recovery by enhancing MOF anchoring strength and increasing specific surface area; the absence of GO leads to unstable MOF loading. In Comparative Example 3, replacing catalytic hydrothermal extraction with traditional acid hydrolysis resulted in a 27.5% decrease in yield and a 19.8% decrease in purity. The nano-catalytic hydrothermal method releases bound chlorogenic acid more efficiently than traditional acid hydrolysis and avoids the degradation of active ingredients by strong acids. In Comparative Example 4, replacing microwave extraction with ultrasound resulted in a 9.5% decrease in yield and a 6.6% decrease in purity. Microwaves have better selective heating and cell disruption capabilities than ultrasound, resulting in more thorough extraction of residual chlorogenic acid from the residue. Comparative Example 5: Replacing the buffer system resulted in a 16.2% decrease in purity and a 4.0% decrease in catalyst recovery. The citrate buffer provided the optimal pH environment for the reaction, while phosphate may cause catalyst passivation. Comparative Example 6: Replacing supercritical drying with conventional drying resulted in a 15.5% decrease in purity, while the yield remained essentially the same. Supercritical fluid drying effectively protected the heat-sensitive chlorogenic acid, avoiding thermal degradation caused by vacuum drying.

[0031] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for extracting chlorogenic acid from honeysuckle, characterized in that, Includes the following steps: (1) Honeysuckle powder obtained by drying and pulverizing honeysuckle; honeysuckle powder is mixed with ethanol solution and a compound enzyme is added for ultrasonic enzymatic hydrolysis; (2) After the enzymatic hydrolysis, the supernatant A containing chlorogenic acid and the residue 1 were obtained by filtration. Ethanol solution was added to the residue 1 for microwave extraction. (3) After microwave extraction, filter to obtain filtrate B and residue II. Mix residue II with citrate-sodium citrate buffer, add Fe3O4@GO@MOFs nanocatalyst, recover the catalyst after hydrothermal reaction, filter to obtain hydrolysate containing chlorogenic acid precursor compound, combine with supernatant A and filtrate B to obtain total extract; (4) Concentrate the total extract under reduced pressure and recover ethanol until the volume of the concentrate is about 1 / 6 to 1 / 8 of the original volume; (5) The concentrate is further concentrated under reduced pressure to a thick paste, and then dried using supercritical fluid drying technology to obtain chlorogenic acid.

2. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, The ratio of honeysuckle powder to ethanol solution is 1g:35-50mL; the compound enzyme includes cellulase and pectinase in a weight ratio of 1:1.5-2.5, and the amount of enzyme added is 1.2wt%-2.2wt% of the dry weight of honeysuckle powder; the enzymatic hydrolysis is performed by ultrasonic hydrolysis at 40-50℃ and 190-200W for 70-100min.

3. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, In step (2), the ethanol solution is an aqueous solution of ethanol with a volume fraction of 40%-50%, and the solid-liquid ratio of the dry weight of the medicinal residue to the ethanol solution in step (2) is 1g:18-22mL.

4. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, The microwave extraction is performed by microwave processing for 15-25 minutes under conditions of microwave power of 300-500W and microwave frequency of 2400-2500MHz.

5. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, The concentration of the citrate-sodium citrate buffer solution is 0.3-0.5 mol / L, pH=4.0-5.0, and the solid-liquid ratio of the residue to the citrate-sodium citrate buffer solution is 1g:18-22mL.

6. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, The preparation method of the Fe3O4@GO@MOFs nanocatalyst includes: resuspending Fe3O4 in an aqueous GO solution with a concentration of 0.5-1.5 mg / mL, ultrasonically dispersing for 30-60 min to uniformly coat the Fe3O4 magnetic core surface, then transferring the mixture to a hydrothermal reactor and reacting at 130-150℃ for 8-10 h, and obtaining Fe3O4@GO composite material after separation and drying; dispersing the Fe3O4@GO composite material in a methanol solution containing zinc nitrate and 2-methylimidazole, stirring and reacting at room temperature for 2-4 h to load MOFs on the Fe3O4@GO surface, and obtaining Fe3O4@GO@MOFs nanocatalyst after separation, washing and drying.

7. The method for extracting chlorogenic acid from honeysuckle according to claim 6, characterized in that, The weight ratio of Fe3O4 to GO is 1g:0.03-0.06g; the ratio of Fe3O4@GO composite material, zinc nitrate, 2-methylimidazole and methanol is 1g:0.45-0.55g:1.6-1.7g:100-120mL.

8. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, In step (3), the ratio of the amount of medicinal residue 2, citric acid-sodium citrate buffer solution and Fe3O4@GO@MOFs nanocatalyst is 1g:18-22mL:0.03-0.05g.

9. The method for extracting chlorogenic acid from honeysuckle according to claim 1, characterized in that, In step (3), the hydrothermal reaction temperature is 160-180℃ and the time is 1.5-2.5h; in step (5), the drying is carried out using carbon dioxide as a supercritical fluid under the conditions of 15-25MPa pressure and 30-40℃ temperature.

10. The application of chlorogenic acid prepared by the extraction method of chlorogenic acid from honeysuckle according to any one of claims 1-9 in antioxidant and anti-inflammatory preparations.

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