Prothioconazole nano-suspension, its preparation method and application

Abstract

The application provides a prothioconazole nano-suspension agent and a preparation method and application thereof, and belongs to the technical field of pesticide preparations. The application provides a prothioconazole nano-suspension agent, which comprises prothioconazole, modified lignin derivatives, a wetting agent and the balance of water. The prothioconazole nano-suspension agent realizes efficient loading preparation of the hydrophobic pesticide prothioconazole under the premise of not using an organic solvent. The preparation of the prothioconazole nano-suspension agent is realized through the strategy of molecular self-assembly of prothioconazole and modified lignin derivatives, the preparation process of traditional suspensions is avoided, and the nano-scale particle size is achieved through the chemical action inside the molecules, so that the prothioconazole nano-suspension agent has good biological activity. The prothioconazole nano-suspension agent also has good leaf surface wetting and adhesion, and can delay the photolysis rate of prothioconazole, so that the contradiction between the production cost and the efficacy of the pesticide and the green and sustainable development is reconciled, and the cost reduction and efficiency increase of the pesticide and the green and sustainable development are truly realized.

Description

Technical Field

[0001] This invention belongs to the field of pesticide formulation technology, specifically relating to a prothioconazole nano-suspension, its preparation method, and its application. Background Technology

[0002] The most important goal of pesticide formulation processing is to maximize the bioactivity of the active ingredients and minimize the risks to the environment and non-target organisms. Dust pollution during the production and use of powders and wettable powders, and phytotoxicity, flammability, and explosiveness caused by volatile organic solvents such as toluene and xylene in emulsifiable concentrates are becoming increasingly prominent issues. Internationally, there is a consensus that pesticide formulations should develop towards water-based, granular, slow-release, and environmentally friendly directions. Water-based formulations, represented by emulsions, microemulsions, and suspensions, granular formulations, represented by water-dispersible granules, and slow-release formulations, represented by microcapsule suspensions, have been successively developed and launched into the market.

[0003] However, these water-based, granular, and slow-release formulations still have significant shortcomings, as shown in Table 1. Addressing the problems and deficiencies of the main pesticide formulations on the market (emulsifiable concentrates, water-in-oil emulsions, microemulsions, suspension concentrates, and water-dispersible granules, etc.), there is an urgent need to develop a pesticide formulation that combines advantages such as being more green, environmentally friendly, energy-saving, highly efficient, and low-cost using novel functional materials and simple preparation processes. This will solve the aforementioned problems and promote the reduction of pesticide use while increasing efficiency, as well as the process of green and sustainable development.

[0004] Prothioconazole is renowned for its broad-spectrum fungicidal activity, exhibiting excellent control efficacy against almost all fungal diseases affecting wheat, while also demonstrating remarkable disease control capabilities on a variety of crops including soybeans, rapeseed, peanuts, and rice. Its wide range of applications and ability to control a diverse range of diseases make it one of the most comprehensive fungicide products on the market today.

[0005] Based on this, a green and environmentally friendly formulation of prothioconazole has been developed, which has the advantages of energy saving, high efficiency and low cost. It is of great significance to the development of the global pesticide market, environmental protection and reduction of health risks to non-target organisms.

[0006] Table 1. Advantages and disadvantages of major conventional pesticide formulations on the market.

[0007] Summary of the Invention

[0008] In view of the deficiencies in the existing technology, the purpose of this invention is to provide a prothioconazole nano-suspension agent, which can improve the shortcomings of traditional pesticide formulations such as emulsifiable concentrates, suspensions, water-in-oil emulsions and microemulsions, and achieve green and sustainable development of pesticides.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] This invention provides a prothioconazole nano-suspension, comprising, by mass percentage: 2%~25% prothioconazole, 2%~45% modified lignin derivative, and the balance water; wherein the modified lignin derivative comprises any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000~10000, and sodium lignin sulfonate with a molecular weight of 52000.

[0011] Preferably, by weight percentage, it comprises: 2.3%~15% prothioconazole, 24%~30% modified lignin derivative, 1%~2% wetting agent, and the balance being water.

[0012] Preferably, the prothioconazole nano-suspension also includes a wetting agent.

[0013] Preferably, the wetting agent includes any one or more of wetting agents 6501, AEO-3, and TO-8.

[0014] This invention provides a method for preparing the prothioconazole nano-suspension described in the above technical solution, comprising:

[0015] The modified lignin derivative was mixed with water to obtain a modified lignin derivative water mixture system.

[0016] The modified lignin derivative aqueous mixture system was sequentially mixed with prothioconazole and a wetting agent to obtain prothioconazole nano-suspension.

[0017] This invention provides the application of the prothioconazole nano-suspension described in the above-described technical solution or the prothioconazole nano-suspension prepared by the preparation method described in the above-described technical solution in improving the pathogen inhibition effect of prothioconazole preparations.

[0018] This invention provides the application of the prothioconazole nano-suspension described in the above-described technical solution or the prothioconazole nano-suspension prepared by the preparation method described in the above-described technical solution in improving the field disease control of prothioconazole formulations.

[0019] This invention provides an application of a modified lignin derivative in the preparation of prothioconazole formulations; the modified lignin derivative includes any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000-10000, and sodium lignin sulfonate with a molecular weight of 52000.

[0020] Preferably, the application includes at least one of the following:

[0021] (1) Reduce the particle size of prothioconazole formulations;

[0022] (2) Improve the stability of prothioconazole preparations;

[0023] (3) Reduce the surface tension of prothioconazole preparations;

[0024] (4) Improve the adhesion of prothioconazole formulations;

[0025] (5) Reduce the contact angle of prothioconazole formulations;

[0026] (6) Improve the antibacterial rate of prothioconazole preparations against pathogens;

[0027] (7) Delay the photolysis rate of prothioconazole in prothioconazole preparations.

[0028] Preferably, the application also includes reducing the toxicity of prothioconazole preparations to non-target cells.

[0029] The beneficial effects of this invention are:

[0030] This invention provides a prothioconazole nano-suspension, comprising, by mass percentage: 2%–25% prothioconazole, 2%–45% modified lignin derivative, and the balance water; the modified lignin derivative includes any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000–10000, and sodium lignin sulfonate with a molecular weight of 52000. This prothioconazole nano-suspension achieves efficient loading preparation of the hydrophobic pesticide prothioconazole without the use of organic solvents. The formulation is prepared by molecular self-assembly of prothioconazole and the low-cost, green material modified lignin derivative, avoiding the energy-intensive mechanical milling process of traditional suspension preparations. Simultaneously, nano-sized particles are achieved through intramolecular chemical interactions, resulting in good bioactivity. In addition, the prothioconazole nano-suspension prepared by this invention also exhibits good leaf wetting and adhesion properties, as well as slowing down the photolysis rate of prothioconazole, thus reconciling the contradictions between pesticide production costs, efficacy, and green sustainability, truly achieving cost reduction and efficiency improvement in pesticides, and promoting green and sustainable development. The results of the examples show that the prothioconazole nano-suspension provided by this invention has a better control effect on pathogens, and its disease control effect is significantly superior to commercially available prothioconazole formulations. In summary, this invention provides a green, energy-saving, efficient, low-cost prothioconazole sodium formulation suitable for industrial production. The prothioconazole nano-suspension provided by this invention, while ensuring efficacy and formulation stability, innovatively improves upon the significant shortcomings of traditional pesticide suspensions, emulsions, microemulsions, emulsifiable concentrates, and water-dispersible granules, achieving green and sustainable development of pesticides. Attached Figure Description

[0031] Figure 1 Images of the prothioconazole nano-suspensions prepared in Examples 1-4;

[0032] Figure 2 The graph shows the results of the self-assembly rate determination when using sodium lignosulfonate of different molecular weights with different proportions of medicinal materials in Example 1.

[0033] Figure 3 Photographs of prothioconazole nano-suspensions prepared by different mixing ratios of sodium lignosulfonate in Application Example 2, after being placed at room temperature for 7 days.

[0034] Figure 4 Particle size distribution of the 200-fold diluted prothioconazole nano-suspension prepared in Examples 1-4;

[0035] Figure 5 The graph shows the change of BS (%) with time and sample height for the prothioconazole nano-suspensions prepared in Examples 1-4, as well as the TSI test results.

[0036] Figure 6 Images of the prothioconazole nano-suspensions prepared in Examples 1 and 4 after thermal and cold storage.

[0037] Figure 7 The surface tension test results of NSC and commercially available dispersible oil suspension diluents in Examples 1-4 and Comparative Example 1 are shown in the figure.

[0038] Figure 8 The figures show the adhesion test results of NSC and commercially available dispersible oil suspension diluted solutions on wheat leaves in Examples 1-4 and Comparative Example 1.

[0039] Figure 9 Examples 1-4, and Comparative Example 1: NSC and commercially available dispersible oil suspension dilutions on wheat leaves over 170 seconds;

[0040] Figure 10 Examples 1-4, and comparative example 1, show the antibacterial results of NSC and commercially available dispersible oil suspension dilutions.

[0041] Figure 11 The graph shows the inhibition rate of NSC and commercially available dispersible oil suspension of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 10 mg / L of prothioconazole.

[0042] Figure 12 The graphs show the inhibition rates of NSC and commercially available dispersible oil suspensions of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 5 mg / L of prothioconazole.

[0043] Figure 13 The graph shows the inhibition rate of NSC and commercially available dispersible oil suspension of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 2.5 mg / L of prothioconazole.

[0044] Figure 14 The graphs show the inhibition rates of NSC and commercially available dispersible oil suspensions of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 1 mg / L of prothioconazole.

[0045] Figure 15 The results of the inhibition rate of NSC and commercially available dispersible oil suspension of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum are shown in the figure.

[0046] Figure 16 The inhibitory effects of three different molecular weights of sodium lignin sulfonate on Fusarium oxysporum.

[0047] Figure 17 Figure 4 shows the field efficacy test results of Example 4 and commercially available 30% prothioconazole dispersible oil suspension.

[0048] Figure 18 The photodegradation curves of NSC and commercially available dispersible oil suspension diluents in Examples 1-4 and Comparative Example 1 are shown.

[0049] Figure 19 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 18.75 mg / L of prothioconazole.

[0050] Figure 20 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 37.5 mg / L of prothioconazole.

[0051] Figure 21 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Example 1 to Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 75 mg / L of prothioconazole.

[0052] Figure 22 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Example 1 to Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 150 mg / L of prothioconazole.

[0053] Figure 23 The figures show the effects of NSC and commercially available dispersible oil suspensions from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 300 mg / L of prothioconazole. Detailed Implementation

[0054] This invention provides a prothioconazole nano-suspension, comprising, by mass percentage: 2%~25% prothioconazole, 2%~45% modified lignin derivative, and the remainder being water; wherein the modified lignin derivative comprises any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000~10000, and sodium lignin sulfonate with a molecular weight of 52000.

[0055] In the following technical solutions of the present invention, there are no special restrictions on the source of each raw material, and conventional commercially available products in the field can be used.

[0056] As an optional embodiment of the present invention, the prothioconazole nano-suspension contains 2% to 25% prothioconazole, which can be 2.3% to 15%, or 2%, 2.3%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%.

[0057] As an optional embodiment of the present invention, the prothioconazole nano-suspension comprises 2% to 45% modified lignin derivatives, which can be 24% to 30%, or 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41%, 42%, 43%, 44%, or 45%. As an optional embodiment of the present invention, the modified lignin derivatives comprise any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000 to 10000, and sodium lignin sulfonate with a molecular weight of 52000. As an optional embodiment of the present invention, when the modified lignin derivative includes any two of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000-10000, and sodium lignin sulfonate with a molecular weight of 52000, the two lignin sulfonates with molecular weights are preferably sodium lignin sulfonate with a molecular weight of 534.51 and sodium lignin sulfonate with a molecular weight of 5000-10000. When the modified sodium lignin sulfonate includes sodium lignin sulfonate with a molecular weight of 534.51 and sodium lignin sulfonate with a molecular weight of 5000-10000, the mass ratio of the two can be 24:(1-3), or 24:1, 24:2, or 24:3.

[0058] In this invention, the modified lignin derivative and prothioconazole are prepared through a molecular self-assembly strategy, which avoids the energy-consuming preparation process of traditional suspension concentrates using machine grinding. At the same time, nanoscale particle size is achieved through internal molecular chemical action, giving prothioconazole better biological activity.

[0059] As an optional embodiment of the present invention, the prothioconazole nano-suspension further includes a wetting agent. In this invention, the mass percentage of the wetting agent in the prothioconazole nano-suspension can be 1% to 3%, specifically 1%, 2%, or 3%. In this invention, the wetting agent in the prothioconazole nano-suspension serves to reduce the surface tension of the drug solution, helping the solution to spread, adhere, and penetrate rapidly on the target leaf. As an optional embodiment of the present invention, the wetting agent includes any one or more of wetting agents 6501, AEO-3, and TO-8.

[0060] As an optional embodiment of the present invention, the prothioconazole nano-suspension comprises the remainder water. The present invention does not specifically limit the source of the water; any water commonly used in prothioconazole formulations in the art may be used.

[0061] This invention provides a method for preparing the prothioconazole nano-suspension described in the above technical solution, comprising:

[0062] The modified lignin derivative was mixed with water to obtain a modified lignin derivative water mixture system.

[0063] The modified lignin derivative aqueous mixture system was sequentially mixed with prothioconazole and a wetting agent to obtain prothioconazole nano-suspension.

[0064] This invention involves mixing modified lignin derivatives with water to obtain a modified lignin derivative-water mixture system. The mixing method is not particularly limited; any conventional mixing method in the art can be used. As an optional embodiment of this invention, when the modified lignin derivative is two or more of the following: sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000-10000, and sodium lignin sulfonate with a molecular weight of 52000, the sodium lignin sulfonates of different molecular weights can be mixed before mixing with water.

[0065] After obtaining the modified lignin derivative aqueous mixture system, this invention sequentially mixes the modified lignin derivative aqueous mixture system with prothioconazole and a wetting agent to obtain a prothioconazole nano-suspension. This invention preferably stirs the modified lignin derivative aqueous mixture system after mixing with prothioconazole; the stirring time can be 1-3 minutes, or 1, 2, or 3 minutes; the stirring can be performed using a glass rod. This stirring allows prothioconazole and the modified lignin derivative to undergo a self-assembly reaction, which is beneficial for obtaining a stable prothioconazole nano-suspension. After stirring, this invention preferably adds a wetting agent to the mixture system to obtain the prothioconazole nano-suspension. This invention preferably stirs the mixture after adding the wetting agent.

[0066] This invention provides the application of the prothioconazole nano-suspension described in the above-described technical solution, or the prothioconazole nano-suspension prepared by the preparation method described in the above-described technical solution, in improving the pathogenic inhibition effect of prothioconazole preparations. The results of the embodiments of this invention show that the prothioconazole nano-suspension prepared by the preparation method of this invention can significantly improve the inhibition rate of prothioconazole preparations against *Fusarium oxysporum*, thereby enhancing the antibacterial effect against the pathogen.

[0067] This invention provides the application of the prothioconazole nano-suspension described in the above-described technical solution or the prothioconazole nano-suspension prepared by the preparation method described in the above-described technical solution in improving the field disease control of prothioconazole formulations.

[0068] This invention provides the application of modified lignin derivatives in the preparation of prothioconazole formulations; the modified lignin derivatives include any one or more of sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000-10000, and sodium lignin sulfonate with a molecular weight of 52000. As an optional embodiment of this invention, the application includes at least one of the following: (1) reducing the particle size of the prothioconazole formulation; (2) improving the stability of the prothioconazole formulation; (3) reducing the surface tension of the prothioconazole formulation; (4) improving the adhesion of the prothioconazole formulation; (5) reducing the contact angle of the prothioconazole formulation; (6) improving the antibacterial rate of the prothioconazole formulation against pathogens; and (7) delaying the photolysis rate of prothioconazole in the prothioconazole formulation. As an optional embodiment of this invention, the application further includes reducing the toxicity of the prothioconazole formulation to non-target cells.

[0069] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the accompanying drawings and embodiments, but these should not be construed as limiting the scope of protection of the present invention.

[0070] The experimental materials used in the following experiments are shown in Table 2.

[0071] Table 2 Experimental Materials

[0072]

[0073] Example 1

[0074] A prothioconazole nano-suspension is prepared by using sodium lignosulfonate with a molecular weight of 534.51 to prepare a 15% prothioconazole nano-suspension. The specific preparation method is as follows:

[0075] Take 24 g of sodium lignosulfonate with a molecular weight of 534.51 and mix it with pure water to a final volume of 84.2 g. Then add 15.8 g of prothioconazole technical grade and stir with a glass rod for 1 minute to obtain a prothioconazole nano-suspension with a drug loading of 15%. Figure 1 As shown.

[0076] Example 2

[0077] A prothioconazole nano-suspension is prepared by using sodium lignosulfonate with a molecular weight of 5000-10000 to prepare a 9% prothioconazole nano-suspension. The specific preparation method is as follows:

[0078] Take 30 g of sodium lignosulfonate with a molecular weight of 5000-10000 and mix it with pure water to a final volume of 90.5 g. Then add 9.5 g of prothioconazole technical grade and stir with a glass rod for 1 minute to obtain a prothioconazole nano-suspension with a drug loading of 9%. Figure 1 As shown.

[0079] Example 3

[0080] A prothioconazole nano-suspension is prepared by using sodium lignosulfonate with a molecular weight of 52,000 to prepare a 2.3% prothioconazole suspension. The specific preparation method is as follows:

[0081] Take 30 g of sodium lignosulfonate with a molecular weight of 52000 and mix it with pure water to a final volume of 97.6 g. Then add 2.4 g of prothioconazole technical grade and stir with a glass rod for 1 minute to obtain a prothioconazole suspension with a loading of 2.3%. Figure 1 As shown.

[0082] Example 4

[0083] A prothioconazole nano-suspension was prepared by using sodium lignosulfonate of different molecular weights to prepare a 15% prothioconazole nano-suspension. The specific preparation method is as follows:

[0084] Take 24 g of sodium lignosulfonate with a molecular weight of 534.51 and mix it with 2 g of sodium lignosulfonate with a molecular weight of 5000-10000. Then mix it with pure water to a final volume of 82.2 g. Next, add 15.8 g of prothioconazole technical grade and stir with a glass rod for 1 minute until the self-assembly reaction is complete. Then add 2 g of wetting agent 6501 and stir evenly with a glass rod to obtain a prothioconazole nano-suspension with a drug loading of 15%. Figure 1 As shown.

[0085] Comparative Example 1

[0086] A prothioconazole nano-suspension agent, prepared by the following method:

[0087] Weigh 15.8g of prothioconazole and 5g of dispersant CP-9 into 79.2g of pure water and mix them. Grind the mixture in a nano-sand mill for 1 hour to obtain a prothioconazole nano-suspension with a drug loading of 15%, which is represented by NSC in the attached figure.

[0088] Application Example 1

[0089] Determination of self-assembly rate of sodium lignosulfonate with different molecular weights

[0090] Experimental Methods: The content of prothioconazole was fixed at 15%. The ratio of prothioconazole to lignin sulfonate of different molecular weights (i.e., lignin sulfonate with a molecular weight of 534.51, lignin sulfonate with a molecular weight of 5000-10000, and lignin sulfonate with a molecular weight of 52000) was adjusted by varying the mass of the lignin sulfonate. The ratios of lignin sulfonate to lignin sulfonate were 5:3, 5:4, 5:5, 5:6, 5:7, 5:8, 5:9, and 5:10. After the prepared solution was thoroughly mixed, samples were taken and the prothioconazole content was determined using high-performance liquid chromatography (HPLC). After standing at room temperature for 1 hour, the supernatant solution of different samples was taken and the prothioconazole content was determined. The self-assembly rate was calculated using the following formula: Self-assembly rate (%) = Prothioconazole content in the supernatant solution / Initial amount of prothioconazole × 100%.

[0091] The results of the self-assembly rate determination for sodium lignin sulfonate of different molecular weights and different proportions of medicinal materials are as follows: Figure 2 As shown in the figure. 534 in the figure represents the self-assembly rate detection chart of different ratios of prothioconazole and sodium lignosulfonate with a molecular weight of 534.51; 1w in the figure represents the self-assembly rate detection chart of different ratios of prothioconazole and sodium lignosulfonate with a molecular weight of 5000-10000; 5.2w in the figure represents the self-assembly rate detection chart of different ratios of prothioconazole and sodium lignosulfonate with a molecular weight of 52000, and so on.

[0092] Depend on Figure 2It can be seen that sodium lignosulfonate with a molecular weight of 534 has the highest self-assembly rate with prothioconazole, reaching 100% self-assembly rate when the ratio of medicinal materials is 5:8. However, the self-assembly rate decreases as the molecular weight increases.

[0093] Application Example 2

[0094] Stability of the combined ratio of sodium lignosulfonate with different molecular weights

[0095] Preparation method: Take 24 g of sodium lignosulfonate with a molecular weight of 534.51 and mix it with 1, 2 or 3 g of sodium lignosulfonate with a molecular weight of 5000-10000. Then mix it with pure water to 82.2 g. Then add 15.8 g of prothioconazole technical material and stir with a glass rod for 1 minute until the self-assembly reaction is complete. Then add 2 g of wetting agent 6501 and stir evenly with a glass rod to obtain a prothioconazole nano-suspension with a drug loading of 15%. The mass fraction of sodium lignosulfonate with a molecular weight of 5000-10000 in the prothioconazole nano-suspension is 1%, 2% and 3%, respectively.

[0096] Prothioconazole nano-suspensions were prepared by mixing different proportions of sodium lignosulfonate. The images of the prothioconazole nano-suspensions after being placed at room temperature for 7 days are shown below. Figure 3 As shown, Figure 3 The percentage in the figure refers to the mass fraction of sodium lignosulfonate with a molecular weight of 5000-10000 in the prothioconazole nano-suspension. The results showed that all three samples with different proportions maintained good stability, without exhibiting unstable phenomena such as stratification or precipitation.

[0097] Application Example 3

[0098] The particle size of droplets in the 200-fold dilution of the prothioconazole nano-suspension prepared in Examples 1-4 was measured using a laser particle size analyzer. The results are as follows: Figure 4 As shown.

[0099] Depend on Figure 4 It can be seen from the particle size test results of the prothioconazole nano-suspensions prepared by sodium lignosulfonate with different molecular weights that, as the molecular weight of sodium lignosulfonate increases, the particle size of the suspension particles formed by molecular self-assembly becomes larger. The particle sizes of the prothioconazole nano-suspension dilute solutions prepared in Examples 1, 2, 3, and 4 are 352 nm, 663 nm, 1431 nm, and 383 nm, respectively.

[0100] Application Example 4

[0101] 1. The stability of the prothioconazole nano-suspensions prepared in Examples 1-4 was evaluated using an emulsion stabilizer. Specifically, the prothioconazole nano-suspensions were placed in sample vials, and each sample was scanned every 5 minutes at 25°C for a total of 6 hours. By measuring the change in backscattered light intensity (BS, %) over time under different sample height conditions, the changes in droplet diameter and phase separation in the prothioconazole nano-suspensions could be monitored, and the TSI value was calculated based on BS to evaluate its stability. The results are as follows: Figure 5 As shown. Figure 5 The graphs show the changes in BS (%) and TSI values ​​of the prothioconazole nano-suspensions prepared in Examples 1-4 over time (0-6 h) and sample height, where A-D are graphs showing the changes in BS (%) of the prothioconazole nano-suspensions prepared in Examples 1-4 over time (0-6 h) and sample height, respectively; E is graph showing the changes in TSI values ​​of the prothioconazole nano-suspensions prepared in Examples 1-4 over time (0-6 h); and F is graph showing the TSI values ​​of the prothioconazole nano-suspensions prepared in Examples 1-4 at 6 h.

[0102] The BS and TSI values ​​obtained from Examples 1-3 show that with the increase of the molecular weight of sodium lignosulfonate, the BS of the prepared prothioconazole nano-suspension changes significantly and the TSI value increases, reaching 1.53, 3.34, and 16.81 respectively. This indicates that the higher the molecular weight of sodium lignosulfonate, the less stable the prepared prothioconazole nano-suspension system becomes. When sodium lignosulfonate of different molecular weights is mixed in a certain proportion, the prepared prothioconazole nano-suspension (Example 4) shows no significant change in BS, and the TSI value after 6 hours is only 0.18, exhibiting excellent stability.

[0103] 2. The prothioconazole nano-suspensions of Examples 1 and 4 were subjected to 14 days of heat storage (54°C) and 7 days of cold storage (0°C), and their stability under extreme conditions was determined by changes in appearance. The prothioconazole nano-suspensions prepared in Examples 1 and 4, which had lower TSI values, were also subjected to 14 days of heat storage and 7 days of cold storage for stability observation. The results are as follows: Figure 6 As shown, A represents the stability of the prothioconazole nano-suspension prepared in Example 1 after 14 days of heat storage and 7 days of cold storage; B represents the stability of the prothioconazole nano-suspension prepared in Example 4 after 14 days of heat storage and 7 days of cold storage.

[0104] Depend on Figure 6 It can be seen that Example 1 showed obvious stratification and instability after hot and cold storage, while Example 4 maintained a uniform appearance and stable state without sedimentation after cold and hot storage, which meets the industrialization standard.

[0105] Application Example 5

[0106] Examples 1-4, Comparative Example 1, and the commercially available 30% prothioconazole dispersible oil suspension were diluted 200 times with pure water. The static surface tension of the diluted solutions was measured using a DCAT21 surface tension meter. The measurement method was the Wilhelmy dipstick method. Before each test, the dipstick was rinsed with deionized water and anhydrous ethanol, then heated with an alcohol lamp until glowing red. After the dipstick cooled to room temperature, the measurement was started. Each sample was measured three times. The surface tension measurement results are as follows: Figure 7 As shown.

[0107] Depend on Figure 7 As can be seen, the surface tension values ​​of Examples 1-3, which did not contain any wetting agent, were as high as those of the NSC in Comparative Example 1, all exceeding 45 mN / m. However, Example 4, which only contained 2% wetting agent, had a surface tension value as low as 28.9 mN / m, lower than the 30.4 mN / m of a commercially available dispersible oil suspension containing a large amount of organic solvent and surfactant.

[0108] Application Example 6

[0109] All samples, including Examples 1-4, Comparative Example 1, and commercially available 30% prothioconazole dispersible oil suspension, were diluted 200-fold with pure water. The adhesion force between the diluted solution and wheat leaves was measured using a DCAT21 surface tension meter equipped with a microbalance system. First, wheat leaves were fixed to a glass slide using double-sided tape and placed on a stage. Then, 5 μL of the diluted solution was injected onto a metal ring using a microsyringe. After the measurement was initiated, the stage slowly rose until it contacted the metal ring containing the droplet. The microbalance recorded the force-distance curve between the droplet and the wheat leaf by sensing the mass change on the metal ring. Each sample was measured three times. The liquid-solid interaction between the droplet and the wheat leaf surface could be characterized by monitoring the change in the adhesion force of the droplet on the ring as a function of the distance between the droplet and the leaf surface. The results are shown below. Figure 8 As shown, A represents the adhesion observation results of pure water; B represents the adhesion observation results of the prothioconazole nano-suspension prepared in Example 1; C represents the adhesion observation results of the prothioconazole nano-suspension prepared in Example 2; D represents the adhesion observation results of the prothioconazole nano-suspension prepared in Example 3; E represents the adhesion observation results of the prothioconazole nano-suspension prepared in Comparative Example 1; F represents the adhesion observation results of the commercially available 30% prothioconazole dispersible oil suspension; G represents the adhesion observation results of the prothioconazole nano-suspension prepared in Example 4; and H represents the comparison results of the adhesion forces of Examples 1-4, Comparative Example 1, and the commercially available 30% prothioconazole dispersible oil suspension.

[0110] Depend on Figure 8It was found that the maximum adhesion force of the prothioconazole nano-suspension prepared in Examples 1-3 on wheat leaves was similar to that of pure water, while the maximum adhesion force of the prothioconazole nano-suspension prepared in Example 4 was similar to that of commercially available dispersible oil suspensions. The greater the maximum adhesion force, the stronger the bond between the droplets and the leaf surface. This indicates that the prothioconazole nano-suspension prepared in Example 4 has superior wetting and deposition effects in field applications, which can improve pesticide utilization.

[0111] Application Example 7

[0112] Examples 1-4, Comparative Example 1, and the commercially available 30% prothioconazole dispersible oil suspension were diluted 200 times with pure water. The dynamic contact angle of the diluted samples on the surface of wheat leaves was measured using an SCA 20 contact angle meter. First, wheat leaves were fixed to a glass slide using double-sided tape, and then placed in the temperature control unit of the contact angle meter. By controlling the syringe pump of the contact angle meter, 4 μL of the diluted solution was injected onto the surface of the wheat leaves on the glass slide. The dynamic contact angle change of the diluted solution on the wheat leaf surface was recorded over 170 s. Each sample was measured three times. The results are shown in Table 3. Figure 9 As shown.

[0113] Table 3. Changes in contact angle of diluted solutions of Examples 1-4, Comparative Example 1, and commercially available 30% prothioconazole dispersible oil suspension.

[0114]

[0115] Note: Oil suspension refers to "commercially available 30% prothioconazole dispersible oil suspension".

[0116] Generally, the contact angle can be used to characterize the wetting and spreading ability of a droplet. A lower contact angle indicates better wetting and spreading. (See Table 3 and...) Figure 9 As shown, the prothioconazole nano-suspensions prepared in Examples 1-3 and the NSC in Comparative Example 1 maintained high contact angles on wheat leaves within 170 seconds, indicating that they did not wet on rice leaves. However, the prothioconazole nano-suspension prepared in Example 4, with only 2% wetting agent added, achieved wetting and spreading on wheat leaves, reducing the contact angle to below 60° within 170 seconds, achieving the same effect as dispersible oil suspensions containing large amounts of organic solvents and surfactants.

[0117] Application Example 8

[0118] The mycelial growth rate method was used to determine the sample's resistance to *Fusarium graminearum* (…). Fusarium pseudograminearum The antibacterial activity of ) was observed in Examples 1-4. Figure 10 The following are respectively represented by A, B, C, and D), Comparative Example 1, and commercially available 30% prothioconazole dispersible oil suspension (…). Figure 10The prothioconazole preparations (represented by OD) were diluted to effective concentrations of 0.5–10 mg / L (i.e., diluted to 0.5, 1, 2.5, 5, and 10 mg / L, respectively), with each treatment repeated three times. Specifically, the prothioconazole preparations were diluted to effective prothioconazole concentrations of 0.5 mg / L, 1 mg / L, 2.5 mg / L, 5 mg / L, and 10 mg / L using PDA medium. *Fusarium graminearum* was then cultured in mediums containing different concentrations of prothioconazole. After incubation at (25±1)℃ for a certain period, the mycelial colony diameter was determined using the cross-crossing method. Inhibition rate = (control colony diameter - treatment colony diameter) / (control colony diameter - mycelial disc diameter 5 mm) × 100%. Results are as follows: Figures 10-15 As shown. Figure 10 Examples 1-4 show the antibacterial results of NSC and commercially available dispersible oil suspension dilutions against Fusarium oxysporum in Comparative Example 1. Figure 11 The graph shows the inhibition rate of NSC and commercially available dispersible oil suspension of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 10 mg / L of prothioconazole. Figure 12 The graphs show the inhibition rates of NSC and commercially available dispersible oil suspensions of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 5 mg / L of prothioconazole. Figure 13 The graph shows the inhibition rate of NSC and commercially available dispersible oil suspension of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 2.5 mg / L of prothioconazole. Figure 14 The graphs show the inhibition rates of NSC and commercially available dispersible oil suspensions of Examples 1-4 and Comparative Example 1 against Fusarium oxysporum at a concentration of 1 mg / L of prothioconazole. Figure 15 The graph shows the inhibition rate of NSC and commercially available dispersible oil suspensions against Fusarium graminearum in Examples 1-4 and Comparative Example 1, respectively, at a concentration of 0.5 mg / L of prothioconazole.

[0119] like Figures 10-15As shown, at all concentrations, the inhibition rates of pathogens in treatments of Examples 2 and 4 were significantly higher than those in NSC and Examples 1 and 3. This indicates that sodium lignosulfonate with a molecular weight of 5000-10000 has a synergistic effect on pathogens (because Examples 2 and 4 both contain sodium lignosulfonate with a molecular weight of 5000-10000, while the other treatments do not). Furthermore, at higher concentrations such as 10, 5, and 2.5 mg / L, the inhibition rates of pathogens in Examples 2 and 4 were also significantly higher than those of commercially available dispersible oil suspensions. This suggests that the addition of sodium lignosulfonate with a molecular weight of 5000-10000 can improve the utilization rate of prothioconazole to some extent and reduce the amount of pesticide used. The fact that commercially available dispersible oil suspensions at concentrations of 0.5–5 mg / L showed higher inhibition rates against pathogens than NSC treatments with nanoparticle size may be due to the high organic solvent content in commercially available dispersible oil suspensions, which to some extent leads to a higher inhibitory effect on pathogens. This indicates that in this experiment, the formulation composition of the preparation itself is more important than particle size in its inhibitory effect on pathogens.

[0120] Application Example 9

[0121] Bioactivity determination of sodium lignin sulfonate of different molecular weights against Fusarium oxysporum

[0122] The method for determining the bioactivity against *Fusarium graminearum* was the same as in Example 8 (prothioconazole bioassay method), except for the sample and concentration. The samples were three different molecular weights of sodium lignin sulfonate. All samples were ultimately diluted to concentrations of 5, 10, 25, 50, and 100 ppm to determine their bioactivity against *Fusarium graminearum*.

[0123] Specifically:

[0124] Sodium lignin sulfonate with a molecular weight of 534.51, sodium lignin sulfonate with a molecular weight of 5000-10000, and sodium lignin sulfonate with a molecular weight of 52000 were dissolved in ultrapure water to obtain a 10% (w / w) mixture. This mixture was then diluted with PDA medium to prepare PDA media containing 5, 10, 25, 50, and 100 ppm of sodium lignin sulfonate with a molecular weight of 534.51; 5, 10, 25, 50, and 100 ppm of sodium lignin sulfonate with a molecular weight of 5000-10000; and 5, 10, 25, 50, and 100 ppm of sodium lignin sulfonate with a molecular weight of 52000. The blank control was PDA medium without sodium lignin sulfonate.

[0125] Then, *Fusarium oxysporum* was cultured using PDA medium containing sodium lignin sulfonate of different molecular weights and concentrations. After incubation at (25±1)℃ for a certain period, the mycelial colony diameter was determined using the cross-crossing method. Inhibition rate = (control colony diameter - treated colony diameter) / (control colony diameter - mycelial disc diameter 5 mm) × 100%. Results are as follows... Figure 16 As shown in the figure, A represents the effect of sodium lignin sulfonate with different molecular weights on Fusarium graminearum colonies; B represents the inhibition rate of sodium lignin sulfonate with a molecular weight of 534.51 on Fusarium graminearum; C represents the inhibition rate of sodium lignin sulfonate with a molecular weight of 5000-10000 on Fusarium graminearum; and D represents the inhibition rate of sodium lignin sulfonate with a molecular weight of 52000 on Fusarium graminearum.

[0126] from Figure 16 It was found that sodium lignin sulfonate with three different molecular weights did not show significant inhibitory activity against Fusarium graminearum, and no increase in concentration resulted in enhanced biological activity. However, when sodium lignin sulfonate with a molecular weight of 5000-10000 was used as a material to self-assemble with prothioconazole to form nano-formulations (Examples 2 and 4), a significant synergistic effect was observed. This indicates that the self-assembled system has good application prospects, and the use of this material can improve the utilization rate of pesticides, achieving the goal of reducing application and increasing efficiency.

[0127] Application Example 10

[0128] Example 4 and field trials of commercially available 30% prothioconazole dispersible oil suspension.

[0129] The experiment was conducted in a wheat field 300m southeast of the Liuqu Xianghe Gas Station on Yuyou Road, Fuping County, Weinan City, Shaanxi Province, at 34°52'17"N"109°17'26"E, at an altitude of 459 meters. The wheat variety was Xinnong 962, and the sowing time was October 18-19, 2024, with a sowing rate of 35-36 catties / mu.

[0130] The experiment was conducted in three treatment cells, each with an area of ​​1600 m². 2 (50×32m). Treatment 1: 40g / mu of commercially available 30% prothioconazole dispersible oil suspension; Treatment 2: 80g / mu of 15% prothioconazole nano suspension; the blank control was treated with water. Drone spraying was used. Drone spraying parameters were as follows: 2L of pesticide per plot, altitude 3m, speed 5m / s, spray width 8m. Two applications were made: one at the early flowering stage (April 26, 2025) and one at the late flowering stage (May 3, 2025). Disease incidence was investigated and recorded 20 days after the last application.

[0131] A five-point survey method was used, with each point measuring 0.25 m.2 Record the disease occurrence level and the corresponding number of diseased ears, and calculate the disease rate, disease index, and disease control efficacy.

[0132] Grading standards: Grade 1: The area of ​​dead ears accounts for less than 1 / 4 of the total ear area; Grade 3: The area of ​​dead ears accounts for 1 / 4 to 1 / 2 of the total ear area; Grade 5: The area of ​​dead ears accounts for 1 / 2 to 3 / 4 of the total ear area; Grade 7: The area of ​​dead ears accounts for 3 / 4 or more of the total ear area.

[0133] Calculation formula:

[0134]

[0135] The disease control efficacy and disease index efficacy (referred to as disease index efficacy) of treatment 1 and treatment 2 are as follows: Figure 17 As shown in the figure. A is a field survey of disease occurrence; B is the disease control efficacy and disease index efficacy of treatment 1 and treatment 2, where OD represents the result corresponding to treatment 1; Example 4 represents the result corresponding to treatment 2.

[0136] from Figure 17 As can be seen from the results, in the field experiment on the control of wheat scab, Example 4 showed a significantly higher effect than commercially available dispersible oil suspensions in controlling wheat scab. This verified the results of the indoor bioassay and also proved that the nano-suspension prepared by sodium lignosulfonate and prothioconazole through molecular self-assembly technology has broad prospects for field application, promoting the reduction of pesticide use and the increase of efficiency, and green and sustainable development.

[0137] Application Example 11

[0138] The prothioconazole nano-suspensions prepared in Examples 1-4, the 15% prothioconazole nano-suspension prepared in Comparative Example 1, and the commercially available 30% prothioconazole dispersible oil suspension were diluted with ultrapure water to a concentration of 250 mg / L, the same as the active ingredient in prothioconazole. The solutions were then placed in a stoppered quartz tube, with a high-pressure mercury lamp as the light source. The quartz tube was positioned 10 cm from the light source. The rotating motor was started and the solution was continuously stirred to ensure uniform illumination. After the photolysis apparatus stabilized, a photolysis experiment was performed. After different illumination times, 1 mL samples were taken, diluted and dissolved in 4 mL of methanol, filtered through a 0.22 μm filter, and the concentration of prothioconazole was determined by HPLC.

[0139] Figure 18 The figures show the photodegradation curves of Examples 1-4 and Comparative Example 1, and the commercially available dispersible oil suspension after dilution. In the figures, Ct is the mass concentration of prothioconazole in the diluted solution at time t (mg / L), C0 is the initial mass concentration of prothioconazole (mg / L), and Ct / C0 represents the percentage of remaining prothioconazole in the diluted solution. Figure 18 The left figure shows the photodegradation curves of different prothioconazole formulations; the right figure shows the actual samples after dilution.

[0140] Figure 18 The results showed that as the molecular weight of sodium lignosulfonate increased, its photoprotective properties became stronger, effectively delaying the photodegradation of prothioconazole. After 3 hours, the remaining percentages of prothioconazole in Examples 1, 2, and 3 were 36.7%, 64.1%, and 70.8%, respectively. For the prothioconazole nano-suspension prepared in Example 4 by mixing sodium lignosulfonate of different molecular weights, the remaining percentage of prothioconazole after 3 hours of UV irradiation was 35.4%, significantly higher than that of commercially available dispersible oil suspensions, which had a remaining percentage of 2.1%. This indicates that using sodium lignosulfonate as a self-assembling material can significantly reduce the photolysis rate of prothioconazole in an aqueous environment and improve its stability, demonstrating its resistance to UV degradation.

[0141] Application Example 12

[0142] The toxicity of Examples 1-4, Comparative Example 1, and commercially available 30% prothioconazole dispersible oil suspension to HEK-293T cells was tested at concentrations ranging from 18.75 to 300 mg / L (i.e., diluted to 18.75 mg / L, 37.5 mg / L, 75 mg / L, 150 mg / L, and 300 mg / L, respectively), with each treatment performed in triplicate.

[0143] Before seeding HEK-293T cells into plates, aspirate the culture medium from the culture flask, wash once with PBS, and add 0.25% trypsin to digest the cells. After discarding the trypsin, add complete culture medium containing 10% fetal bovine serum (the complete culture medium consists of 10% FBS in DMEM high-glucose medium + 1% L-glutamine; 1% NEAA) and pipette the cells. Then, seed the HEK-293T cell suspension at a density of 10,000 cells per well into 96-well plates, adding 100 µL of culture medium to each well, and incubate overnight at 37°C and 5% CO2. Next, add samples of different concentrations diluted above into the well plates, continue culturing for 24 h, aspirate the original culture medium, add 1 mL of medium containing 10% CCK8 to each well, and continue culturing for 2 h. Then, thoroughly homogenize the liquid and add it into 96-well plates, using wells containing cells in growth medium without samples as controls, with the proliferation rate set to 100%. Each well contains cells, and the process is repeated 3 times. Cell viability was assessed using the CCK-8 assay. Optical density (OD) values ​​were measured at 450 nm using a microplate reader. Cell viability (%) = (A sample - A blank) / (A control - A blank) × 100%. Results are as follows: Figures 19-23 As shown. Figure 19Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 18.75 mg / L of prothioconazole. Figure 20 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 37.5 mg / L of prothioconazole. Figure 21 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Example 1 to Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 75 mg / L of prothioconazole. Figure 22 Figure 1 shows the effect of NSC and commercially available dispersible oil suspension from Example 1 to Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 150 mg / L of prothioconazole. Figure 23 The figures show the effects of NSC and commercially available dispersible oil suspensions from Examples 1-4 and Comparative Example 1 on the survival rate of HEK-293T cells at an effective concentration of 300 mg / L of prothioconazole.

[0144] pass Figures 19-23 It can be seen that, compared with commercially available dispersible oil suspensions and NSCs, the prothioconazole nano-suspension formed by molecular self-assembly using sodium lignosulfonate exhibits the same or even lower toxicity to HEK-293T cells. This indicates that the prothioconazole nano-suspension prepared in this invention is more in line with the requirements of green and sustainable development in terms of its toxicity to non-target organisms compared with commercially available dispersible oil suspensions and conventional nano-suspensions, and there is no situation where the non-target toxicity is higher due to the reduction in particle size or the use of sodium lignosulfonate material.

[0145] 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. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A propiconazole nano-suspension characterized in that, The composition comprises, by mass percentage, propiconazole 2.3-15%, modified lignin derivative 24-30%, wetting agent 1-2%, and the balance of water; the modified lignin derivative is sodium lignosulfonate with a molecular weight of 534.51 and sodium lignosulfonate with a molecular weight of 5000-10000.

2. The propiconazole nano-suspension according to claim 1, characterized in that, The wetting agent comprises any one or two or more of wetting agent 6501, AEO-3, and TO-8.

3. A process for the preparation of a propiconazole nano-suspension as claimed in claim 1 or 2, characterized in that, The application comprises the following steps: The modified lignin derivative is mixed with water to obtain a modified lignin derivative water mixture; The modified lignin derivative water mixture is sequentially mixed with propiconazole and the wetting agent to obtain the propiconazole nano-suspension.

4. The application of the propiconazole nano-suspension of claim 1 or 2 or the propiconazole nano-suspension prepared by the preparation method of claim 3 in improving the pathogenic bacteria inhibition effect of propiconazole preparation.

5. The application of the propiconazole nano-suspension of claim 1 or 2 or the propiconazole nano-suspension prepared by the preparation method of claim 3 in improving the field disease control of propiconazole preparation.

6. The application of the propiconazole nano-suspension of claim 1 or 2 or the propiconazole nano-suspension prepared by the preparation method of claim 3 in preparing propiconazole preparation.

7. Use according to claim 6, characterized in that, The application comprises at least one of the following: (1) reducing the particle size of propiconazole preparation; (2) improving the stability of propiconazole preparation; (3) reducing the surface tension of propiconazole preparation; (4) improving the adhesion of propiconazole preparation; (5) reducing the contact angle of propiconazole preparation; (6) improving the antibacterial rate of propiconazole preparation on pathogenic bacteria; (7) delaying the photolysis rate of propiconazole in propiconazole preparation.

8. Use according to claim 6, characterized in that, The application also comprises reducing the toxicity of propiconazole preparation on non-target cells.

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