Chitosan functionalized microspheres, preparation method and application thereof

Abstract

The application provides a kind of chitosan functionalized microspheres and its preparation method and application, it is to different particle size polystyrene / divinylbenzene polymer microspheres PSDVB is added to 1,2-dichloroethane and is carried out swelling treatment;Then chloroacetyl chloride is added in the microspheres of swelling treatment, then add aluminium chloride AlCl3 and carry out reaction;After reaction, the microspheres are filtered, washed, and finally vacuum dried to obtain chloromethylated microspheres PSDVB-Cl;The prepared PSDVB-Cl is added to solvent, then chitosan and sodium bicarbonate are added to carry out reaction, and functionalized microspheres are prepared;The prepared functionalized microspheres are washed, vacuum dried to obtain chitosan functionalized microspheres.The prepared chitosan functionalized microspheres are used for adsorbing flavonoid compounds.The chitosan functionalized microspheres obtained by the application have simple preparation process, chitosan modification on the surface of microspheres enhances hydrogen bond effect, and enhances adsorption force for target molecule flavonoid compounds.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation and application of natural product separation materials, and particularly relates to chitosan functionalized microspheres and a preparation method and application thereof. Background Art

[0002] Flavonoids have antioxidant, antifungal, antiviral, anticancer and hypoglycemic properties, and have great medical potential in the treatment of cardiovascular diseases, cerebrovascular diseases, cancer, inflammation, etc. Traditional methods for enriching flavonoids mainly include solvent extraction, supercritical fluid extraction, microwave-assisted extraction, etc. However, most of these methods have problems such as being time-consuming, cumbersome, and having poor selectivity, resulting in separation difficulties and thus a waste of resources. PSDVB has the advantages of extremely strong chemical stability, heat resistance, acid and alkali resistance, adjustable pore size, controllable morphology, and diverse functional groups, and is widely used in the enrichment and separation of natural products and biomacromolecules. However, its adsorption selectivity and adsorption capacity for compounds are poor.

[0003] Chinese invention patent publication number CN112774643 A discloses a method for separating and extracting rutin using molecular imprinting technology. The method first prepares carboxyl-functionalized magnetic nanospheres; then, they are bound to a phenylboronic acid ligand, using rutin as a template molecule, to produce a carrier-template complex. Finally, they are mixed with the hydrophilic functional monomer polyethyleneimine to re-immobilize the template molecule rutin, resulting in a solid polymer. Finally, a series of treatments are performed to obtain the boronic acid-affinity rutin molecularly imprinted magnetic nanospheres. However, this method has a complex synthesis process, making it difficult to industrialize, resulting in a low adsorption capacity of only approximately 7.35 mg / g and high production costs. Chinese invention patent publication number CN113413884 A discloses a method for preparing flavonoid molecularly imprinted microspheres. The preparation method comprises: A) first, mixing amino-modified silica-based microspheres with a flavonoid compound; B) mixing the flavonoid-adsorbed microspheres with a solution of ethyl orthosilicate and acetic acid, and eluting the template molecule to produce the flavonoid molecularly imprinted microspheres. This method consumes a large amount of organic solvent, is prone to environmental pollution, and is not conducive to mass production. Chinese invention patent publication number CN 110835421 A discloses a flavonoid glycoside adsorption resin, which is prepared as follows: using a macroporous resin as a matrix, first using glycidyl methacrylate as a functional monomer, then grafting a long-chain polymer onto the surface of the macroporous resin, and finally opening the ring with 3-aminophenylboronic acid to introduce the organic long-chain polymer, ultimately obtaining the flavonoid glycoside adsorption resin APBA / pGMA / macroporous resin. This method has a complex synthesis route, consumes a lot of time, and is relatively costly. Summary of the Invention

[0004] The application provides a chitosan functionalized microsphere and a preparation method and application thereof.

[0005] The preparation method of the chitosan functionalized microsphere comprises the following steps:

[0006] 1) adding polystyrene / divinylbenzene polymer microspheres PSDVB with different particle sizes into 1,2-dichloroethane for swelling treatment;

[0007] The PSDVB with different particle sizes is PSDVB microspheres with a particle size of 5-100 μm.

[0008] 2) adding chloroacetyl chloride into the microspheres subjected to the swelling treatment in 1), and then adding aluminum trichloride AlCl3 for reaction; after the reaction is completed, the microspheres are filtered, and are washed with water and ethanol for several times until no precipitate is generated when AgNO3 solution is added, and finally vacuum drying to obtain chloromethylated microspheres PSDVB-Cl;

[0009] The mass ratio of the chloroacetyl chloride to the PSDVB is 0.1-5:1, and the mass ratio of the AlCl3 to the PSDVB is 0.1-5:1.

[0010] The reaction is performed at a reaction time of 5-24 h and a reaction temperature of 30-80 ℃, and the stirring speed is 80-200 rpm.

[0011] 3) adding the PSDVB-Cl prepared in step 2) into a solvent, and then adding chitosan and sodium bicarbonate for reaction to prepare functionalized microspheres; after the prepared functionalized microspheres are washed, vacuum drying obtains the chitosan functionalized microspheres PSDVB-CS;

[0012] The mass ratio of the chloromethylated microspheres PSDVB-Cl to the solvent and the chitosan is 1:10-60:0.1-1.

[0013] The solvent is dichloroethane, ethanol, methanol or N,N-dimethylformamide aqueous solution in different proportions.

[0014] The washing of the prepared functionalized microspheres is washing the obtained microspheres with 0.1% hydrochloric acid aqueous solution, distilled water and ethanol.

[0015] The vacuum drying is vacuum drying at 60 ℃.

[0016] The prepared chitosan functionalized microspheres are used for adsorbing flavonoid compounds such as rutin and quercetin.

[0017] Compared with the prior art, the application has the following advantages:

[0018] 1. The preparation process of chitosan-functionalized PSDVB microspheres is simple and easy to operate. Chitosan modification on the surface of the microspheres enhances hydrogen bonding and the adsorption of PSDVB-CS on the target flavonoid compound.

[0019] 2. Chitosan functionalized microspheres can be regenerated and reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : XPS spectrum of chitosan functionalized microspheres;

[0021] Figure 2 : Nitrogen adsorption / desorption curve; DETAILED DESCRIPTION

[0022] The present invention is described in detail below through specific embodiments and drawings.

[0023] Example 1 Material Synthesis

[0024] (1) Weigh 15 g of 5 μm PSDVB into a three-necked round-bottom flask and add 300 mL of 1,2-dichloroethane to swell overnight;

[0025] (2) Weigh 30g of chloroacetyl chloride and add it to (1), then add 45g of AlCl3, and react at 40℃ for 12h. After the reaction, filter the microspheres, wash them with water and ethanol several times, respectively, until there is no precipitation when adding AgNO3 solution, and finally dry them in vacuum to obtain chloromethylated microspheres, namely PSDVB-Cl;

[0026] (3) 4 g of PSDVB-Cl was added to a three-necked round-bottom flask, and 100 mL of 1,2-dichloroethane was added to swell overnight. 2 g of chitosan and 0.5 g of sodium bicarbonate were added, and the mixture was reacted at 60 °C for 12 h. After the reaction, the filtrate was discarded, and the obtained microspheres were repeatedly washed with 0.1% HCl aqueous solution, distilled water and ethanol, and finally dried in vacuum at 60 °C for 12 h to obtain chitosan-functionalized microspheres PSDVB-CS.

[0027] Through XPS spectrum ( Figure 1 ) shows that there is nitrogen on the resin, indicating that chitosan is successfully modified. The nitrogen adsorption / desorption spectrum ( Figure 2 ) indicates that there is almost no effect on the specific surface area before and after modification;

[0028] Example 2 Material Synthesis

[0029] (1) Weigh 15 g of 10 μm PSDVB into a three-necked round-bottom flask and add 300 mL of 1,2-dichloromethane to swell overnight;

[0030] (2) Weigh 30 g of chloroacetyl chloride into (1), and then add 45 g of AICI3. React at 40 °C for 12 h. After the reaction is completed, filter the microspheres, and then wash them with water, ethanol, and so on until no precipitate is formed when AgN03 solution is added. Finally, dry the microspheres under vacuum to obtain chloromethylated microspheres, i.e., PSDVB-Cl.

[0031] (3) Weigh 4 g of PSDVB-Cl into a three-necked round-bottom flask, and then add 100 mL of 1,2-dichloromethane to swell overnight. Add 2 g of chitosan and 0.5 g of sodium bicarbonate, and then react at 60 °C for 12 h. After the reaction is completed, discard the filtrate, and then wash the obtained microspheres with 0.1% HC1 aqueous solution, distilled water, and ethanol. Finally, dry the microspheres under vacuum at 60 °C for 12 h to obtain chitosan functionalized microspheres, i.e., PSDVB-CS.

[0032] Example 3 Material Synthesis

[0033] (1) Weigh 15 g of 20 μm PSDVB into a three-necked round-bottom flask, and then add 300 mL of 1,2-dichloromethane to swell overnight.

[0034] (2) Weigh 30 g of chloroacetyl chloride into (1), and then add 45 g of AICI3. React at 40 °C for 12 h. After the reaction is completed, filter the microspheres, and then wash them with water, ethanol, and so on until no precipitate is formed when AgN03 solution is added. Finally, dry the microspheres under vacuum to obtain chloromethylated microspheres, i.e., PSDVB-Cl.

[0035] (3) Weigh 4 g of PSDVB-Cl into a three-necked round-bottom flask, and then add 100 mL of 1,2-dichloromethane to swell overnight. Add 2 g of chitosan and 0.5 g of sodium bicarbonate, and then react at 60 °C for 12 h. After the reaction is completed, discard the filtrate, and then wash the obtained microspheres with 0.1% HC1 aqueous solution, distilled water, and ethanol. Finally, dry the microspheres under vacuum at 60 °C for 12 h to obtain chitosan functionalized microspheres, i.e., PSDVB-CS.

[0036] Example 4 Material Synthesis

[0037] (1) Weigh 15 g of 20 μm PSDVB into a three-necked round-bottom flask, and then add 300 mL of 1,2-dichloromethane to swell overnight.

[0038] (2) Weigh 30 g of chloroacetyl chloride into (1), and then add 45 g of AICI3. React at 40 °C for 12 h. After the reaction is completed, filter the microspheres, and then wash them with water, ethanol, and so on until no precipitate is formed when AgN03 solution is added. Finally, dry the microspheres under vacuum to obtain chloromethylated microspheres, i.e., PSDVB-Cl.

[0039] (3) 8 g of PSDVB-Cl was added to a three-necked round-bottom flask, and 200 mL of 1,2-dichloromethane was added to swell overnight. 4 g of chitosan and 1 g of sodium bicarbonate were added, and the reaction was carried out at 60 °C for 12 h. After the reaction, the filtrate was discarded, and the obtained microspheres were repeatedly washed with 0.1% HCl aqueous solution, distilled water and ethanol, and finally dried in vacuum at 60 °C for 12 h to obtain chitosan-functionalized microspheres PSDVB-CS.

[0040] Example 5 Adsorption experiment

[0041] The prepared PSDVB-CS with different particle sizes were used to adsorb flavonoids such as rutin and quercetin. The compounds rutin and quercetin were prepared to a concentration of 0.2 mg·mL -1 20 mg of PSDVB-CS material of different particle sizes was accurately weighed and placed in a 100 mL conical flask. The adsorption was allowed to proceed in a constant temperature shaker (298.15 K, 125 rpm) for 6 hours to allow the resin to reach adsorption equilibrium. The concentration of the adsorbed residual solution was determined by HPLC, and the adsorption amount and adsorption rate were calculated (Table 1).

[0042] Table 1: Adsorption capacity of flavonoids by PSDVB-CS with different particle sizes

[0043] Example 1 Example 2 Example 3 Example 4 Adsorption capacity (quercetin) 30mg / g 28mg / g 31mg / g 34mg / g Adsorption rate (quercetin) 28％ 24.5％ 30.2％ 31.8％ Adsorption capacity (rutin) 132mg / g 135mg / g 138mg / g 139mg / g Adsorption rate (rutin) 78.5％ 74.3％ 79.2％ 80.1％

[0044] The results show that the chitosan functionalized microspheres PSDVB-CS prepared in the present invention have a high adsorption capacity for flavonoids.

Claims

1. A chitosan functionalized microsphere, characterized in that: The preparation method of chitosan functionalized microspheres comprises the following steps: 1) Polystyrene / divinylbenzene polymer microspheres (PSDVB) of different particle sizes were added to 1,2-dichloroethane for swelling treatment; 2) adding chloroacetyl chloride to the swollen microspheres treated in 1) and then adding aluminum chloride (AlCl3) to react; after the reaction, filtering the microspheres, washing them several times with water and ethanol respectively until no precipitation is produced by adding AgNO3 solution, and finally vacuum drying to obtain chloromethylated microspheres PSDVB-Cl; the mass ratio of chloroacetyl chloride to PSDVB is 0.1-5:1; the mass ratio of AlCl3 to PSDVB is 0.1-5:1; 3) adding the PSDVB-Cl prepared in step 2) to a solvent, and then adding chitosan and sodium bicarbonate to react to obtain functionalized microspheres; washing the prepared functionalized microspheres, and vacuum drying to obtain chitosan functionalized microspheres PSDVB-CS; The mass ratio of the chloromethylated microspheres PSDVB-Cl to the solvent and chitosan is 1:10~60:0.1~1; The washing step is to wash the obtained microspheres with 0.1% HCl aqueous solution, distilled water and ethanol.

2. The chitosan functionalized microspheres according to claim 1, wherein The particle size of the polymer microspheres PSDVB is 5-100 μm.

3. The chitosan functionalized microspheres according to claim 1, wherein In the step 2), the reaction time is 5-24 h, the reaction temperature is 30-80° C., and the stirring speed is 80-200 rpm.

4. The chitosan functionalized microspheres according to claim 1, wherein The vacuum drying described in 3) is vacuum drying at 60°C.

5. Use of the chitosan functionalized microspheres according to claim 1 in adsorbing flavonoids.

6. A method for adsorbing flavonoids, characterized in that: The method is to use the chitosan functionalized microspheres described in claim 1 to adsorb flavonoids.

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