Method for program separation of molecularly imprinted resin with similar structure compounds

Abstract

The method comprises the following steps: adding a certain amount of a structurally similar compound A into a solution for dissolving, adding pretreated macroporous adsorption resin, then adding a dopamine Tris-HCl solution, and stirring at room temperature to obtain MIP-A-PDA; reacting a certain amount of a temperature-sensitive switch anchoring agent, a temperature-sensitive monomer, a compound B with a similar structure, an initiator and the MIP-A-PDA at a certain temperature; and after the reaction is finished, filtering the mixture, eluting the template at a certain temperature, and drying to obtain the molecularly imprinted resin capable of program separation of the similar-structure compound. According to the method, a molecular imprinting technology is combined with macroporous adsorption resin, and molecular imprinting resin capable of program separation of the structurally-similar compounds in natural products is adopted, so that the specific recognition performance of the structurally-similar compounds can be improved, the problem that the structurally-similar compounds are difficult to separate is solved, the mass transfer resistance of a target object in a separation medium can be reduced, and the separation efficiency is improved. The adsorption capacity of structurally similar compounds is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of natural product separation, and particularly relates to a method for molecularly imprinting resin capable of programmably separating structurally similar compounds. Background Art

[0002] The composition of natural products is very complex. Each natural product often contains a huge number of active compounds with complex structures, including a certain number of monomeric compounds with similar structures. Research shows that monomeric compounds with different structures have different physiological effects and often different activities, and the effects of some drugs are even opposite. Therefore, it is very necessary to separate the active compounds with similar structures in natural products.

[0003] However, due to the similar chemical structures and physical and chemical properties of structurally similar compounds, their separation is difficult. At the same time, many of the active monomeric compounds in natural products are still heat-sensitive or have large molecular sizes, further increasing the separation difficulty. At present, industrial separation of structurally similar components mainly uses technologies such as rectification, extraction, membrane separation, and adsorption separation. Among them, adsorption separation technology can be carried out under conditions close to normal temperature and pressure, and has the advantages of low energy consumption, no phase change involved, simple process, large processing capacity, and easy operation, and is an ideal separation method. However, traditional adsorption separation generally has problems such as weak molecular recognition ability of adsorbents, low density of functional groups, small adsorption capacity, and slow diffusion in pores, resulting in low separation efficiency.

[0004] Therefore, there is an urgent need for an efficient and environmentally friendly adsorption separation technology to achieve the separation of structurally similar active monomeric compounds in natural products, which is of great significance for enhancing drug efficacy, reducing adverse reactions, and increasing the safety and effectiveness of drug use. Summary of the Invention

[0005] The purpose of the present invention is to solve the problems of difficult separation, low efficiency, and high cost of structurally similar active monomeric compounds in the prior art, and to provide a molecularly imprinted resin for programmably separating structurally similar compounds in natural product extraction solutions and a preparation method thereof.

[0006] To solve the above technical problems, the technical scheme adopted by the present invention is as follows:

[0007] The present invention first discloses a method for molecularly imprinting resin capable of programmably separating structurally similar compounds, including the following steps:

[0008] S1. Add a certain amount of structurally similar compound A to a solution to dissolve it, add the pretreated macroporous adsorption resin, then add dopamine Tris-HCl solution, disperse it by ultrasonic wave, stir and react at room temperature. After the reaction is completed, filter the mixture, wash it with distilled water, and dry it to obtain MIP-A-PDA;

[0009] S2. Add a certain amount of MIP-A-PDA and a thermosensitive switch anchoring agent to a solution for dissolution, and stir and react for a certain period of time. After the reaction is completed, filter the mixture and rinse it with distilled water to obtain MIP-A-PDA-M;

[0010] S3. Weigh a certain amount of thermosensitive monomer and structural analog B, dissolve them with a solution, then successively add MIP-A-PDA-M and an initiator, and react at a certain temperature for a period of time. After the reaction is completed, filter the mixture and rinse it with distilled water to obtain MIP-A-PDA-B;

[0011] S4. Elute the template from MIP-A-PDA-B with a methanol-acetic acid solution at a certain temperature, and dry it to obtain a molecularly imprinted resin capable of programmably separating structural analogs.

[0012] Furthermore, the solution described in step S1 includes: distilled water, Tris-HCl aqueous solution, Tris-HCl methanol solution, and Tris-HCl ethanol solution.

[0013] Furthermore, the Tris-HCl methanol solution is prepared by the following method:

[0014] It is prepared by mixing Tris-HCl and a methanol solution in a volume ratio of 10:1 to 4:5;

[0015] The Tris-HCl ethanol solution is prepared by the following method:

[0016] It is prepared by mixing Tris-HCl and an ethanol solution in a volume ratio of 10:1 to 4:5.

[0017] Furthermore, the pretreated macroporous adsorption resin described in step S1 is selected from any one of NKA-9, AB-8, and D101 types; the dosage ratio of the structural analog A to the macroporous adsorption resin = 1:10 to 1:1 mmol / g; the volume ratio of the macroporous adsorption resin to the solution is 1:80 to 1:200 g / mL; the concentration of the dopamine Tris-HCl solution is 1 to 30 mg / mL, pH = 8 to 9, and its added volume ratio to the macroporous adsorption resin is 100:1 to 250:1 mL / g; the ultrasonic dispersion time is 2 to 10 min, and the stirring reaction time at room temperature is 2 to 12 h.

[0018] Furthermore, the thermosensitive switch anchoring agent described in step S2 is selected from any one of CuSO4·5H2O, FeSO4·7H2O, and CuCl2·2H2O; the mixing and stirring time is 30 to 120 min.

[0019] Further, the dosage ratio of the structural analog B to MIP-A-PDA-M in step S3 = 1:10 (mmol / g) to 1:1 (mmol / g).

[0020] Further, the thermosensitive monomer described in step S3 is selected from: a mixture of monomer A and monomer B with a mass ratio of 9:1 to 6:4; monomer A includes: N-isopropylacrylamide, N-ethylacrylamide, N-vinylcaprolactam; monomer B includes: acrylamide, butyl acrylate, N-isopropylacrylamide, N-ethylacrylamide, N-vinylcaprolactam; the solution is distilled water; the initiator is selected from ammonium persulfate or hydrogen peroxide.

[0021] Further, the certain temperature in step S3 is 20 - 40 °C, and the reaction for a certain time is 2 - 12 h.

[0022] Further, the certain temperature in step S4 is 20 - 70 °C, and the volume ratio of the methanol - acetic acid solution is methanol:acetic acid = 8:2 to 10:0.

[0023] The present invention also discloses a molecularly imprinted resin of a structurally similar compound separated by any of the above methods.

[0024] The beneficial effects of the present invention are as follows:

[0025] 1. The present invention can achieve the programmed separation of structurally similar compounds through simple external temperature regulation, and the overall process is simple, the reaction conditions are mild, environmentally friendly, the production cost is low, and it is easy to be promoted to industrial applications. It can provide a reference for the programmed separation of other various structurally similar compounds in natural products and has a relatively broad application prospect.

[0026] 2. The present invention combines molecular imprinting technology with macroporous adsorption resin having large pore size, high specific surface area, stable structure, and good regeneration performance. The molecularly imprinted resin that can programmably separate structurally similar compounds in natural products can not only improve the specific recognition performance of structurally similar compounds, solve the problem of difficult separation of structurally similar compounds, but also reduce the mass transfer resistance of the target in the separation medium and improve the adsorption capacity of structurally similar compounds. Description of the Drawings

[0027] Figure 1 It is the infrared spectrum of macroporous adsorption resin, dopamine, thermosensitive switch, and molecularly imprinted resin that can programmably separate structurally similar compounds quercetin and quercitrin;

[0028] Figure 2 It is the scanning electron micrograph of the internal morphology of the molecularly imprinted resin that can programmably separate structurally similar compounds quercetin and quercitrin;

[0029] Figure 3 Effect of the dosages of different temperature-sensitive monomers on the VPTT values of molecularly imprinted resins for programmable separation of structurally similar compounds quercetin and quercitrin;

[0030] Figure 4 Adsorption kinetic curves of representative structurally similar compounds quercetin and quercitrin on molecularly imprinted resins for programmable separation of structurally similar compounds;

[0031] Figure 5 Release kinetic curves of representative structurally similar compounds quercetin and quercitrin on molecularly imprinted resins for programmable separation of structurally similar compounds when the external temperature is higher than the VPTT value of the molecularly imprinted resin (a) and when the external temperature is lower than the VPTT value of the molecularly imprinted resin (b), respectively. Specific embodiments

[0032] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0033] Example 1

[0034] Dissolve 0.1 mmol of quercetin in 80 mL of Tris-HCl:EtOH = 10:1 (v:v) solution, add 1 g of pretreated macroporous adsorption resin AB-8, then add 100 mL of dopamine Tris-HCl solution with a concentration of 1 mg / mL and pH = 9, ultrasonically disperse for 2 min, stir and react at room temperature for 12 h, and obtain MIP-A-PDA after drying. Put the prepared MIP-A-PDA and 6 g of CuSO4·5H2O into 80 mL of distilled water, stir and mix for 120 min, then filter the mixture and rinse with distilled water to obtain MIP-A-PDA-M. Then weigh 1.8 g of N-vinylcaprolactam, 0.2 g of butyl acrylate, 0.1 mmol of quercitrin and 0.4 g of hydrogen peroxide, and stir and react at room temperature for 6 h. After the reaction, filter the mixture and rinse with distilled water to obtain MIP-A-PDA-B. Elute the template of MIP-A-PDA-B with methanol:acetic acid = 8:2 (v:v) solution at 20 °C, and dry to obtain the molecularly imprinted resin for programmable separation of structurally similar compounds.

[0035] Example 2

[0036] Dissolve 0.3 mmol of quercetin in 180 mL of Tris-HCl:MeOH = 2:1 (v:v) solution, add 1 g of pretreated D101 macroporous adsorption resin, then add 200 mL of dopamine Tris-HCl solution with a concentration of 10 mg / mL and pH = 8.5, ultrasonically disperse for 6 min, stir and react at room temperature for 4 h, and obtain MIP-A-PDA after drying. Put the prepared MIP-A-PDA and 6 g of FeSO4·7H2O into 80 mL of distilled water, stir and mix for 30 min, then filter the mixture and rinse with distilled water to obtain MIP-A-PDA-M. Then weigh 1.7 g of N-isopropylacrylamide, 0.3 g of acrylamide, 0.3 mmol of quercitrin and 0.4 g of ammonium persulfate, and stir and react at 40 °C for 2 h. After the reaction, filter the mixture and rinse with distilled water to obtain MIP-A-PDA-B. Elute the template with methanol solution at 35 °C for the molecularly imprinted resin capable of programmably separating structurally similar compounds, and dry to obtain it.

[0037] Example 3

[0038] Dissolve 1 mmol of quercetin in 200 mL of Tris-HCl aqueous solution, add 1 g of pretreated NKA-9 macroporous adsorption resin, then add 250 mL of dopamine Tris-HCl solution with a concentration of 30 mg / mL and pH = 8, ultrasonically disperse for 10 min, stir and react at room temperature for 2 h, and obtain MIP-A-PDA after drying. Put the prepared MIP-A-PDA and 6 g of FeSO4·7H2O into 80 mL of distilled water, stir and mix for 60 min, then filter the mixture and rinse with distilled water to obtain MIP-A-PDA-M. Then weigh 1.4 g of N-ethylacrylamide, 0.6 g of acrylamide, 1 mmol of quercitrin and 0.4 g of hydrogen peroxide, and stir and react at 20 °C for 12 h. After the reaction, filter the mixture and rinse with distilled water to obtain MIP-A-PDA-B. Elute the template with methanol:acetic acid = 9:1 (v:v) solution at 70 °C for the molecularly imprinted resin capable of programmably separating structurally similar compounds, and dry to obtain it.

[0039] Test Example 1

[0040] Use the molecularly imprinted resin capable of programmably separating structurally similar compounds prepared in Example 2 to analyze the composition of its functional groups by Fourier transform infrared spectroscopy, and analyze the characteristic peaks of the sample in the range of 4000 - 400 cm -1 -1, and the results are as shown in the appendix Figure 1 shown. At the same time, use field emission scanning electron microscopy to characterize its microscopic morphology, and the results are as shown in the appendix Figure 2 shown. AppendixFigure 1 The infrared spectrum of -1 shows that there are absorption peaks at 3150 - 3500 cm -1 , 2972 cm -1 , 1460 cm -1 , 1385 cm -1 and 1170 cm -1 . The absorption peak at 3150 - 3500 cm -1 is the stretching vibration peak of N - H. The peak at 2972 cm -1 is the stretching vibration peak of - CH3 and - CH2 -. The peak at 1460 cm -1 is the asymmetric bending vibration peak of - CH3. The peak at 1385 cm -1 is the peak formed by the symmetric deformation vibration of the dimethyl group on the isopropyl group. The peak at 1170 cm Figure 2 corresponds to the skeletal vibration peak of the isopropyl group. From the microscopic morphology characterization of Figure 1 and Figure 2 , it can be seen that there are pore structures inside the material, and obvious grafting layers can be observed. From

[0041] In addition, the effects of different dosages of thermosensitive monomers on the volume phase transition temperature (VPTT value) of the programmable separation molecularly imprinted resin were investigated. It was found that when the dosage of the thermosensitive monomer changed, the VPTT value of the molecularly imprinted resin changed significantly. See Figure 3 . At the same time, in order to further study the adsorption behavior of structurally similar compounds on the prepared programmable separation molecularly imprinted resin for structurally similar compounds, the changes in the adsorption amounts of the representative structurally similar compounds quercetin and quercitrin with time during the adsorption process, and the release rates of the representative structurally similar compounds quercetin and quercitrin with temperature change were investigated respectively, so as to reveal the dynamic interaction between the adsorbate and the adsorbent and the programmable release effect. The results are shown in Figure 4 , Figure 5 . From Figure 4 , it can be seen that within the first 90 min, the adsorption amounts of the molecularly imprinted resin for the representative structurally similar compounds quercetin and quercitrin both increased rapidly. At this time, the adsorption capacities of quercetin and quercitrin reached 85% and 87% of the equilibrium value respectively. After 90 min, the growth of the adsorption amounts of the molecularly imprinted resin for quercetin and quercitrin began to slow down. When the time reached 180 min, the adsorption capacity tended to be stable and basically reached the adsorption equilibrium. From Figure 5It can be seen that when the external temperature is higher than the VPTT value of the molecularly imprinted resin, the molecularly imprinted resin mainly releases quercitrin, while when the external temperature becomes lower than the VPTT value of the molecularly imprinted resin, the molecularly imprinted resin mainly releases quercetin. The above results indicate that the prepared molecularly imprinted resin has good adsorption and controlled release properties, and can achieve temperature-controlled programmed separation of representative structurally similar compounds.

[0042] The description and drawings of the present invention are considered illustrative rather than restrictive. Based on the present invention, those skilled in the art can make some substitutions and deformations of some technical features without creative labor according to the disclosed technical content, and all are within the protection scope of the present invention.

Claims

1. A method for preparing a molecularly imprinted resin for programmable separation of structurally similar compounds, comprising the following steps: S1. Add a certain amount of structurally similar compound A to a solution for dissolution, add the pretreated macroporous adsorption resin, then add dopamine Tris-HCl solution, ultrasonically disperse, stir and react at room temperature. After the reaction, filter the mixture, rinse with distilled water, and dry to obtain MIP-A-PDA; S2. Add a certain amount of MIP-A-PDA and a thermosensitive switch anchoring agent to a solution for dissolution, stir and react for a certain time. After the reaction, filter the mixture, rinse with distilled water to obtain MIP-A-PDA-M; S3. Weigh a certain amount of thermosensitive monomer and structurally similar compound B, dissolve them with a solution, then sequentially add MIP-A-PDA-M and an initiator, react at a certain temperature for a period of time. After the reaction, filter the mixture, rinse with distilled water to obtain MIP-A-PDA-B; S4. Elute the template from MIP-A-PDA-B with a methanol-acetic acid solution at a certain temperature, and dry to obtain the molecularly imprinted resin for programmable separation of structurally similar compounds.

2. The method according to claim 1, wherein: The solution described in step S1 includes: distilled water, Tris-HCl aqueous solution, Tris-HCl methanol solution, Tris-HCl ethanol solution.

3. The method according to claim 2, wherein: The Tris-HCl methanol solution is prepared by the following method: Tris-HCl and methanol solution are prepared in a volume ratio of 10:1 to 4:5; The Tris-HCl ethanol solution is prepared by the following method: Tris-HCl and ethanol solution are prepared in a volume ratio of 10:1 to 4:

5.

4. The method according to claim 1, wherein: The pretreated macroporous adsorption resin described in step S1 is selected from any one of NKA-9, AB-8, and D101 types; The dosage ratio of the structurally similar compound A to the macroporous adsorption resin = 1:10 to 1:1 mmol / g; The volume ratio of the macroporous adsorption resin to the solution is 1:80 to 1:200 g / mL; The concentration of the dopamine Tris-HCl solution is 1 to 30 mg / mL, pH = 8 to 9, and the volume ratio of its addition to the macroporous adsorption resin is 100:1 to 250:1 mL / g; The ultrasonic dispersion time is 2 to 10 min, and the stirring reaction time at room temperature is 2 to 12 h.

5. The method according to claim 1, wherein: The thermosensitive switch anchoring agent described in step S2 is selected from any one of CuSO4·5H2O, FeSO4·7H2O, and CuCl2·2H2O; The mixing and stirring time is 30 to 120 min.

6. The method according to claim 1, wherein: The dosage ratio of the structurally similar compound B to MIP-A-PDA-M in step S3 = 1:10 (mmol / g) to 1:1 (mmol / g).

7. The method according to claim 1, wherein: The thermosensitive monomer described in step S3 is selected from: a mixture of monomer A and monomer B with a mass ratio of 9:1 to 6:4; Monomer A includes: N-isopropylacrylamide, N-ethylacrylamide, N-vinylcaprolactam; Monomer B includes: acrylamide, butyl acrylate, N-isopropylacrylamide, N-ethylacrylamide, N-vinylcaprolactam; The solution is distilled water; The initiator is selected from ammonium persulfate or hydrogen peroxide.

8. According to the method described in claim 1, wherein: The certain temperature in step S3 is 20-40 °C, and the reaction for a certain time is 2-12 h.

9. According to the method described in claim 1, wherein: The certain temperature in step S4 is 20-70 °C, and the volume ratio of the methanol-acetic acid solution is methanol:acetic acid = 8:2 to 10:

0.

10. A molecularly imprinted resin of a structurally similar compound separated by any one of the methods described in claims 1-9.

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