Nanocellulose molecularly imprinted aerogel for targeted separation of paclitaxel and preparation method and application thereof

Abstract

The application belongs to the technical field of imprint adsorption materials, and particularly relates to a nanocellulose molecular imprinting aerogel for targeted separation of paclitaxel, and a preparation method and application thereof. The preparation method comprises the following steps: mixing defatted cotton and sulfuric acid, and performing acidolysis to obtain nanocellulose; mixing a sodium alginate solution, a nanocellulose solution and an inorganic calcium salt solution, and performing crosslinking and drying to obtain nanocellulose aerogel; mixing 3-(methacryloyloxy)propyl trimethoxysilane, anhydrous ethanol, glacial acetic acid and nanocellulose aerogel, and performing silanization reaction to obtain silanized nanocellulose aerogel; mixing paclitaxel, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and the silanized nanocellulose aerogel, and then performing polymerization reaction, and then removing a template to obtain the nanocellulose molecular imprinting aerogel. The preparation method is simple, and has high targeting for paclitaxel.

Description

Technical Field

[0001] This invention belongs to the field of imprinted adsorption materials technology, specifically relating to a nanocellulose molecularly imprinted aerogel for targeted separation of baccatin III, its preparation method, and its application. Background Technology

[0002] Baccatin III is an important natural product with a 6 / 8 / 6 skeleton in taxanes, possessing certain antitumor activity. It is a precursor for the semi-synthetic production of the anticancer drug paclitaxel and is widely considered an inactive derivative of paclitaxel. For a long time, the global medical and pharmaceutical fields have had a significant demand for taxanes. However, yew plants grow slowly, and paclitaxel has a complex structure, resulting in extremely low concentrations in plants (0.1 g / kg). Therefore, the efficient isolation and development of paclitaxel semi-synthetic precursors (baccatin III) is currently one of the necessary ways to address the paclitaxel shortage.

[0003] In existing technologies, Baccatin III is mostly separated and enriched through methods such as cell suspension culture (CN105524954A), solid phase extraction (CN1670018A), combined forward and reverse chromatography (CN1442413A), and adsorption using carbon fiber materials (CN106008407A). These processes are complex, cumbersome, and expensive. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a nanocellulose molecularly imprinted aerogel for targeted separation of baccatin III, its preparation method, and its application. The preparation method provided by this invention is simple and exhibits high targeting specificity for baccatin III.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing nanofiber cellulose molecularly imprinted aerogels for targeted separation of baccatin III, comprising the following steps:

[0007] Defatted cotton and sulfuric acid were mixed and acid-hydrolyzed to obtain nanocellulose;

[0008] An aqueous solution of sodium alginate and a solution of nanocellulose were mixed, and the resulting mixture was then mixed with an inorganic calcium salt solution. The mixture was then cross-linked and dried sequentially to obtain nanocellulose aerogel.

[0009] 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol, glacial acetic acid and nanocellulose aerogel were mixed and silanized to obtain silanized nanocellulose aerogel.

[0010] Bacartin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and the silanized nanocellulose aerogel were mixed and polymerized under a protective atmosphere. The resulting product was then subjected to template removal to obtain the nanocellulose molecularly imprinted aerogel.

[0011] Preferably, the sulfuric acid has a mass concentration of 55-65%.

[0012] Preferably, the mass concentration of the aqueous solution of sodium alginate is 1-3%, and the mass concentration of the solution of nanocellulose is 1-3%; the mass ratio of sodium alginate to nanocellulose in the mixed system is 2:0.5-2.

[0013] Preferably, the aqueous solution of sodium alginate and the solution of nanocellulose are mixed at a temperature of 40–60°C for a time of 0.8–1.2 h.

[0014] Preferably, the inorganic calcium salt solution includes a CaCl2 solution; the mass concentration of the inorganic calcium salt solution is 1-5%; and the mass-to-volume ratio of the mixed system to the inorganic calcium salt solution is 0.5-1.5g:5-15mL.

[0015] Preferably, the molar ratio of baccatin III to acrylamide is 1:15-25; and the molar ratio of baccatin III to trimethylolpropane trimethacrylate is 1:80-100.

[0016] Preferably, the mass ratio of the baccatiten III to the silanized nanocellulose aerogel is 1:20-25.

[0017] Preferably, the polymerization reaction is carried out at a temperature of 55–65°C for a duration of 22–26 hours.

[0018] This invention also provides a nanocellulose molecularly imprinted aerogel prepared by the above-described preparation method, wherein the specific surface area of ​​the nanocellulose molecularly imprinted aerogel is 4.5–5 m². 2 / g.

[0019] This invention also provides the application of the above-described nanocellulose molecularly imprinted aerogel as a targeted adsorption material in the enrichment of Bacardiin III.

[0020] This invention provides a method for preparing nanocellulose molecularly imprinted aerogels for targeted separation of baccatin III, comprising the following steps: mixing defatted cotton and sulfuric acid for acid hydrolysis to obtain nanocellulose; mixing an aqueous solution of sodium alginate and a solution of nanocellulose, then mixing the resulting mixture with an inorganic calcium salt solution, and sequentially performing crosslinking and drying to obtain nanocellulose aerogels; mixing 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol, glacial acetic acid, and the nanocellulose aerogels for silanization to obtain silanized nanocellulose aerogels; mixing baccatin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate, and the silanized nanocellulose aerogels, and performing a polymerization reaction under a protective atmosphere, followed by template removal of the resulting product to obtain the nanocellulose molecularly imprinted aerogels. This invention further utilizes the combination of sodium alginate and nanocellulose with Ca... 2+ Cross-linking, sodium alginate is a polyanionic polysaccharide salt that cross-links with Ca... 2+ Cross-linking was performed to combine the abundant hydroxyl groups on the nanocellulose to prepare nanocellulose aerogels. Then, 3-(methacryloyloxy)propyltrimethoxysilane was used to graft and modify the nanocellulose aerogels via silicon-oxygen bonds, resulting in silanized nanocellulose aerogels (imprinted carrier materials). Subsequently, using baccatin III as a template molecule and acrylamide as a functional monomer, polymerization was carried out on the surface of the silanized nanocellulose aerogels under the initiation of trimethylolpropane trimethacrylate and an initiator. The three-dimensional network structure of the nanocellulose aerogels, with its excellent support and large specific surface area, provided a foundation for the construction of specific targeting sites. Then, by removing the template molecule, numerous cavities with the same structure as baccatin III were formed, resulting in nanocellulose molecularly imprinted aerogels with high targeting functionality for baccatin III. Attached Figure Description

[0021] Figure 1 This is a scanning electron microscope image of the nanocellulose molecularly imprinted aerogel prepared in Example 1;

[0022] Figure 2 These are infrared spectroscopy results for nanocellulose (NC), sodium alginate (SA), nanocellulose aerogel (NCAG), silanized nanocellulose aerogel (NCAG-Si), nanocellulose molecularly imprinted aerogel (NCAG-BacMIP) prepared in Example 1, and non-molecularly imprinted aerogel (NCAG-BacNIP) prepared in Comparative Example 1.

[0023] Figure 3 The diagram shows the kinetic model analysis of the adsorption of Baccatin III by the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1.

[0024] Figure 4 The isothermal adsorption model analysis diagram of Bacardiin III adsorption on the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1 is shown.

[0025] Figure 5 The images show the selective adsorption of four taxane compounds by the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1.

[0026] Figure 6 This is a liquid chromatography analysis of the aerogels prepared in Example 1 and Comparative Example 1 as targeted adsorption materials in the enrichment of Baccatin III. Detailed Implementation

[0027] This invention provides a method for preparing nanofiber cellulose molecularly imprinted aerogels for targeted separation of baccatin III, comprising the following steps:

[0028] Defatted cotton and sulfuric acid were mixed and acid-hydrolyzed to obtain nanocellulose;

[0029] An aqueous solution of sodium alginate and a solution of nanocellulose were mixed, and the resulting mixture was then mixed with an inorganic calcium salt solution. The mixture was then cross-linked and dried sequentially to obtain nanocellulose aerogel.

[0030] 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol, glacial acetic acid and nanocellulose aerogel were mixed and silanized to obtain silanized nanocellulose aerogel.

[0031] Bacartin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and the silanized nanocellulose aerogel were mixed and polymerized under a protective atmosphere. The resulting product was then subjected to template removal to obtain the nanocellulose molecularly imprinted aerogel.

[0032] This invention involves mixing defatted cotton and sulfuric acid, followed by acid hydrolysis to obtain nanocellulose.

[0033] In this invention, the mass concentration of the sulfuric acid is preferably 55-65%, more preferably 62-64%. In this invention, the mass ratio of the degreased cotton to the volume of the sulfuric acid is 5-7 g: 100-200 mL, more preferably 6 g: 150 mL.

[0034] In this invention, prior to acid hydrolysis, it is preferable to further grind the degreased cotton. In this invention, the ground degreased cotton is in powder form. In this invention, the grinding is preferably performed to a particle size of <1 mm.

[0035] In this invention, the acid hydrolysis temperature is preferably 40-50°C, more preferably 40-45°C, and the time is preferably 2.5-3.5 h, more preferably 3 h.

[0036] In this invention, after acid hydrolysis, the precipitate obtained by acid hydrolysis is preferably further subjected to impurity removal, dialysis and drying in sequence.

[0037] In this invention, the preferred method for impurity removal is centrifugation, which removes impurities and acidic water from the upper layer. In this invention, dialysis thoroughly removes excess acid and small molecule impurities. In this invention, the preferred drying method is freeze-drying; the specific operation of freeze-drying is not limited, and any operation well-known in the art can be used.

[0038] In this invention, the particle size of the obtained nanocellulose after drying is preferably <100nm.

[0039] After obtaining nanocellulose, the present invention mixes an aqueous solution of sodium alginate and a solution of nanocellulose, and then mixes the resulting mixture with an inorganic calcium salt solution, and performs cross-linking and drying in sequence to obtain nanocellulose aerogel.

[0040] In this invention, the mass concentration of the sodium alginate aqueous solution is preferably 1-3 wt%, more preferably 2 wt%. In this invention, the mass concentration of the nanocellulose solution is preferably 1-3 wt%, more preferably 2 wt%. In this invention, the mass ratio of sodium alginate to nanocellulose is preferably 2:0.5-2, more preferably 2:1-1.5. In this invention, the mixing temperature of the sodium alginate aqueous solution and the nanocellulose solution is preferably 40-60°C, more preferably 45-55°C, and the mixing time is preferably 40-80 min, more preferably 60 min.

[0041] In this invention, the inorganic calcium salt solution preferably includes a CaCl2 solution. The mass concentration of the inorganic calcium salt solution is preferably 1-5%, more preferably 2-4%. In this invention, the mass ratio of the sodium alginate / cellulose composite gel to the volume ratio of the inorganic calcium salt solution is 0.5-1.5 g: 5-15 mL, more preferably 1 g: 10 mL.

[0042] In this invention, the crosslinking temperature is preferably room temperature, and the time is preferably 8–12 hours, more preferably 10 hours. In this invention, the drying is preferably freeze-drying, and the freeze-drying temperature is preferably -80°C, and the time is preferably 24 hours.

[0043] After obtaining the nanocellulose aerogel, the present invention mixes 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol, glacial acetic acid and nanocellulose aerogel, and carries out a silanization reaction to obtain silanized nanocellulose aerogel.

[0044] In this invention, the volume ratio of anhydrous ethanol to glacial acetic acid is preferably 3:0.5-1.5, more preferably 3:1.0. In this invention, the volume ratio of 3-(methacryloyloxy)propyltrimethoxysilane to anhydrous ethanol is preferably 2-4:8-12, more preferably 3:10. In this invention, the temperature of the hydrolysis reaction is preferably 55-65°C, more preferably 58-62°C; the time is preferably 0.8-1.2 h, more preferably 1 h.

[0045] In this invention, the mixing is preferably a first mixing of 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol and glacial acetic acid, followed by a second mixing with nanocellulose aerogel.

[0046] In this invention, the temperature of the silanization reaction is preferably 55-65°C, more preferably 58-62°C; the time is preferably 2-4 hours, more preferably 3 hours.

[0047] In this issuance, after the silanization reaction, it is preferable to further wash the product of the silanization reaction, preferably with methanol as the washing reagent, and preferably with washing until neutral.

[0048] After obtaining the silanized nanocellulose aerogel, the present invention mixes bacartin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and the silanized nanocellulose aerogel, and carries out a polymerization reaction under a protective atmosphere. The resulting product is then subjected to template removal to obtain the nanocellulose molecularly imprinted aerogel.

[0049] In this invention, the molar ratio of baccatin III to acrylamide is preferably 1:15-25, more preferably 1:20. In this invention, the molar ratio of baccatin III to trimethylolpropane trimethacrylate is preferably 1:80-100, more preferably 1:90. In this invention, the mass ratio of baccatin III to silanized nanocellulose aerogel is 1:20-25, more preferably 1:25. In this invention, the molar ratio of acrylamide to azobisisobutyronitrile is preferably 1:120.

[0050] In this invention, baccatin III and acrylamide are preferably used as a mixture of baccatin III and acrylamide solutions. In this invention, methanol is preferably used as the solvent for both the baccatin III solution and the acrylamide solution.

[0051] In this invention, the preferred method for mixing the baccatin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and silanized nanocellulose aerogel is to dissolve the baccatin III and acrylamide in methanol, and then mix the resulting solution with the azobisisobutyronitrile, trimethylolpropane trimethacrylate and silanized nanocellulose aerogel.

[0052] In this invention, the mass concentration of baccatin III in the solution is preferably 0.4–0.6 mg / mL, more preferably 0.5 mg / mL. In this invention, the dissolution is preferably carried out under stirring conditions, and the stirring speed is preferably 20–40 rpm, more preferably 30 rpm.

[0053] In this invention, the protective atmosphere is preferably nitrogen. In this invention, the polymerization reaction temperature is preferably 55–65°C, more preferably 58–62°C; the reaction time is preferably 22–26 h, more preferably 25 h.

[0054] In this invention, the template removal is preferably performed by mixing the product obtained from the polymerization reaction with a template removal solution to remove the template. In this invention, the template removal solution is preferably a methanol solution of acetic acid; the mass concentration of acetic acid in the methanol solution is preferably 8%. In this invention, the elution method is preferably ultrasonic elution.

[0055] In this issuance, after template removal, it is preferable to further wash the template-removed product, preferably with methanol as the washing reagent, and preferably with washing until neutral.

[0056] This invention first combines sodium alginate and nanocellulose. Sodium alginate, a polyanionic polysaccharide salt, is cross-linked with CaCl2 to bind to the abundant hydroxyl groups on nanocellulose, thus preparing a nanocellulose aerogel. The nanocellulose aerogel is then modified by silanizing agents through siloxane grafting, resulting in an imprinted carrier material. Combining surface molecular imprinting technology, bulk polymerization is employed using baccatin III as a template molecule and acrylamide as a functional monomer. The polymerization reaction occurs on the surface of the silanized nanocellulose aerogel under the cross-linking of trimethylolpropane trimethacrylate and initiation by azobisisobutyronitrile. The unique three-dimensional network structure of the nanocellulose aerogel provides excellent support and a large specific surface area, laying the foundation for the construction of specific targeting sites. The template molecule is removed using an eluent, forming numerous cavities. This results in a nanocellulose molecularly imprinted aerogel with the function of targeting and separating the taxane compound baccatin III.

[0057] This invention also provides a nanocellulose molecularly imprinted aerogel prepared by the aforementioned method, wherein the specific surface area of ​​the nanocellulose molecularly imprinted aerogel is preferably 4.5–5 m². 2 / g, more preferably 4.86m 2 / g.

[0058] The present invention also provides the application of the aforementioned nanocellulose molecularly imprinted aerogel as a targeted adsorption material in the enrichment of Bacardiin III.

[0059] To further illustrate the present invention, the following detailed description of the embodiments is provided in conjunction with the present invention, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0060] Example 1

[0061] Grind 6g of defatted cotton and add it to 100mL of 64wt% H2SO4. Hydrolyze the mixture at 45℃ for 3h, and stop the reaction with 2L of deionized water. After precipitation, centrifuge several times to remove the supernatant acidic water, dialyze to neutral, and freeze-dry to obtain nanocellulose.

[0062] 3g of sodium alginate and 1.5g of nanocellulose were dissolved separately. Then, the aqueous solution of sodium alginate (2wt%) and the nanocellulose solution (2wt%) were mixed at 50℃ for 1h. 150mL of the resulting mixture was poured into a 3wt% CaCl2 solution and left to stand overnight (12h) for crosslinking. The crosslinked product was then washed (until neutral) and freeze-dried (at -80℃ for 24h) to obtain nanocellulose aerogel.

[0063] 9 mL of 3-(methacryloyloxy)propyltrimethoxysilane was placed in a mixed solution of 120 mL of anhydrous ethanol and glacial acetic acid (volume ratio of anhydrous ethanol to glacial acetic acid was 3:1). Then, 6 g of nanocellulose aerogel was added to the solution and stirred for 3 h for silanization reaction. The product was then washed until neutral to obtain silanized nanocellulose aerogel.

[0064] 0.025 mmol of baccatin III and 0.5 mmol of acrylamide were dissolved in 30 mL of methanol and reacted with stirring at room temperature for 8 h. 10 mg of azobisisobutyronitrile, 1.5 mmol of trimethylolpropane trimethacrylate, and 700 mg of silanized cellulose nanoparticles aerogel were added to the resulting solution. Polymerization was carried out at 60 °C under nitrogen protection for 24 h. After solid-liquid separation, the template molecules were removed with an 8 wt.% acetic acid methanol solution, and the mixture was washed until neutral to obtain the cellulose nanoparticle molecularly imprinted aerogel (NCAG-BacMIP).

[0065] Comparative Example 1

[0066] The only difference between Comparative Example 1 and Example 1 is that Baccatin III was not added, resulting in nanocellulose non-molecularly imprinted aerogel (NCAG-BacNIP).

[0067] Comparative Example 2

[0068] The only difference between Comparative Example 2 and Example 1 is that 64 wt% sulfuric acid was replaced with 40 wt% glacial acetic acid solution, and the nanocellulose molecularly imprinted aerogel with the function of targeted separation of Baccatin III was not obtained.

[0069] Comparative Example 3

[0070] The only difference between Comparative Example 3 and Example 1 is that the sodium alginate solution was replaced with chitosan solution, and the nanocellulose molecularly imprinted aerogel with the function of targeted separation of Baccatin III could not be obtained.

[0071] Comparative Example 4

[0072] The only difference between Comparative Example 4 and Example 1 is that acrylamide was replaced with polylactic acid. As a result, the nanocellulose molecularly imprinted aerogel with the function of targeted separation of Baccatin III was not obtained.

[0073] The present invention also performed scanning electron microscopy analysis on the nanocellulose molecularly imprinted aerogel prepared in Example 1, see [see details]. Figure 1 ,from Figure 1 It can be seen that the three-dimensional network structure of the nanocellulose molecularly imprinted aerogel is filled with molecularly imprinted polymers, indicating that the grafting was successful.

[0074] Figure 2 Infrared spectroscopy images of cellulose nanoparticles (NC), sodium alginate (SA), cellulose nanoparticle aerogel (NCAG), silanized cellulose nanoparticle aerogel (NCAG-Si), the cellulose nanoparticle molecularly imprinted aerogel prepared in Example 1 (NCAG-BacMIP), and the non-molecularly imprinted aerogel prepared in Comparative Example 1 (NCAG-BacNIP) are shown. Figure 2 It can be seen that each material is at 3441cm -1 A broad and strong absorption peak is observed at and near wavelengths, which is caused by the stretching vibration of -OH groups in the material. This confirms that the surfaces of nanocellulose (NC), sodium alginate (SA), nanocellulose aerogel (NCAG), silanized nanocellulose aerogel (NCAG-Si), the prepared nanocellulose molecularly imprinted aerogel (NCAG-BacMIP), and nanocellulose non-molecularly imprinted aerogel (NCAG-BacNIP) contain a large number of -OH groups. At 1614 cm⁻¹... -1 and 1409cm -1 These represent the -COO- asymmetric vibrational peak and the -COO- symmetric stretching vibrational peak of sodium alginate, respectively. In the NC spectrum, at 2850 cm⁻¹... -1 It is a CH stretching vibration, 1629 cm. -1and 1430cm -1 These are the -COOH asymmetric stretching vibration and the -COOH symmetric stretching vibration, respectively. The movement of -OH groups in the nanocellulose aerogel indicates the presence of strong intermolecular forces (hydrogen bonds). After silanization, the [value] is 2931 cm⁻¹. -1 2853cm -1 This can be attributed to the symmetric and asymmetric stretching vibrations of -CH2 in the two silane coupling agents. 1056 cm⁻¹ -1 and 1172cm -1 The Si-O-Si and Si-OC absorption bands overlap with the strong COC vibrational bands in cellulose nanocrystals, making them difficult to detect. This is evident in the molecularly imprinted and non-imprinted cellulose nanogels with targeted separation capabilities for the taxane compound baccatin III, at a depth of 1729 cm⁻¹. -1 The vibrational band at the C=O stretching point confirms the presence of C=O groups and the successful grafting of molecularly imprinted polymers onto the surface of silanized cellulose nanogels. (1620 cm⁻¹) -1 It is an NH stretching vibration. 1268cm -1 The characteristic peaks indicate the successful preparation of nanocellulose molecularly imprinted aerogels and non-imprinted molecularly imprinted aerogels capable of targeting the separation of taxane compounds such as baccatin III.

[0075] Figure 3 The diagram shows the kinetic model analysis of the adsorption of Baccatin III by the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1. It shows that the pseudo-second-order kinetics is more suitable for explaining the adsorption process of Baccatin III by the nanocellulose molecularly imprinted aerogel, indicating that this adsorption is a chemical process and the adsorption capacity is proportional to the number of active sites on the adsorbent.

[0076] Figure 4 These are isothermal adsorption model analysis diagrams of Baccatin III adsorption on the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1. Figure 4 It can be seen that the nanocellulose molecularly imprinted aerogel conforms to the Langmuir model, and its adsorption process is a monolayer and easy to carry out.

[0077] Figure 5 This is a selective adsorption diagram of four taxane compounds for the nanocellulose molecularly imprinted aerogel prepared in Example 1 and the nanocellulose non-molecularly imprinted aerogel prepared in Comparative Example 1. The adsorption experiment was conducted by placing 50 mg of nanocellulose molecularly imprinted aerogel or nanocellulose non-molecularly imprinted aerogel in a 0.15 mg / mL container. -1The adsorption of taxane compounds in a mixed solution was carried out in a shaker for 4 hours. The adsorption results are shown below. Figure 5 ,from Figure 5 It can be seen that the nanocellulose molecularly imprinted aerogel provided by the present invention has extremely strong targeted adsorption capacity for baccatin III (Bac III in the figure) and a very large adsorption amount. Moreover, the imprinting factor (IF) shows that the nanocellulose molecularly imprinted aerogel provided by the present invention has excellent specific adsorption effect on baccatin III.

[0078] The present invention also tested the performance of the aerogels prepared in Example 1 and Comparative Example 1 as targeted adsorbents for enriching baccatin III in Taxus chinensis. Figure 6 This is a liquid chromatography analysis chromatogram of the aerogels prepared in Example 1 and Comparative Example 1 as targeted adsorption materials in the enrichment of Baccatin III. The test method is as follows:

[0079] (1) Targeted enrichment of baccatin III in Taxus chinensis

[0080] 10g of Taxus chinensis powder was ground into powder using a grinder and added to 60mL of ethyl acetate-acetone (1:1, v:v) solution. The mixture was extracted using an ultrasonic extractor for 30min. This process was repeated three times. The extracts were combined and concentrated by rotary evaporation to obtain crude Bacartin III extract.

[0081] The crude extract of Bacardiin III was dissolved in methanol, and the supernatant was taken for testing.

[0082] (2) Enrichment

[0083] 50 mg of the nanocellulose molecularly imprinted aerogel prepared in Example 1 was added to a 4 mL sample vial containing crude baccatin III extract (supernatant). The vial was placed in a stable temperature shaker at 30 °C for 1440 min for adsorption, and then removed. The concentration of baccatin III before and after adsorption was determined by high performance liquid chromatography.

[0084] Control: Nanocellulose non-molecularly imprinted aerogel (NCAG-BacNIP) was used as a control.

[0085] The content of Bacartin III is calculated using this formula.

[0086] Content = (C × V) / m × 100%

[0087] C represents the concentration of baccatin III in the crude extract of Taxus chinensis.

[0088] V is the volume of the desorption solution of Taxus chinensis.

[0089] m represents the mass of the nanocellulose molecularly imprinted aerogel.

[0090] Table 1 Mass content of Bacartin III in different solutions

[0091]

[0092] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A method for preparing a nanocellulose molecularly imprinted aerogel for targeted separation of baccatin III, comprising the following steps: Defatted cotton and sulfuric acid were mixed and acid-hydrolyzed to obtain nanocellulose; An aqueous solution of sodium alginate and a solution of nanocellulose were mixed, and the resulting mixture was then mixed with an inorganic calcium salt solution. The mixture was then cross-linked and dried sequentially to obtain nanocellulose aerogel. 3-(methacryloyloxy)propyltrimethoxysilane, anhydrous ethanol, glacial acetic acid and nanocellulose aerogel were mixed and silanized to obtain silanized nanocellulose aerogel. Bacartin III, acrylamide, azobisisobutyronitrile, trimethylolpropane trimethacrylate and the silanized nanocellulose aerogel were mixed and polymerized under a protective atmosphere. The resulting product was then subjected to template removal to obtain the nanocellulose molecularly imprinted aerogel. The sodium alginate aqueous solution has a mass concentration of 1-3%, and the nanocellulose solution has a mass concentration of 1-3%; the mass ratio of sodium alginate to nanocellulose in the mixed system is 2:0.5-2. The mass ratio of Baccatin III to silanized nanocellulose aerogel is 1:20-25; The polymerization reaction is carried out at a temperature of 55–65°C for 22–26 hours.

2. The preparation method according to claim 1, characterized in that, The sulfuric acid has a mass concentration of 55-65%.

3. The preparation method according to claim 1, characterized in that, The aqueous solution of sodium alginate and the solution of nanocellulose are mixed at a temperature of 40–60°C for a time of 0.8–1.2 h.

4. The preparation method according to claim 1, characterized in that, The inorganic calcium salt solution includes a CaCl2 solution; the mass concentration of the inorganic calcium salt solution is 1-5%; the mass-volume ratio of the mixed system and the inorganic calcium salt solution is 0.5-1.5g:5-15mL.

5. The preparation method according to claim 1, characterized in that, The molar ratio of baccatin III to acrylamide is 1:15-25; the molar ratio of baccatin III to trimethylolpropane trimethacrylate is 1:80-100.

6. The nanocellulose molecularly imprinted aerogel prepared by the preparation method according to any one of claims 1 to 5, characterized in that, The specific surface area of ​​the nanocellulose molecularly imprinted aerogel is 4.5–5 m². 2 / g.

7. The application of the nanocellulose molecularly imprinted aerogel according to claim 6 as a targeted adsorption material in the enrichment of Bacardi III.

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