Method for extracting Chinese herbal medicine by ultra-supercritical CO2

Abstract

The invention discloses a method for extracting Chinese herbal medicine by ultra-supercritical CO2, which comprises the following steps: extracting the Chinese herbal medicine by using CO2 as an extracting solvent under the conditions that the extraction pressure is 80-200MPa and the extraction temperature is 40-80 DEG C to obtain an extract; performing three-stage separation on the extract to obtain a Chinese herbal medicine extract; wherein the separation pressure of the three-stage separation is as follows: the first stage is 50-80 MPa, the second stage is 30-40 MPa, and the third stage is 10-20 MPa. According to the technical scheme, Chinese herbal medicine macromolecules and high-polarity substances can be extracted, an entrainer or an auxiliary does not need to be added, and the method has the advantages of being free of pollution, free of additives, free of solvent residues, good in separation capacity, high in extraction rate, low in energy consumption and reasonable in process.

Description

Technical Field

[0001] The invention relates to the technical field of extraction and separation, and in particular to a method for extracting Chinese herbal medicines using ultra-supercritical CO2. Background Art

[0002] In the related technology, supercritical CO2 can extract small molecular volatile substances. However, it is difficult to extract large molecular high polar substances in Chinese herbal medicines, such as sugars, glycosides, flavonoids, terpenes, alkaloids, steroids, tannins, etc. through conventional supercritical fluid extraction or water distillation, which makes it difficult to extract large molecular high polar substances in Chinese herbal medicines. Summary of the invention

[0003] The main purpose of the present invention is to provide a method for extracting Chinese herbal medicine using ultra-supercritical CO2, aiming at extracting macromolecules and highly polar substances of Chinese herbal medicine.

[0004] To achieve the above object, the method for extracting Chinese herbal medicine using ultra-supercritical CO2 provided by the present invention comprises the following steps: Under the conditions of extraction pressure of 80-200MPa and extraction temperature of 40-80℃, CO2 is used as extraction solvent to extract Chinese herbal medicines to obtain all effective components in Chinese herbal medicines; The extract is separated to obtain all effective components in the Chinese herbal medicine; wherein the separation pressure of the three-stage separation is 10-80MPa.

[0005] In one embodiment, the extraction pressure is 80-100 MPa, and the extraction temperature is 45-55°C; or, the extraction pressure is 100-150 MPa, and the extraction temperature is 70-80°C.

[0006] In one embodiment, the molecular weight of the Chinese herbal extract is greater than 1000 Daltons.

[0007] In one embodiment, the step of separating the extract comprises the following steps: The extract is separated in the first stage to obtain a first extract; The extract is separated in the second stage to obtain a second extract; The separation pressure of the first stage separation is 50-80 MPa, and the separation pressure of the second stage separation is 30-40 MPa.

[0008] In one embodiment, the separation temperature of the first stage separation is 40-50°C; and / or the separation temperature of the second stage separation is 40-60°C.

[0009] In one embodiment, the molecular weight of the first extract is greater than or equal to 5000 Daltons; and / or the molecular weight of the second extract is 1000-4000 Daltons.

[0010] In one embodiment, it is characterized in that the cycle extraction time of the method is 2-3 hours; and / or the CO2 flow rate is 15-25L / h; and / or the CO2 purity is above ‌5N.

[0011] In one embodiment, the particle size of the Chinese herbal medicine is 270-1000 μm.

[0012] In one embodiment, before the extraction step, the following steps are also included: The spheres are mixed with Chinese herbal medicines; wherein the weight ratio of the spheres to the Chinese herbal medicines is 20:(80-100), the spheres include one or more of quartz spheres, alumina spheres or zirconium spheres, and the diameter of the spheres is 3-5 mm.

[0013] In one embodiment, the segmented separation further comprises the following steps: The extract is separated in the third stage to obtain a third extract; wherein the separation pressure of the third stage separation is 10-20 MPa.

[0014] In one embodiment, the molecular weight of the third extract is less than 900 Daltons.

[0015] The technical solution of the present invention uses CO2 to extract large molecular and highly polar effective components in Chinese herbal medicines under ultra-high supercritical pressure (>100MPa) and relatively low temperature (<80C°), so that large molecular substances and highly polar substances can be dissolved by CO2 without any damage, and separated by separation means, so that complete active ingredients can be extracted, which greatly improves the extraction rate, makes up for the shortcoming that conventional supercritical fluid extraction technology can only extract volatile, small molecular and low polar substances, solves many extraction problems in the preparation process of Chinese herbal medicines, and lays a foundation for the high-end preparation of Chinese herbal medicines and innovation of Western medicine.

[0016] Moreover, this technical solution does not require the addition of entrainers or auxiliary agents, and has the advantages of no pollution, no additives, no solvent residue, good separation ability, high extraction rate, low energy consumption, and reasonable process. It is highly practical and can be widely used in the field of high-end pharmaceutical preparation. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] It should be noted that if the meaning of "and / or" appears in the full text is to include three parallel solutions, taking "A and / or B" as an example, it includes solution A, solution B, or a solution that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0019] "Include", "comprising", "containing", "containing", "having" or other variations herein are intended to cover non-closed inclusions, and no distinction is made between these terms. The term "comprising" means that other steps and ingredients that do not affect the final result may be added. The term "comprising" also includes the terms "mainly consisting of..." and "essentially consisting of..." The compositions and methods / processes of the present invention include, consist of, and are essentially composed of the necessary elements and restrictions described herein and any additional or optional ingredients, components, steps or restrictions described herein. All numerical values ​​or expressions used in the specification and claims involving component amounts, process conditions, etc. should be understood to be modified by "about" in all cases. All ranges involving the same component or property include endpoints, which can be independently combined. Since these ranges are continuous, they include every numerical value between the minimum and maximum values. It should also be understood that any numerical range cited in this application is intended to include all sub-ranges within the range. As used herein, "parts by weight", "parts by weight", "parts by mass" or "parts by mass" are used interchangeably, and the parts by weight may be any fixed weight expressed in milligrams, grams or kilograms (such as 1 mg, 1 g, 2 g, 5 g, or 1 kg, etc.). For example, a composition consisting of 1 part by weight of component a and 9 parts by weight of component b may be a composition consisting of 1 gram of component a + 9 grams of component b, or 10 grams of component a + 90 grams of component b, etc.

[0020] The invention provides a method for extracting Chinese herbal medicine using ultra-supercritical CO2.

[0021] Ultra-supercritical CO2 extraction, also known as ultra-high pressure supercritical CO2 extraction, is a technology that uses supercritical carbon dioxide to extract substances under ultra-high pressure and supercritical conditions. Under ultra-high pressure conditions, the physical state of supercritical carbon dioxide is between gas and liquid, with high solubility and high permeability, and can effectively extract various components. Among them, ultra-high pressure refers to a pressure greater than or equal to 100MPa.

[0022] In an embodiment of the present invention, the method for extracting Chinese herbal medicine by ultra-supercritical CO2 comprises the following steps: S10, extracting the Chinese herbal medicine using CO2 as an extraction solvent at an extraction pressure of 80-200 MPa and an extraction temperature of 40-80° C. to obtain an extract; S20, separating the extract to obtain a Chinese herbal medicine extract; wherein the separation pressure is 10-80 MPa.

[0023] Specifically, ultra-supercritical CO2 extraction is under ultra-high pressure supercritical state, the density of carbon dioxide is close to that of liquid, and at the same time it has the diffusion performance of gas. At this time, the interface between gas and liquid disappears, and the surface tension is zero. Under the conditions of extraction pressure of 80-200MPa and extraction temperature of 40-80℃, which are higher than the critical temperature and critical pressure respectively, carbon dioxide has the dual characteristics of gas and liquid, greatly increasing the solubility of carbon dioxide, and exerting the maximum solubility enhancement effect, so that macromolecules and high polar substances are dissolved from Chinese herbal medicines and dissolved in carbon dioxide. Through the separation pressure of 10-80MPa, the ultra-supercritical carbon dioxide becomes gas, and macromolecules and high polar substances are precipitated, so that macromolecules and high polar substances of Chinese herbal medicines can be extracted.

[0024] It is understandable that the Chinese herbal medicine can be Chinese herbal medicine, or crushed particles of Chinese herbal medicine slices, or crushed particles of Chinese herbal medicine after formulation. In order to avoid the introduction of pathogenic substances, the Chinese herbal medicine can be disinfected. In one embodiment, ultraviolet rays are used to disinfect the Chinese herbal medicine before step S10.

[0025] In step S10, the Chinese herbal medicine can be placed in an extraction kettle for extraction, the carbon dioxide bottle provides carbon dioxide, the ultra-high pressure supercritical CO2 extraction device is started (maximum pressure 200MPa, temperature ≤80°C), the extraction pressure is set to 80-200MPa, the extraction temperature is set to 40-80°C, and the extract is obtained, thereby extracting the macromolecular substances and high polar substances of the Chinese herbal medicine.

[0026] In step S20, under the condition of separation pressure of 10-80MPa, the separator separates the extract, separates the macromolecular substances and high polar substances from the ultra-supercritical carbon dioxide medium, thereby extracting the macromolecular substances and high polar substances of Chinese herbal medicine. After separation, the carbon dioxide can be recovered by a recovery system. Specifically, the recovery system can include a filter, a cooler, a carbon dioxide bottle, etc. The separated carbon dioxide gas can be recovered after depressurization to 12MPa, filtered by a filter, liquefied by a cooler, and then enters a storage tank or a carbon dioxide bottle for continued recycling.

[0027] It should be noted that the separator can be connected to a chromatograph, a mass spectrometer and other detection instruments to directly perform online detection on the separated macromolecular substances and high-polar substances, so that different macromolecular substances and high-polar substances can be separated in a directional manner to obtain different macromolecular substances and high-polar substances. The chromatograph can include a liquid chromatograph and a gas chromatograph, and the mass spectrometer can include an organic mass spectrometer. The ultra-high pressure supercritical CO2 extraction device can include a high pressure system (maximum pressure 160MPa), a high pressure CO2 fluid extraction system, a control system, etc.

[0028] The technical solution of the present invention uses CO2 to extract macromolecular and highly polar effective components in Chinese herbal medicines under supercritical ultra-high pressure (>80MPa) and relatively low temperature (<80C°), so that macromolecular substances and highly polar substances can be dissolved by CO2 without any damage, and separated by separation means, so that complete active ingredients can be extracted, which greatly improves the extraction rate, makes up for the shortcoming that conventional supercritical fluid extraction technology can only extract volatile, small molecular and low polar substances, solves many extraction problems in the preparation process of Chinese herbal medicines, and lays a foundation for the high-end preparation of Chinese herbal medicines and innovation of Western medicine.

[0029] Moreover, this technical solution does not require the addition of entrainers or auxiliary agents, and has the advantages of no pollution, no additives, no solvent residue, good separation ability, high extraction rate, low energy consumption, and reasonable process. It is highly practical and can be widely used in the field of high-end pharmaceutical preparation.

[0030] The Chinese herbal medicine in the method of extracting Chinese herbal medicine with ultra-supercritical CO2 can be a single Chinese herbal medicine or a combination of multiple Chinese herbal medicines. In one embodiment, when extracting a single Chinese herbal medicine, the extraction pressure is 80-100MPa and the extraction temperature is 45-55°C; or, when extracting multiple Chinese herbal medicines, the extraction pressure is 100-150MPa and the extraction temperature is 70-80°C, so as to extract different macromolecular substances and highly polar substances.

[0031] In one embodiment, the molecular weight of the Chinese herbal extract is greater than 1000 Daltons. In other words, the molecular weight of the extracted macromolecular substance is not a conventional small molecule.

[0032] In one embodiment, the step of separating the extract in step S20 comprises the following steps: S21, separating the extract in the first stage to obtain a first extract; S22, separating the extract in the second stage to obtain a second extract; The separation pressure of the first stage separation is 50-80 MPa, and the separation pressure of the second stage separation is 30-40 MPa.

[0033] According to the different separation pressures of step S21 and step S22, different macromolecular substances and high polar substances extracted by carbon dioxide are precipitated respectively, thereby obtaining different macromolecular substances and high polar substances. It is understood that the first extract is separated by the first separator, and the second extract is separated by the second separator. It is understood that the first, second or third only represents one, and does not limit the order, and the second stage separation may be performed first, and then the first stage separation.

[0034] In one embodiment, the separation temperature of the first stage separation is 40-50° C. and / or the separation temperature of the second stage separation is 40-60° C. Different macromolecular substances and highly polar substances are separated at different temperatures.

[0035] In one embodiment, the molecular weight of the first extract is greater than or equal to 5000 Daltons, that is, after extraction, under a separation pressure of 50-80 MPa, a first extract with a molecular weight greater than or equal to 5000 Daltons can be separated.

[0036] In one embodiment, the molecular weight of the second extract is 1000-4000 Daltons. That is, under the separation pressure of 30-40 MPa, a second extract with a molecular weight of 1000-4000 Daltons can be separated.

[0037] In one embodiment, the method for extracting Chinese herbal medicine with ultra-supercritical CO2 is continuous extraction, so as to maximize the extraction of macromolecular substances and high polar substances in Chinese herbal medicine, and further improve the extraction rate. In one embodiment, the cycle extraction time of the method for extracting Chinese herbal medicine with ultra-supercritical CO2 is 2-3 hours. Furthermore, the number of cycle extractions is 2-3 times per shift.

[0038] In one embodiment, the CO2 flow rate is 15-25 L / h, thereby ensuring the extraction efficiency while reducing energy consumption.

[0039] In one embodiment, the CO2 purity is 5N or above. 5N means that the purity of the gas is 99.999%, that is, the impurities are only 10ppm for every one million gas masses; similarly, 6N means that the purity of the gas is very high, usually 99.9999%, that is, the impurities are only 1ppm for every one million gas masses. By introducing carbon dioxide with a purity of 5N or above, on the one hand, impurities can be avoided, and on the other hand, the extraction rate and separation capacity can be ensured, thereby further improving the extraction rate of the method.

[0040] Before step S10, the Chinese herbal medicine can be dried and then crushed, or the Chinese herbal medicine powder can be directly obtained. If the particle size of the Chinese herbal medicine is too large, it is not conducive to dissolution and extraction. If the particle size of the Chinese herbal medicine is too small, it will cause agglomeration and affect the extraction effect. In one embodiment, the particle size of the Chinese herbal medicine is 270-1000 μm, which is not easy to agglomerate and is also conducive to full contact with carbon dioxide, increasing the contact area, so that carbon dioxide can fully dissolve the macromolecular substances and high-polar substances of the Chinese herbal medicine, and further improve the extraction rate of the method. The Chinese herbal medicine can be crushed using an anti-corrosion airflow mill and graded by a grading screen to improve the extraction efficiency.

[0041] In one embodiment, before the extraction step S10, the following steps are also included: S30, mixing spheres with Chinese herbal medicines; wherein the weight ratio of the spheres to the Chinese herbal medicines is 20:(80-100), the spheres include one or more of quartz spheres, alumina spheres or zirconium spheres, and the diameter of the spheres is 3-5 mm.

[0042] By adding the spheres, a void network can be formed, allowing the carbon dioxide to smoothly and evenly enter the powder of the Chinese herbal medicine, allowing the carbon dioxide to further fully contact the Chinese herbal medicine, thereby improving the extraction rate of the method.

[0043] In one embodiment, the segmented separation further comprises the following steps: S23, performing third-stage separation on the extract to obtain a third extract; wherein the separation pressure of the third-stage separation is 10-20 MPa.

[0044] In step S23, the extract is subjected to a third stage separation, and the separation pressure of the third stage separation is 10-20 MPa, and the separation temperature can be 20-30° C. The molecular weight of the third extract can be below 900 Daltons. In other words, the method can not only extract macromolecular substances and high-polar substances from Chinese herbal medicines, but also extract and separate small molecular low-polar substances with a molecular weight of less than 900 Daltons from Chinese herbal medicines.

[0045] The embodiments of the present invention will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If specific conditions are not specified in the examples, they are carried out according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0046] Example 1 Extraction of Lutein from Chinese Herbal Medicines Lutein belongs to carotenoids and is a natural pigment with bright color, strong coloring power, good antioxidant properties, and rich nutritional and health value. It is widely found in vegetables, flowers, fruits, and some algae plants. It has the functions of scavenging free radicals, preventing lipid peroxidation, delaying senile arteriosclerosis, preventing middle-aged macular degeneration, and regulating human immunity. However, the substance of this plant has high polarity and high hydroxyl group, and is not easy to extract using traditional normal pressure or low pressure supercritical fluid extraction processes.

[0047] The ultra-supercritical CO2 extraction process is used to extract lutein from Chinese herbal medicine. Taking marigold as an example, 100 kg of marigold is finely ground into 16 meshes, mixed evenly with glass balls with a diameter of 5 mm at a weight ratio of 80:20, and then placed in an extraction kettle and sealed for extraction and separation. The steps are as follows: S10, extracting the Chinese herbal medicine using CO2 as an extraction solvent under the conditions of an extraction pressure of 100 MPa and an extraction temperature of 50° C. to obtain an extract; S21, first-stage separation of the extract to obtain a first extract; S22, separating the extract in the second stage to obtain a second extract; S23, separating the extract in the third stage to obtain a third extract; The separation pressure of the first stage separation is 60MPa, and the separation temperature of the first stage separation is 50°C; the separation pressure of the second stage separation is 30MPa, and the separation temperature of the second stage separation is 40°C; the separation pressure of the third stage separation is 15MPa, and the separation temperature of the third stage separation is 30°C. The CO2 flow rate is 25L / h, and the extraction time is 2 hours.

[0048] The experiment obtained 1.936 kg of lutein from the second extract and the third extract. It is known that the total mass of lutein in 100 kg of marigold is 2 kg, and the calculated extraction rate is 96.8%.

[0049] Example 2 Extraction of saponins from Chinese herbal medicines Chinese herbal saponins are macromolecular compounds with complex structures, which are composed of sugar chains, triterpenes, steroids or steroidal alkaloids connected by carbon-oxygen bonds, and are widely present in the stems, leaves and roots of Chinese herbal medicines. The method of extracting Chinese herbal medicines with ultra-supercritical CO2 of the present application can extract the highest concentration of products under ultra-high pressure and low temperature. Compared with the conventional supercritical CO2 extraction method, it has the advantages of high saponin content and no solvent residue.

[0050] Among them, diosgenin is diosgenin extracted and separated from plants of the Dioscoreaceae family, with a molecular formula of C 45 H 72 C 16 , relative molecular mass 869.08, and its structural formula is 3-hydroxy-25R-spirosterene.

[0051] Taking yellow yam as an example, 9.77 kg of dried hydrolyzate of yellow yam was put into an extraction kettle, which was sealed and then extracted and separated. The steps are as follows: S10, extracting the Chinese herbal medicine using CO2 as an extraction solvent under the conditions of an extraction pressure of 85 MPa and an extraction temperature of 55° C. to obtain an extract; S21, first-stage separation of the extract to obtain a first extract; S22, separating the extract in the second stage to obtain a second extract; S23, separating the extract in the third stage to obtain a third extract; The separation pressure of the first stage separation is 65MPa, and the separation temperature of the first stage separation is 50°C; the separation pressure of the second stage separation is 35MPa, and the separation temperature of the second stage separation is 40°C; the separation pressure of the third stage separation is 12MPa, and the separation temperature of the third stage separation is 20°C. The CO2 flow rate is 12 L / h, and the extraction time is 2 hours.

[0052] After separation, the extracts were mixed and determined by thin layer chromatography, and most of the extracts (>80%) were diosgenin. Gas chromatography analysis detected 9.38 kg of diosgenin, and the diosgenin extraction rate was calculated to be 96.0%, indicating that there were fewer impurities, and the product yield was calculated to be 93.8%.

[0053] Example 3 Extraction of various Chinese herbal medicines The method of ultra-supercritical CO2 extraction of Chinese herbal medicine in this application is used to extract a variety of Chinese herbal medicine formulas, "Ganmaoling Granules" with the national medicine standard Z53020096, containing trifoliate bitter, golden calendula, wild chrysanthemum, hawthorn, caffeine, and peppermint oil, but does not contain any western medicine ingredients.

[0054] 10 kg of Tripterygium wilfordii, Calendula officinalis, Chrysanthemum officinale, Prunus armeniaca, caffeine and peppermint oil were crushed into 50 meshes, mixed evenly with 5 mm diameter quartz balls at a weight ratio of 80:20, loaded into an extraction kettle, sealed, and extracted and separated, the steps are as follows: S10, extracting the Chinese herbal medicine using CO2 as an extraction solvent under the conditions of an extraction pressure of 120 MPa and an extraction temperature of 80° C. to obtain an extract; S21, first-stage separation of the extract to obtain a first extract; S22, separating the extract in the second stage to obtain a second extract; S23, separating the extract in the third stage to obtain a third extract; The separation pressure of the first stage separation is 80MPa, and the separation temperature of the first stage separation is 60°C; the separation pressure of the second stage separation is 50MPa, and the separation temperature of the second stage separation is 40°C; the separation pressure of the third stage separation is 15MPa, and the separation temperature of the third stage separation is 30°C. The CO2 flow rate is 25L / h, and the extraction time is 3 hours.

[0055] A total of 9.85 kg of separated extracts from different stages were obtained, and the yield of effective components was calculated to be 98.5%.

[0056] Its ingredients were tested and 187 components were obtained, the main ingredients of which were α-pinene, glucuronic acid, anthraquinone glycosides, phytosterol-β, chrysanthemum lactone, chrysanthemum alcohol, parthenol, ursolic acid, oleic acid, menthol, caffeine, etc.

[0057] From Examples 1 to 3, it can be seen that the method of extracting Chinese herbal medicines with ultra-supercritical CO2 of the present application can extract single or multiple Chinese herbal medicines, extract and separate macromolecular substances and highly polar substances in Chinese herbal medicines, and the method has a high extraction rate and strong separation ability, and does not require the addition of entrainers or additives, is pollution-free, residue-free, and green and environmentally friendly. In addition, carbon dioxide can be recycled to reduce the extraction cost.

[0058] Comparative test on extracting Chinese herbal medicine Forsythia suspensa Forsythia suspensa is a plant of the Oleaceae family, and its dried fruit is generally used as medicine. The main components of Forsythia suspensa are alkenes, alcohols, glycosides, triterpenes, flavonoids, etc.

[0059] Super supercritical CO2 method (SSFE), supercritical CO2 method (SFE) and steam distillation (SD) were used to extract Forsythia suspensa, and their components and contents were analyzed. The results are shown in Table 1.

[0060] Table 1 Extraction results of Forsythia suspensa According to the above table, the method of extracting Chinese herbal medicine with ultra-supercritical CO2 of the present application extracts 33 components in total, including alkenes, alcohols, glycosides, triterpenes, flavonoids and alkaloids. Comparing the steam distillation method, the supercritical CO2 method and the ultra-supercritical CO2 method of the present application, the types of compounds extracted by the steam distillation method and the supercritical CO2 method are similar. Although the content of some compounds in the steam distillation method is higher than that in the supercritical CO2 method, the supercritical CO2 method has slightly more compounds than the steam distillation method, and the extraction rate of most compounds is also slightly higher than that of the steam distillation method.

[0061] The ultra-supercritical CO2 method of the present application has much more extraction types and extraction rates than the steam distillation method and the supercritical CO2 method, especially the ultra-supercritical CO2 method can extract almost all the compounds contained in Forsythia suspensa, including glycosides, triterpenes, flavonoids and alkaloids with larger molecular weight components. This shows that the ultra-supercritical CO2 method of the present application can extract macromolecular substances and highly polar substances in Chinese herbal medicines, and has a wide range of extraction types and a high extraction rate.

[0062] The raw materials and equipment used in the present invention, unless otherwise specified, are all commonly used raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art. Unless otherwise specified, the meanings of the terms in this specification are the same as those generally understood by those skilled in the art, but in case of conflict, the definitions in this specification shall prevail.

[0063] The foregoing examples are merely illustrative and are used to explain some features of the method of the present invention. The appended claims are intended to claim the widest possible range that can be conceived, and the embodiments presented herein are only illustrations of selected implementations according to the combination of all possible embodiments. Therefore, it is the applicant's intention that the appended claims are not limited by the selection of examples that illustrate the features of the present invention. Some numerical ranges used in the claims also include sub-ranges within them, and changes in these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A method for extracting Chinese herbal medicine using ultra-supercritical CO2, characterized in that: The following steps are involved: Under the conditions of extraction pressure of 80-200 MPa and extraction temperature of 40-80° C., CO2 is used as an extraction solvent to extract the Chinese herbal medicine to obtain an extract; The extract is separated to obtain a Chinese herbal medicine extract; wherein the separation pressure is 10-80 MPa.

2. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 1, characterized in that: The extraction pressure is 80-100 MPa, and the extraction temperature is 45-55° C.; or, The extraction pressure is 100-150MPa, and the extraction temperature is 70-80°C.

3. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 2, characterized in that: The molecular weight of the Chinese herbal extract is greater than 1000 Daltons.

4. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 2, characterized in that: The step of separating the extract comprises the following steps: The extract is separated in the first stage to obtain a first extract; The extract is separated in the second stage to obtain a second extract; The extract is separated in the third stage to obtain a third extract; The separation pressure of the first stage separation is 50-80 MPa, the separation pressure of the second stage separation is 30-40 MPa, and the separation pressure of the third stage separation is 10-20 MPa.

5. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 4, characterized in that: The separation temperature of the first stage separation is 40-50°C; and / or, The separation temperature of the second stage separation is 40-60°C.

6. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 5, characterized in that: The molecular weight of the first extract is greater than or equal to 5000 Daltons; and / or, The molecular weight of the second extract is 1000-4000 Daltons; and / or, The molecular weight of the third extract is below 900 Daltons.

7. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 according to any one of claims 1 to 6, characterized in that: The method has a cycle extraction time of 2-3 hours; and / or, The CO2 flow rate is 15-25 L / h; and / or, The CO2 purity is above ‌5N.

8. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 according to any one of claims 1 to 6, characterized in that: The particle size of the Chinese herbal medicine is 270-1000 μm.

9. The method for extracting Chinese herbal medicine using ultra-supercritical CO2 as claimed in claim 8, characterized in that: Before the extraction step, the following steps are also included: The spheres are mixed with Chinese herbal medicine particles; wherein the weight ratio of the spheres to the Chinese herbal medicine is 20:(80-100), the spheres include one or more of quartz spheres, alumina spheres or zirconium spheres, and the diameter of the spheres is 3-5 mm.

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