Method for extracting lactone from tender ginkgo leaves and purifying by molecular distillation technology

Abstract

The invention relates to the field of food and medicine, in particular to a method for extracting lactone from tender ginkgo leaves and purifying by a molecular distillation technology, which comprises the following steps of: 1, slowly baking the tender ginkgo leaves at low temperature, 2, releasing the components of the tender ginkgo leaves by microwaves, 3, extracting the components by ultrasonic waves, 4, carrying out centrifugal separation and 5, carrying out molecular distillation. The method disclosed by the invention aims to extract lactone compounds from tender ginkgo leaves in an environment-friendly and mild condition manner, and purification and separation of the compounds are realized by utilizing microwave-ultrasonic synergistic assisted ionic liquid extraction and a molecular distillation technology, according to the present invention, the specific type of the ionic liquid is adopted as the extraction solvent so as to effectively dissolve the lactone component in the ginkgo tender leaf, the microwave is combined to greatly accelerate the release of the intracellular substance and improve the extraction efficiency, and the molecular distillation technology achieves the precise separation of different types of the lactone so as to improve the comprehensive utilization value of the ginkgo tender leaf.

Description

Technical Field

[0001] The invention relates to the field of food and medicine, and in particular to a method for extracting lactone from young ginkgo leaves and purifying it using molecular distillation technology. Background Art

[0002] Ginkgo biloba is a plant of the Ginkgoaceae family and the Ginkgo genus. Ginkgo biloba leaves have the effects of promoting blood circulation and removing blood stasis, dredge meridians and relieve pain, astringe the lungs and relieve asthma, and remove turbidity and reduce fat. Ginkgo biloba extract has obvious effects on the treatment of coronary heart disease, angina pectoris and hyperlipidemia. It can improve the symptoms of dizziness, chest tightness, palpitations, shortness of breath, fatigue and other symptoms of patients with coronary heart disease, improve cardiac blood flow, protect ischemic myocardium, reduce cholesterol, triglycerides, and increase high-density lipoprotein, which is of great significance for the prevention of cardiovascular and cerebrovascular diseases. Other studies have shown that ginkgo biloba extract has certain antibacterial and anti-bacterial adhesion effects in the oral cavity. It has been reported in the literature that the content of lactone components (mainly including ginkgolide A, B and C) contained in ginkgo biloba leaves has an upward trend from 4 months to 8 months, reaching the maximum value in 8-9 months, and then began to decline rapidly; there are also research results showing that the total lactone content is the highest in 5 months, and the content begins to decline significantly after 9 months, and the content reaches the lowest in 11 months. These results provide a theoretical basis for timely harvesting of ginkgo leaves and their rational development and utilization. In summary, the contents of total flavonoids and total lactones in ginkgo leaves of different ages are different in different growing seasons. The lactone content of young ginkgo leaves is relatively high, while the total flavonoid content of old leaves is higher.

[0003] The main reasons for the difficulty in extracting ginkgolides include the difficulty in separation due to their similar molecular structures, as well as the complexity and high cost of the extraction methods. The molecular structures of ginkgolide monomers are very similar, so their separation is relatively difficult. Currently, common separation methods include high-performance liquid chromatography, high-speed countercurrent chromatography and column chromatography. Although these methods are effective, they are generally complex and costly, and have a long operation cycle, which increases the difficulty of extraction.

[0004] In the prior art, such as publication number CN102070647B, a method for separating ginkgolide B from a ginkgolide mixture is disclosed. This method uses an ionic liquid or a binary mixed solvent consisting of ionic liquid water as an extractant, and adopts a fractional extraction method to efficiently separate ginkgolide B from a mixture containing ginkgolide homologues such as ginkgolide A, B, and C. Although this method has the advantages of high separation efficiency, low solvent consumption, safety and environmental protection, and easy industrial production, the ionic liquid is used as an extractant for separation and purification, rather than as an extractant, and there is no use of microwave ultrasound synergistic assistance to improve the extraction efficiency.

[0005] Publication No. CN109810789A. The invention discloses a method for removing germs by ultrasonic oscillation-multi-stage cyclone separation technology, and adopts supercritical CO2 extraction and molecular distillation integrated technology to obtain ginkgo essential oil, so as to achieve the purpose of separating impurities and enriching functional substances. The unsaturated fatty acids in the ginkgo essential oil extracted by this method account for more than 92% of the total fatty acids, the total flavonoids are more than 0.10%, and it contains bilobalide and ginkgolide A, B, C, and the total terpenoid lactones are more than 0.02%. The disadvantage is that the supercritical CO2 extraction and molecular distillation integrated technology is not only very expensive, but also the supercritical CO2 extraction is better for extraction than for separation and purification.

[0006] Therefore, in view of the above-mentioned difficulty in separating lactones from young ginkgo leaves and the complexity of existing extraction methods, a method for extracting lactones from young ginkgo leaves and purifying them using molecular distillation technology can be designed. Summary of the invention

[0007] In order to overcome the difficulty of extracting lactones from young leaves of Ginkgo biloba and the complexity of existing extraction methods.

[0008] The technical solution of the present invention is: a method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology, the steps of which are as follows:

[0009] Step 1: Remove impurities from the freshly picked young ginkgo leaves, gently wipe off the dust on the surface of the young ginkgo leaves, spread them flat on the drying rack and send them into the drying equipment for low-temperature slow drying. After the drying process is completed, grind the dried young ginkgo leaves into fine powder, sieve them, and put them in a dark place for later use;

[0010] Step 2: Take out the ginkgo leaf powder, carefully add it to the ionic liquid, and use a stirring stick to fully mix the ginkgo leaf powder and the ionic liquid. Put the mixed solution into a microwave extractor with set parameters, start the microwave extractor, and the microwave extractor quickly heats the mixed solution to promote the effective release of the target components in the ginkgo leaf.

[0011] Step 3: Take out the ginkgo leaf solution and further stir it evenly until the ginkgo leaf solution is uniform and consistent without precipitation or stratification, then immediately pour it into a 200 mL beaker and put it into an ultrasonic cell crusher with set parameters for ultrasonic extraction. The ultrasonic cell crusher destroys the cell wall of the ginkgo leaf by generating high-frequency vibration waves until the expected extraction effect is achieved.

[0012] Step 4: After the extraction is completed, carefully take out the beaker containing the extract from the ultrasonic cell crusher, slowly pour the solution into the special centrifuge tube of the low-speed centrifuge, seal the centrifuge tube and put it into the low-speed centrifuge with set parameters, start the low-speed centrifuge to let the solution in the centrifuge tube gradually separate into layers, the liquid is located in the upper layer, and the solid particles are thrown to the bottom of the centrifuge tube to form a precipitate;

[0013] Step 5: Separate the product in step 4 by molecular distillation to obtain bilobalide and ginkgolide A, B, and C.

[0014] Preferably, the ginkgo leaf powder in step one is sieved through a 50-75 mesh sieve, and the particle size of the ginkgo leaf powder in step one needs to be less than 0.3 mm.

[0015] Preferably, the ionic liquid in step 2 is one of 1-butyl-3-methylimidazolium tetrafluoroborate, potassium hexafluorophosphate, and 2-methylpyridine alkyl carbon chain salt.

[0016] Preferably, in step 2, the amount of ginkgo leaf powder used is 2.0 g, and the amount of ionic liquid used is 100 mL.

[0017] Preferably, in step 2, the microwave power is 100 W and the microwave time is 5 min.

[0018] Preferably, in step three, the ultrasonic gap and ultrasonic time are 2s / 2s, the ultrasonic power is 200W, and the ultrasonic time is 3min.

[0019] Preferably, in step 4, the rotation speed is 1500 r / min and the centrifugation time is 2 min.

[0020] Beneficial effects of the present invention:

[0021] The method of the present invention is dedicated to extracting lactone compounds from young ginkgo leaves under environmentally friendly and mild conditions, and uses microwave ultrasound synergistically assisted ionic liquid extraction and molecular distillation technology to achieve purification and separation of these compounds. The microwave ultrasound synergistically assisted ionic liquid extraction method uses a specific type of ionic liquid as an extraction solvent, which can effectively dissolve the lactone components in the young ginkgo leaves. Combined with microwaves, it greatly accelerates the release of intracellular substances and improves the extraction efficiency. Among them, the molecular distillation technology realizes the precise separation of different types of lactones, thereby improving the comprehensive utilization value of the young ginkgo leaves. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the embodiments.

[0023] Example 1

[0024] The present invention provides an embodiment: a method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology, the steps of which are as follows:

[0025] Step 1: Remove impurities from the freshly picked young ginkgo leaves, gently wipe off the dust on the surface of the young ginkgo leaves, spread them flat on the drying rack and send them into the drying equipment for low-temperature slow drying. After the drying process is completed, grind the dried young ginkgo leaves into fine powder, sieve through a 50-mesh sieve, the particle size of the young ginkgo leaf powder must be less than 0.3mm, and put it in a dark place for later use;

[0026] Step 2: Take out 2.0g of ginkgo leaf powder, carefully add it into 100mL of potassium hexafluorophosphate ionic liquid, and use a stirring stick to fully mix the ginkgo leaf powder and the ionic liquid. Put the mixed solution into a microwave extractor with set parameters, microwave power 100W, microwave time 5min, start the microwave extractor, and the microwave extractor quickly heats the mixed solution to promote the effective release of the target components in the ginkgo leaf.

[0027] Step 3: Take out the ginkgo leaf solution and further stir it evenly until the ginkgo leaf solution is uniform and consistent without precipitation or stratification, then immediately pour it into a 200 mL beaker and put it into an ultrasonic cell crusher with set parameters, with an ultrasonic gap and ultrasonic time of 2s / 2s, an ultrasonic power of 200W, and an ultrasonic time of 3min for ultrasonic extraction. The ultrasonic cell crusher destroys the cell wall of the ginkgo leaf by generating high-frequency vibration waves until the expected extraction effect is achieved;

[0028] Step 4: After the extraction is completed, carefully take out the beaker containing the extract from the ultrasonic cell crusher, slowly pour the solution into the special centrifuge tube of the low-speed centrifuge, seal the centrifuge tube and put it into the low-speed centrifuge with set parameters, the speed is 1500r / min, the centrifugation time is 2min, start the low-speed centrifuge to let the solution in the centrifuge tube gradually separate into layers, the liquid is located in the upper layer, and the solid particles are thrown to the bottom of the centrifuge tube to form a precipitate;

[0029] Step 5: Separate the product in step 4 by molecular distillation to obtain bilobalide and ginkgolide A, B, and C.

[0030] Example 2

[0031] The present invention provides an embodiment: a method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology, the steps of which are as follows:

[0032] Step 1: Remove impurities from the freshly picked young ginkgo leaves, gently wipe off the dust on the surface of the young ginkgo leaves, spread them flat on the drying rack and send them into the drying equipment for low-temperature slow drying. After the drying process is completed, grind the dried young ginkgo leaves into fine powder, sieve through a 50-mesh sieve, the particle size of the young ginkgo leaf powder must be less than 0.3mm, and put it in a dark place for later use;

[0033] Step 2: Take out 2.0g of ginkgo leaf powder, carefully add it into 100ml of L2-methylpyridine alkyl carbon chain salt ionic liquid, and use a stirring stick to fully mix the ginkgo leaf powder and the ionic liquid, put the mixed solution into a microwave extractor with set parameters, microwave power 100W, microwave time 5min, start the microwave extractor, and the microwave extractor quickly heats the mixed solution to promote the effective release of the target components in the ginkgo leaf;

[0034] Step 3: Take out the ginkgo leaf solution and further stir it evenly until the ginkgo leaf solution is uniform and consistent without precipitation or stratification, then immediately pour it into a 200 mL beaker and put it into an ultrasonic cell crusher with set parameters, with an ultrasonic gap and ultrasonic time of 2s / 2s, an ultrasonic power of 200W, and an ultrasonic time of 3min for ultrasonic extraction. The ultrasonic cell crusher destroys the cell wall of the ginkgo leaf by generating high-frequency vibration waves until the expected extraction effect is achieved;

[0035] Step 4: After the extraction is completed, carefully take out the beaker containing the extract from the ultrasonic cell crusher, slowly pour the solution into the special centrifuge tube of the low-speed centrifuge, seal the centrifuge tube and put it into the low-speed centrifuge with set parameters, the speed is 1500r / min, the centrifugation time is 2min, start the low-speed centrifuge to let the solution in the centrifuge tube gradually separate into layers, the liquid is located in the upper layer, and the solid particles are thrown to the bottom of the centrifuge tube to form a precipitate;

[0036] Step 5: Separate the product in step 4 by molecular distillation to obtain bilobalide and ginkgolide A, B, and C.

Claims

1. A method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology, characterized in that: The steps are as follows: Step 1: Remove impurities from the freshly picked young ginkgo leaves, gently wipe off the dust on the surface of the young ginkgo leaves, spread them flat on the drying rack and send them into the drying equipment for low-temperature slow drying. After the drying process is completed, grind the dried young ginkgo leaves into fine powder, sieve them, and put them in a dark place for later use; Step 2: Take out the ginkgo leaf powder, carefully add it to the ionic liquid, and use a stirring stick to fully mix the ginkgo leaf powder and the ionic liquid. Put the mixed solution into a microwave extractor with set parameters, start the microwave extractor, and the microwave extractor quickly heats the mixed solution to promote the effective release of the target components in the ginkgo leaf. Step 3: Take out the ginkgo leaf solution and further stir it evenly until the ginkgo leaf solution is uniform and consistent without precipitation or stratification, then immediately pour it into a 200 mL beaker and put it into an ultrasonic cell crusher with set parameters for ultrasonic extraction. The ultrasonic cell crusher destroys the cell wall of the ginkgo leaf by generating high-frequency vibration waves until the expected extraction effect is achieved. Step 4: After the extraction is completed, carefully take out the beaker containing the extract from the ultrasonic cell crusher, slowly pour the solution into the special centrifuge tube of the low-speed centrifuge, seal the centrifuge tube and put it into the low-speed centrifuge with set parameters, start the low-speed centrifuge to let the solution in the centrifuge tube gradually separate into layers, the liquid is located in the upper layer, and the solid particles are thrown to the bottom of the centrifuge tube to form a precipitate; Step 5: Separate the product in step 4 by molecular distillation to obtain bilobalide and ginkgolide A, B, and C.

2. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 1, the ginkgo leaf powder is passed through a 50-75 mesh sieve, and the particle size of the ginkgo leaf powder in step 1 must be less than 0.3 mm.

3. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 2, the ionic liquid is one of 1-butyl-3-methylimidazolium tetrafluoroborate, potassium hexafluorophosphate, and 2-methylpyridine alkyl carbon chain salt.

4. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 2, the amount of ginkgo leaf powder used is 2.0 g, and the amount of ionic liquid used is 100 mL.

5. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 2, the microwave power is 100 W and the microwave time is 5 min.

6. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 3, the ultrasonic gap and ultrasonic time are 2s / 2s, the ultrasonic power is 200W, and the ultrasonic time is 3min.

7. The method for extracting lactone from young leaves of Ginkgo biloba and purifying it by molecular distillation technology according to claim 1, characterized in that: In step 4, the rotation speed is 1500r / min and the centrifugation time is 2min.