Bamboo mould inhibitor based on trimethyl anisole and preparation method thereof

Abstract

The invention discloses a bamboo mould inhibitor based on trimethyl anisole and a preparation method thereof. The preparation method comprises the following steps: adding absolute ethyl alcohol into a trimethyl anisole stock solution; adding chitosan into an acetic acid solution, and stirring to obtain a chitosan solution; adding alpha-cyclodextrin into an acetic acid solution, and stirring to obtain a cyclodextrin solution; adding a trimethyl anisole solution diluted by ethanol into the cyclodextrin solution, and stirring to obtain a mixed solution; performing ultrasonic treatment on the mixed solution, and performing freeze drying; then, firstly adding the product into a chitosan solution, stirring, then adding glycerol, continuously stirring, and carrying out ultrasonic treatment on the mixture obtained by stirring; according to the bamboo wood mould inhibitor, trimethyl anisole serves as a core mould inhibitor component, the good film-forming property of chitosan and the high adsorbability and inclusion property of cyclodextrin are fully utilized, trimethyl anisole is stably attached to and acts on the surface of bamboo wood, and slow release of the core mould inhibitor component and synergistic mould inhibition of chitosan are achieved; the lasting time of the mildew-proof effect is prolonged, the method is green and environment-friendly, the process is simple, and the comprehensive cost is low.

Description

Technical Field

[0001] This invention relates to the field of bamboo antifungal agents, specifically a bamboo antifungal agent based on trimethyl anisole and its preparation method. Background Technology

[0002] Bamboo is a natural, renewable, recyclable, and biodegradable biomaterial widely used in human production and daily life. However, untreated bamboo, due to its rich content of sugars, proteins, and starches, is susceptible to contamination and damage from molds such as Aspergillus niger, Penicillium, and Mucor, leading to mildew, discoloration, and other problems that affect its lifespan and performance, thus reducing its value. Therefore, the development of anti-mold technologies and products for bamboo is of significant research importance and practical value.

[0003] Currently, commonly used antifungal agents for bamboo are mainly organic compounds, such as organotin compounds, benzimidazoles, nitriles, phenols, or quaternary ammonium salts. These are often highly toxic and irritating, and some even contain heavy metals or highly toxic substances, posing significant harm to humans and animals. Long-term use can also cause serious environmental pollution and is difficult to degrade. In recent years, antifungal agents based on nanometals, such as nano-copper, nano-silver, and nano-zinc oxide, have also been studied. However, problems such as nano-metal ion aggregation, environmental safety, and high cost still exist.

[0004] Trimethylanisole is mainly used as an organic synthesis intermediate in the preparation of fragrances, dyes, pharmaceuticals, and pesticides. It is insoluble in water but readily soluble in organic solvents such as ethanol, and is a derivative of anisole. An experimental study was conducted on the antibacterial properties of trimethylanisole on bamboo. The results showed that trimethylanisole possesses good laboratory antibacterial and antifungal properties. A 10% concentration of trimethylanisole in ethanol showed control efficacy of 74.37%, 99.22%, and 91.38% against Aspergillus niger, Penicillium citrinum, and Trichoderma viride, respectively. The laboratory antifungal effect on these three molds was as follows: Figure 1 As shown in (a1), (b1), (a2), (b2), (c1), and (c2), a highly efficient bamboo antifungal agent can be prepared based on trimethyl anisole. During the research, it was found that trimethyl anisole ethanol solution alone exhibits volatilization and loss; further improvements in its adhesion and stability are needed for its application on bamboo. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a bamboo antifungal agent based on trimethyl anisole and its preparation method, which addresses the shortcomings of the prior art. The bamboo antifungal agent based on trimethyl anisole and its preparation method are simple, environmentally friendly, and have long-lasting antifungal performance. The antifungal agent uses trimethyl anisole as the core antifungal and antibacterial component, coupled with the good film-forming properties of chitosan and the high adsorption of α-cyclodextrin, so that trimethyl anisole can be permanently preserved in the antifungal agent and act on the surface of bamboo. In addition, the core component is released slowly during the antifungal performance, which effectively improves the antifungal performance of bamboo.

[0006] To achieve the above-mentioned technical objectives, the technical solution adopted by the present invention is as follows:

[0007] A bamboo antifungal agent based on trimethyl anisole comprises the following components: trimethyl anisole, anhydrous ethanol, chitosan, acetic acid solution, α-cyclodextrin, and glycerol.

[0008] To achieve the above-mentioned technical objectives, another technical solution adopted by the present invention is as follows:

[0009] A method for preparing a bamboo antifungal agent based on trimethyl anisole includes the following steps:

[0010] S1. Add anhydrous ethanol to the trimethyl anisole stock solution to dilute the stock solution;

[0011] S2. Add chitosan to an acetic acid solution and stir with a magnetic stirrer at a certain temperature until the chitosan is completely dissolved to obtain a chitosan solution.

[0012] S3. Add α-cyclodextrin to acetic acid solution, stir to dissolve, and prepare cyclodextrin solution;

[0013] S4. At a certain temperature, the trimethyl anisole solution diluted with ethanol in step S1 is added to the cyclodextrin solution in step S3, and the mixture is stirred with a magnetic stirrer to obtain a mixed solution.

[0014] S5. The mixed solution is first subjected to ultrasonic treatment, and then freeze-dried.

[0015] S6. The product obtained by freeze-drying in step S5 is first added to the chitosan solution in step S2 and stirred, then glycerol is added and stirred again. Finally, the mixture obtained by stirring is ultrasonically treated to obtain a bamboo antifungal agent based on trimethyl anisole.

[0016] As a further improvement of the present invention, in step S1, the concentration of the trimethylanisole stock solution after being diluted with anhydrous ethanol is 5%~20%.

[0017] As a further improvement of the present invention, in step S2: the concentration of acetic acid solution is 1%, the temperature of magnetic stirrer is 60°C, the stirring time is 60 min, and the concentration of chitosan solution after complete dissolution is controlled at 2%.

[0018] As a further improvement of the present invention, in step S3, the concentration of the acetic acid solution is 1%, and the concentration of the cyclodextrin solution is controlled at 3%.

[0019] As a further improvement of the present invention, in step S4, the working temperature of the magnetic stirrer is 65°C and the stirring time is 3 hours.

[0020] As a further improvement of the present invention, in step S5, the ultrasonic treatment time of the mixed solution is 30 min, the freeze-drying temperature is -50℃, and the freeze-drying time is 1 h.

[0021] As a further improvement of the present invention, in step S6, the freeze-dried product is first added to the chitosan solution and stirred for 30 minutes, then glycerol with a concentration of 2.5% is added and stirred for another 30 minutes, and the mixed solution obtained by stirring is ultrasonically treated for 2 hours.

[0022] The beneficial effects of this invention are as follows:

[0023] (i) The present invention uses trimethyl anisole as the core component of the antifungal agent, which is widely available.

[0024] (ii) In this invention, chitosan and α-cyclodextrin are mixed with trimethyl anisole to prepare a composite antifungal agent, which makes full use of the good film-forming properties of chitosan and the high adsorption properties (inclusion properties) of cyclodextrin, and controls the release rate of the adsorbed (inclusion) substances to achieve the slow release of the core antifungal component and the synergistic antifungal effect of chitosan, thus prolonging the duration of the antifungal effect. Attached Figure Description

[0025] Figure 1 The image shows the anti-mildew effect of treating bamboo with trimethyl anisole ethanol solution.

[0026] Figure 1 (a1) in the figure shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) without being coated with trimethyl anisole ethanol solution.

[0027] Figure 1 (a2) shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and application of trimethyl anisole ethanol solution.

[0028] Figure 1(b1) shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) without the application of trimethyl anisole ethanol solution.

[0029] Figure 1 (b2) shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and application of trimethyl anisole ethanol solution.

[0030] Figure 1 (c1) in the figure shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and without the application of trimethyl anisole ethanol solution.

[0031] Figure 1 (c2) in the figure shows the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and application of trimethyl anisole ethanol solution.

[0032] Figure 2 The image shows the anti-mold effect of a bamboo anti-mold agent prepared at a concentration of 5% on bamboo.

[0033] Figure 2 (a1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 1.

[0034] Figure 2 (a2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and coating with the bamboo antifungal agent based on trimethyl anisole prepared in Example 1.

[0035] Figure 2 (b1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 1.

[0036] Figure 2 (b2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 1.

[0037] Figure 2 (c1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 1.

[0038] Figure 2(c2) is a graph showing the infection status of bamboo samples 28 days after inoculating natural bamboo with the tested mold strain (Trichoderma viride) and coating it with the bamboo antifungal agent based on trimethyl anisole prepared in Example 1.

[0039] Figure 3 The image shows the anti-mold effect of a bamboo anti-mold agent prepared at a concentration of 7.5%.

[0040] Figure 3 (a1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0041] Figure 3 (a2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0042] Figure 3 (b1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0043] Figure 3 (b2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0044] Figure 3 (c1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0045] Figure 3 (c2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 2.

[0046] Figure 4 The image shows the anti-mold effect of a bamboo anti-mold agent prepared at a concentration of 10% on bamboo.

[0047] Figure 4 (a1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3.

[0048] Figure 4(a2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Aspergillus niger) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3.

[0049] Figure 4 (b1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3.

[0050] Figure 4 (b2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Penicillium citrinum) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3.

[0051] Figure 4 (c1) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and without coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3.

[0052] Figure 4 (c2) is a graph showing the infection status of bamboo samples 28 days after inoculation with the tested mold strain (Trichoderma viride) and coating with the trimethylanisole-based bamboo antifungal agent prepared in Example 3. Detailed Implementation

[0053] The specific embodiments of the present invention will be further described below:

[0054] Example 1:

[0055] A bamboo antifungal agent based on trimethyl anisole and its preparation method, comprising the following steps:

[0056] (a) Add anhydrous ethanol to the trimethyl anisole stock solution and dilute the stock solution to a concentration of 5%;

[0057] (ii) Add 2g of chitosan to a 1% (v / v) acetic acid solution and stir at 60°C for 1h with a magnetic stirrer to ensure complete dissolution of chitosan, to obtain a 2% (w / v) chitosan solution;

[0058] (iii) Add 3g of α-cyclodextrin to a 1% (v / v) acetic acid solution, stir to dissolve, and prepare a 3% (w / v) cyclodextrin solution;

[0059] (iv) At 65°C, a 5% trimethylanisole ethanol solution was added to a 3% (w / v) cyclodextrin solution and magnetically stirred for 3 hours to obtain a mixed solution;

[0060] (v) The mixed solution is sonicated for 30 min and then freeze-dried at -50℃ for 1 h;

[0061] (vi) The dried product is added to a 2% (w / v) chitosan solution and stirred for 30 min. Then, 2.5% (v / v) glycerol is added and stirred for another 30 min. The mixture is ultrasonically treated for 2 h to obtain a bamboo antifungal agent based on trimethyl anisole.

[0062] The prepared bamboo antifungal agent was applied to bamboo with a loading of 5.8%. Antifungal efficacy tests were conducted on bamboo samples according to GB / T18261—2013, "Test Methods for the Control Efficacy of Antifungal Agents against Wood Molds and Discoloration Fungi". Mold culture medium (2% maltose and 1.5% agar by mass) was poured into sterilized glass petri dishes. After cooling, the tested mold species (Aspergillus niger, Penicillium citrinum, and Trichoderma viride) were inoculated. The dishes were incubated at 28℃ and 85% relative humidity for 7 days. A sterilized U-shaped glass rod was placed on the culture medium, and then the sterilized bamboo sample to be tested was placed on top. The infection value of the bamboo samples was checked after 28 days. The infection status of the three molds was as follows: Figure 2 The results are shown in (a1), (b1), (a2), (b2), (c1), and (c2). The results show that the 5% concentration (i.e., the original solution diluted to a concentration of 5%) of the bamboo antifungal agent prepared has a control efficacy of 95.97%, 97.52%, and 98.12% against Aspergillus niger, Penicillium citrinum, and Trichoderma viride, respectively.

[0063] Example 2:

[0064] A bamboo antifungal agent based on trimethyl anisole and its preparation method, comprising the following steps:

[0065] (a) Add anhydrous ethanol to the trimethyl anisole stock solution and dilute the stock solution to a concentration of 7.5%;

[0066] (ii) Add 2g of chitosan to a 1% (v / v) acetic acid solution and stir at 60°C for 1h with a magnetic stirrer to ensure complete dissolution of chitosan, to obtain a 2% (w / v) chitosan solution;

[0067] (iii) Add 3g of α-cyclodextrin to a 1% (v / v) acetic acid solution, stir to dissolve, and prepare a 3% (w / v) cyclodextrin solution;

[0068] (iv) At 65°C, a 5% trimethylanisole ethanol solution was added to a 3% (w / v) cyclodextrin solution and magnetically stirred for 3 hours to obtain a mixed solution;

[0069] (v) The mixed solution is sonicated for 30 min and then freeze-dried at -50℃ for 1 h;

[0070] (vi) The dried product is added to a 2% (w / v) chitosan solution and stirred for 30 min. Then, 2.5% (v / v) glycerol is added and stirred for another 30 min. The mixture is ultrasonically treated for 2 h to obtain a bamboo antifungal agent based on trimethyl anisole.

[0071] The prepared bamboo antifungal agent was applied to bamboo with a loading of 6.0%. Antifungal efficacy tests were conducted on bamboo samples according to GB / T18261—2013, "Test Methods for the Control Efficacy of Antifungal Agents against Wood Molds and Discoloration Fungi". Mold culture medium (2% maltose and 1.5% agar by mass) was poured into sterilized glass petri dishes. After cooling, the tested mold species (Aspergillus niger, Penicillium citrinum, and Trichoderma viride) were inoculated. The dishes were incubated at 28 ℃ and 85% relative humidity for 7 days. A sterilized U-shaped glass rod was placed on the culture medium, and then the sterilized bamboo sample to be tested was placed on top. The infection value of the bamboo samples was checked after 28 days. The infection status of the three molds was as follows: Figure 3 The results are shown in (a1), (a2), (b1), (b2), (c1), and (c2). The prepared 7.5% concentration (i.e., the original solution diluted to a concentration of 7.5%) bamboo antifungal agent showed control efficiencies of 96.74%, 99.35%, and 99.68% against Aspergillus niger, Penicillium citrinum, and Trichoderma viride, respectively.

[0072] Example 3:

[0073] A bamboo antifungal agent based on trimethyl anisole and its preparation method, comprising the following steps:

[0074] (a) Add anhydrous ethanol to the trimethyl anisole stock solution and dilute the stock solution to a concentration of 10%;

[0075] (ii) Add 2g of chitosan to a 1% (v / v) acetic acid solution and stir at 60°C for 1h with a magnetic stirrer to ensure complete dissolution of chitosan, to obtain a 2% (w / v) chitosan solution;

[0076] (iii) Add 3g of α-cyclodextrin to a 1% (v / v) acetic acid solution, stir to dissolve, and prepare a 3% (w / v) cyclodextrin solution;

[0077] (iv) At 65°C, a 5% trimethylanisole ethanol solution was added to a 3% (w / v) cyclodextrin solution and magnetically stirred for 3 hours to obtain a mixed solution;

[0078] (v) The mixed solution is sonicated for 30 min and then freeze-dried at -50℃ for 1 h;

[0079] (vi) The dried product is added to a 2% (w / v) chitosan solution and stirred for 30 min. Then, 2.5% (v / v) glycerol is added and stirred for another 30 min. The mixture is ultrasonically treated for 2 h to obtain a bamboo antifungal agent based on trimethyl anisole.

[0080] The prepared bamboo antifungal agent was applied to bamboo with a loading of 6.2%. Antifungal efficacy tests were conducted on bamboo samples according to GB / T18261—2013, "Test Methods for the Control Efficacy of Antifungal Agents against Wood Molds and Discoloration Fungi". Mold culture medium (2% maltose and 1.5% agar by mass) was poured into sterilized glass petri dishes. After cooling, the tested mold species (Aspergillus niger, Penicillium citrinum, and Trichoderma viride) were inoculated. The dishes were incubated at 28 ℃ and 85% relative humidity for 7 days. A sterilized U-shaped glass rod was placed on the culture medium, and then the sterilized bamboo sample to be tested was placed on top. The infection value of the bamboo samples was checked after 28 days. The infection status of the three molds was as follows: Figure 4 The results are shown in (a1), (a2), (b1), (b2), (c1), and (c2). The results show that the bamboo antifungal agent prepared at a concentration of 10% (i.e., the original solution diluted to a concentration of 10%) has a control efficacy of 99.75%, 99.85%, and 99.95% against Aspergillus niger, Penicillium citrinum, and Trichoderma viride, respectively. Figure 2 - Figure 4 The natural bamboo in Figure (c) was inoculated with the tested mold strain (Trichoderma viride) and was also contaminated with blackberries over a period of 28 days.

[0081] In this invention, when the concentration of trimethyl anisole in acetic acid solution is 10%, its control efficacy against the three types of mold on bamboo reaches over 99%. The antifungal agent prepared by diluting trimethyl anisole to a concentration of 20% also exhibits control efficiencies of 99.90%, 99.93%, and 99.97% against the three types of mold, respectively, all demonstrating excellent antifungal effects.

[0082] In the above embodiments, in step (ii): the concentration of the acetic acid solution can be 1%~5% (v / v), the temperature of the magnetic stirrer can be 50~70℃, the stirring time can be 40~80min, and the concentration of the completely dissolved chitosan solution can be controlled at 2%~5% (w / v). In step (iii): the concentration of the acetic acid solution can be 1%~5% (v / v), and the concentration of the cyclodextrin solution can be controlled at 3%~5% (w / v). In step (iv): the operating temperature of the magnetic stirrer can be 50~70℃, and the stirring time can be 2~4h. In step (v): the ultrasonic treatment time of the mixed solution can be 30~60min, the freeze-drying temperature can be -40℃~-55℃, and the freeze-drying time can be 1~2h. In step (six): the freeze-dried product is first added to the chitosan solution and stirred for 30-45 minutes. After adding 2.5% glycerol, the stirring time is 30-45 minutes. The ultrasonic treatment time of the mixed solution obtained by stirring is 2-3 hours.

[0083] The scope of protection of this invention includes, but is not limited to, the above embodiments. The scope of protection of this invention is defined by the claims. Any substitutions, modifications, or improvements to this technology that are easily conceived by those skilled in the art fall within the scope of protection of this invention.

Claims

1. A trimethylanisole-based bamboo wood mildew preventive agent characterized by comprising: The method comprises the following steps:

2. A process for the preparation of a trimethylanisole based bamboo wood mildew preventive agent, characterized by, S1, adding anhydrous ethanol to the trimethyl anisole stock solution, and then diluting the stock solution; S2, adding chitosan to the acetic acid solution, and stirring at a certain temperature by a magnetic stirrer until the chitosan is completely dissolved to obtain a chitosan solution; S3, adding α-cyclodextrin to the acetic acid solution, and preparing a cyclodextrin solution after stirring and dissolving; S4, at a certain temperature, adding the trimethyl anisole solution diluted by ethanol in step S1 to the cyclodextrin solution in step S3, and obtaining a mixed solution after stirring by a magnetic stirrer; S5, ultrasonic treatment is first performed on the mixed solution, and then freeze-drying is performed; S6, the product after freeze-drying in step S5 is first added to the chitosan solution in step S2 for stirring, then glycerol is added for further stirring, and finally the obtained mixture is ultrasonically treated to obtain a trimethyl anisole-based bamboo antifungal agent. In step S1, the concentration of the trimethyl anisole stock solution diluted by anhydrous ethanol is 5%-20%.

3. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, In step S2, the concentration of the acetic acid solution is 1%, the temperature of the magnetic stirrer is 60℃, the stirring time is 60min, and the concentration of the completely dissolved chitosan solution is controlled to be 2%.

4. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, In step S3, the concentration of the acetic acid solution is 1%, and the concentration of the cyclodextrin solution is controlled to be 3%.

5. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, In step S4, the working temperature of the magnetic stirrer is 65℃, and the stirring time is 3h.

6. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, In step S5, the ultrasonic treatment time of the mixed solution is 30min, the freeze-drying temperature is-50℃, and the freeze-drying time is 1h.

7. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, In step S6, the product after freeze-drying is first added to the chitosan solution for stirring for 30min, then glycerol with a concentration of 2.5% is added for further stirring for 30min, and the ultrasonic treatment time of the obtained mixed solution is 2h.

8. The method for preparing the bamboo antifungal agent based on trimethyl anisole according to claim 1, characterized in that, ​

Images