A bactericide containing an amino-oligosaccharide and a method for preparing the same

Abstract

This application relates to the field of pesticide fungicides, specifically disclosing a fungicide containing amino oligosaccharides and its preparation method. The fungicide containing amino oligosaccharides comprises the following raw materials in the following mass percentages: active ingredient 1.35-1.6%, synergistic agent 1.2-1.5%, wetting and dispersing agent 3-6%, antifreeze agent 5-8%, preservative 0.1-0.2%, and deionized water to 100%; the active ingredient comprises amino oligosaccharides and octochlor acetate in a mass ratio of 1:2-5. This application, by preparing a fungicide containing amino oligosaccharides, improves the antibacterial effect, avoids the development of drug resistance, and achieves efficient control of bacterial angular leaf spot disease in cucumbers.

Description

Technical Field

[0001] This application relates to the field of pesticide fungicides, and more specifically, to a fungicide containing an amino oligosaccharide and a method for preparing the same. Background Technology

[0002] Bacterial angular leaf spot of cucumber is a common and serious bacterial disease in cucumber production, caused by the bacterium *Pseudomonas syringae*, a pathogenic bacterium of cucumber. It primarily affects leaves, fruits, and stems, leading to premature leaf senescence, reduced fruit marketability, and decreased cucumber yield. Amino oligosaccharides and octenamine are commonly used to treat bacterial angular leaf spot in cucumber. Amino oligosaccharides (also known as chitosan oligosaccharides) are low-toxicity, environmentally friendly biopesticides, mainly derived from the degradation products of chitin. They have a dual function of agricultural disease prevention and plant growth promotion, and are highly safe for both ecology and humans. Oxenin, also known as a fungicide, is a cationic compound that can penetrate into the plant or adhere to its surface. By disrupting the cell membranes of pathogens and inhibiting their nucleic acid synthesis, it directly kills or inhibits pathogens such as bacteria, viruses, and some fungi, preventing the spread of disease. Low concentrations of octenamine can stimulate the thickening of plant epidermal cells, inducing the production of phytoalexins and other disease-resistant substances, enhancing the plant's own resistance to disease, and reducing the probability of subsequent disease outbreaks.

[0003] In the prior art, Chinese invention patent application CN107549170A discloses a bactericidal composition comprising an active component and an auxiliary component. The active component is an amino oligosaccharide, ningnanmycin, and octenylamine acetate, with the active component comprising 5%–50% by weight. Through the combined action of these three active ingredients, the bactericidal effect is improved and plant growth is promoted, resulting in a highly antibacterial bactericidal composition for the control of bacterial, fungal, and viral diseases in fruit trees, vegetables, and field crops. However, ningnanmycin carries a significant risk of drug resistance, and octenylamine acetate, as a single antibacterial component, shows low efficacy against bacterial angular leaf spot in cucumbers.

[0004] Therefore, there is an urgent need to provide a fungicide with high antibacterial activity, which not only has excellent antibacterial effect but also avoids the development of drug resistance, thus achieving efficient prevention and control of bacterial angular leaf spot in cucumbers. Summary of the Invention

[0005] To achieve efficient control of bacterial angular leaf spot in cucumbers, this application provides a fungicide containing amino oligosaccharides and its preparation method.

[0006] In a first aspect, the bactericide containing amino oligosaccharides provided in this application adopts the following technical solution: A bactericide containing amino oligosaccharides, comprising the following raw materials in weight percentages: The active ingredient comprises 1.35-1.6%, the synergistic component comprises 1.2-1.5%, the wetting and dispersing agent comprises 3-6%, the antifreeze comprises 5-8%, the preservative comprises 0.1-0.2%, and deionized water comprises 100%. The active ingredient comprises amino oligosaccharides and octylamine acetate in a mass ratio of 1:2-5.

[0007] By employing the above-mentioned technical solutions, amino oligosaccharides indirectly activate the salicylic acid signaling pathway in plants, promoting the synthesis of disease-resistant substances such as phytoalexins and chitinases, thereby inducing disease resistance in cucumbers. Furthermore, amino oligosaccharides contain a large number of amino groups, which bind to the negatively charged phosphate groups of bacteria. The linear oligosaccharide chains of amino oligosaccharides can also insert into the phospholipid bilayer gaps of the cell membrane, disrupting the integrity of the bacterial cell membrane and thus killing the bacteria. The combined use of octochlor acetate and amino oligosaccharides synergistically further disrupts the cell membrane, and octochlor acetate can penetrate into the cell interior. It interferes with the bacterial nucleic acid and protein synthesis process, inhibiting bacterial proliferation; the synergistic component can increase the bactericidal effect of amino oligosaccharides and octylamine acetate, and has the function of repairing angular leaf spot, further increasing the control effect on bacterial angular leaf spot; the wetting and dispersing agent can disperse the water-insoluble substances in the synergistic component, while the antifreeze agent can lower the freezing point, prevent the formulation from freezing during low-temperature storage, and has a solubilizing effect. It works synergistically with the wetting and dispersing agent to improve the solubility of the synergistic component, improve the stability of the fungicide, and achieve highly efficient control of bacterial angular leaf spot.

[0008] Optionally, the mass ratio of the amino oligosaccharide to octylamine acetate is 1:3.

[0009] By adopting the above technical solution and the above active component ratio, the resistance-inducing effect of amino oligosaccharide on cucumber bacterial angular leaf spot can be fully utilized, and the amino oligosaccharide and octochlor acetate have a highly efficient synergistic effect in killing pathogenic bacteria, thus further effectively preventing and controlling cucumber bacterial angular leaf spot.

[0010] Optionally, the active component further includes ethylenediaminetetraacetic acid (EDTA), wherein the mass ratio of the amino oligosaccharide to EDTA is 1:1-2.

[0011] By adopting the above technical solution, ethylenediaminetetraacetic acid (EDTA) can act as a metal ion chelating agent, binding calcium and magnesium ions on the surface of Pseudomonas syringae cell membranes, reducing the stability of lipopolysaccharide structure, disintegrating the bacterial outer membrane, and working synergistically with amino oligosaccharides to destroy the integrity of bacterial cell structure, which helps antibacterial components penetrate into the cell and enhances the bactericidal effect.

[0012] Optionally, the synergistic components include salicylic acid and alginic acid, with a mass ratio of salicylic acid to alginic acid of 2-4:1.

[0013] By adopting the above technical solutions, salicylic acid, as a signaling molecule, can directly activate the salicylic acid signaling pathway, increase the production of lignin in leaves, and lignin can be deposited in the leaf cell wall to form a three-dimensional cross-linked structure, improve the mechanical strength of the cell wall, and prevent bacterial invasion. The calcium element of alginic acid can strengthen the cell wall structure of cucumber leaves and work synergistically with salicylic acid to prevent bacteria from penetrating plant cells and improve disease resistance. In addition, alginic acid can promote chlorophyll synthesis in cucumber leaves, repair the yellowing tissue around lesions, and improve the absorption of water and nutrients by cucumbers by providing nutrients and stimulating root growth, thus accelerating the repair process in the later stages of angular leaf spot treatment.

[0014] Optionally, the mass ratio of salicylic acid to alginic acid is 3:1.

[0015] By adopting the above technical solution, the ratio of ethylenediaminetetraacetic acid, salicylic acid and alginic acid is optimized to balance the bactericidal, antibacterial and leaf repair effects, thereby improving the bactericide's efficacy against bacterial angular leaf spot.

[0016] Optionally, the wetting and dispersing agent comprises sodium lauroyl sarcosinate and cocamidopropyl betaine in a mass ratio of 1:1-2.

[0017] By adopting the above technical solutions, sodium lauroyl sarcosinate, as an anionic surfactant, can generate electrostatic repulsion with the carboxyl group of alginate, preventing molecular chain entanglement that leads to increased viscosity of the bactericide and avoiding uneven distribution of the drug concentration. Cocamidopropyl betaine, as an amphoteric surfactant, has a hydrophobic coconut oil group combined with a salicylic acid benzene ring, and polar groups forming hydrogen bonds with the carboxyl group of salicylic acid and the hydroxyl group of alginate, further dispersing salicylic acid and alginate, preventing the effective components from being released at low temperatures or when diluted with water, and improving the antibacterial effect. In addition, sodium lauroyl sarcosinate and cocamidopropyl betaine have low surface tension, which can promote the rapid spread of the drug solution to cover the leaf surface, kill pathogens adsorbed on cucumber leaves, and the amphoteric structure of cocamidopropyl betaine can form a weak interaction with the waxy layer of cucumber leaves, reducing drug loss and prolonging the duration of antibacterial action.

[0018] Optionally, the antifreeze is at least one of ethylene glycol, propylene glycol, and glycerol; the preservative is at least one of Kathon and potassium sorbate.

[0019] By adopting the above technical solution, the antifreeze dissolves in water, and the alcohol molecules can hinder the movement of water molecules, preventing water molecules from changing from a liquid to a gaseous state, thus reducing the vapor pressure of the bactericide and lowering its freezing point. In addition, the hydrogen bonds of the antifreeze can combine with the carboxyl and hydroxyl groups of salicylic acid, and its polar segments can insert into the hydrophobic regions of salicylic acid aggregates. Working synergistically with the wetting and dispersing agents, it promotes the gradual dispersion of aggregates into smaller molecular clusters, further preventing salicylic acid precipitation and improving the bactericide's control effect. The preservative can inhibit the growth of mold and yeast in the bactericide and prevent the formulation from deteriorating during storage.

[0020] Secondly, this application provides a method for preparing a bactericide containing amino oligosaccharides, comprising the following steps: Add wetting and dispersing agents, antifreeze agents, and preservatives to deionized water, mix well, add active ingredients and synergistic components, and shake at 30-40℃ until a transparent homogeneous solution is formed, thus obtaining a bactericide containing amino oligosaccharides.

[0021] By adopting the above technical solution, under the action of wetting and dispersing agents and antifreeze agents, the active components and synergistic components can be uniformly dispersed in deionized water. The preservatives prevent the growth of mold and yeast in deionized water, forming a stable bactericide. Moreover, the operation is simple and conducive to subsequent industrial production.

[0022] In summary, this application has the following beneficial effects: 1. This application preferably uses a combination of amino oligosaccharide, octazine acetate, and EDTA to induce disease resistance in cucumbers and directly disrupt the integrity of bacterial cell membranes, thereby killing pathogens. The synergistic component can be used in combination with amino oligosaccharide to further induce disease resistance in cucumbers, prevent bacterial invasion, and improve the control effect. The wetting and dispersing agent works together with the antifreeze to prevent the synergistic component in the fungicide from being released, maintain the stability of the fungicide, and the wetting and dispersing agent can increase the spreadability of the solution and prolong the duration of action, thereby improving the fungicidal effect.

[0023] 2. This application uses a combination of salicylic acid and alginic acid to assist amino oligosaccharides in inducing antibacterial activity, and alginic acid can increase the late-stage repair efficiency of angular leaf spot leaves, further improving the control effect.

[0024] 3. This application improves the dispersion stability of synergistic components in fungicides by using sodium lauroyl sarcosinate and cocamidopropyl betaine in combination, and also increases the leaf spreadability of the fungicide, prolongs the duration of efficacy, and achieves efficient control of bacterial angular leaf spot in cucumbers. Detailed Implementation

[0025] The following embodiments provide a further detailed description of this application. Example

[0026] In the following examples, amino oligosaccharides were purchased from Xi'an Kangnuo Chemical Co., Ltd., with a purity of 90% and an industrial grade; octochlor acetate was purchased from Xi'an Jiake Agrochemical Co., Ltd., with a purity of 99%; sodium lauroyl sarcosinate was purchased from Hubei Jiahuixingcheng Biotechnology Co., Ltd., with product number 546214; cocamidopropyl betaine was purchased from Sichuan Kulinan Technology Co., Ltd., with a purity of 99%; and Kathon was purchased from Jinan Shanhai Chemical Technology Co., Ltd., with a purity of 99%.

[0027] Examples 1-10: A bactericide containing amino oligosaccharides, the raw material amounts are shown in Table 1, the antifreeze is propylene glycol, and the preservative is Kathon. The preparation method of the above-mentioned bactericide containing amino oligosaccharides includes the following steps: Add wetting and dispersing agent, antifreeze agent and preservative to deionized water, stir for 30 min to mix evenly, add active component and synergistic component, shake at 35℃ for 3 h to form a transparent homogeneous solution, and prepare bactericide containing amino oligosaccharide.

[0028] Table 1 shows the raw material dosage of the bactericide containing amino oligosaccharides in the examples. Table 2 shows the raw material usage of the bactericides containing amino oligosaccharides in Comparative Examples 1-3. Comparative Example 5: The bactericide containing amino oligosaccharides was replaced by an equal amount of 3.2% amino oligosaccharide·octenamide soluble concentrate; the 3.2% amino oligosaccharide·octenamide soluble concentrate was purchased from Shandong Daimengde Biotechnology Co., Ltd.

[0029] Comparative Example 6: The bactericide containing amino oligosaccharides was replaced by an equal amount of 2% amino oligosaccharide aqueous solution; the 2% amino oligosaccharide aqueous solution was purchased from Kepu Biochemical Co., Ltd., Puyang City, Henan Province.

[0030] Comparative Example 7: The bactericide containing amino oligosaccharides was replaced by an equal amount of 1.2% octenamine acetate aqueous solution; the 1.2% octenamine acetate aqueous solution was purchased from Zhejiang Changxing First Chemical Co., Ltd. The bactericide containing amino oligosaccharides was prepared according to the methods in the examples and comparative examples, and its performance was tested according to the following methods. The test results are recorded in Table 3.

[0031] 1. Stability: The thermal storage stability was detected according to GB / T 19136-2021 "Determination Method for Thermal Storage Stability of Pesticides". Experimental steps: Seal the test sample in a glass bottle, store it in a constant temperature oven at 54 ± 2 °C for 14 days, take it out, put it in a desiccator, and cool it to room temperature; complete the determination of specified items such as the mass fraction of the active ingredient within 24 hours. It is also possible to directly use the original commercial package for the thermal storage test. If the relative decomposition rate of the active ingredient content is less than 5.0%, and the pH value and dilution stability still meet the standard requirements, it is considered qualified; The low temperature stability was detected according to GB / T 19137 "Determination Method for Low Temperature Stability of Pesticides". Experimental steps: Pipette 100 mL of the sample into a centrifuge tube, cool it to (0 ± 2) °C in a refrigerator, keep the centrifuge tube and its contents at (0 ± 2) °C for 1 hour, and stir it every 15 minutes for 15 seconds each time. Check and record whether there is precipitation of solid matter or oil. Put the centrifuge tube back into the refrigerator and continue to place it at (0 ± 2) °C for 7 days. After 7 days, take out the centrifuge tube, let it stand at room temperature (not exceeding 20 °C) for 3 hours, and centrifuge for 15 minutes (the relative centrifugal force at the top of the tube is 500 g - 600 g, where g is the acceleration due to gravity), record the volume of the separated matter at the bottom of the tube (accurate to 0.05 mL). If the volume of the precipitated matter does not exceed 0.3 mL, it is considered qualified; For dilution stability, use a pipette to suck 5 mL of the liquid agent, place it in a 100 mL graduated cylinder, dilute it to the scale with standard hard water, mix well, put this graduated cylinder into a constant temperature water bath at 30 °C ± 1 °C, and let it stand for 1 hour. If the diluted liquid is uniform and there is no precipitation, it is considered qualified; Determine the stability test results according to the following three situations: (1) If the low temperature stability and dilution stability are qualified, but the thermal storage stability is unqualified, it means the thermal storage stability is unqualified; (2) If the thermal storage stability and dilution stability are qualified, but the low temperature stability is unqualified, it means the low temperature stability is unqualified; (3) If the low temperature stability and thermal storage stability are qualified, but the dilution stability is unqualified, it means the dilution stability is unqualified.

[0032] 2. Field test: It was detected according to GB / T 17980.110-2004 "Pesticide Field Efficacy Test Standards (Part 2) - Part 110: Fungicides for Controlling Bacterial Angular Leaf Spot of Cucumber". The test field was a greenhouse with a total area of 935 m 2 , about 85 m long and about 11 m wide. The area of each plot was about 0.8 m (width) × 10 m (length) = 8 m 2 . A protective row of about 0.5 m was set between each plot. The test had 16 treatments, each treatment had 4 replicates, a total of 64 plots. The experimental examples, comparative examples, and blank control treatments were arranged in a randomized block design.

[0033] The experimental crop was Biyu No. 2 cucumber. A two-stage dilution method was used for pesticide preparation. After being transferred to the sprayer, the pesticide was thoroughly shaken to ensure a uniform solution. The entire plant was sprayed evenly. The blank control plot was sprayed with clean water first, followed by the control plots of the example and comparative treatments. The treatment plots were sprayed evenly, progressing from low to high concentration. The sprayer was washed with clean water before each pesticide treatment. The water usage was 50L per acre, and the pesticide dosage was 100-240 ml / acre. The pesticide was sprayed twice consecutively, with a 7-day interval. Three sampling points were taken from each plot, with 5 plants at each point. The control effect was investigated and recorded 7 days after the first application and 7 days after the second application. The efficacy was calculated as follows: Disease index = (∑(number of diseased leaves at each level × relative level value) / total number of leaves investigated × 9) × 100; Control effect (%) = (1 - (disease index before treatment in the blank control area × disease index after treatment in the treatment area) / (disease index after treatment in the blank control area × disease index before treatment in the treatment area)) × 100. On the day of the first application, the weather at the test site was cloudy with a temperature of 28.6℃ and a relative humidity of 65.7%. On the day of the second application, the weather at the test site was sunny with a temperature of 27.8℃ and a relative humidity of 60.5%. The dosage of pesticide in Examples 1-7 and Comparative Example 1 was 240 ml / mu, the dosage of pesticide in Comparative Example 4 was 100 ml / mu, and the dosage of pesticide in Comparative Examples 5 and 6 was 144 ml / mu.

[0034] Table 3. Results of bactericide tests containing amino oligosaccharides in the examples and comparative examples. As shown in Table 3, the fungicide containing amino oligosaccharides prepared in Example 1 of this application has good stability and control effect. Compared with Example 1, the control effect of Examples 2-5 was slightly reduced by adjusting the internal ratio of active component, synergistic component and wetting and dispersing agent. This may be due to the weakening of synergistic effect caused by the ratio exceeding the optimal ratio. Compared with Example 1, Example 6 showed that without the addition of ethylenediaminetetraacetic acid, the control effect in the field trial was significantly reduced compared with Examples 1-5. This may be due to the lack of ethylenediaminetetraacetic acid, which weakens its synergistic destructive effect on bacterial cell membranes with amino oligosaccharides, thereby undermining the synergistic effect of the two. Compared with Example 1 and Comparative Example 1, it can be seen from Examples 7-8 that adding only one of salicylic acid and alginic acid reduced the control effect in the field trial. This may be because the synergistic effect of salicylic acid and alginic acid was destroyed, thereby weakening the improvement of the mechanical strength of plant cell walls. In Examples 9-10, adding only one of sodium lauroyl sarcosinate and cocamidopropyl betaine resulted in the fungicide having unsatisfactory dilution stability. This may be because the synergistic effect of sodium lauroyl sarcosinate and cocamidopropyl betaine disappeared, weakening the dispersion effect on alginic acid and salicylic acid, and failing to effectively inhibit the aggregation and precipitation of synergistic components (alginic acid and salicylic acid), ultimately leading to unsatisfactory dilution stability.

[0035] Comparing Comparative Example 2 with Example 1, it can be seen that without the addition of a wetting and dispersing agent, the dilution stabilizer of the fungicide was substandard. This may be because the lack of necessary dispersing agents caused the synergistic components (alginic acid and salicylic acid) to precipitate after dilution. Comparing Comparative Example 3 with Example 1, it can be seen that without the addition of an antifreeze agent, the low-temperature stabilizer of the fungicide was substandard. This may be because the lack of propylene glycol caused an increase in the freezing point of the solution and prevented it from working synergistically with the wetting and dispersing agent, leading to the precipitation of salicylic acid and alginic acid. Comparing Comparative Example 4 with Example 1, it can be seen that without the addition of ethylenediaminetetraacetic acid, salicylic acid, and alginic acid, the control effect in the field trial was significantly reduced. This may be because in Example 1, the above three components, together with amino oligosaccharides and octochlor acetate, constituted a multi-component synergistic antibacterial mechanism, which jointly enhanced the control effect against cucumber bacterial angular leaf spot. In Comparative Example 4, the lack of these components caused the synergistic mechanism to fail, and it was difficult to achieve a good field control effect through the single synergistic effect of amino oligosaccharides and octochlor acetate.

[0036] Comparing Comparative Example 5 with Example 1, it can be seen that when the fungicide was replaced by an equal amount of 3.2% amino oligosaccharide·octenylamine soluble solution, the control effect of the fungicide was slightly better than that of 3.2% amino oligosaccharide·octenylamine soluble solution. This may be because the synergistic effect of the compounding components with the active components can better exert the fungicidal and disease-resistant properties of amino oligosaccharide and octenylamine acetate, achieving high antibacterial effect at low concentrations. This has potential value in reducing formulation costs, environmental pollution, and drug resistance of Pseudomonas syringae. Comparing Comparative Example 6 with Comparative Example 4, it can be seen that when the fungicide was replaced by an equal amount of 2% amino oligosaccharide aqueous solution, the control effect was reduced. This may be because the system... The absence of octenyl acetate in the fungicide weakens its synergistic antibacterial mechanism with amino oligosaccharides, thus reducing the combined destructive effect of the two on bacterial cell membranes and consequently affecting the control efficacy. Comparing Comparative Example 7 with Comparative Example 4, replacing the fungicide with an equal amount of 1.2% octenyl acetate aqueous solution reduced the control efficacy. This may be because octenyl acetate alone only has a fungicidal function; the absence of amino oligosaccharides renders the synergistic fungicidal mechanism ineffective. Furthermore, as an anti-bacterial component against cucumber bacterial angular leaf spot, the absence of amino oligosaccharides reduces the synthesis of anti-bacterial substances such as cucumber phytoalexins and chitinases, further decreasing the field control efficacy.

[0037] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A bactericide containing amino oligosaccharides, characterized in that, Raw materials including the following percentages by mass: The active ingredient comprises 1.35-1.6%, the synergistic component comprises 1.2-1.5%, the wetting and dispersing agent comprises 3-6%, the antifreeze comprises 5-8%, the preservative comprises 0.1-0.2%, and deionized water comprises 100%. The active ingredient comprises amino oligosaccharides and octylamine acetate in a mass ratio of 1:2-5.

2. The bactericide containing amino oligosaccharides according to claim 1, characterized in that, The mass ratio of the amino oligosaccharide to octylamine acetate is 1:

3.

3. The bactericide containing amino oligosaccharides according to claim 1, characterized in that, The active component also includes ethylenediaminetetraacetic acid, and the mass ratio of the amino oligosaccharide to ethylenediaminetetraacetic acid is 1:1-2.

4. The bactericide containing amino oligosaccharides according to claim 1, characterized in that, The synergistic components include salicylic acid and alginic acid, with a mass ratio of salicylic acid to alginic acid of 2-4:

1.

5. A bactericide containing an amino oligosaccharide according to claim 4, characterized in that, The mass ratio of salicylic acid to alginic acid is 3:

1.

6. The bactericide containing amino oligosaccharides according to claim 1, characterized in that, The wetting and dispersing agent comprises sodium lauroyl sarcosinate and cocamidopropyl betaine in a mass ratio of 1:1-2.

7. The bactericide containing amino oligosaccharides according to claim 1, characterized in that, The antifreeze is at least one of ethylene glycol, propylene glycol, and glycerol; the preservative is at least one of Kathon and potassium sorbate.

8. A method for preparing a bactericide containing an amino oligosaccharide according to any one of claims 1-7, characterized in that, Includes the following steps: Add wetting and dispersing agents, antifreeze agents, and preservatives to deionized water, mix well, add active ingredients and synergistic components, and shake at 30-40℃ until a transparent homogeneous solution is formed, thus obtaining a bactericide containing amino oligosaccharides.

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