阅读说明：本技术 一种高速逆流色谱分离纯化麦芽糖基环糊精的方法 (Method for separating and purifying maltose cyclodextrin by high-speed counter-current chromatography ) 是由 王金鹏 吴雪 邱超 金征宇 于 2020-12-23 设计创作，主要内容包括：本发明公开了一种高速逆流色谱分离纯化麦芽糖基环糊精的方法,属于分离纯化技术领域。本发明以膜分离纯化后的麦芽糖基环糊精制备体系为样品溶液,再以高速逆流色谱分离纯化目标产物,配合使用特点的两相溶剂体系磷酸二氢钾水溶液-丙酮-乙醇,建立了一种高效简便的麦芽糖基环糊精分离纯化方法。该方法最终结果固定相保留率为67％,所得纯度达93％。(The invention discloses a method for separating and purifying maltose-based cyclodextrin by high-speed counter-current chromatography, belonging to the technical field of separation and purification. The invention takes a maltose cyclodextrin preparation system after membrane separation and purification as a sample solution, then separates and purifies a target product by high-speed counter-current chromatography, and establishes a high-efficiency, simple and convenient method for separating and purifying maltose cyclodextrin by matching with a two-phase solvent system potassium dihydrogen phosphate aqueous solution-acetone-ethanol with use characteristics. The final result of the method is that the stationary phase retention rate is 67%, and the obtained purity reaches 93%.)

1. A method for separating, purifying and separating maltosyl-beta-cyclodextrin based on high-speed countercurrent chromatography is characterized in that a two-phase solvent system of the high-speed countercurrent chromatography is potassium dihydrogen phosphate aqueous solution-acetone-ethanol, the upper phase is used as a stationary phase, and the lower phase is used as a mobile phase.

2. The method of claim 1, wherein the aqueous solution of monopotassium phosphate is a 30% aqueous solution of monopotassium phosphate; the volume ratio of the 30% potassium dihydrogen phosphate aqueous solution to the acetone and the ethanol is 6:1.5: 2.

3. The method according to claim 1, characterized in that it comprises: preparing a two-phase solvent system, dissolving a maltosyl cyclodextrin sample in a mobile phase, pumping the upper phase and the lower phase once, and collecting effluent liquid.

4. The method of any one of claims 1 to 3, wherein the high-speed countercurrent chromatography is performed at a host rotation speed of 800r/min and a mobile phase pumping flow rate of 2 mL/min.

5. A method of preparing a maltosyl cyclodextrin, the method comprising the steps of:

(1) dissolving maltose and cyclodextrin in a phosphate buffer solution, adding pullulanase to carry out enzymatic reaction, and obtaining a reaction solution after the reaction is finished;

(2) diluting the reaction solution obtained in the step (1), then performing nanofiltration treatment, and collecting trapped fluid;

(3) concentrating and drying trapped fluid to obtain a maltosyl cyclodextrin crude product;

(4) separating and purifying the obtained crude maltosyl cyclodextrin by the method according to any one of claims 1 to 4 to obtain maltosyl cyclodextrin.

6. The method according to claim 5, wherein the mass ratio of maltose to cyclodextrin in step (1) is 1: (4-6).

7. The method according to claim 5, wherein the buffer solution in step (1) has a pH of 5.0 and is added in an amount of 2 to 5mL/1g maltose.

8. The method according to claim 5, wherein the pullulanase is added in an amount of 300U/g in step (1).

9. The method according to claim 5, wherein the temperature of the enzymatic reaction in step (1) is 60 ℃; the time is 60 h.

10. The method according to any one of claims 5 to 9, wherein the dilution in step (2) is to dilute the reaction solution to a solid content of 8% to 10%.

Technical Field

The invention relates to a method for separating and purifying maltose-based cyclodextrin by high-speed counter-current chromatography, belonging to the technical field of separation and purification.

Background

Cyclodextrins (CD) are a class of cyclic oligosaccharides produced by the action of glucosyltransferases (CGTase) produced by certain species of Bacillus on starch. Typically 6-13D-glucopyranose units are linked by alpha- (1 → 4) -glycosidic linkagesAnd the most common of the two are alpha-, beta-and gamma-cyclodextrin, and the polymerization degrees are respectively 6, 7 and 8. The cyclodextrin can be included with different guest molecules through intermolecular interaction due to the unique cavity structure with hydrophilic exterior and hydrophobic interior to form a host-guest compound, and is widely applied to the industries of pharmacy, chemical engineering, food and the like. Beta-cyclodextrin is the only product which is produced in large quantity and widely applied in the industry at present due to strong inclusion ability, simple production process and low cost, but the solubility of the beta-cyclodextrin is small (25 ℃, 1.8g/100mL H)₂O), greatly limiting its range of application.

The maltosyl-beta-cyclodextrin is a cyclodextrin derivative obtained by modifying cyclodextrin with an enzyme. Compared with the parent cyclodextrin, the maltosyl cyclodextrin has the advantages of larger water solubility, better embedding performance, good biocompatibility, low hemolytic effect and the like, and has wider application prospect in the fields of food, medicines and the like. However, the separation and purification of maltosyl- β -cyclodextrin is very difficult. Currently, the maltosyl-beta-cyclodextrin is mainly prepared by taking maltose and cyclodextrin as substrates and performing reverse synthesis of pullulanase. The product obtained by the method is complex, and the reaction system is high in viscosity and semi-solid, so that the process for separating single cyclodextrin is complex and time-consuming, the production cost is increased, and the large-scale production cannot be realized in industry.

The existing separation method mainly concentrates chromatographic column separation, such as trimethyl-beta-cyclodextrin isomer separation by utilizing a reverse phase column and a graphite carbonization column, the method has the advantages of small preparation amount in one step, easy blockage of the chromatographic column, long time consumption and incapability of meeting the requirement of industrial mass production. Therefore, there is still a need to develop a method for realizing single, large-scale and rapid separation and purification of branched cyclodextrin.

Disclosure of Invention

The technical problem is as follows: aiming at the defects of the prior art, a method for separating and purifying the maltosyl-beta-cyclodextrin by high-speed countercurrent chromatography is provided. High-speed countercurrent chromatography (HSCCC) is a liquid-liquid chromatographic separation technology developed in recent years, and a stationary phase and a mobile phase are both liquid, so that irreversible adsorption is avoided, and the method has the advantages of high efficiency, rapidness, good reproducibility and the like, and is widely applied to separation and purification of natural compounds. At present, no report of separating and purifying the maltosyl cyclodextrin by high-speed counter-current chromatography exists.

The technical scheme is as follows:

the invention provides a method for separating, purifying and separating maltosyl-beta-cyclodextrin based on high-speed countercurrent chromatography, wherein a two-phase solvent system of the high-speed countercurrent chromatography is potassium dihydrogen phosphate aqueous solution-acetone-ethanol, the upper phase is used as a stationary phase, and the lower phase is used as a mobile phase.

In one embodiment of the invention, the aqueous solution of monopotassium phosphate is a 30% aqueous solution of monopotassium phosphate; the volume ratio of the 30% potassium dihydrogen phosphate aqueous solution to the acetone and the ethanol is 6:1.5: 2.

In one embodiment of the invention, the method comprises: preparing the two-phase solvent system, dissolving the maltosyl cyclodextrin sample in the mobile phase, pumping the upper phase and the lower phase once, and collecting effluent liquid.

In one embodiment of the invention, the high-speed countercurrent chromatography has a host rotation speed of 800r/min and a mobile phase pumping inflow speed of 2 mL/min.

The present invention also provides a method for preparing maltosyl cyclodextrin, the method comprising the steps of:

(1) dissolving maltose and cyclodextrin in a phosphate buffer solution, adding pullulanase to carry out enzymatic reaction, and obtaining a reaction solution after the reaction is finished;

(2) diluting the reaction solution obtained in the step (1), then performing nanofiltration treatment, and collecting trapped fluid;

(3) concentrating and drying trapped fluid to obtain a maltosyl cyclodextrin crude product;

(4) purifying and separating the obtained maltose-based cyclodextrin crude product by high-speed counter-current chromatography to obtain maltose-based cyclodextrin; the high-speed counter-current chromatography purification and separation method is the purification and separation method.

In one embodiment of the present invention, the mass ratio of maltose to cyclodextrin in step (1) is 1: (4-6). Preferably 1: 5.

in one embodiment of the present invention, the buffer solution in step (1) has a pH of 5.0 and is added in an amount of 2 to 5mL/1g maltose. Preferably 2.5mL/g maltose.

In one embodiment of the present invention, pullulanase is added in an amount of 300U/g β -CD in step (1).

In one embodiment of the present invention, the temperature of the enzymatic reaction in step (1) is 60 ℃; the time is 60 h.

In one embodiment of the present invention, the dilution in the step (2) is to dilute the reaction solution to a solid content of 8% to 10%.

In one embodiment of the present invention, the nanofiltration in step (2) is intermittent constant volume nanofiltration, provided that: the molecular weight cut-off of the membrane is 1000Da, the operation temperature is 40 ℃, the operation pressure is 0.4MPa, the volume factor ratio is 0.33, and the circulation is carried out for 4-5 times.

In one embodiment of the present invention, the drying in step (3) is spray drying.

In one embodiment of the present invention, the preparation method specifically comprises the following steps:

(1) preparation of maltose cyclodextrin: weighing a proper amount of maltose and cyclodextrin, dissolving in a phosphate buffer solution, and adding pullulanase for reaction to obtain maltose-based cyclodextrin;

(2) and (4) nanofiltration: diluting the reaction solution, then carrying out intermittent constant-volume nanofiltration treatment, and collecting trapped fluid;

(3) and (3) drying: drying the solution after nanofiltration to obtain maltosyl cyclodextrin;

(4) separating the maltosyl cyclodextrin by high-speed counter-current chromatography: selecting potassium dihydrogen phosphate aqueous solution-acetone-ethanol to prepare a two-phase solvent system: sequentially adding potassium dihydrogen phosphate water solution, acetone and ethanol into a separating funnel, sufficiently shaking, standing for 12h for layering, separating upper and lower phases, respectively performing ultrasonic degassing for 20min to obtain upper phase as stationary phase and lower phase as mobile phase; dissolving the maltosyl cyclodextrin into the mobile phase, pumping the upper phase and the lower phase once, and collecting the effluent.

Has the advantages that:

the invention takes a membrane separation and purification maltose cyclodextrin preparation system as a sample solution, and then separates and purifies a target product by high-speed counter-current chromatography, thereby establishing a high-efficiency, simple and convenient separation and purification method of maltose cyclodextrin. The final result of the method is that the stationary phase retention rate is 67%, and the obtained purity is 93.2%.

Drawings

FIG. 1 is a high performance liquid chromatogram of an initial synthesis system of maltosyl cyclodextrin obtained in step (1) in example 1;

FIG. 2 is a high performance liquid chromatogram of the spray-dried powder of maltosyl cyclodextrin obtained in step (3) of example 1;

FIG. 3 is a high performance liquid chromatogram of the maltosyl cyclodextrin concentrate obtained in step (4) of example 1;

FIG. 4 is a high-speed liquid chromatogram of maltose, cyclodextrin, and maltosyl cyclodextrin standard samples.

Detailed Description

The technical solution of the present invention will be described in detail with reference to the accompanying drawings and the detailed description.

The related stationary phase retention rate is as follows: the ratio of the volume occupied by the stationary phase in the CCC column to the volume of the CCC column; which is used for reflecting the layering time of the solvent system.

The HPLC maltosyl cyclodextrin purity determination process comprises the following steps: x Amide column (2.5 μm,2.1 mm. times.75 mm); a detector: RID-10A; mobile phase: 65% acetonitrile (v/v); column temperature: room temperature; flow rate: 1 mL/min; sample introduction amount: 20 μ L

Example 1:

(1) weighing 4g of beta-CD and 20.31g of maltose, adding the beta-CD and the maltose into 9.7ml of ph5.0 acetic acid buffer solution, adding 0.6ml (300 mu/g of beta-CD) of pullulanase, taking out after reacting for 60h at 60 ℃, inactivating the enzyme in a boiling water bath for 15min to obtain a maltosyl cyclodextrin reaction primary system;

(2) diluting the reaction system by using pure water by 6 times to obtain a material liquid with the material concentration of 8%, carrying out intermittent constant volume percolation at 40 ℃ under the condition that a 4bar nanofiltration membrane is 1000Da, adding pure water with the same volume as that of a permeation liquid into an intercepted liquid when the volume of the intercepted liquid is 1/3 of the volume of a stock solution, continuing nanofiltration treatment, and circulating for 8 times in the way;

(3) spray-drying the trapped fluid after nanofiltration at the temperature of 25 ℃ and the rotating speed of a peristaltic pump of 5r/min to obtain maltosyl cyclodextrin spray-dried powder;

(4) the high-speed counter-current chromatography solvent system adopts 30 percent sodium dihydrogen phosphate: ethanol: placing the solvent system in a separating funnel, shaking uniformly, standing for layering, and after balancing for a period of time, separating an upper phase from a lower phase, wherein the upper phase is a stationary phase, and the lower phase is a mobile phase; dissolving 15mg of the maltodextrin powder obtained in the step (3) in a mobile phase for later use. Adopting a TBE-300A preparative countercurrent chromatograph produced by Shanghai Hotan Biotechnology GmbH, setting the rotation speed of a main machine at 800r/min, the flow rate of a mobile phase at 2ml/min, the operation temperature at room temperature, and collecting the effluent of a target peak component for 30-35min to obtain the maltosyl cyclodextrin concentrated solution.

Comparing the HPLC chromatograms in FIGS. 1-3, it can be seen that most of the maltose is removed after the synthesis system of maltose-based cyclodextrin is subjected to nanofiltration. Further purifying by high-speed counter-current chromatography to obtain the maltosyl cyclodextrin with the purity of 93.2%. The stationary phase retention was 67%.

FIG. 3 is a high performance liquid chromatogram of the maltodextrin concentrate obtained in this example; the corresponding compositional results are shown in table 1.

Table 1 shows the results of the composition of the maltodextrin concentrate obtained in example 1

Components	Peak response value	Concentration (mg/mL)	Purity of
				β-CD	8570	0.15	6.8％
Mal-β-CD	27938	2.05	93.2％

Example 2:

(1) weighing 4g of beta-CD and 20.31g of maltose, adding the beta-CD and the maltose into 9.7ml of ph5.0 acetic acid buffer solution, adding 0.6ml (300 mu/g of beta-CD) of pullulanase, taking out after reacting for 60h at 60 ℃, inactivating the enzyme in a boiling water bath for 15min to obtain a maltosyl cyclodextrin reaction primary system;

(2) diluting the reaction system by 5 times with pure water to obtain a material liquid with a material concentration of 10%, performing intermittent constant volume percolation at 40 ℃ under the condition that a 4bar nanofiltration membrane is 1000Da, adding pure water with the same volume as that of a permeation liquid into an intercepted liquid when the volume of the intercepted liquid is 1/3 of the volume of a stock solution, continuing nanofiltration treatment, and circulating for 8 times in the way;

(3) spray-drying the trapped fluid after nanofiltration at the temperature of 25 ℃ and the rotating speed of a peristaltic pump of 5r/min to obtain maltosyl cyclodextrin spray-dried powder;

(4) the high-speed counter-current chromatography solvent system adopts 30 percent sodium dihydrogen phosphate: ethanol: placing the solvent system in a separating funnel, shaking uniformly, standing for layering, after balancing for a period of time, separating an upper phase and a lower phase, wherein the upper phase is a stationary phase, the lower phase is a mobile phase, and dissolving 15mg of maltose-based cyclodextrin powder in the mobile phase for later use.

Adopting a TBE-300A preparative countercurrent chromatograph produced by Shanghai Hotan Biotechnology GmbH, setting the rotation speed of a main machine at 800r/min, the flow rate of a mobile phase at 2ml/min, the operation temperature at room temperature, and collecting the effluent of a target peak component for 30-35min to obtain the maltosyl cyclodextrin concentrated solution.

The purity of the maltosyl cyclodextrin concentrated solution can reach 88.31 percent by HPLC. The stationary phase retention rate was 60%.

Comparative example 1

The preparation process was the same as in example 1, except that the solvent system was changed to 30% sodium dihydrogen phosphate: ethanol is 6:2, the layering time of a solvent system without acetone is about 1min, and when the countercurrent chromatography separation is carried out, the stationary phase is almost completely lost before the material separation, so that the method is not suitable for the high-speed countercurrent chromatography separation.

Comparative example 2

The preparation process was the same as in example 1, except that the solvent system was changed to 30% sodium dihydrogen phosphate: ethanol: acetone ═ 6:1.5:2, and the final maltosyl cyclodextrin purity was only 60% by test.

Comparative example 3

The preparation process was the same as in example 1, except that the solvent system was changed to 15% sodium dihydrogen phosphate: acetone: ethanol ═ 6:1.5: 2. Tests show that maltose, beta-cyclodextrin and maltosyl cyclodextrin cannot be effectively separated.

Comparative example 4

The preparation process was the same as in example 1, except that the solvent system was changed to 30% ammonium sulfate: ethanol ═ 6: 2. Tests show that the partition coefficients of maltose, beta-cyclodextrin and maltosyl cyclodextrin are too high, so that the separation cannot be effectively carried out, and the method is not suitable for high-speed countercurrent chromatography.