Extraction process of ginkgolide
阅读说明：本技术 一种银杏内酯的提取工艺 (Extraction process of ginkgolide ) 是由 凌国庆 陈磊 刘怀红 褚斌 张南南 李国学 方威 于 2021-02-04 设计创作，主要内容包括：本发明公开一种银杏内酯的提取工艺,包括如下步骤：(1)将银杏提取液经有机酸活化后的陶瓷膜过滤,得到陶瓷膜滤液；(2)将陶瓷膜滤液经以下工艺条件中的任意一个或多个参数处理,即得银杏内酯；(2i)萃取；(2ii)吸附、解吸；(2iii)经纳滤膜纳滤浓缩；(2iv)蒸发；(2v)结晶；(2vi)干燥。本发明所采用的陶瓷膜不仅可以耐受高温、高压、化学腐蚀,使用寿命长,而且采用活化处理后的陶瓷膜,可有效过滤去除悬浮物、胶体、大分子植物蛋白,提高产品质量,降低浊度,提高收率。(The invention discloses a process for extracting ginkgolide, which comprises the following steps: (1) filtering the ginkgo biloba extract by a ceramic membrane activated by organic acid to obtain a ceramic membrane filtrate; (2) treating the ceramic membrane filtrate by any one or more parameters of the following process conditions to obtain bilobalide; (2i) extracting; (2ii) adsorption and desorption; (2iii) nanofiltration concentration by a nanofiltration membrane; (2iv) evaporation; (2v) crystallization; (2vi) drying. The ceramic membrane adopted by the invention can not only resist high temperature, high pressure and chemical corrosion and has long service life, but also can effectively filter and remove suspended matters, colloids and macromolecular vegetable proteins by adopting the ceramic membrane after activation treatment, thereby improving the product quality, reducing the turbidity and improving the yield.)
1. The extraction process of ginkgolides is characterized by comprising the following steps of:
(1) filtering the ginkgo biloba extract by a ceramic membrane activated by organic acid to obtain a ceramic membrane filtrate;
(2) treating the ceramic membrane filtrate by any one or more parameters of the following process conditions to obtain bilobalide;
(2i) extracting;
(2ii) adsorption and desorption;
(2iii) nanofiltration concentration by a nanofiltration membrane;
(2iv) evaporation;
(2v) crystallization;
(2vi) drying.
2. The process for extracting ginkgolides according to claim 1, wherein in the step (1), the ceramic membrane is activated by the organic acid, the ceramic membrane is placed in a closed container, the organic acid solution is heated to boiling, and the ceramic membrane is subjected to activation reaction by a vacuum vapor deposition method.
3. The process for extracting ginkgolides as claimed in claim 2, wherein the ceramic membrane is soaked in deionized water for 6-12 h, dried and activated by organic acid.
4. The process for extracting ginkgolides according to claim 2, wherein the solvent of the organic acid solution is any one or a combination of methanol and ethanol, and the concentration is 0.05-0.2 mol/L.
5. The process for extracting ginkgolides according to claim 2, wherein the time of the activation reaction is 1-6 hours.
6. The process for extracting ginkgolides of claim 1, wherein in step (1), the average pore diameter of the support of the ceramic membrane is 2-5 μm.
7. The process for extracting ginkgolides according to claim 1, wherein in step (1), the average pore diameter of the separation layer of the ceramic membrane is 5 to 50 nm.
8. The process for extracting ginkgolides according to claim 1, wherein in the step (1), the temperature of filtration is 10 to 90 ℃, the pressure is 0.1 to 0.8MPa, and the flow rate of the membrane surface is 1 to 6 m/s.
9. The process for extracting ginkgolides of claim 1, wherein in step (2ii), the adsorption is performed by polyamide resin.
10. The extraction process of ginkgolides of claim 1, wherein in step (2iii), the nanofiltration membrane is a roll-type nanofiltration membrane, and the molecular weight cut-off is 100-800 Da; the nanofiltration concentration temperature is 10-60 ℃, and the pressure is 0.5-4.0 MPa.
Technical Field
The invention belongs to the field of natural medicine extraction, and particularly relates to a process for extracting ginkgolides.
Background
Folium Ginkgo is dry leaf of Ginkgo biloba L. Collected in autumn when the leaves are still green, and dried in time. Generally, the cultivation is artificial cultivation, and the cultivation areas are from north to Liaoning, from south to Guangdong, from east to Zhejiang, from west to Shaanxi, Gansu, from southwest to Sichuan, Guizhou, Yunnan and the like. It has effects of promoting blood circulation, removing blood stasis, dredging collaterals, relieving pain, astringing lung, relieving asthma, eliminating turbid pathogen, and reducing blood lipid. Can be used for treating blood stasis, obstruction of collaterals, thoracic obstruction, cardialgia, apoplexy, hemiplegia, cough with asthma due to lung deficiency, and hyperlipidemia. Ginkgo Biloba leaf Extract (GBE) is a product with rich effective components extracted from ginkgo Biloba leaves by using a proper solvent. Various preparations prepared by taking GBE as a raw material are widely applied to the fields of medicines, health-care products, food additives, functional beverages, cosmetics and the like. The product is one of the most successful cases of botanical drugs (belonging to traditional Chinese medicines) developed by modern science and technology. The ginkgo extract mainly contains bilobalide, ginkgetin, ginkgo polysaccharide, ginkgolic acid, shikimic acid, fat-soluble impurities, vegetable protein, colloid and other impurities, and has complex components, high extraction difficulty and high cost.
The ginkgolides are classified into Ginkgolide A (GA), Ginkgolide B (GB), Ginkgolide C (GC), Ginkgolide M (GM) and Ginkgolide J (GJ), which are diterpenoids, and the difference is that the number of contained hydroxyl groups and the positions of the connected hydroxyl groups are different, as shown in FIG. 1. The ginkgolide molecule has a unique twelve-carbon skeleton structure, is embedded with a tert-butyl group and six five-membered rings, and comprises a spirononane ring, a tetrahydrofuran ring and three lactone rings. The ginkgolide has strong specific inhibition effect on Platelet Activating Factor (PAF) receptor. PAF is an endogenous phospholipid secreted by platelets and various inflammatory tissues, is the most effective platelet aggregation inducer discovered to date, and is closely related to the generation and development of a plurality of diseases. The ginkgolide is considered as a natural PAF receptor antagonist with the most clinical application prospect, and the antagonistic activity of the ginkgolide is closely related to the chemical structure. When R3 is a hydroxyl group or the number of hydroxyl groups in the lactone structure is increased, antagonistic activity against PAF is decreased; and when R2 is hydroxyl and R3 is H, the activity is obviously enhanced, wherein the antagonism of the ginkgolide B on PAF is strongest, and the research on the pharmacological action of the ginkgolide B is most concentrated so far.
The main components of ginkgo leaf, bilobalide, ginkgetin, ginkgo polysaccharide and shikimic acid can be used as medicine, but the ginkgolic acid has no definite medical clinical application. After being taken into the body, the side reaction of excessive expansion of the capillary network is easy to generate. The symptoms of flushing and sweating, numbness of the lips and blood vessel stimulation are easy to appear. Therefore, in extracting bilobalide, ginkgetin, ginkgo polysaccharide and shikimic acid from ginkgo leaves, it is necessary to remove ginkgolic acid at the same time. At present, the domestic method for removing ginkgolic acid is mainly to extract by adding petroleum ether and separate the ginkgolic acid by utilizing the characteristic of low solubility of the ginkgolic acid in the petroleum ether; or deacidifying with resin to remove ginkgolic acid.
At present, the mainstream extraction and purification methods of bilobalide and ginkgetin comprise the following steps: solvent extraction, column extraction, solvent extraction-column extraction, supercritical extraction, chromatography or column chromatography purification, etc. The following disadvantages are mainly present: (1) the consumption of organic solvent is large, the cost of raw materials is high, the organic solvent is unsafe, all electrical equipment in an extraction workshop must adopt explosion-proof grade, and the cost is greatly increased; (2) the ginkgolic acid is removed by adopting petroleum ether extraction or deacidification resin, the production process flow is increased, the production cost is high, and the introduced impurities are removed; (3) the method has the advantages of multiple steps, long route, low product purity and low yield; (4) serious pollution and serious environmental protection problem. (5) Is not suitable for large-scale production and has high unit yield cost.
Disclosure of Invention
The purpose of the invention is as follows: the invention aims to solve the technical problem of providing the extraction process of the ginkgolides, which has the advantages of low production cost, safe and reliable process, low investment, high product quality and high yield aiming at the defects of the prior art.
In order to solve the technical problems, the invention discloses a process for extracting ginkgolides, which comprises the following steps:
(1) filtering the ginkgo biloba extract by a ceramic membrane activated by organic acid to obtain a ceramic membrane filtrate;
(2) treating the ceramic membrane filtrate by any one or more parameters of the following process conditions to obtain bilobalide;
(2i) extraction of
(2ii) adsorption and desorption
(2iii) nanofiltration concentration with nanofiltration membrane
(2iv) Evaporation
(2v) crystallization
(2vi) drying.
In the step (1), the mass content of ginkgolides in the ginkgo extracting solution is 0.01-5%, and impurities mainly comprise suspended matters, vegetable oil, vegetable protein, vegetable fibers, vegetable pigments, tannin, microorganisms and the like; the preparation method of the ginkgo biloba extract comprises the steps of concentrating the crude extract of ginkgo biloba and carrying out solid-liquid separation.
Wherein, the crude extract of ginkgo leaves is obtained by crushing ginkgo and extracting with ethanol; wherein the ethanol extraction is extraction by 60% ethanol solution; wherein the extraction times are 6 times; wherein the extraction temperature is 50-80 ℃.
Wherein, the concentration is evaporation concentration, and in the process, ethanol can be recovered; preferably, the concentration is about 6 times by evaporation.
Wherein, the solid-liquid separation is centrifugation; preferably, the solid-liquid separation is centrifugation by a disk centrifuge; further preferably, the rotation speed of the centrifugation is 6000-8000 rpm.
In the step (1), the organic acid is activated by placing the ceramic membrane in a closed container, heating the organic acid solution to boil, and performing activation reaction on the ceramic membrane by a vacuum vapor deposition method.
Preferably, the ceramic membrane is placed in an activator, a vacuum device is started, and simultaneously, the organic acid solution is heated to boiling, and the ceramic membrane is activated by the organic acid through a vacuum gas phase method.
Preferably, the ceramic membrane is soaked in deionized water for 6-12 hours, and is activated by organic acid after being dried; further preferably, the drying is carried out at the temperature of 80-120 ℃ for 10-12 h.
Wherein the solvent of the organic acid solution is any one or a combination of methanol and ethanol, and the concentration is 0.05-0.2 mol/L.
Preferably, the organic acid has the formula CnH2n-2O4The structural formula is HOOC- (CH)2)n-COOH; wherein n is any one integer from 2 to 6; preferably, the organic acid is succinic acid, malonic acid, glutaric acid or oxalic acid.
Wherein the vacuum degree of the vacuum vapor deposition method is 10-90 kPa.
Wherein the activation reaction time is 1-6 h.
Preferably, after the activation reaction is finished, cleaning and drying are carried out; further preferably, the cleaning is performed by deionized water for three times; further preferably, the drying is carried out for 4-12 h at the temperature of 80-120 ℃.
In the step (1), the ceramic membrane is a single-channel ceramic ultrafiltration membrane or a multi-channel ceramic ultrafiltration membrane, and is preferably multi-channel ceramic ultrafiltration.
In the step (1), the ceramic membrane includes a support and a separation layer.
Wherein the average pore diameter of the support is 2-5 μm.
Preferably, the porosity of the support is 30% to 45%; more preferably, the material of the support is alumina.
Wherein the average pore diameter of the separation layer (namely the membrane layer) is 5-50 nm.
Preferably, the separation layer of the ceramic membrane is formed by sintering titanium oxide with the particle size of 10-500 nm at 680-800 ℃.
When the average pore diameter of the multi-channel ceramic membrane separation layer is 5nm, the flux is only 40% of the flux of 50nm (the average pore diameter of the ceramic membrane separation layer), and the pressure of 0.8MPa is required as the driving force for the operation of the membrane equipment; when the average pore diameter of the multi-channel ceramic membrane separation layer is 50nm, the initial flux is 20% larger than the flux of 20nm (the average pore diameter of the ceramic membrane separation layer), and is 16% larger than the flux of 30nm (the average pore diameter of the ceramic membrane separation layer), but the flux is attenuated quickly, and vegetable protein, colloid and pigment can permeate the ceramic membrane separation layer, so that the quality of filtrate is reduced.
In the step (1), the filtering temperature is 10-90 ℃, preferably 10-80 ℃, more preferably 30-50 ℃, and still more preferably 40 ℃.
In the step (1), the filtration pressure is 0.1 to 0.8MPa, preferably 0.25 to 0.4MPa, and more preferably 0.35 MPa.
More preferably, when the average pore diameter of the ceramic membrane separation layer is 20-30 nm, the temperature is 40 ℃, and the pressure is 0.35MPa, the filtration flux is large, the flux is slowly reduced, the energy consumption is low, the product recovery rate is high, the filtrate quality is good, and meanwhile, the removal rate of the ginkgolic acid reaches more than 99.9%. Filtering and clarifying by a ceramic membrane separation layer, removing impurities such as suspended matters, macromolecular proteins, colloids and ginkgoic acids in the ginkgo leaf extracting solution, and improving the quality of filtrate of the ceramic membrane.
In the step (1), the flow rate of the filtered membrane surface is 1-6 m/s.
In the step (2), preferably, the ceramic membrane filtrate is subjected to (2i) extraction, (2ii) adsorption and desorption, (2iii) nanofiltration concentration by a nanofiltration membrane, (2iv) evaporation, (2v) crystallization, and (2vi) drying in sequence to obtain the ginkgolides.
In the step (2i), the ceramic membrane filtrate is extracted by ethyl acetate to obtain an organic phase and a water phase; preferably, the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1.
In the step (2ii), the adsorption is to adsorb the organic phase by polyamide resin, and the desorption is to desorb ethanol solution to obtain desorption solution.
Wherein the mesh number of the polyamide resin is 20-80 meshes, preferably 40-50 meshes, and more preferably 40 meshes; the flow rate of adsorption is 1-6 BV/h, preferably 2-4 BV/h, and further preferably 3 BV/h; most preferably, the mesh number of the polyamide resin is 40 meshes, and the flow rate is 3BV/h, so that the adsorption effect of the polyamide is optimal, the adsorption effect can be ensured, and the using amount of the ethanol analysis solution is relatively small. The purity of the ginkgolide is further improved by adsorbing the ginkgolide onto polyamide resin.
Wherein, the concentration of the ethanol solution is 50 to 75 percent, and preferably 60 percent; the flow rate of desorption is 1-4 BV/h; the dosage of the ethanol solution is 2-3 BV. The ginkgolides are desorbed from the polyamide resin by ethanol desorption, so that the ginkgolides with high purity and high concentration can be obtained.
In the step (2iii), the nanofiltration membrane is concentrated to concentrate the desorption solution through the nanofiltration membrane, the obtained nanofiltration concentrated solution is ginkgolide concentrated solution, and simultaneously ethanol is recovered.
In the step (2iii), the nanofiltration membrane is a roll-type nanofiltration membrane, and the molecular weight cutoff is 100-800 Da, preferably 150-300 Da; in the nanofiltration process, when the molecular weight cut-off of the nanofiltration membrane is 100Da, the flux is only 40% of that of the nanofiltration membrane with the molecular weight of 800Da, and 2.5MPa pressure is required as the driving force for the operation of membrane equipment; when the molecular weight cut-off of the nanofiltration membrane is 800Da, the flux is 25% larger than that of the nanofiltration membrane with the molecular weight of 300Da and 40% larger than that of the nanofiltration membrane with the molecular weight of 150Da, but about 5% of products penetrate through the nanofiltration membrane, and the product yield is reduced.
Wherein the nanofiltration concentration temperature is 10-60 ℃, preferably 10-50 ℃, and further preferably 30 ℃.
Wherein the pressure of nanofiltration concentration is 0.5-4.0 MPa, preferably 1.0-3.0 MPa, and more preferably 2.5 MPa.
More preferably, when the temperature is 30 ℃, the pressure is 2.5MPa, and the molecular weight cut-off of the nanofiltration membrane is 150-300 Da, the filtration flux is stable, the concentration can be nearly 5 times, the cut-off rate of the product is more than 99.9%, meanwhile, the nanofiltration membrane does not cut off monovalent salt, and more than 75% of monovalent salt can be removed after concentration.
In the step (2iv), the evaporation is to evaporate the ginkgolide concentrated solution.
In the present invention, the ethanol solution refers to a mass ratio unless otherwise specified.
Has the advantages that: compared with the prior art, the invention has the following advantages:
1. the ceramic membrane adopted by the invention can not only resist high temperature, high pressure and chemical corrosion and has long service life, but also can effectively filter and remove suspended matters, colloids and macromolecular vegetable proteins by adopting the ceramic membrane after activation treatment, thereby improving the product quality, reducing the turbidity and improving the yield.
2. The method adopts the ceramic membrane after the activation treatment to filter the gingko to extract the centrifugate, can remove more than 99.9 percent of ginkgoic acid by one step, reduces the working procedure of adding petroleum ether for extraction in the traditional process, and reduces the production cost. In addition, 99.8% of vegetable oily impurities can be removed, the quality of the filtrate is high, the feeding load of polyamide resin in the subsequent working section is reduced, and the using amount of ethyl acetate is reduced.
3. The extraction process adopts a nanofiltration membrane to pre-concentrate the polyamide resin desorption solution, and can reduce the ethanol evaporation capacity by more than 80 percent. The membrane concentration can concentrate the ginkgolide at low temperature, reduce the loss of the ginkgolide caused by degradation during high-temperature evaporation, improve the yield of the ginkgolide, reduce the production energy consumption and reduce the production cost.
4. The extraction process of the invention adopts membrane separation equipment and polyamide resin equipment, thus reducing the floor area of the equipment and lowering the capital cost. The process carries out a large amount of optimization work on the parameters of new equipment and the traditional process to obtain the optimal production process parameters, ensures the efficient and energy-saving operation of production, and simultaneously has higher product quality. The production process is energy-saving, has high automation degree compared with the traditional production process, can save 60 percent of labor cost, and has remarkable economic benefit.
Drawings
The foregoing and/or other advantages of the invention will become further apparent from the following detailed description of the invention when taken in conjunction with the accompanying drawings.
FIG. 1 shows the chemical structure of ginkgolide A, B, C, J, K, M.
FIG. 2 is a schematic view of the process for extracting ginkgolides of the present invention.
FIG. 3 is a graph of the ceramic membrane filtrate obtained in example 3; wherein, A is ceramic membrane filtrate which is just filtered; b is the ceramic membrane filtrate after 2 hours of filtration.
FIG. 4 is a graph of the ceramic membrane filtrate obtained in comparative example 1; wherein, A is ceramic membrane filtrate which is just filtered; b is the ceramic membrane filtrate after 2 hours of filtration.
Detailed Description
The experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents and materials are commercially available, unless otherwise specified.
In the following examples, the polyamide resins used have the formula [ NH- (CH)2)5-CO]nIs prepared from epsilon-caprolactam.
In the following examples, the support is made of alumina unless otherwise specified.
In the following examples, unless otherwise specified, the term "turbidity after the ceramic membrane filtrate was generated" means turbidity after 2 hours of filtration.
In the following examples, the bilobalide and the impurity content are all mass percent.
Example 1: the extraction of bilobalide was performed according to the scheme shown in fig. 2:
(1) crushing ginkgo leaves to 20 meshes, leaching the ginkgo leaves by using a 60% ethanol solution at 50-80 ℃, and extracting for 6 times to obtain a crude extract of the ginkgo leaves;
(2) evaporating and concentrating the crude extract obtained in the step (1) for 6 times to obtain a concentrated solution of ginkgo leaf extract, and simultaneously recovering ethanol;
(3) centrifuging the concentrated solution of folium Ginkgo extract obtained in step (2) at 6000rpm/min for 10min to obtain centrifugal solution of folium Ginkgo extract, wherein bilobalide content is 0.15%, and impurity content is 5.3%;
(4) filtering and clarifying the ginkgo biloba extract centrifugate obtained in the step (3) by using an activated and modified ceramic ultrafiltration membrane, and removing impurities to obtain a ceramic membrane filtrate, wherein the content of ginkgolides is 0.55 percent, and the content of impurities is 0.56 percent;
wherein, before the activation modification of the ceramic ultrafiltration membrane, the aperture of the support body is 3 μm, and the porosity is 30%; the aperture of the separation layer is 50 nm; the separation layer is formed by firing titanium oxide with the particle size of 100nm at high temperature of 680 ℃; the ceramic ultrafiltration membrane is obtained by activating an ethanol solution with malonic acid as an activating agent;
wherein the filtering temperature is 20 ℃, the pressure is 0.2MPa, and the membrane surface flow rate is 4 m/s;
(5) extracting the ceramic membrane filtrate obtained in the step (4) by ethyl acetate to respectively obtain a water phase and an organic phase; wherein the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1;
(6) adsorbing the organic phase obtained in the step (5) by 80-mesh polyamide resin (the flow rate is 6BV/h, the adsorption multiple is 3 times), and desorbing by using 50% ethanol solution to obtain desorption solution, wherein the flow rate of the ethanol is 4BV/h, and the using amount of the ethanol is 3 BV;
(7) concentrating the desorption solution obtained in the step (6) at 20 ℃ and 0.5MPa through a roll-type ultrafiltration membrane (the molecular weight cutoff is 800 Da);
(8) and (4) evaporating, crystallizing and drying the nanofiltration membrane concentrated solution in the step (7) to obtain the ginkgolides.
In the step (4), the activation process of the ceramic membrane comprises the following steps:
(a) soaking the ceramic membrane in deionized water for 12h, and drying at 100 ℃ for 10 h;
(b) placing the ceramic membrane obtained in the step (a) in an activator, starting a vacuum device, heating 0.2mol/L malonic acid solution in a round-bottom flask to boil, and carrying out activation reaction for 3 hours, wherein the vacuum degree is 10 kPa;
(c) and (c) washing the ceramic membrane obtained in the step (b) with deionized water for three times, and drying for 10 hours at 100 ℃.
The ceramic membrane has the advantages of large aperture, low temperature and pressure, high flux, and high ginkgolic acid content in the filtrate; the nanofiltration membrane has higher molecular weight cut-off, lower pressure, lower flux and larger loss of ginkgolides.
The yield of the finally obtained ginkgolides is 75.6 percent, the purity of the ginkgolides is 93.6 percent, the removal rate of ginkgolic acid is 98.6 percent, and the turbidity of the ceramic membrane filtrate is 12NTU after the turbidity phenomenon occurs.
Example 2: the extraction of bilobalide was performed according to the scheme shown in fig. 2:
(1) crushing ginkgo leaves to 5 meshes, leaching the ginkgo leaves by using a 60% ethanol solution at 50-80 ℃, and extracting for 6 times to obtain a crude extract of the ginkgo leaves;
(2) evaporating and concentrating the crude extract obtained in the step (1) for 6 times to obtain a concentrated solution of ginkgo leaf extract, and simultaneously recovering ethanol;
(3) centrifuging the concentrated solution of folium Ginkgo extract obtained in step (2) by a disk centrifuge at 6000rpm/min for 10min to obtain centrifugal solution of folium Ginkgo extract, wherein the content of bilobalide is 0.15%, and the content of impurities is 5.5%;
(4) filtering and clarifying the gingko extracting centrifugate obtained in the step (3) by using an activated and modified ceramic ultrafiltration membrane, and removing impurities to obtain a ceramic membrane filtrate, wherein the content of bilobalide is 0.16%, and the content of impurities is 0.32%;
wherein, before the activation modification of the ceramic membrane ultrafiltration membrane, the aperture of the support body is 2 μm, and the porosity is 30%; the aperture of the separation layer is 20 nm; the separation layer is formed by firing titanium oxide with the particle size of 30nm at the high temperature of 750 ℃; the ceramic ultrafiltration membrane is obtained by activating ethanol solution with succinic acid as an activating agent;
wherein the filtering temperature is 60 ℃, the pressure is 0.2MPa, and the membrane surface flow rate is 4 m/s;
(5) extracting the ceramic membrane filtrate obtained in the step (4) by ethyl acetate to respectively obtain a water phase and an organic phase; wherein the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1;
(6) adsorbing the organic phase obtained in the step (5) by 20-mesh polyamide resin (the flow rate is 1BV/h, the adsorption multiple is 1 time), desorbing by 75% ethanol to obtain desorption solution, wherein the flow rate of the ethanol is 1BV/h, and the using amount of the ethanol is 2 BV;
(7) concentrating the desorption solution obtained in the step (6) at 60 ℃ and 4.0MPa through a nanofiltration membrane to form a roll type ultrafiltration membrane (the molecular weight cutoff is 100 Da);
(8) and (4) evaporating, crystallizing and drying the nanofiltration membrane concentrated solution in the step (7) to obtain the ginkgolides.
In the step (4), the activation process of the ceramic membrane comprises the following steps:
(a) soaking the ceramic membrane in deionized water for 12h, and drying at 100 ℃ for 10 h;
(b) placing the ceramic membrane obtained in the step (a) in an activator, starting a vacuum device, heating a 0.05mol/L succinic acid solution in a round-bottom flask to boil, and carrying out activation reaction for 5 hours, wherein the vacuum degree is 90 kPa;
(c) and (c) washing the ceramic membrane obtained in the step (b) with deionized water for three times, and drying for 4 hours at 100 ℃.
The ceramic membrane of the embodiment has smaller aperture, lower pressure, higher temperature, lower ceramic membrane flux, good filtrate quality and low ginkgolic acid content which is below 1 ppm; the nanofiltration membrane has low molecular weight cut-off and high pressure. The nanofiltration membrane has low filtration flux, but the yield of the ginkgolides in the step is high.
The yield of the finally obtained ginkgolide is 97.8 percent, the purity of the ginkgolide is 99.2 percent, the removal rate of ginkgoic acid is 99.9 percent, the quality of the ceramic membrane filtrate is good, and the turbidity is 1.8 NTU.
Example 3: the extraction of bilobalide was performed according to the scheme shown in fig. 2:
(1) crushing ginkgo leaves to 40 meshes, leaching the ginkgo leaves by using a 60% ethanol solution at 50-80 ℃, and extracting for 6 times to obtain a crude extract of the ginkgo leaves;
(2) evaporating and concentrating the crude extract obtained in the step (1) for 6 times to obtain a concentrated solution of ginkgo leaf extract, and simultaneously recovering ethanol;
(3) centrifuging the concentrated solution of folium Ginkgo extract obtained in step (2) with a disc centrifuge at 8000rpm/min for 10min to obtain centrifugal solution of folium Ginkgo extract, wherein the content of bilobalide is 0.16%, and the content of impurities is 5.6%;
(4) filtering and clarifying the gingko extraction centrifugate obtained in the step (3) by using an activated and modified ceramic ultrafiltration membrane, and removing impurities to obtain a ceramic membrane filtrate as shown in a figure 3, wherein the content of bilobalide is 0.173%, and the content of impurities is 0.19%; wherein, the turbidity of A is 1.0 NTU; the turbidity of B was 2.0 NTU.
Before the activation modification of the ceramic membrane ultrafiltration membrane, the pore diameter of a support body is 2 mu m, and the porosity is 35%; the aperture of the separation layer is 30 nm; the separation layer is formed by firing titanium oxide with the particle size of 50nm at the high temperature of 700 ℃; the ceramic ultrafiltration membrane is obtained by activating an ethanol solution with oxalic acid as an activating agent;
wherein the temperature of the filtration is 40 ℃, the pressure is 0.35MPa, and the flow rate of the membrane surface is 4.5 m/s;
(5) extracting the ceramic membrane filtrate obtained in the step (4) by ethyl acetate to respectively obtain a water phase and an organic phase; wherein the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1;
(6) adsorbing the organic phase obtained in the step (5) by 40-mesh polyamide resin (the flow rate is 3BV/h, the adsorption multiple is 4 times), desorbing by 75% ethanol to obtain desorption solution, wherein the flow rate of the ethanol is 1BV/h, and the using amount of the ethanol is 3 BV;
(7) concentrating the desorption solution obtained in the step (6) at 30 ℃ and 2.5MPa through a roll-type ultrafiltration membrane (the molecular weight cutoff is 150 Da);
(8) and (4) evaporating, crystallizing and drying the nanofiltration membrane concentrated solution in the step (7) to obtain the ginkgolides.
In the step (4), the activation process of the ceramic membrane comprises the following steps:
(a) soaking the ceramic membrane in deionized water for 10h, and drying at 100 ℃ for 12 h;
(b) placing the ceramic membrane obtained in the step (a) in an activator, starting a vacuum device, heating 0.2mol/L oxalic acid solution in a round-bottom flask to boil, and carrying out activation reaction for 6 hours, wherein the vacuum degree is 20 kPa;
(c) and (c) washing the ceramic membrane obtained in the step (b) with deionized water for three times, and drying at 100 ℃ for 12 hours.
The ceramic membrane has moderate aperture, temperature and pressure, high and stable flux, good filtrate quality, high ginkgolic acid removal rate up to 99.9%, and low content below 0.5ppm by detection; the nanofiltration membrane has moderate filtering pressure, larger flux and high yield of the ginkgolide, and is more suitable for industrial production.
The yield of the finally obtained ginkgolide is 98.3 percent, the purity of the ginkgolide is 99.5 percent, the removal rate of ginkgoic acid is 99.9 percent, the quality of the ceramic membrane filtrate is good, and the turbidity is 1.0 NTU.
Example 4: the extraction of bilobalide was performed according to the scheme shown in fig. 2:
(1) crushing ginkgo leaves to 30 meshes, leaching the ginkgo leaves by using a 60% ethanol solution at 50-80 ℃, and extracting for 6 times to obtain a crude extract of the ginkgo leaves;
(2) evaporating and concentrating the crude extract obtained in the step (1) for 6 times to obtain a concentrated solution of ginkgo leaf extract, and simultaneously recovering ethanol;
(3) centrifuging the concentrated solution of folium Ginkgo extract obtained in step (2) by disk centrifuge at 6000rpm/min for 10min to obtain centrifugal solution of folium Ginkgo extract, wherein the content of bilobalide is 0.151%, and the content of impurities is 5.25%;
(4) filtering and clarifying the gingko extracting centrifugate obtained in the step (3) by using an activated and modified ceramic ultrafiltration membrane, and removing impurities to obtain a ceramic membrane filtrate, wherein the content of bilobalide is 0.163%, and the content of impurities is 0.24%;
before the activation modification of the ceramic membrane ultrafiltration membrane, the pore diameter of a support body is 2 mu m, and the porosity is 35%; the aperture of the separation layer is 5 nm; the separation layer is formed by firing titanium oxide with the particle size of 10nm at the high temperature of 800 ℃; the ceramic ultrafiltration membrane is obtained by activating an ethanol solution with glutaric acid as an activating agent;
wherein the filtering temperature is 60 ℃, the pressure is 0.8MPa, and the membrane surface flow rate is 5 m/s;
(5) extracting the ceramic membrane filtrate obtained in the step (4) by ethyl acetate to respectively obtain a water phase and an organic phase; wherein the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1;
(6) adsorbing the organic phase obtained in the step (5) by 40-mesh polyamide resin (the flow rate is 2BV/h, the adsorption multiple is 4 times), desorbing by 60% ethanol to obtain desorption solution, wherein the flow rate of the ethanol is 2BV/h, and the using amount of the ethanol is 2 BV;
(7) concentrating the desorption solution obtained in the step (6) at 30 ℃ and 2.5MPa through a nanofiltration membrane to form a roll type ultrafiltration membrane (the molecular weight cutoff is 150 Da);
(8) and (4) evaporating, crystallizing and drying the nanofiltration membrane concentrated solution in the step (7) to obtain the ginkgolides.
In the step (4), the activation process of the ceramic membrane comprises the following steps:
(a) soaking the ceramic membrane in deionized water for 12h, and drying at 100 ℃ for 12 h;
(b) placing the ceramic membrane obtained in the step (a) in an activator, starting a vacuum device, heating a 0.1mol/L glutaric acid solution in a round-bottom flask to boil, and carrying out activation reaction for 2 hours, wherein the vacuum degree is 30 kPa;
(c) and (c) washing the ceramic membrane obtained in the step (b) with deionized water for three times, and drying for 10 hours at 100 ℃.
The ceramic membrane has small pore size and high filtering temperature, the filtering pressure liquid to be maintained is high, the filtrate is filtered and clarified, but the phenomenon of back turbidity can occur, the energy consumption is high, and a part of products can be intercepted by the ceramic membrane. The flux of the ceramic membrane is low, the intercepted molecular weight of the nanofiltration membrane is proper, the pressure is moderate, the flux is high, the yield of the ginkgolides in the nanofiltration membrane process is high, but the total yield is low.
The yield of the finally obtained ginkgolide is 94.3 percent, the purity of the ginkgolide is 99.1 percent, the removal rate of ginkgoic acid is 97.3 percent, the quality of the ceramic membrane filtrate is good, and the turbidity is 1.4 NTU.
Example 5: the extraction of bilobalide was performed according to the scheme shown in fig. 2:
(1) crushing ginkgo leaves to 20 meshes, leaching the ginkgo leaves by using a 60% ethanol solution at 50-80 ℃, and extracting for 6 times to obtain a crude extract of the ginkgo leaves;
(2) evaporating and concentrating the crude extract obtained in the step (1) for 6 times to obtain a concentrated solution of ginkgo leaf extract, and simultaneously recovering ethanol;
(3) centrifuging the concentrated solution of folium Ginkgo extract obtained in step (2) by a disk centrifuge at 6000rpm/min for 10min to obtain centrifugal solution of folium Ginkgo extract, wherein the content of bilobalide is 0.155%, and the content of impurities is 5.6%;
(4) filtering and clarifying the gingko extracting centrifugate obtained in the step (3) by using an activated and modified ceramic ultrafiltration membrane, and removing impurities to obtain a ceramic membrane filtrate, wherein the content of bilobalide is 0.166 percent, and the content of impurities is 0.27 percent;
before the activation modification of the ceramic membrane ultrafiltration membrane, the pore diameter of a support body is 2 mu m, and the porosity is 35%; the aperture of the separation layer is 10 nm; the separation layer is formed by firing titanium oxide with the particle size of 20nm at the high temperature of 800 ℃; the ceramic ultrafiltration membrane is obtained by activating an ethanol solution with malonic acid as an activating agent;
wherein the filtering temperature is 30 ℃, the pressure is 0.6MPa, and the membrane surface flow rate is 3 m/s;
(5) extracting the ceramic membrane filtrate obtained in the step (4) by ethyl acetate to respectively obtain a water phase and an organic phase; wherein the volume ratio of the ethyl acetate to the ceramic membrane filtrate is 1: 3-1: 1;
(6) adsorbing the organic phase obtained in the step (5) by 30-mesh polyamide resin (the flow rate is 3BV/h, the adsorption multiple is 3 times), desorbing by 70% ethanol to obtain desorption solution, wherein the flow rate of the ethanol is 2BV/h, and the using amount of the ethanol is 2 BV;
(7) concentrating the desorption solution obtained in the step (6) at 40 ℃ and 2.0MPa through a roll-type ultrafiltration membrane (the molecular weight cutoff is 300 Da);
(8) and (4) evaporating, crystallizing and drying the nanofiltration membrane concentrated solution in the step (7) to obtain the ginkgolides.
In the step (4), the activation process of the ceramic membrane comprises the following steps:
(a) soaking the ceramic membrane in deionized water for 12h, and drying at 100 ℃ for 10 h;
(b) placing the ceramic membrane obtained in the step (a) in an activator, starting a vacuum device, heating 0.05mol/L malonic acid solution in a round-bottom flask to boil, and carrying out activation reaction for 4 hours, wherein the vacuum degree is 50 kPa;
(c) and (c) washing the ceramic membrane obtained in the step (b) with deionized water for three times, and drying for 10 hours at 100 ℃.
The ceramic membrane has small aperture, moderate filtering temperature and relatively high pressure, and can ensure effective filtering and clarification. The ceramic membrane flux is low, the operation energy consumption is higher, but the filtrate quality is good, the rear turbidity phenomenon cannot be generated, and the content of ginkgoic acid is very low and is below 1 ppm; the nanofiltration membrane has slightly larger molecular weight cut-off and large flux, and the yield of the ginkgolides is slightly reduced compared with that of the embodiment 3.
The yield of the finally obtained ginkgolide is 92.9 percent, the purity of the ginkgolide is 98.5 percent, the removal rate of ginkgoic acid is 99.7 percent, the quality of the ceramic membrane filtrate is good, and the turbidity is 1.5 NTU.
Comparative example 1
As in example 3, only the ceramic membrane was replaced with an unactivated ceramic membrane, and the resulting ceramic membrane filtrate was as shown in fig. 4, with a bilobalide content of 0.153% and an impurity content of 1.36%; wherein, the turbidity of A is 10.0 NTU; the turbidity of B was 78.0 NTU.
The yield of the finally obtained ginkgolides is 75%, the purity of the ginkgolides is 86%, the removal rate of ginkgolic acid is 43%, the quality of the ceramic membrane filtrate is poor, and the turbidity of the ceramic membrane filtrate after 2 hours is 78NTU (turbidity removal) phenomenon.
The invention provides a concept and a method of an extraction process of ginkgolides, and a number of methods and ways for implementing the technical scheme are provided, the above description is only a preferred embodiment of the invention, it should be noted that, for those skilled in the art, a number of improvements and decorations can be made without departing from the principle of the invention, and these improvements and decorations should also be regarded as the protection scope of the invention. All the components not specified in the present embodiment can be realized by the prior art.