Codonopsis pilosula extract with high codonopsis pilosula polysaccharide content as well as preparation method and application of codonopsis pilosula extract

Abstract

The invention relates to the field of plant extraction, and particularly discloses a codonopsis pilosula extract with high codonopsis pilosula polysaccharide content and a preparation method and application thereof.The preparation method comprises the following steps that firstly, a codonopsis pilosula raw material is soaked in a soaking solution, then the codonopsis pilosula raw material is adjusted to be neutral, dried, smashed and screened, and codonopsis pilosula powder is obtained; codonopsis pilosula powder is subjected to supercritical carbon dioxide extraction with a mixture of ionic liquid and water as an entrainer to obtain an extract, the prepared extract is re-extracted with water and then filtered, a codonopsis pilosula extracting solution is prepared, and the ionic liquid at least comprises imidazole ionic liquid with the anion being hexafluorophosphate; drying the codonopsis pilosula extracting solution obtained in the step S2 to obtain a codonopsis pilosula extract; the invention also discloses the codonopsis pilosula extract with high codonopsis pilosula polysaccharide content prepared by the method and application of the codonopsis pilosula extract in health care products, cosmetics, food additives or medicines. The method has the characteristics that the extraction rate of polysaccharide in codonopsis pilosula is increased, and the codonopsis pilosula extract with more active components is obtained.

Description

Technical Field

[0001] The present application relates to the field of plant extraction, and more specifically, to a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content, and a preparation method and application thereof. Background Art

[0002] Codonopsis pilosula is the root of the plant Codonopsis pilosula of the Campanulaceae family. It is sweet and mild in nature, non-toxic, and has the effects of promoting fluid production and relieving cough, tonifying the middle and replenishing qi. It is used for spleen and lung qi deficiency, poor appetite and fatigue, cough and weak asthma, insufficient qi and blood, sallow complexion, palpitations and shortness of breath, loss of body fluid and thirst, internal heat and thirst. It is a traditional tonic medicine in my country.

[0003] Codonopsis extract is an extract extracted from the dried root of Codonopsis pilosula, which has multiple effects. Codonopsis extract is mainly composed of various active ingredients in Codonopsis pilosula, including polysaccharides, saponins, flavonoids, steroids, etc. Codonopsis extract can enhance human immunity, protect the liver, regulate blood sugar, promote blood circulation, and is widely used in various fields.

[0004] Codonopsis polysaccharide is one of the important active ingredients in Codonopsis extract, which has the functions of enhancing immunity, regulating blood sugar, and promoting intestinal health. The content of the above active ingredients not only helps to enhance the biological activity and pharmacological effects of Codonopsis extract, but also can improve the efficacy and expand its application areas.

[0005] At present, the commonly used methods for extracting Codonopsis pilosula extracts from Codonopsis pilosula include ethanol extraction, hot water extraction, etc. However, the hot water extraction method uses a relatively low temperature to extract Codonopsis pilosula polysaccharides, resulting in a low extraction rate of Codonopsis pilosula polysaccharides. The extraction rate increases with increasing temperature, but the extracted Codonopsis pilosula polysaccharides decompose when heated, which leads to a decrease in the extraction rate. The ethanol extraction method requires the use of a large amount of organic solvents, which is relatively costly and has average extraction efficiency. It is necessary to provide a new extraction method to improve the extraction effect of active ingredients, especially Codonopsis pilosula polysaccharides, and increase the active ingredient content of Codonopsis pilosula extracts. Summary of the invention

[0006] In order to improve the extraction rate of polysaccharides in Codonopsis pilosula and obtain a Codonopsis pilosula extract with a higher content of active ingredients, the present application provides a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content, and a preparation method and application thereof.

[0007] In the first aspect, the present application provides a method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content, using the following technical scheme: A method for preparing a codonopsis pilosula extract having a high codonopsis pilosula polysaccharide content, comprising the following steps: S1, soaking the raw material of Codonopsis pilosula in a soaking solution, adjusting it to neutrality and drying it, and then crushing and sieving it to obtain Codonopsis pilosula powder; S2, extracting the codonopsis pilosula powder with a mixture of ionic liquid and water as an entrainer through supercritical carbon dioxide to obtain an extract, re-extracting the obtained extract with water and filtering it to obtain a codonopsis pilosula extract, wherein the ionic liquid at least includes an imidazole ionic liquid whose anion is hexafluorophosphate; S3, drying the Codonopsis pilosula extract obtained in step S2 to obtain a Codonopsis pilosula extract; The soaking liquid in step S1 is a mixture of citric acid, potassium chloride, tea saponin and water.

[0008] By adopting the above technical scheme, in the present application, the raw material of Codonopsis pilosula is first soaked in an soaking solution, and the addition of citric acid in the soaking solution is more conducive to the softening and swelling of the cell wall of Codonopsis pilosula, which is beneficial to the release of active substances and improves the subsequent extraction rate. The addition of tea saponin not only has a surface active wetting effect, thereby promoting the dissolution of Codonopsis pilosula polysaccharides, but also forms a stable complex with Codonopsis pilosula saponins, significantly improving the solubility of saponins in water, and has a positive synergistic effect on its biological activity, preventing the reaction of saponins with citric acid to cause the conversion and generation of Codonopsis pilosula saponins. The addition of potassium chloride may affect the permeability of the cell wall of Codonopsis pilosula, promote the dissolution of polysaccharides and saponins from the cells, increase the contact opportunity with supercritical carbon dioxide, so that more active ingredients such as polysaccharides and saponins in Codonopsis pilosula are dissolved, and the final extraction amount is more. After soaking, the mixture is adjusted to neutral grinding and then extracted with supercritical carbon dioxide, and the extraction rate of the effective ingredients of polysaccharides and saponins is higher.

[0009] Moreover, when supercritical carbon dioxide extraction is adopted, a mixture of imidazole ionic liquid and water is used as an entrainer, and the anion of the imidazole ionic liquid is hexafluorophosphate. The imidazole ionic liquid with hexafluorophosphate as an anion is selected as the entrainer, which is insoluble in water, and the acidic environment of the imidazole phosphate ionic liquid can destroy the cell wall structure of Codonopsis pilosula. In combination with the extraction of supercritical carbon dioxide gas, the polysaccharides and saponins in the cells can be more easily released into the extract through the cell wall, and the imidazole phosphate ionic liquid can enhance its solubility in the ionic liquid. Then water is used for re-extraction, the Codonopsis pilosula extract is soluble in water, while the ionic liquid is insoluble in water, thereby realizing the separation and recycling of the ionic liquid. Moreover, the potassium chloride added to the soaking solution is dissolved in water during supercritical extraction, which also changes the distribution coefficient of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins in the supercritical fluid, and finally the extraction amount of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins is greater.

[0010] Optionally, the ionic liquid contains at least 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate, and further contains one or more of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate, 1-propyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethylimidazolium hexafluorophosphate, 1-octyl-2,3-dimethylimidazolium hexafluorophosphate, 1-dodecyl-2,3-dimethylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium hexafluorophosphate, and 1-dodecyl-3-methylimidazolium hexafluorophosphate.

[0011] By adopting the above technical scheme, a mixture of the above two imidazole ionic liquids is selected in the present application. The ionic liquids are insoluble in water to facilitate subsequent separation. More importantly, 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate ionic liquid is added. Its hydroxyl functional group forms hydrogen bonds with Codonopsis pilosula polysaccharides and saponins, which is beneficial to their dissolution. The amino functional groups contained therein are not only beneficial to neutralize the acidic environment, but also create pH conditions that are more conducive to the dissolution of polysaccharides and saponins.

[0012] Optionally, the ionic liquid is a mixture of 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and 1-ethyl-2,3-dimethylimidazole hexafluorophosphate in a mass ratio of 1:(0.6-0.8).

[0013] By adopting the above technical solution, the extraction effect of Codonopsis pilosula extract is better when the above ionic liquid is selected.

[0014] Optionally, dicyclohexylcarbodiimide is further added to the extract, and the added mass ratio of dicyclohexylcarbodiimide to imidazole ionic liquid is 1:(15-18).

[0015] By adopting the above technical scheme, it is found that the amount of polysaccharides finally extracted is further increased, probably because the monosaccharides in Codonopsis pilosula generate monosaccharide amines such as glucosamine under the action of amino groups, and dehydrate and condense to form polysaccharides under the action of dicyclohexylcarbodiimide condensation agent.

[0016] Optionally, hydroxypropyl β-cyclodextrin is further added to the soaking liquid, and the added amount of hydroxypropyl β-cyclodextrin is 2-3 times the mass of citric acid.

[0017] By adopting the above technical scheme, the addition of hydroxypropyl β-cyclodextrin in the soaking solution can not only increase the dissolution of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins, which is beneficial to the subsequent extraction, but also can realize the inclusion of polysaccharides through its cavity structure to form a stable inclusion complex. Its good water solubility is more conducive to the dissolution of polysaccharides and saponins from the raw materials, and it can also form a certain protection for the polysaccharides, preventing the subsequent destruction of the polysaccharides under the conditions of supercritical carbon dioxide temperature and pressure, thereby improving the final polysaccharide extraction rate.

[0018] Optionally, the soaking liquid is prepared by mixing citric acid, potassium chloride, tea saponin and water in a mass ratio of 0.5:(2-3):(0.3-0.5):(20-25); In step S2, the added mass ratio of the imidazolium ions to water is 1:(0.8-1.2), and the added amount of the entrainer is 2-5wt% of the Codonopsis pilosula powder.

[0019] By adopting the above technical solution, adding a small amount of ionic liquid and water can achieve a good synergistic effect.

[0020] Optionally, the specific operation of supercritical carbon dioxide extraction in step S2 is: First, the extraction temperature is 35-45°C and the extraction pressure is 25-30MPa for 1-2h, then the temperature is increased to 55-65°C and the extraction pressure is 30-35MPa for 1-2h, and then the temperature is decreased to 25-35°C and the extraction pressure is 10-15MPa for 40-60min to obtain an extract.

[0021] By adopting the above technical scheme, the present application is first carried out under relatively high pressure and high temperature conditions, which has a better extraction effect on codonopsis polysaccharides and saponins, and then the temperature and pressure are continued to be increased for extraction, which helps to enhance the solubility and mass transfer performance of supercritical carbon dioxide and has a higher extraction efficiency. Then, the short-term treatment after cooling and reducing pressure is more conducive to the dissolution and separation of the above-mentioned active ingredients, and finally a larger amount of polysaccharides and saponins extracted in the codonopsis extract is obtained.

[0022] Optionally, in step S3, ethanol is first added to the Codonopsis pilosula extract in step S2 to precipitate, and separated to obtain a precipitate and a filtrate. The precipitate is washed with alcohol and acetone to obtain Codonopsis pilosula polysaccharide, and the filtrate is dried to obtain a Codonopsis pilosula extract containing saponins.

[0023] By adopting the above technical scheme, in the present application, the Codonopsis pilosula extract obtained after supercritical carbon dioxide extraction is directly subjected to alcohol precipitation to obtain Codonopsis pilosula polysaccharide. Moreover, since tea saponin is soluble in ethanol, the purification of the polysaccharide can also be achieved. It is found that the yield of Codonopsis pilosula polysaccharide is higher and its impurities are less, which is more conducive to the subsequent separation of Codonopsis pilosula polysaccharide, and the operation is simple and the yield is high.

[0024] In a second aspect, the present application provides a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content, using the following technical solution: a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content is prepared by the preparation method.

[0025] By adopting the above technical scheme, the extract of Codonopsis pilosula polysaccharide and Codonopsis pilosula dried extract obtained by the method provided in this application contains more Codonopsis pilosula polysaccharide, and the polysaccharide can be separated directly by alcohol precipitation after supercritical gas extraction, which is simple and convenient and produces more polysaccharide.

[0026] In a third aspect, the present application provides an application of a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content, using the following technical solution: The invention discloses an application of a codonopsis pilosula extract with high codonopsis pilosula polysaccharide content in health products, cosmetics, food additives or medicines.

[0027] In summary, this application has the following beneficial effects: 1. In the present application, the raw material of Codonopsis pilosula is first soaked in a soaking solution. The addition of citric acid in the soaking solution is more conducive to the softening and swelling of the cell wall of Codonopsis pilosula, which is beneficial to the release of active substances and improves the subsequent extraction rate. The addition of tea saponin forms a stable complex with Codonopsis pilosula saponins, significantly improves the solubility of saponins in water, and has a positive synergistic effect on its biological activity, preventing the reaction of saponins with citric acid to cause the conversion and generation of Codonopsis pilosula saponins. The addition of potassium chloride may affect the permeability of the cell wall of Codonopsis pilosula, promote the dissolution of polysaccharides and saponins from the cells, increase the contact opportunity with supercritical carbon dioxide, so that more active ingredients such as polysaccharides and saponins in Codonopsis pilosula are dissolved, and the final extraction amount is more. After soaking, it is adjusted to neutral pulverization and then extracted by supercritical carbon dioxide, and the extraction rate of the effective ingredients of polysaccharides and saponins is higher; 2. In the present application, when supercritical carbon dioxide extraction is used, a mixture of imidazole ionic liquid and water is used as an entrainer, and the anion of the imidazole ionic liquid is hexafluorophosphate. The imidazole ionic liquid with hexafluorophosphate as an anion is selected as the entrainer, which is insoluble in water, and the acidic environment of the imidazole phosphate ionic liquid can destroy the cell wall structure of Codonopsis pilosula. With the extraction of supercritical carbon dioxide gas, the polysaccharides and saponins in the cells can be more easily released into the extract through the cell wall, and the imidazole phosphate ionic liquid can enhance its solubility in the ionic liquid. Then water is used for re-extraction. The Codonopsis pilosula extract is soluble in water, while the ionic liquid is insoluble in water, thereby realizing the separation and recycling of the ionic liquid. Moreover, the potassium chloride added to the soaking solution is dissolved in water during supercritical extraction, which also changes the distribution coefficient of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins in the supercritical fluid, and finally the extraction amount of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins is greater; 3. In the present application, when supercritical carbon dioxide extraction is adopted, a mixture of imidazole ionic liquid and water is used as an entrainer, and the anion of the imidazole ionic liquid is hexafluorophosphate. The imidazole ionic liquid with hexafluorophosphate as an anion is selected as the entrainer, which is insoluble in water, and the acidic environment of the imidazole phosphate ionic liquid can destroy the cell wall structure of Codonopsis pilosula. In combination with the extraction of supercritical carbon dioxide gas, the polysaccharides and saponins in the cells can be more easily released into the extract through the cell wall, and the imidazole phosphate ionic liquid can enhance its solubility in the ionic liquid. Then water is used for re-extraction, the Codonopsis pilosula extract is soluble in water, while the ionic liquid is insoluble in water, thereby realizing the separation and recycling of the ionic liquid. Moreover, the potassium chloride added to the soaking solution is dissolved in water during supercritical extraction, which also changes the distribution coefficient of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins in the supercritical fluid, and finally the extraction amount of Codonopsis pilosula polysaccharides and Codonopsis pilosula saponins is greater. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in conjunction with the examples. It is particularly noted that if no specific conditions are specified in the following examples, the experiments are carried out according to conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the raw materials used in the following examples can be obtained from common commercial sources.

[0029] The Codonopsis pilosula raw material in the following examples is Codonopsis pilosula from Shaanxi Province.

[0030] Example 1 A method for preparing a codonopsis pilosula extract having a high codonopsis pilosula polysaccharide content, comprising the following steps: S1, take 5kg of Codonopsis raw material and soak it in soaking liquid for 40min, the soaking liquid does not cover the Codonopsis raw material, then add alkali to adjust to neutrality and then dry, then crush and pass through 80 mesh sieve to obtain Codonopsis powder; S2, using a mixture of ionic liquid and water as an entrainer for Codonopsis pilosula powder, the entrainer is added in an amount of 3wt% of the Codonopsis pilosula powder, and extracting it through supercritical carbon dioxide to obtain an extract, re-extracting the obtained extract with water and filtering it to obtain a Codonopsis pilosula extract, and the specific operation of supercritical carbon dioxide extraction is: First, the extraction temperature is 50°C and the extraction pressure is 28MPa for 1.5h, then the temperature is increased to 60°C and the extraction pressure is 32MPa for 1.5h, and then the temperature is decreased to 30°C and the extraction pressure is 12MPa for 50min to obtain an extract; S3. Drying the Codonopsis pilosula extract obtained in step S2 to obtain a Codonopsis pilosula extract. More specifically, in step S3, firstly adding ethanol to the obtained Codonopsis pilosula extract, wherein the mass ratio of ethanol to the Codonopsis pilosula extract is 1:2.5, and the mixture is allowed to stand for precipitation and filtered to separate to obtain a precipitate and a filtrate. The precipitate is washed with alcohol and acetone to obtain Codonopsis pilosula polysaccharide, and the filtrate is dried to remove the solvent to obtain a Codonopsis pilosula extract containing saponins.

[0031] The soaking solution in step S1 is prepared by mixing citric acid, potassium chloride, tea saponin and water in a mass ratio of 0.5:2.5:0.4:22; The ionic liquid in step S2 is a mixture of 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate in a mass ratio of 1:0.7; and the added mass ratio of imidazole ions to water is 1:1.

[0032] Example 2 A method for preparing a codonopsis pilosula extract having a high codonopsis pilosula polysaccharide content, comprising the following steps: S1, take 5kg of Codonopsis pilosula raw material and soak it in soaking liquid for 30min, the soaking liquid does not cover the Codonopsis pilosula raw material, then add alkali to adjust to neutrality and then dry, then crush and pass through 80 mesh sieve to obtain Codonopsis pilosula powder; S2, using a mixture of ionic liquid and water as an entrainer for Codonopsis pilosula powder, the amount of the entrainer added is 2wt% of the Codonopsis pilosula powder, extracting the extract by supercritical carbon dioxide, re-extracting the obtained extract with water and filtering it to obtain Codonopsis pilosula extract, the specific operation of supercritical carbon dioxide extraction is: First, the extraction temperature is 35°C and the extraction pressure is 25MPa for 2h, then the temperature is increased to 55°C and the extraction pressure is 30MPa for 2h, and then the temperature is decreased to 25°C and the extraction pressure is 10MPa for 60min to obtain an extract; S3. Drying the Codonopsis pilosula extract obtained in step S2 to obtain a Codonopsis pilosula extract. More specifically, in step S3, firstly adding ethanol to the obtained Codonopsis pilosula extract, wherein the mass ratio of ethanol to the Codonopsis pilosula extract is 1:2, and the mixture is allowed to stand for precipitation and filtered to separate to obtain a precipitate and a filtrate. The precipitate is washed with alcohol and acetone to obtain Codonopsis pilosula polysaccharide, and the filtrate is dried to remove the solvent to obtain a Codonopsis pilosula extract containing saponins.

[0033] The soaking solution in step S1 is prepared by mixing citric acid, potassium chloride, tea saponin and water in a mass ratio of 0.5:2:0.3:20; The ionic liquid in step S2 is a mixture of 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate in a mass ratio of 1:0.6; and the added mass ratio of imidazole ions to water is 1:0.8.

[0034] Example 3 A method for preparing a codonopsis pilosula extract having a high codonopsis pilosula polysaccharide content, comprising the following steps: S1, take 5kg of Codonopsis raw material and soak it in the soaking liquid for 50min, the soaking liquid does not cover the Codonopsis raw material, then add alkali to adjust to neutrality and then dry, then crush and pass through 80 mesh sieve to obtain Codonopsis powder; S2, using a mixture of ionic liquid and water as an entrainer for Codonopsis pilosula powder, the amount of the entrainer added is 5wt% of the Codonopsis pilosula powder, extracting the extract by supercritical carbon dioxide, re-extracting the obtained extract with water and filtering it to obtain Codonopsis pilosula extract, the specific operation of supercritical carbon dioxide extraction is: First, the extraction temperature is 45°C and the extraction pressure is 30MPa for 1 hour, then the temperature is increased to 65°C and the extraction pressure is 35MPa for 1 hour, and then the temperature is decreased to 35°C and the extraction pressure is 15MPa for 40 minutes to obtain an extract; S3. Drying the Codonopsis pilosula extract obtained in step S2 to obtain a Codonopsis pilosula extract; more specifically, in step S3, firstly adding ethanol to the obtained Codonopsis pilosula extract, with the mass ratio of ethanol to Codonopsis pilosula extract being 1:3, allowing to stand for precipitation and filtering to separate to obtain a precipitate and a filtrate, washing the precipitate with alcohol and acetone to obtain Codonopsis pilosula polysaccharide, and drying the filtrate to remove the solvent to obtain a Codonopsis pilosula extract containing saponins.

[0035] The soaking solution in step S1 is prepared by mixing citric acid, potassium chloride, tea saponin and water in a mass ratio of 0.5:3:0.5:25; The ionic liquid in step S2 is a mixture of 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate in a mass ratio of 1:0.8; and the added mass ratio of imidazole ions to water is 1:1.2.

[0036] Example 4 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that hydroxypropyl β-cyclodextrin is also added to the soaking solution in step S1, and the added amount of hydroxypropyl β-cyclodextrin is 2 times the mass of citric acid.

[0037] Example 5 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that hydroxypropyl β-cyclodextrin is also added to the soaking solution in step S1, and the added amount of hydroxypropyl β-cyclodextrin is 3 times the mass of citric acid.

[0038] Example 6 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that dicyclohexylcarbodiimide is also added to the extract obtained after supercritical carbon dioxide extraction in step S2, and the added mass ratio of dicyclohexylcarbodiimide to ionic liquid is 1:15.

[0039] Example 7 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that dicyclohexylcarbodiimide is also added to the extract obtained after supercritical carbon dioxide extraction in step S2, and the added mass ratio of dicyclohexylcarbodiimide to ionic liquid is 1:16.

[0040] Example 8 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that dicyclohexylcarbodiimide is also added to the extract obtained after supercritical carbon dioxide extraction in step S2, and the added mass ratio of dicyclohexylcarbodiimide to ionic liquid is 1:18.

[0041] Example 9 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that the ionic liquid in step S2 is 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate.

[0042] Example 10 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that the ionic liquid in step S2 is a mixture of 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate and 1-hexyl-3-methylimidazolium hexafluorophosphate in a mass ratio of 1:0.7.

[0043] Comparative Example 1 A method for preparing a codonopsis pilosula extract with a high codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that in step S1, the codonopsis pilosula raw material is not soaked in an soaking solution, but is directly crushed through 80 mesh to obtain codonopsis pilosula powder for processing.

[0044] Comparative Example 2 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that no tea saponin is added to the soaking solution.

[0045] Comparative Example 3 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that potassium chloride is not added to the soaking solution.

[0046] Comparative Example 4 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that no entrainer is added during the supercritical carbon dioxide extraction in step S2.

[0047] Comparative Example 5 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that the ionic liquid in the entrainer is replaced by potassium chloride in an equal amount.

[0048] Comparative Example 6 A method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content is carried out according to the method in Example 1, except that the ionic liquid in step S2 is 2-hydroxy-N,N,N-trimethylethylamine hexafluorophosphate.

[0049] Performance Testing A uniform batch of Codonopsis pilosula was processed according to the method in the above embodiment and comparative example, and the Codonopsis pilosula polysaccharide obtained in step S3 in the above embodiment and comparative example was counted. The statistical results of the yield of Codonopsis pilosula polysaccharide are shown in Table 1 below.

[0050] Table 1: Referring to the test results in Table 1 above, it can be seen that the yield of codonopsis polysaccharide in the embodiment of the present application is significantly higher than that in the comparative example. In step S3 of the embodiment, the codonopsis extract can also be directly dried without alcohol precipitation to separate the polysaccharide. When the yield of codonopsis polysaccharide in the embodiment of the present application is high, when the codonopsis extract is directly prepared without alcohol precipitation, the codonopsis polysaccharide content in the natural extract is higher. When the codonopsis extract is prepared by directly drying the codonopsis extract, the codonopsis polysaccharide content in the codonopsis extract of embodiments 1-3 can be detected to be 32-38%.

[0051] Referring to the test results of Example 1 and Example 4-5, it can be seen that when hydroxypropyl β-cyclodextrin is added to the soaking solution, on the one hand, due to its inclusion complex with polysaccharides, it helps to improve its dissolution, and it also protects the polysaccharides, reducing the subsequent losses caused by temperature and pressure, and the polysaccharide extraction is significantly increased. Combined with the test results of Examples 6-8, it can be seen that when water-insoluble dicyclohexylcarbodiimide is added to the subsequent extract, it plays a condensation role, further increasing the amount of polysaccharides. Referring to Example 1, Example 9 and Example 10, when the ionic liquid uses a single ionic liquid or two imidazole ionic liquids, the polysaccharide yield is reduced.

[0052] Referring to the test results of Example 1 and Comparative Example 1, when the Codonopsis raw material is directly processed without soaking treatment, the polysaccharide yield is significantly reduced. Combined with the test results of Comparative Examples 2 and 3, when potassium chloride or tea saponin is not added to the soaking solution, the polysaccharide yield is also reduced; combined with the test results of Comparative Example 4 or Comparative Example 5, when no entrainer is added in Comparative Example 4, the Codonopsis polysaccharide yield is significantly reduced, and when potassium chloride is used as the entrainer in Comparative Example 5, although the yield is improved, it is still significantly lower than that in Example 1. Combined with the test results of Comparative Example 6, when only 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate is used as the ionic liquid, the polysaccharide yield is also significantly reduced. In Example 1, 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and an imidazole ionic liquid with hexafluorophosphate as the anion are selected for better extraction effect.

[0053] In addition, the saponin content in the Codonopsis pilosula extract obtained in step S3 was tested, and the test results are shown in Table 2 below: Table 2: Combined with the test results in Table 2 above, the method provided in the present application also has a good extraction effect on codonopsis saponins.

[0054] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for preparing a codonopsis pilosula extract having a high codonopsis pilosula polysaccharide content, characterized in that: The following steps are involved: S1, soaking the raw material of Codonopsis pilosula in a soaking solution, adjusting it to neutrality and drying it, and then crushing and sieving it to obtain Codonopsis pilosula powder; S2, extracting the codonopsis pilosula powder with a mixture of ionic liquid and water as an entrainer through supercritical carbon dioxide to obtain an extract, re-extracting the obtained extract with water and filtering it to obtain a codonopsis pilosula extract, wherein the ionic liquid at least includes an imidazole ionic liquid whose anion is hexafluorophosphate; S3, drying the Codonopsis pilosula extract obtained in step S2 to obtain a Codonopsis pilosula extract; The soaking liquid in step S1 is a mixture of citric acid, potassium chloride, tea saponin and water.

2. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: The ionic liquid at least contains 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate, and further contains one or more of 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-2,3-dimethylimidazolium hexafluorophosphate, 1-propyl-2,3-dimethylimidazolium hexafluorophosphate, 1-butyl-2,3-dimethylimidazolium hexafluorophosphate, 1-hexyl-2,3-dimethylimidazolium hexafluorophosphate, 1-octyl-2,3-dimethylimidazolium hexafluorophosphate, 1-dodecyl-2,3-dimethylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-octyl-3-methylimidazolium hexafluorophosphate, and 1-dodecyl-3-methylimidazolium hexafluorophosphate.

3. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: The ionic liquid is a mixture of 2-hydroxy-N, N, N-trimethylethylamine hexafluorophosphate and 1-ethyl-2,3-dimethylimidazole hexafluorophosphate in a mass ratio of 1:(0.6-0.8).

4. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: Hydroxypropyl beta-cyclodextrin is also added to the soaking liquid, and the added amount of hydroxypropyl beta-cyclodextrin is 2-3 times the mass of citric acid.

5. The method for preparing a Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: Dicyclohexylcarbodiimide is also added to the extract, and the added mass ratio of dicyclohexylcarbodiimide to imidazole ionic liquid is 1:(15-18).

6. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: The soaking liquid is prepared by mixing citric acid, potassium chloride, tea saponin and water in a mass ratio of 0.5: (2-3): (0.3-0.5): (20-25); In step S2, the added mass ratio of the imidazolium ions to water is 1:(0.8-1.2), and the added amount of the entrainer is 2-5wt% of the Codonopsis pilosula powder.

7. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: The specific operation of supercritical carbon dioxide extraction in step S2 is: First, the extraction temperature is 35-45°C and the extraction pressure is 25-30MPa for 1-2h, then the temperature is increased to 55-65°C and the extraction pressure is 30-35MPa for 1-2h, and then the temperature is decreased to 25-35°C and the extraction pressure is 10-15MPa for 40-60min to obtain an extract.

8. The method for preparing a Codonopsis pilosula extract having a high Codonopsis pilosula polysaccharide content according to claim 1, characterized in that: In step S3, ethanol is first added to the Codonopsis pilosula extract in step S2 to precipitate, and the precipitate and filtrate are separated. The precipitate is washed with alcohol and acetone to obtain Codonopsis pilosula polysaccharide, and the filtrate is dried to obtain the Codonopsis pilosula extract containing saponins.

9. A Codonopsis pilosula extract with a high Codonopsis pilosula polysaccharide content obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the Codonopsis pilosula extract with high Codonopsis pilosula polysaccharide content as claimed in claim 9 in health products, cosmetics, food additives or medicines.

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