A hemicellulose-based antibacterial agent, and a preparation method and application thereof

Abstract

The application belongs to the field of biological medicine and fine chemicals, and particularly relates to a hemicellulose-based antibacterial agent and a preparation method and application thereof. The preparation method comprises: performing acetylation modification reaction on hemicellulose to obtain acetylated hemicellulose; dissolving the obtained acetylated hemicellulose in a solvent, adding aldehydes and a nitrogen source to perform Hantz reaction to obtain multi-component modified hemicellulose; dissolving the multi-component modified hemicellulose in a modified solvent system, adding an aminoglycoside antibiotic to perform enamine modification to obtain enamine modified hemicellulose. The aldehyde component and the nitrogen source are used to perform Hantz multi-component reaction modification on the acetylated hemicellulose, and modified hemicellulose with a substitution degree easy to control and suitable antibacterial properties is obtained. The enamine modified hemicellulose prepared through multi-component reaction modification has the advantages of good antibacterial property, suitable hydrophilicity and hydrophobicity, safety, simple preparation and low cost.

Description

Technical Field

[0001] This invention belongs to the field of biomedicine and fine chemicals, specifically relating to a hemicellulose-based antibacterial agent, its preparation method, and its application. Background Technology

[0002] In the field of antibacterial material development, many antibacterial agents on the market currently suffer from poor biocompatibility, poor biodegradability, and high toxicity. Therefore, the development of natural, green, and safe antibacterial agents is urgently needed. Hemicellulose is a widely available biomolecule with significant application potential in the field of antibacterial agents. First, hemicellulose mainly originates from agricultural waste (such as corn cobs, camellia fruit shells, and sugarcane bagasse) and forestry processing residues, making the raw materials abundant and extremely inexpensive. Second, hemicellulose itself is non-toxic, has good biocompatibility, and can completely degrade in the natural environment, overcoming the drawbacks of traditional metal ion antibacterial agents (such as nano-silver) that easily induce microbial resistance and potential environmental and ecological risks. Third, hemicellulose contains abundant functional groups such as carboxyl and acetyl groups, possessing certain antibacterial properties. However, the antibacterial performance of native hemicellulose is still relatively weak, making it difficult to apply in areas requiring high antibacterial performance. The abundant hydroxyl groups in the hemicellulose structure provide numerous modification sites.

[0003] Therefore, developing a novel antibacterial agent based on hemicellulose is of great scientific significance and application value for realizing the high-value utilization of hemicellulose and promoting the green upgrading of biomedical materials. Summary of the Invention

[0004] To address the shortcomings and deficiencies of existing technologies, the primary objective of this invention is to provide a method for preparing a hemicellulose-based antibacterial agent. This method involves modifying acetylated hemicellulose through a combination of multi-component cyclization and enaminering to obtain modified hemicellulose with easily controllable substitution degrees, suitable hydrophilic / hydrophobic properties, and safety.

[0005] Another object of the present invention is to provide a hemicellulose-based antibacterial agent prepared by the above preparation method.

[0006] Another object of the present invention is to provide the application of the above-mentioned hemicellulose-based antibacterial agent.

[0007] The objective of this invention is achieved through the following technical solution:

[0008] A method for preparing a hemicellulose-based antibacterial agent includes the following steps:

[0009] (1) Acetylation modification of hemicellulose yields acetylated hemicellulose;

[0010] (2) The obtained acetylated hemicellulose was dissolved in a solvent, and aldehydes and nitrogen sources were added to carry out the Hantz reaction to obtain multi-component modified hemicellulose;

[0011] (3) Dissolve the multi-component modified hemicellulose in a modified solvent system, add aminoglycoside antibiotics for enamine modification, and purify after the reaction to obtain enamine modified hemicellulose, i.e. the hemicellulose-based antibacterial agent.

[0012] Preferably, the raw material for hemicellulose in step (1) includes at least one of bagasse, corn cob, crop straw, rice husk and camellia fruit shell.

[0013] Preferably, in step (1), the acetylation reagent used for the acetylation modification reaction of hemicellulose is at least one of tert-butyl acetoacetate, methyl acetoacetate, ethyl acetoacetate, and diene.

[0014] Preferably, in step (1), when performing the acetylation modification reaction on hemicellulose, the hemicellulose is first dissolved in a solvent, wherein the solvent is at least one of acetate buffer, dimethyl sulfoxide, tetrahydrofuran, water, dimethylformamide (DMF) / lithium chloride system and ionic liquid.

[0015] More preferably, the temperature for dissolving hemicellulose is 60℃~80℃, and the time is 1~2 h.

[0016] Preferably, the conditions for the acetylation modification reaction of hemicellulose in step (1) are: temperature 110~130℃, reaction time 6~8 h, and molar ratio of hemicellulose to acetylation reagent between 1:20 and 1:7.

[0017] Preferably, after the acetylation modification reaction of hemicellulose in step (1), a purification reaction is also included, specifically: adjusting the pH of the solution to 6.5, adding at least one of ethanol (95 (v / v)% ethanol or anhydrous ethanol) in 3 to 6 times the volume of the reaction solution, centrifuging the precipitate, washing and freeze-drying to obtain acetylated hemicellulose.

[0018] Preferably, the solvent in step (2) is at least one of acetate buffer, dimethyl sulfoxide, tetrahydrofuran, water, dimethylformamide (DMF) / lithium chloride system and ionic liquid.

[0019] Preferably, the solid-liquid ratio of acetylated hemicellulose to solvent in step (2) is 1:50~1:25 (g:mL); the dissolution temperature is 60℃~90℃ and the time is 1 h~3 h.

[0020] Preferably, the aldehydes mentioned in step (2) are at least one of benzaldehyde, propionaldehyde, butyraldehyde, and dodecylaldehyde; and the nitrogen source is at least one of methylamine, ethylamine, and acetic acid.

[0021] Preferably, the molar ratio of acetylated hemicellulose, aldehyde component and nitrogen source component in the Hantz reaction in step (2) is 1:0.1:0.1 to 1:1:3, more preferably 1:0.1:0.1 to 1:0.5:0.5.

[0022] Preferably, the temperature of the Hantz reaction in step (2) is 60℃~80℃ and the reaction time is 5h~8h.

[0023] Preferably, after the Hantz reaction in step (2) is completed, a purification step is also included: after the reaction is completed, 3 to 6 times the volume of ethanol (at least one of 95 (v / v)% ethanol and anhydrous ethanol) is added to the reaction solution to precipitate, centrifuge, wash, freeze dry and grind to obtain multi-component modified hemicellulose.

[0024] Preferably, in step (3), the solid-liquid ratio of the multi-component modified hemicellulose and the modified solvent system is 1 g:10 mL to 1 g:100 mL, more preferably 1 g:30 mL to 1 g:50 mL; the modified solvent system is one of water, ethanol, or a mixture of water and ethanol.

[0025] Preferably, in step (3), the aminoglycoside antibiotic is one of kanamycin, gentamicin sulfate, or neomycin.

[0026] Preferably, in step (3), the aminoglycoside antibiotic is in excess relative to the multi-component modified hemicellulose, the enamidation modification reaction time is 24 h to 48 h, and the reaction temperature is 40 to 60 °C.

[0027] Preferably, the specific purification steps in step (3) are as follows: the reaction solution is transferred to a dialysis bag with a specification of 3500Da~5000Da, and the dialysis time is 3~5 days; after the dialysis is completed, the precipitate is centrifuged, freeze-dried and ground to obtain enamined modified hemicellulose.

[0028] The present invention also provides a hemicellulose-based antibacterial agent prepared by the above method.

[0029] The hemicellulose-based antibacterial agent described in this invention can be used as an antibacterial agent in fine chemicals, such as cosmetic additives, food packaging, and medical device coatings.

[0030] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0031] This invention introduces acetyl groups onto the hemicellulose backbone and utilizes the Hantz reaction to introduce long-chain alkyl aldehydes (such as dodecyl aldehyde), which not only modulates the hydrophobicity of hemicellulose and enhances its interaction with the cell membrane, but also provides new reaction sites for subsequent functionalization.

[0032] Enamine modification is an effective method for constructing chemical bonds through the condensation of amino and carbonyl groups. This invention uses this reaction to covalently bind amino-containing antibiotics (such as gentamicin sulfate) to a hemicellulose backbone modified by the Hantz reaction. This modification not only preserves the biological activity of the antibiotic but also endows hemicellulose with synergistic antibacterial properties, enabling it to exhibit superior antibacterial effects in complex biological environments. Attached Figure Description

[0033] Figure 1 The infrared spectrum of bagasse AAX prepared in Example 3;

[0034] Figure 2 XPS images of bagasse AAX prepared in Example 3, where (a) is the XPS spectrum, (b) is the C1s spectrum, and (c) is the O1s spectrum;

[0035] Figure 3 The hydrogen NMR spectrum of sugarcane bagasse AAX prepared in Example 3;

[0036] Figure 4 Infrared spectra of the MCR-X series samples prepared in Example 3;

[0037] Figure 5 Infrared spectra of the En-X series prepared in Example 3;

[0038] Figure 6 SEM morphology images of the En-X series prepared in Example 3;

[0039] Figure 7 Antibacterial test of Escherichia coli in the En-X series samples prepared in Example 3;

[0040] Figure 8 Antimicrobial test of Staphylococcus aureus on the En-X series samples prepared in Example 3;

[0041] Figure 9 Cytotoxicity assay of En-X4 prepared in Example 3. Detailed Implementation

[0042] The present invention will be further described in detail below with reference to embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto. All raw materials involved in the present invention can be purchased directly from the market. For process parameters not specifically specified, conventional techniques can be referred to.

[0043] Example 1

[0044] (1) Weigh approximately 1 g of corn cob hemicellulose into a 50 mL three-necked flask, add 40 mL of DMF, heat to 65 °C, and dissolve for approximately 1 h. Then heat to 110 °C, set the molar ratio of hemicellulose to acetylation reagent to (1:7), add methyl acetoacetate, and react for 6 h. After the reaction is complete, add three volumes of anhydrous ethanol to the solution and stir to precipitate, then let stand overnight. Centrifuge to collect the precipitate, and wash the precipitate three times with anhydrous ethanol. After the precipitate has been allowed to stand for a period of time to evaporate, freeze-dry, grind into powder, and obtain acetylated hemicellulose, denoted as AAX.

[0045] (2) Acetylated hemicellulose and DMF were added to a reaction vessel at a feed-to-liquid ratio of 1:25 (g:mL), and the mixture was heated to 60℃ to dissolve until homogeneous. Then, formaldehyde and ammonium acetate were added at the set molar ratio (acetylated hemicellulose:formaldehyde:ammonium acetate = 1:1:2, molar ratio), and the reaction was carried out at 60℃ for about 5 h. After the reaction was completed, three volumes of anhydrous ethanol were added to the solution and stirred to precipitate the precipitate, which was then allowed to stand overnight. The precipitate was collected by centrifugation and washed three times with anhydrous ethanol. After the precipitate was allowed to stand for a period of time to evaporate, it was freeze-dried and ground into powder to obtain multi-component modified hemicellulose, denoted as MCR-X.

[0046] (3) Weigh approximately 0.3 g of multi-component modified hemicellulose and dissolve it in 30 mL of aqueous solution, labeled as solution 1. The reaction temperature was 65℃, and the dissolution time was 36 h. Weigh 0.3226 g of gentamicin sulfate and dissolve it in 30 mL of water, labeled as solution 2. Mix solutions 1 and 2 and react for 24 h, keeping the reaction temperature and rotation speed constant. After the reaction, transfer the mixture to a dialysis bag with a specification of 3500 Da and dialyze for 3 days, changing the water three times a day. After dialysis, centrifuge, freeze dry, and grind into powder to obtain enamined modified hemicellulose, labeled as En-X. Perform antibacterial tests on the prepared sample, using the inhibition zone method, with Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC29213) as the bacterial strains.

[0047] Example 2

[0048] (1) Weigh approximately 1 g of camellia fruit shell hemicellulose and 50 mL of DMSO, heat to 70 °C, and dissolve for approximately 1.5 h. Then heat to 125 °C, set the molar ratio of hemicellulose to acetylation reagent to (1:8), add ethyl acetoacetate, and react for 7 h. After the reaction is complete, add 5 times the volume of anhydrous ethanol to the solution and stir to precipitate it, then let it stand overnight. Centrifuge to collect the precipitate, and wash the precipitate 3 times with anhydrous ethanol. After the precipitate has been allowed to stand for a period of time to evaporate, freeze-dry it, grind it into powder, and obtain acetylated hemicellulose, denoted as AAX.

[0049] (2) Acetylated hemicellulose and DMSO were added to a reaction vessel at a feed-to-liquid ratio of 1:40 (g:mL), and the mixture was heated to 75℃ to dissolve until homogeneous. Then, propionaldehyde and ethylammonium were added at the set molar ratio (acetylated hemicellulose:propionaldehyde:ethylammonium = 1:1:1.5, molar ratio), and the reaction was carried out at 60℃ for about 6.5 h. After the reaction was completed, 5 times the volume of anhydrous ethanol was added to the solution and stirred to precipitate the precipitate, which was then allowed to stand overnight. The precipitate was collected by centrifugation and washed three times with anhydrous ethanol. After the precipitate was allowed to stand for a period of time to evaporate, it was freeze-dried and ground into powder to obtain multi-component modified hemicellulose, denoted as MCR-X.

[0050] (3) Weigh approximately 0.3 g of multi-component modified hemicellulose and dissolve it in a 40 mL mixture of water and anhydrous ethanol, labeled as solution 1. The volume ratio of water to anhydrous ethanol is 7:3. The reaction temperature is 50℃, and the solution is dissolved for 36 h. Weigh 0.4231 g of gentamicin sulfate and dissolve it in a 40 mL mixture of water and anhydrous ethanol, labeled as solution 2. Mix solutions 1 and 2 and react for 36 h, keeping the reaction temperature constant. After the reaction, transfer the mixture to a dialysis bag with a capacity of 4000 Da and dialyze for 4 days, changing the water three times a day. After dialysis, centrifuge, freeze-dry, and grind into powder to obtain enamined modified hemicellulose, labeled as En-X. Perform antibacterial tests on the prepared sample using the inhibition zone method. The bacterial strains selected are Escherichia coli (ATCC25922) and Staphylococcus aureus (ATCC29213).

[0051] Example 3

[0052] (1) Weigh approximately 1 g of bagasse hemicellulose and 50 mL of DMSO, heat to 70 °C, and dissolve for approximately 2 h. Then heat to 125 °C, set the molar ratio of hemicellulose to acetylation reagent to (1:10), add tert-butyl acetoacetate, and react for 8 h. After the reaction is complete, add three volumes of anhydrous ethanol to the solution and stir to precipitate, then let stand overnight. Centrifuge to collect the precipitate and wash it four times with anhydrous ethanol. After the precipitate has been allowed to stand for a period of time to evaporate, freeze-dry it, grind it into powder, and obtain acetylated hemicellulose, denoted as AAX.

[0053] (2) Acetylated hemicellulose and DMSO were added to a reaction vessel at a feed-to-liquid ratio of 1:50 (g:mL), and the mixture was heated to 130℃ to dissolve until homogeneous. Then, dodecaldehyde and ammonium acetate were added at the set molar ratio (acetylated hemicellulose: dodecaldehyde: ammonium acetate = 1:1, molar ratio), and the reaction was carried out at 90℃ for about 3 h. After the reaction was completed, 6 volumes of anhydrous ethanol were added to the solution and stirred to precipitate the precipitate, which was then allowed to stand overnight. The precipitate was collected by centrifugation and washed three times with anhydrous ethanol. After the precipitate was allowed to stand for a period of time to evaporate, it was freeze-dried and ground into powder to obtain multi-component modified hemicellulose. In the Hantz reaction, five molar ratios of AAX, ammonium acetate, and dodecylaldehyde were set at 1:0.1:0.1, 1:0.2:0.2, 1:0.3:0.3, 1:0.4:0.4, and 1:0.5:0.5, respectively, to prepare five samples, which were denoted as MCR-X1, MCR-X2, MCR-X3, MCR-X4, and MCR-X5.

[0054] (3) Weigh approximately 0.3 g of the multi-component reactive modified hemicellulose and dissolve it in a 50 mL mixture of water and anhydrous ethanol, labeled as solution 1. The reaction temperature was 40 °C, the rotation speed was 400 rpm, and the dissolution time was 24 h. Weigh 0.5 g of gentamicin sulfate and dissolve it in 50 mL of water, labeled as solution 2. Then mix solutions 1 and 2 and react for 48 h, keeping the reaction temperature and rotation speed constant. After the reaction is complete, transfer the mixture to a 5000 Da dialysis bag and dialyze for 5 days, changing the water three times a day. After dialysis, centrifuge, freeze-dry, and grind into powder to obtain enamined modified hemicellulose, labeled as En-X. The enamined modified hemicellulose was prepared according to the following molar ratios of AAX, ammonium acetate, and dodecylaldehyde: 1:0.1:0.1, 1:0.2:0.2, 1:0.3:0.3, 1:0.4:0.4, and 1:0.5:0.5, respectively, and was designated as En-X1, En-X2, En-X3, En-X4, and En-X5. Antimicrobial tests were performed on the prepared samples using the inhibition zone method, with *Escherichia coli* (ATCC25922) and *Staphylococcus aureus* (ATCC29213) as the bacterial strains.

[0055] Figure 1 The image shows the infrared spectrum of AAX from bagasse prepared in Example 3, at 3471.7 cm⁻¹. -1 The peak at 1751.3 cm⁻¹ is the absorption peak of the -OH stretching vibration on the hemicellulose backbone; -1 The characteristic absorption peak at 1649 cm⁻¹ corresponds to the stretching vibration of the carbonyl group in the ketone structure of the acetyl group. -1The strong absorption peak at 1384 cm⁻¹ is due to the C=C stretching vibration in the intramolecularly hydrogen-bonded enol structure. This "double peak" phenomenon strongly demonstrates that the acetyl group was successfully grafted onto the hemicellulose molecular chain in the form of a keto-enol tautomerism. -1 The absorption peak observed at 1151.4 cm⁻¹ is due to the bending vibration of the -CH₃ group in the acetyl group, while the peak at 1151.4 cm⁻¹ is due to the bending vibration of the -CH₃ group in the acetyl group. -1 The peak signal at [location] represents the stretching vibration of the newly formed ester bond COC. Meanwhile, the peak signal representing hemicellulose at 1043.4 cm⁻¹... -1 The peaks are characteristic fingerprints of the pyranose rings in the hemicellulose matrix structure.

[0056] Figure 2 The XPS image of the bagasse AAX prepared in step (1) of Example 3 is shown. XPS testing revealed characteristic peaks of O1s and C1s at 531.48 eV and 285.28 eV, respectively. By separating the C1s peak, a C=O peak formed on the hemicellulose surface was observed at 285 eV. Furthermore, a characteristic peak of O=CC appeared at 531.48 eV, further indicating the presence of acetyl groups on the acetylated hemicellulose surface. A 1H NMR spectrum was then performed. Figure 3 The 1H NMR spectrum of the bagasse AAX prepared in step (1) of Example 3 shows characteristic peaks at 3.57 and 2.19 ppm, corresponding to hydrogen atoms on the methylene and methyl groups of the acetyl group, respectively. Characteristic peaks in the 3.5-6.0 ppm range correspond to the characteristic peaks of the sugar rings in the cellulose skeleton. The characteristic peaks at different chemical shifts in the spectrum correspond to hydrogen atoms on different groups. Figure 1 , Figure 2 , Figure 3 This fully demonstrates that acetylated hemicellulose has been successfully prepared.

[0057] Figure 4 Infrared spectra of the MCR-X series samples prepared in step (2) of Example 3 and AAX from bagasse. Compared with AAX, the modified MCR-X series samples showed better infrared spectra in the 1800-1500 cm⁻¹ range. -1 The region exhibits significant structural evolution, at 1624.0 cm. -1 The strong and sharp new absorption peak at 2931.7 cm⁻¹ represents the conjugate stretching vibrations of C=N and C=C in the newly constructed pyridine heterocyclic system after the Hantz reaction. -1 The peak intensity of the saturated CH stretching vibration at this point is significantly enhanced compared to AAX, indicating that the long-chain aliphatic hydrocarbon groups in the dodecyl molecule have been successfully loaded onto the hemicellulose backbone. (1323.1 cm⁻¹) -1The newly appearing absorption peak is due to the CN stretching vibration in the heterocyclic system. Observation of the series of spectra from MCR-X1 to MCR-X5 shows that the relative intensity of the above characteristic peaks exhibits a clear gradient response with changes in the molar ratio of reactants. In the Hantz reaction, the molar ratios of AAX, ammonium acetate, and dodecylaldehyde were set to five different ratios: 1:0.1:0.1, 1:0.2:0.2, 1:0.3:0.3, 1:0.4:0.4, and 1:0.5:0.5. Quantitative elemental analysis was performed on samples with these five different ratios. The nitrogen content varied among the samples, ranging from 0.046% to 2.281%. The nitrogen content increased with increasing amounts of ammonium acetate and dodecylaldehyde, because a pyridine heterocycle was attached to the original AAX molecular skeleton after the Hantz reaction.

[0058] Table 1

[0059]

[0060] Figure 5 This is the infrared spectrum of the En-X series. At 3448.6 cm⁻¹ -1 The broad and intense peak is mainly composed of the superposition of -OH and -NH stretching vibrations. Due to the extensive presence of hydrogen bonds within and between molecules, this peak is relatively broad. (2929.7 cm⁻¹) -1 The absorption peak at 1747.4 cm⁻¹ corresponds to the -CH stretching vibration. -1 The absorption peak is at C=O. Gentamicin sulfate exists in sulfate form, where the amino group is protonated to form -NH. 3+ Therefore, at 1625.9cm -1 The peak of the NH bending vibration appears at 1045.4 cm⁻¹. -1 The peaks at that point represent the stretching vibrations of CO and CC in the pyranose ring and the bending vibrations of C-OH. Figure 6 The images show the SEM morphology of the En-X series. As can be seen from the figures, En-X1 and En-X3 samples are mainly composed of irregular blocky particles. The particles exhibit sharp edges and gravel-like geometric features, indicating good structural integrity and high packing density. In En-X2, the surface of the large particles is no longer smooth but covered with numerous secondary microstructures, exhibiting significant wrinkles and slight flaking characteristics. En-X4 displays a unique morphology, no longer composed of single sharp particles but presenting as a loose, porous, sponge-like aggregate. This structure is formed by interconnected tiny polygonal segments, creating a complex, highly developed three-dimensional porous network. While the En-X5 sample still has a blocky morphology, the overall particle size is significantly smaller than that of En-X1 and En-X3. A large number of small, relatively regular particles are loosely packed, resulting in a higher specific surface area.

[0061] Antibacterial tests for Escherichia coli and Staphylococcus aureus were performed on the En-X series samples, respectively. Figure 7 and Figure 8 It can be seen that, compared with the control group, En-X has antibacterial activity against both Escherichia coli and Staphylococcus aureus. Figure 7 For Escherichia coli, the antibacterial activity decreases sequentially from En-X1 to En-X5, with the inhibition zone diameter of En-X1 being 14.0 mm (as shown in Table 2). Therefore, in the Hamtz reaction, when the molar ratio of hemicellulose, ammonium acetate, and dodecylaldehyde is 1:0.1:0.1, adding an excess of gentamicin sulfate can achieve better antibacterial effects. Figure 8 For Staphylococcus aureus, the antibacterial effect of the En-X series samples first increased and then decreased, with En-X4 exhibiting the largest inhibition zone diameter at 16.7 mm (as shown in Table 3). At this point, the molar ratio of hemicellulose, ammonium acetate, and dodecylaldehyde was 1:0.4:0.4, and adding excess gentamicin sulfate yielded a better antibacterial effect.

[0062] Table 2

[0063]

[0064] Table 3

[0065]

[0066] En-X4 was selected for cytotoxicity testing, such as Figure 9 The stock solution (30 mg / mL) was diluted 1000-fold, 100-fold, and 10-fold, respectively. L929 mouse fibroblasts were co-cultured with the sample solution for 24 hours, and a CCK8 cytotoxicity assay was performed. The graph shows that the relative cell activity increases with increasing dilution factor. At a concentration of 0.03 mg / mL, the relative cell activity was 99.5%; at 0.3 mg / mL, it was 95.2%; at 3 mg / mL, it was 85.4%; and at 30 mg / mL, it was 78.6%. When cell activity was below 70%, the test solution was considered cytotoxic. Therefore, En-X4 is not cytotoxic and is safe to use.

[0067] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for preparing a hemicellulose-based antibacterial agent, characterized in that, Includes the following steps: (1) Acetylation modification of hemicellulose yields acetylated hemicellulose; (2) The obtained acetylated hemicellulose was dissolved in a solvent, and aldehydes and nitrogen sources were added to carry out the Hantz reaction to obtain multi-component modified hemicellulose; (3) Dissolve the multi-component modified hemicellulose in a modified solvent system, add aminoglycoside antibiotics for enamine modification, and purify after the reaction to obtain enamine modified hemicellulose, i.e. the hemicellulose-based antibacterial agent.

2. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, In step (1), the acetylation reagent used for the acetylation modification reaction of hemicellulose is at least one of tert-butyl acetoacetate, methyl acetoacetate, ethyl acetoacetate, and diene.

3. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, The conditions for the acetylation modification reaction of hemicellulose in step (1) are: temperature 110~130 ℃, reaction time 6~8 h, and molar ratio of hemicellulose to acetylation reagent between 1:20 and 1:

7.

4. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, The solvent mentioned in step (2) is at least one of acetate buffer, dimethyl sulfoxide, tetrahydrofuran, water, dimethylformamide / lithium chloride system and ionic liquid; In step (2), the solid-liquid ratio of acetylated hemicellulose to solvent is 1:50~1:25 g:mL; the dissolution temperature is 60℃~90℃ and the time is 1 h~3 h.

5. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, The aldehydes mentioned in step (2) are at least one of benzaldehyde, propionaldehyde, butyraldehyde, and dodecaldehyde; the nitrogen source is at least one of methylamine, ethylamine, and acetic acid. In step (2), the molar ratio of acetylated hemicellulose, aldehyde components and nitrogen source components in the Hantz reaction is 1:0.1:0.1~1:1:

3.

6. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, The temperature of the Hantz reaction in step (2) is 60℃~80℃, and the reaction time is 5h~8h.

7. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, In step (3), the solid-liquid ratio of the multi-component modified hemicellulose and the modified solvent system is 1 g: 10 mL to 1 g: 100 mL; the modified solvent system is one of water, ethanol, or a mixture of water and ethanol.

8. The method for preparing a hemicellulose-based antibacterial agent according to claim 1, characterized in that, In step (3), the aminoglycoside antibiotic is one of kanamycin, gentamicin sulfate, and neomycin; the aminoglycoside antibiotic is in excess relative to the multi-component modified hemicellulose, the enamidation modification reaction time is 24 h to 48 h, and the reaction temperature is 40 to 60 °C.

9. A hemicellulose-based antibacterial agent prepared by the preparation method according to any one of claims 1-8.

10. The use of the hemicellulose-based antibacterial agent according to claim 9 in the preparation of antibacterial agents.

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