Preparation method of sodium crocin

Abstract

The present invention belongs to the technical field of natural drug chemistry, relates to the technical field of extraction and separation of natural plant active ingredients, and specifically relates to a method for preparing sodium crocetin. The preparation method comprises the following steps: (1) extraction; (2) hydrolysis; (3) acid precipitation; (4) centrifugal washing; (5) NaOH reaction to remove impurities; (6) centrifugal washing; (7) refining; (8) acidification and centrifugal washing; (9) salt formation and centrifugal washing; (10) vacuum drying. The preparation process steps are relatively simple to operate, the production cycle is short, and the preparation process route is stable. During the preparation process, crocetin is further processed to obtain sodium crocetin, thereby significantly improving its bioavailability.

Description

Technical Field

[0001] The invention belongs to the technical field of natural drug chemistry, relates to the technical field of extraction and separation of natural plant active ingredients, and specifically relates to a method for preparing sodium crocetin. Background Art

[0002] Crocetin is a carotenoid component with a polyunsaturated conjugated olefinic acid structure and high crystallinity. Crocetin is almost insoluble in water, hexane, ethanol and other common organic solvents. Crocetin has a wide range of pharmacological activities, such as anti-tumor, anti-atherosclerosis, anti-hypertension and treatment of hemorrhagic shock.

[0003] Crocetin and its sodium salt contain a series of conjugated double bonds, which make them have strong antioxidant activity. They can be used as scavengers of singlet oxygen. At the same time, they can effectively reduce the destructive effect of free radicals on red blood cells and subcellular membrane structures, and inhibit the damage of free radicals to DNA. In addition, crocetin and its sodium salt also have biological activities in protecting cardiovascular and cerebrovascular, resisting cardiovascular system diseases, resisting atherosclerosis, and preventing and treating diabetic complications. Studies have shown that crocetin and its sodium salt can also effectively inhibit the proliferation of cancer cells, including pancreatic cancer, lung cancer, glioma, and breast cancer cells. In addition, they also have an important regulatory effect on liver lipid metabolism. Therefore, crocetin and its sodium salt have potential broad application prospects in medicine, and the development of sodium crocetin has high medical application value.

[0004] Crocetin is a type of chemical component naturally present in plants such as gardenia. Except for a small part in free form, most of it exists in plants such as saffron and gardenia in the form of glycosides combined with sugar. At present, the technology of artificial synthesis of crocetin is still immature, and crocetin is mainly obtained and prepared by natural plant extraction. Studies have found that some natural plants are rich in crocetin, and the more representative ones are the fruits of saffron, a plant of the Iridaceae family, and the fruits of the genus Gardenia, a plant of the Rubiaceae family.

[0005]

[0006] Water Gardenia contains abundant crocetin, which is cheap and has abundant raw material sources, and is an ideal plant raw material for extracting crocetin and its sodium salt. Water Gardenia belongs to a food and medicine dual-purpose food, which has effects such as protecting liver, promoting gallbladder function, lowering blood pressure, calming, stopping bleeding, and detumescence. Water Gardenia is nontoxic, and the raw material is cheap and easy to obtain, and the content of crocetin is high, so it is a good raw material for extracting crocetin. However, crocetin solubility is poor, and it is almost insoluble in water, so there are some restrictions in drug development and application.

[0007] The present invention aims to provide a method for extracting and preparing sodium crocetin from gardenia jasminoides, wherein crocetin is further processed to obtain sodium crocetin, and sodium crocetin has a certain solubility in water, thereby increasing and improving its bioavailability. Summary of the invention

[0008] In order to overcome the above technical problems, the present invention provides a method for preparing sodium crocetin from gardenia jasminoides. The preparation method is simple to operate, has a short production cycle, and a stable process. The bioavailability thereof is significantly improved, and a high-purity separation and preparation method of a large amount of sodium crocetin can be achieved. The purity of the prepared sodium crocetin is as high as 96% or more.

[0009] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0010] A method for preparing sodium crocetin comprises the following steps:

[0011] (1) Extraction: crush the Gardenia jasminoides slices, add 1-10 times the volume of 60-80% ethanol to an extraction tank, heat and stir, and extract three times at a temperature of 40-70° C. After the extraction is completed, release the extract to a liquid storage tank through a double filter;

[0012] (2) Hydrolysis: The extract in the liquid storage tank in (1) is pumped into a hydrolysis tank, potassium hydroxide is added to obtain a hydrolyzate, and a hydrolysis reaction is carried out at 40-80° C. to obtain a hydrolyzate;

[0013] (3) Acid precipitation: add citric acid to the hydrolyzate, stir, and acid precipitate until the pH value of the acid precipitation liquid reaches 4.0-7.0, and let it stand for 12-30 hours;

[0014] (4) Centrifugal washing: centrifuge the acid precipitate from (3), wash with purified water and ethanol in sequence, and obtain crocetin;

[0015] (5) Sodium hydroxide reaction to remove impurities: prepare a sodium hydroxide aqueous solution with a mass fraction of 4-8wt%, and react the sodium hydroxide solution with crocetin to remove impurities;

[0016] (6) Centrifugal washing: centrifuge the sodium hydroxide reaction solution in (5), collect the centrifugal residue and the centrifugal liquid; add a sodium hydroxide aqueous solution containing 4-6% of the mass of the centrifugal residue to the centrifugal residue for washing, centrifuge, collect the centrifugal residue and the sodium hydroxide washing liquid; then wash the centrifugal residue with ethanol, centrifuge, collect the ethanol washing liquid, mix the centrifugal liquid after the sodium hydroxide reaction, the sodium hydroxide washing liquid and the ethanol washing liquid, and obtain a sodium crocetin intermediate;

[0017] (7) Purification: The sodium crocetin intermediate is dissolved in water, centrifuged, filtered, and the filtrate is collected;

[0018] (8) Acidification and centrifugal washing: acidifying the filtrate in (7), centrifuging the acidified liquid, collecting centrifugal residues, washing the centrifugal residues with ethanol, centrifuging, and collecting the centrifugal residues; then washing the centrifugal residues with purified water, collecting the centrifugal residues, and obtaining an acidified product;

[0019] (9) Salting and centrifugal washing: preparing a sodium hydroxide aqueous solution with a mass fraction of 1-6 wt%, washing the acidified product with the sodium hydroxide aqueous solution and ethanol, collecting the washing liquid, and obtaining a sodium crocetin wet product;

[0020] (10) Vacuum drying: The wet sodium crocetin product is vacuum dried to obtain purified sodium crocetin.

[0021] Preferably, in (1), the water gardenia slices are crushed, and 1-10 times the volume of 60-80% ethanol is added to the extraction tank for the first time, and extracted at 40-70°C for 1-3 hours; the second time, 1-10 times the volume of 60-80% ethanol is continued to be added, and the extraction is carried out at 40-70°C for 20-60 minutes; the third time, 1-10 times the volume of 60-80% ethanol is continued to be added, and the extraction is carried out at 40-70°C for 20-60 minutes.

[0022] Preferably, in (1), the water gardenia slices are crushed, and 1-10 times the volume of ethanol with a concentration of 60-80% is added to the extraction tank for the first time, heated and stirred, and forced circulation is started when the temperature rises to 40-70°C. When the temperature reaches 40-70°C during the forced circulation process, the timing is started, and the extraction is performed for 1-3 hours; after the extraction is completed, the extract is released to the liquid storage tank through a double filter; for the second time, 1-10 times the volume of ethanol with a concentration of 60-80% of the medicinal material is continued to be added to the extraction tank, stirring and heating are started, and when the temperature rises to 40-70°C, forced circulation is started for 10-30 minutes, and extraction is performed for 20-60 minutes; after the extraction is completed, the extract is released to the liquid storage tank through a double filter; for the third time, 1-10 times the volume of ethanol with a concentration of 60-80% of the medicinal material is continued to be added to the extraction tank, stirring and heating are started, and when the temperature reaches 40-70°C during the forced circulation process, extraction is performed for 20-60 minutes, and after the extraction is completed, the extract is released to the liquid storage tank through a double filter;

[0023] Preferably, in (2), the content of potassium hydroxide in the hydrolyzate is 1-8% of the total volume of the hydrolyzate.

[0024] Preferably, in (3), during the acid precipitation process, the mixture is allowed to stand for 12-20 hours.

[0025] Preferably, in (5), the sodium hydroxide solution is a 4 wt % sodium hydroxide aqueous solution;

[0026] Preferably, in (6), the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass fraction of 1-8 wt %, preferably a 4 wt % sodium hydroxide aqueous solution.

[0027] Preferably, in (8), the acidifying acid is citric acid.

[0028] Preferably, in (9), the sodium hydroxide solution is a 4 wt % sodium hydroxide aqueous solution.

[0029] Preferably, in (10), the vacuum degree of the vacuum drying is -0.06 to -0.1 MPa, the drying temperature is 40-70°C, and the drying time is 24-48 hours.

[0030] Compared with the prior art, the technical advantages of the present invention are:

[0031] (1) The present invention provides a method for extracting and preparing sodium crocetin from Gardenia jasminoides. The method of the preparation process is simple to operate, has a short production cycle, and a stable preparation process route, and can achieve large-scale high-purity preparation of sodium crocetin. In addition, in the preparation process of the present invention, crocetin is further processed to obtain sodium crocetin, thereby significantly improving its bioavailability.

[0032] (2) In the present invention, the extraction of effective ingredients is carried out at a specific temperature and time, which can effectively improve the extraction efficiency of crocetin in Gardenia jasminoides, and the specific extraction temperature can effectively reduce the content of other impurities and improve the purity and extraction amount of crocetin.

[0033] (3) The use of citric acid for acid precipitation in the present invention can effectively improve the acid precipitation efficiency and the conversion rate of crocetin compared with conventional inorganic acids such as hydrochloric acid, acetic acid, sulfuric acid, etc., thereby increasing the content and purity of sodium crocetin in the final product.

[0034] (4) The use of 1-6 wt % sodium hydroxide aqueous solution for salt formation and centrifugal washing in the present invention can effectively improve the yield and purity of the obtained sodium crocetin. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 : Flow chart of preparation of sodium crocetin.

[0036] The present invention will be further described with reference to the accompanying drawings and embodiments: DETAILED DESCRIPTION

[0037] The present invention is described below by specific examples to make the technical solution of the present invention easier to understand and grasp, but the present invention is not limited thereto. The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are all commercially available unless otherwise specified.

[0038] Example 1

[0039] (1) Extraction: Take the water gardenia medicinal material slices and grind them with a grinder pre-installed with a stainless steel screen. Use 75% ethanol for extraction. For the first time, add 75% ethanol twice the amount of the medicinal material to the extraction tank, check whether there is leakage at the bottom of the tank, if there is no leakage, start stirring, put in the processed water gardenia medicinal material, turn on heating, start forced circulation when the temperature rises to 50°C, start timing when the temperature reaches 50°C during the forced circulation process, and extract for 1 hour. When the extraction reaches 30 minutes, turn on forced circulation again for 10 minutes. After the extraction is completed, release the extract to the storage tank through the double filter. For the second time, add 75% ethanol once the medicinal material, start stirring and heating, start forced circulation when the temperature rises to 50°C for 10 minutes, and extract for 30 minutes. After the extraction is completed, release the extract to the storage tank through the double filter. For the third time, add 75% ethanol once the medicinal material, start stirring and heating, start forced circulation when the temperature reaches 50°C during the forced circulation process, and extract for 30 minutes.

[0040] (2) Hydrolysis: Pump the drug solution into the hydrolysis tank, start stirring, add potassium hydroxide solution (preparation of potassium hydroxide solution: weigh 1.6 times the amount of water as potassium hydroxide, slowly add potassium hydroxide to dissolve. Wear protective gear during the operation and be careful of alkali burns) to make the potassium hydroxide content in the extract reach 6% of the total volume of the extract and the water dissolved in potassium hydroxide, then turn on the heating and maintain 60°C for hydrolysis. After the hydrolysis is completed, stop heating. Pump the reaction solution into the alcohol precipitation tank and turn on the chilled water for cooling.

[0041] (3) Acid precipitation: Pump the hydrolyzate into the alcohol precipitation tank, turn on the chilled water and stir, and let the hydrolyzate cool down to below room temperature. Add citric acid solution, stir until the pH value of the acid precipitation reaches 6.0, and let it stand for 12 hours.

[0042] (4) Centrifugal washing: Pump the acid precipitate into the centrifuge and turn on the centrifuge. After centrifugation, collect the centrifugal residue and add purified water to wash once. Pump the washing liquid into the centrifuge and turn on the centrifuge. After centrifugation, collect the centrifugal residue and add appropriate amount of ethanol to wash once. Pump the washing liquid into the centrifuge and turn on the centrifuge. After centrifugation, collect the crude product.

[0043] (5) NaOH reaction impurity removal: Prepare the amount of purified water required for the 4% sodium hydroxide reaction solution, then use an appropriate amount of water to dissolve NaOH and set aside. Then use the remaining water to disperse the crude product. Finally, pour the prepared NaOH solution into the dispersion and stir.

[0044] (6) Centrifugal washing: Pump the alkaline reaction liquid into a centrifuge and turn on the centrifuge. After centrifugation, collect the centrifugal residue and add a 4% NaOH aqueous solution to the centrifugal residue for washing once. Pump the washing liquid into the centrifuge and turn on the centrifuge. After centrifugation, collect the centrifugal residue and add ethanol for washing once. Pump the washing liquid into the centrifuge and turn on the centrifuge. After centrifugation, collect the intermediate product.

[0045] (7) Purification: Dissolve the sodium crocetin intermediate in water, then pump the reconstituted solution into a centrifuge and start the centrifuge. After centrifugation, collect the centrifuge liquid and filter it by ultrafiltration.

[0046] (8) Acidification and centrifugal washing: Weigh an appropriate amount of acid, dissolve it in water, then add the acid solution to the filtrate while stirring, and stir to acidify. Pump the acidified solution into a centrifuge and centrifuge it. After centrifugation, collect the centrifuge residue and add ethanol solution to wash it once. Pump the washing liquid into a centrifuge and centrifuge it. After centrifugation, collect the centrifuge residue and add purified water to wash it once. Pump the washing liquid into a centrifuge. After centrifugation, collect the intermediate product.

[0047] (9) Salting and centrifugal washing: Prepare 4% sodium hydroxide first and set aside. Then disperse the crude product with water, pour the prepared NaOH solution into the dispersion and stir. Pump the reaction liquid into a centrifuge, turn on the centrifuge, collect the centrifugal residue after centrifugation, and add 4% NaOH aqueous solution to wash once. Pump the washing liquid into a centrifuge, turn on the centrifuge, collect the centrifugal residue after centrifugation, and add ethanol solution to wash once. Pump the washing liquid into a centrifuge, turn on the centrifuge, collect the centrifugal residue after centrifugation, and add ethanol solution to wash once. Pump the washing liquid into a centrifuge, turn on the centrifuge, collect the wet pure product after centrifugation.

[0048] (10) Vacuum drying: Place the wet pure product into a drying oven, turn on heating and vacuum, control the vacuum degree to -0.08 MPa, the drying temperature to 40°C, and the drying time to 24 hours.

[0049] The purity test was performed using HPLC, and the results showed that the purity of sodium crocetin was 99.5%.

[0050] The above detailed description is a specific description of one feasible embodiment of the present invention. The embodiment is not intended to limit the patent scope of the present invention. Any equivalent implementation or modification that does not deviate from the present invention should be included in the scope of the technical solution of the present invention.

Claims

1. A method for preparing sodium crocetin, comprising the following steps: (1) Extraction: crush the Gardenia jasminoides slices, add 1-10 times the volume of 60-80% ethanol to the extraction tank, heat and stir, and extract three times at a temperature of 40-70°C. After the extraction is completed, release the extract through a double filter into a liquid storage tank; (2) Hydrolysis: The extract in the liquid storage tank in (1) is pumped into a hydrolysis tank, potassium hydroxide is added to obtain a hydrolyzate, and a hydrolysis reaction is carried out at 40-80° C. to obtain a hydrolyzate; (3) Acid precipitation: Add citric acid to the hydrolyzate, stir, and acid precipitate until the pH value of the acid precipitation liquid reaches 4.0-7.0, and let it stand for 12-30 hours; (4) Centrifugal washing: centrifuge the acid precipitation product in (3), wash it with purified water and ethanol in sequence, and obtain crocetin; (5) Sodium hydroxide reaction to remove impurities: prepare a sodium hydroxide aqueous solution with a mass fraction of 4-8wt%, and react the sodium hydroxide solution with crocetin to remove impurities; (6) Centrifugal washing: centrifuge the sodium hydroxide reaction liquid in (5), collect the centrifugal residue and the centrifugal liquid; add a sodium hydroxide aqueous solution containing 4-6% by weight of the centrifugal residue to the centrifugal residue for washing, centrifuge, collect the centrifugal residue and the sodium hydroxide washing liquid; then wash the centrifugal residue with ethanol, centrifuge, collect the ethanol washing liquid, mix the centrifugal liquid after the sodium hydroxide reaction, the sodium hydroxide washing liquid and the ethanol washing liquid, and obtain a sodium crocetin intermediate; (7) Purification: The sodium crocetin intermediate is dissolved in water, centrifuged, filtered, and the filtrate is collected; (8) Acidification and centrifugal washing: Acidify the filtrate in (7), centrifuge the acidified liquid, collect the centrifugal residue, wash the centrifugal residue with ethanol, centrifuge, and collect the centrifugal residue; then wash the centrifugal residue with purified water, collect the centrifugal residue, and obtain an acidified product; (9) Salt formation and centrifugal washing: prepare a sodium hydroxide aqueous solution with a mass fraction of 1-6 wt%, wash the acidified product with the sodium hydroxide aqueous solution and ethanol, collect the washing liquid, and obtain a sodium crocetin wet product; (10) Vacuum drying: The wet product of sodium crocetin is vacuum dried to obtain purified sodium crocetin; (1), add 1-10 times the volume of 60-80% ethanol to the extraction tank for the first time, and extract at 40-70°C for 1-3 hours; the second time, continue to add 1-10 times the volume of 60-80% ethanol to the medicinal material, and extract at 40-70°C for 20-60 minutes; the third time, continue to add 1-10 times the volume of 60-80% ethanol to the medicinal material, and extract at 40-70°C for 20-60 minutes.

2. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: (2), the content of potassium hydroxide in the hydrolyzate is 1-8% of the total volume of the hydrolyzate.

3. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: (3), during the acid precipitation process, the mixture is allowed to stand for 12-20 hours.

4. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: (5), the sodium hydroxide solution is a 4 wt % sodium hydroxide aqueous solution.

5. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: In (6), the sodium hydroxide solution is a sodium hydroxide aqueous solution with a mass fraction of 1-8wt%.

6. The method for preparing sodium crocetin as claimed in claim 5, characterized in that: The sodium hydroxide solution is a 4wt% sodium hydroxide aqueous solution.

7. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: In (8), the acidifying acid is citric acid.

8. The method for preparing sodium crocetin as claimed in claim 1, characterized in that: (9), the sodium hydroxide solution is a 4 wt % sodium hydroxide aqueous solution.

9. The method for preparing sodium crocetin as claimed in any one of claims 1 to 8, characterized in that: In (10), the vacuum degree of the vacuum drying is -0.06 to -0.1 MPa, the drying temperature is 40 to 70° C., and the drying time is 24 to 48 hours.

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