Nitrogen-rich triazine COF material, preparation method thereof and application of nitrogen-rich triazine COF material in separation and purification of phenylethanoid glycoside compounds

Abstract

The invention provides a nitrogen-rich triazine COF material, a preparation method thereof and application of the nitrogen-rich triazine COF material in separation and purification of phenylethanoid glycoside compounds, and belongs to the technical field of preparation of functional materials and separation and purification of natural products. According to the invention, based on a network chemical design, 4, 4 ', 4' '-(1, 3, 5-triazinyl-2, 4, 6-triyl) tribenzaldehyde (TFPT) and 2, 4, 6-tri (4-aminophenyl)-1, 3, 5-triazine (TA) are used as construction units, and the COF material with a nitrogen-rich triazine ring structure is formed by self-assembly from bottom to top through a Schiff base reaction; the COF material is mild in synthesis condition, controllable in structure and easy to functionalize; the COF material can be used as an adsorbent and has good application in separation and purification of phenylethanoid glycoside compounds.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of functional material preparation and natural product separation and purification, and particularly relates to a nitrogen-rich triazine COF material, a preparation method thereof and application of the nitrogen-rich triazine COF material in separation and purification of phenylethanoid glycosides. BACKGROUND

[0002] Mucroniaflavone (ACT) is a phenylethanoid glycoside compound derived from traditional tonic medicine Cistanche, which has a wide range of biological activities and pharmacological effects. Studies have shown that ACT can effectively promote neuronal repair and play a neuroprotective function, and also shows good potential in anti-atherosclerosis and inhibition of tumor cell proliferation, so it is highly concerned in the fields of medicine, health food and high-end cosmetics. However, the content of ACT in natural Cistanche is extremely low, and its molecular structure is sensitive to temperature, acid-base and other treatment conditions, and it is easy to degrade or inactivate under severe conditions, so that the large-scale acquisition of high-purity ACT faces severe challenges. Therefore, it is essential to develop a mild, efficient and selective separation and purification technology for the effective use of ACT.

[0003] Among various separation methods, adsorption method is widely considered as an advantageous technical path for ACT purification due to its simple operation, low energy consumption, easy scaling-up and recyclable adsorbent. Although traditional adsorbents have certain adsorption capacity, they still have problems such as limited specific surface area, uncontrollable pore structure, difficult modification of surface chemical properties and low selectivity for target, which limit their application effect in the separation of high-purity ACT. In recent years, COF materials have shown significant advantages in adsorption separation due to their high specific surface area, customizable pore structure and easy functionalization of surface properties. By reasonably designing the building units and reaction path, the pore size, topological structure and surface functional groups of COF materials can be accurately controlled, so as to realize efficient recognition and selective adsorption of specific target molecules. The application of COF materials in the separation and purification of ACT is expected to overcome the limitations of traditional adsorbents and provide a new strategy for the green and efficient extraction of active ingredients of Cistanche. However, some existing COF materials have low selectivity and small adsorption capacity for ACT due to low acting force. Therefore, it is necessary to develop a new COF material for the separation and purification of mucroniaflavone. SUMMARY

[0004] In view of some deficiencies in the prior art, the application provides a nitrogen-rich triazine COF material, a preparation method thereof and application of the nitrogen-rich triazine COF material in separation and purification of phenylethanoid glycosides; the application is based on reticular chemical design, and a COF material with a nitrogen-rich triazine ring structure is formed by self-assembly from bottom to top through a Schiff base reaction with TFPT and TA as building units; the COF material has mild synthesis conditions, a controllable structure and is easy to functionalize; and the COF material can be used as an adsorbent and has good application in separation and purification of phenylethanoid glycosides.

[0005] In order to achieve the above technical purposes, the application adopts the following technical means: The application first provides a preparation method of a nitrogen-rich triazine COF material, comprising the following steps: 4,4',4''-(1,3,5-triazine ring-2,4,6-triyl) benzaldehyde (TFPT) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TA) are mixed in a solvent, and then a suspension is obtained through ultrasonic treatment; The suspension is frozen in a liquid nitrogen bath, degassed by pumping, and then sealed, followed by sealed standing at a certain temperature, washing, drying, and obtaining the nitrogen-rich triazine COF material.

[0006] Preferably, the use amount of 4,4',4''-(1,3,5-triazine ring-2,4,6-triyl) benzaldehyde (TFPT) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TA) is 0.01-0.4 mmol: 0.01-0.4 mmol.

[0007] Preferably, the solvent comprises a mixture of 1,4-dioxane and mesitylene, and the volume ratio of 1,4-dioxane to mesitylene in the mixture is 3.0 mL: 3.0 mL.

[0008] Preferably, the ultrasonic treatment time is 5-20 min.

[0009] Preferably, the degassing time by pumping is 1-10 min.

[0010] Preferably, the sealed standing condition at a certain temperature is sealed standing at 70-200 DEG C for 10-96 h. The drying condition is standing in a vacuum drying box at 50-100 DEG C for 5-24 h.

[0011] The application further provides the nitrogen-rich triazine COF material prepared by the method, and the nitrogen-rich triazine COF material has a regular hollow spherical cluster structure, has a plurality of hierarchical pores in the inside, has a uniform pore size distribution, and has a high specific surface area; the nitrogen-rich triazine COF material has a pore size of 3.04 nm and a specific surface area of 1108.01 m2 / g.

[0012] The application further provides application of the nitrogen-rich triazine COF material in separation and purification of phenylethanoid glycosides.

[0013] Preferably, the source of the phenylethanoid glycosides includes Cistanche.

[0014] Preferably, the phenylethanoid glycosides include verbascoside.

[0015] Compared with the prior art, the application has the following beneficial effects: (1) The application is based on reticular chemical design, and a nitrogen-rich triazine COF material is formed by self-assembly from bottom to top through a Schiff base reaction of 4,4',4''-(1,3,5-triazine ring-2,4,6-triyl) triphenyl formaldehyde (TFPT) and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TA) as building units, and the nitrogen-rich triazine COF material can solve the problems of low selectivity and poor stability existing in the prior separation technology; the nitrogen-rich triazine COF material has mild synthesis conditions, a controllable structure, and is easy to functionalize. In the preparation process of the nitrogen-rich triazine COF material, the difference in the number of triazine rings in the ligand significantly affects the material properties: when the ligand contains one triazine ring, TA and TFPT react to form a spherical structure, and when there is no triazine ring, the structure is a sheet-shaped approximate spherical structure. The nitrogen-rich triazine COF material obtained by the application has a regular morphology, rich active sites, and good stability.

[0016] (2) The core advantage of the nitrogen-rich triazine COF material obtained by the application lies in the unique nitrogen-rich electronic structure of the triazine ring unit, which can interact with ACT molecules in multiple ways, thereby realizing high selectivity and high capacity adsorption separation. The specific mechanism includes: the nitrogen atoms in the triazine ring can form a stable multiple hydrogen bond network with multiple phenolic hydroxyl groups and glycoside hydroxyl groups in the ACT molecules, realizing specific binding similar to biological recognition; donor-acceptor type π-π stacking: strong donor-acceptor (D-A) interaction can occur between the electron-deficient triazine ring and the electron-rich benzene ring in ACT, further enhancing the adsorption capacity and selectivity; the triazine ring is connected by a high-bond-energy C=N covalent bond to form an aromatic skeleton, so that the COF material has excellent chemical stability, is resistant to acid, alkali and various organic solvents, and is suitable for complex extraction environments.

[0017] (3) The nitrogen-rich triazine COF material of the present invention has a maximum adsorption capacity of 256.27 ± 7.13 mg / g for ACT and a maximum selectivity coefficient of 7.43 ± 0.21, showing excellent separation performance. Therefore, the nitrogen-rich triazine COF material of the present invention has good application potential and industrialization prospects in the separation and purification of phenylethanol glycosides, especially verbascosides from Cistanche deserticola. Attached Figure Description

[0018] Figure 1 This is a transmission electron microscope (TEM) image of the nitrogen-rich triazine COF-1 prepared in Example 1 (scale bar is 1 μm).

[0019] Figure 2 This is a transmission electron microscope (TEM) image of the nitrogen-rich triazine COF-3 prepared in Comparative Example 1 (scale bar: 1 μm).

[0020] Figure 3 This is a transmission electron microscope (TEM) image of the non-triazine COF prepared in Comparative Example 3 (scale bar is 1 μm). Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited thereto. Experimental methods in the embodiments that do not specify specific conditions are performed under conventional conditions; reagents and materials used, unless otherwise specified, are commercially available.

[0022] Example 1: 0.2 mmol of 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde (TFPT) and 0.2 mmol of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TA) were added to a 25 mL solvent storage bottle. Then, 3.0 mL of 1,4-dioxane and 3.0 mL of mesitylene were added to obtain solution A. Solution A was then sonicated at room temperature for 5 min to obtain suspension B.

[0023] The solvent storage bottle containing suspension B was frozen in a liquid nitrogen bath, degassed by a pump for 5 minutes and circulated three times before being sealed. Then the solvent storage bottle was placed in a 120°C forced-air drying oven and sealed for 72 h. Subsequently, it was washed three times by centrifugation with N,N-dimethylacetamide, water and acetone and then dried in an 80°C vacuum drying oven for 12 h to obtain the nitrogen-rich triazine COF-1.

[0024] The transmission electron microscope image of the nitrogen-rich triazine COF-1 material is shown below. Figure 1 As shown, by Figure 1 It can be seen that the nitrogen-rich triazine COF-1 exhibits a hollow spherical cluster morphology.

[0025] This embodiment also conducts performance tests on the prepared nitrogen-rich triazine COF-1, and the test steps are as follows: The prepared nitrogen-rich triazine COF-1 was used for ACT / ECH adsorption selectivity testing. A mixed solution of ACT and ECH with a concentration of 0.5 mg / mL and 0.5 mg / mL was prepared in an Erlenmeyer flask, and 10 mg of nitrogen-rich triazine COF-1 material was added. The mixture was placed in a shaker (150 rpm) for adsorption for 24 h. After that, samples were taken and the amount of solute in the solution was measured by high performance liquid chromatography.

[0026] Test results showed that its ACT adsorption capacity was 256.27 mg / g and its selectivity was 7.43.

[0027] Example 2: 0.1 mmol of 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde (TFPT) and 0.1 mmol of 2,4,6-tris(4-aminophenyl)-1,3,5-triazine (TA) were added to a 25 mL solvent storage bottle. Then, 1.5 mL of 1,4-dioxane and 1.5 mL of mesitylene were added to obtain solution A. Solution A was then sonicated at room temperature for 5 min to obtain suspension B. The solvent storage bottle containing suspension B was frozen in a liquid nitrogen bath, degassed by a pump for 5 minutes and circulated three times before being sealed. Then the solvent storage bottle was placed in a 120°C forced-air drying oven and sealed for 72 h. Subsequently, it was washed three times by centrifugation with N,N-dimethylacetamide, water and acetone and then dried in an 80°C vacuum drying oven for 12 h to obtain the nitrogen-rich triazine COF-2.

[0028] This embodiment also conducts performance tests on the prepared nitrogen-rich triazine COF-2, and the test steps are as follows: (1) The prepared nitrogen-rich triazine COF-2 was used for ACT / ECH adsorption selectivity testing; (2) Prepare a mixed solution of ACT and ECH with a concentration of 0.5 mg / mL in an Erlenmeyer flask and add 10 mg of nitrogen-rich triazine COF-2 material. Place the flask in a shaker (150 rpm) for adsorption for 24 h. Then take a sample and measure the amount of solute in the solution using high performance liquid chromatography.

[0029] Test results showed that its ACT adsorption capacity was 245.16 mg / g and the selectivity was 7.05.

[0030] Comparative Example 1: 0.2 mmol of 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde (TFPT) and 0.2 mmol of 1,3,5-tris(4-aminophenyl)benzene (TP) were added to a 25 mL solvent storage bottle. Then, 3.0 mL of 1,4-dioxane and 3.0 mL of mesitylene were added to obtain solution A. Solution A was then sonicated at room temperature for 5 min to obtain suspension B. The solvent storage bottle containing suspension B was frozen in a liquid nitrogen bath, degassed by a pump for 5 minutes and circulated three times before being sealed. Then the solvent storage bottle was placed in a 120°C forced-air drying oven and sealed for 72 h. Subsequently, it was washed three times by centrifugation with N,N-dimethylacetamide, water and acetone and then dried in an 80°C vacuum drying oven for 12 h to obtain the nitrogen-rich triazine COF-3.

[0031] The transmission electron microscope image of the nitrogen-rich triazine COF-3 material is shown below. Figure 2 As shown, by Figure 2 It can be seen that the nitrogen-rich triazine COF-3 exhibits a solid spherical cluster morphology.

[0032] This embodiment also conducts performance tests on the prepared nitrogen-rich triazine COF-3. The test steps are as follows: (1) The prepared nitrogen-rich triazine COF-3 was used for ACT / ECH adsorption selectivity testing; (2) Prepare a mixed solution of ACT and ECH with a concentration of 0.5 mg / mL in an Erlenmeyer flask and add 10 mg of nitrogen-rich triazine COF-3 material. Place the flask in a shaker (150 rpm) for adsorption for 24 h. Then take a sample and measure the amount of solute in the solution using high performance liquid chromatography.

[0033] The test results showed that its ACT adsorption capacity was 243.43 mg / g and the selectivity was 6.28. It can be seen that due to the change of the synthetic ligand, the morphology of the final COF material is different. After the morphology changed from hollow to solid, the adsorption performance and selectivity of the material decreased.

[0034] Comparative Example 2: 0.1 mmol of 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde (TFPT) and 0.1 mmol of 1,3,5-tris(4-aminophenyl)benzene (TP) were added to a 25 mL solvent storage bottle. Then, 1.5 mL of 1,4-dioxane and 1.5 mL of mesitylene were added to obtain solution A. Solution A was then sonicated at room temperature for 5 min to obtain suspension B. The solvent storage bottle containing suspension B was frozen in a liquid nitrogen bath, degassed by a pump for 5 minutes and circulated three times before being sealed. Then the solvent storage bottle was placed in a 120°C forced-air drying oven and sealed for 72 h. Subsequently, it was washed three times by centrifugation with N,N-dimethylacetamide, water and acetone and then dried in an 80°C vacuum drying oven for 12 h to obtain the nitrogen-rich triazine COF-4.

[0035] This embodiment also conducts performance tests on the prepared nitrogen-rich triazine COF-4, and the test steps are as follows: (1) The prepared nitrogen-rich triazine COF-4 was used for ACT / ECH adsorption selectivity testing; (2) Prepare a mixed solution of ACT and ECH with a concentration of 0.5 mg / mL in an Erlenmeyer flask and add 10 mg of nitrogen-rich triazine COF-4 material. Place the flask in a shaker (150 rpm) for adsorption for 24 h. Then take a sample and measure the amount of solute in the solution using high performance liquid chromatography.

[0036] Test results showed that its ACT adsorption capacity was 214.67 mg / g and its selectivity was 5.87.

[0037] Comparative Example 3: 0.2 mmol of 1,3,5-tris(4-formylphenyl)benzene (TFPB) and 0.2 mmol of 1,3,5-tris(4-aminophenyl)benzene (TP) were added to a 25 mL solvent storage bottle. Then, 3.0 mL of 1,4-dioxane and 3.0 mL of mesitylene were added to obtain solution A. Solution A was then sonicated at room temperature for 5 min to obtain suspension B.

[0038] The solvent storage bottle containing suspension B was frozen in a liquid nitrogen bath, degassed by a pump for 5 minutes and circulated three times before being sealed. Then the solvent storage bottle was placed in a 120°C forced-air drying oven and sealed for 72 h. Subsequently, it was washed three times by centrifugation with N,N-dimethylacetamide, water and acetone and then dried in an 80°C vacuum drying oven for 12 h to obtain the non-triazine COF.

[0039] The transmission electron microscope image of the non-triazine COF material is shown below. Figure 1 As shown, by Figure 1 It can be seen that the non-triazine COFs exhibit a plate-like, approximately spherical, cluster-like morphology.

[0040] This embodiment also performs performance tests on the prepared non-triazine COF, and the test steps are as follows: (1) The prepared non-triazine COF was used for ACT / ECH adsorption selectivity testing; (2) Prepare a mixed solution of ACT and ECH with a concentration of 0.5 mg / mL in an Erlenmeyer flask and add 10 mg of non-triazine COF material. Place the flask in a shaker (150 rpm) for adsorption for 24 h. Then take a sample and measure the amount of solute in the solution using high performance liquid chromatography.

[0041] Test results showed that its ACT adsorption capacity was 224.63 mg / g and the selectivity was 5.12.

[0042] In summary, this invention provides a nitrogen-rich triazine COF material, its preparation method, and its application in the separation and purification of phenylethanoid glycosides. Based on network chemistry design, this invention uses TFPT and TA as building blocks to form a nitrogen-rich triazine ring structure through bottom-up self-assembly via Schiff base reaction. The COF material exhibits mild synthesis conditions, controllable structure, and ease of functionalization. Furthermore, the COF material can serve as an adsorbent and has excellent applications in the separation and purification of phenylethanoid glycosides.

[0043] The embodiments described above are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any obvious improvements, substitutions or modifications that can be made by those skilled in the art without departing from the essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for preparing a nitrogen-rich triazine-based COF material, characterized in that, include: 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine were mixed in a solvent and then sonicated to obtain a suspension. The suspension was frozen in a liquid nitrogen bath, degassed by a pump, and then sealed. It was then sealed and allowed to stand at a certain temperature, washed, and dried to obtain the nitrogen-rich triazine COF material.

2. The method for preparing nitrogen-rich triazine-based COF materials according to claim 1, characterized in that, The dosage relationship between 4,4',4''-(1,3,5-triazinecyclo-2,4,6-triyl)tribenzaldehyde and 2,4,6-tris(4-aminophenyl)-1,3,5-triazine is 0.01~0.4 mmol: 0.01~0.4 mmol.

3. The method for preparing nitrogen-rich triazine-based COF materials according to claim 1, characterized in that, The solvent comprises a mixture of 1,4-dioxane and mesitylene, wherein the volume ratio of 1,4-dioxane to mesitylene is 3.0 mL: 3.0 mL.

4. The method for preparing nitrogen-rich triazine-based COF materials according to claim 1, characterized in that, The ultrasonic treatment time is 5 to 20 minutes.

5. The method for preparing nitrogen-rich triazine-based COF materials according to claim 1, characterized in that, The pump degasses for 1 to 10 minutes.

6. The method for preparing nitrogen-rich triazine-based COF materials according to claim 1, characterized in that, The conditions for sealing and standing at a certain temperature are: sealing and standing at 70~200℃ for 10~96 h; The drying conditions are as follows: stand in a vacuum drying oven at 50~100℃ for 5~24 h.

7. The nitrogen-rich triazine COF material prepared by the preparation method according to any one of claims 1 to 6, wherein the nitrogen-rich triazine COF material has a regular hollow spherical cluster structure, has multi-level channels inside, uniform pore size distribution, and high specific surface area; the pore size of the nitrogen-rich triazine COF material is 3.04 nm, and the specific surface area is 1108.01 m2 / g.

8. The application of the nitrogen-rich triazine COF material according to claim 7 in the separation and purification of phenylethanol glycosides.

9. The application according to claim 8, characterized in that, The sources of the phenylethanol glycosides include Cistanche deserticola.

10. The application according to claim 8, characterized in that, The phenylethanol glycosides include verbascoside.

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