Pesticide composition based on marine bioactive substances and preparation method thereof

Abstract

The invention relates to the technical field of pesticides, in particular to a pesticide composition based on marine bioactive substances and a preparation method of the pesticide composition. The environment-friendly water-based detergent is prepared from the following raw materials in percentage by weight: 20 to 25 percent of sulfated brown algae polyphenol microcapsules, 8 to 12 percent of sodium alginate, 0.1 to 1 percent of phosphatidylcholine, 2 to 3 percent of alkylphenol polyoxyethylene ether, 1 to 3 percent of fatty alcohol-polyoxyethylene ether, 0.5 to 2 percent of azone, 2 to 5 percent of propylene glycol, 0.2 to 1 percent of organic silicon defoaming agent and the balance of water. According to the pesticide composition prepared by the invention, through slow release and targeted release, the lasting period is prolonged, and the bioavailability is improved. Meanwhile, non-target organism exposure is reduced, and ecological toxicity is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticides, and in particular to a pesticide composition based on marine biological active substances and a preparation method thereof. Background Art

[0002] With the continuous development of global agricultural production, pesticides play a vital role in ensuring the yield and quality of crops. The long-term use of traditional chemical pesticides has led to the enhancement of pathogen resistance and the intensification of environmental pollution. In my country alone, the annual loss of agricultural product exports due to pesticide residues amounts to tens of billions of yuan. Marine organisms have evolved unique secondary metabolites in extreme environments such as high pressure and high salt. Their active substances have the advantages of good environmental compatibility, strong targeting, and are not easy to induce resistance. For example, chitosan derivatives can achieve a high antibacterial rate by destroying the cell membrane of pathogens, while activating the expression of resistance genes in plant systems to increase crop yields; 3DTA compounds found in marine fungi can not only inhibit a variety of plant pathogens, but also show herbicidal activity.

[0003] As an important part of marine biological resources, algae contain rich biologically active substances. Flavonoids, alkaloids and other substances produced by marine algae play antibacterial effects by interfering with DNA synthesis and inhibiting histidine decarboxylase, while new antimicrobial peptides isolated from marine biofilms still maintain significant inhibitory effects on drug-resistant strains. For example, the bisindolepyrrole compounds isolated from marine actinomycetes have a significant killing effect on lepidopteran pests; alginate polysaccharides extracted from seaweed have multiple physiological activities such as anticoagulation, antithrombosis, and lipid regulation.

[0004] In the existing technology, there are many types of marine active substances, traditional screening methods are inefficient, and most active ingredients are easily oxidized, inactivated or degraded during extraction and processing, resulting in unstable effects in practical applications. In addition, the enzymatic hydrolysis products of marine bioactive peptides have poor functional targeting, which affects the accuracy of the final pesticide formulation. At the same time, the scope of action of a single marine active ingredient is limited, resulting in a lower-than-expected protective effect. Summary of the invention

[0005] In order to solve the problems mentioned in the above background technology, the present invention provides a pesticide composition based on marine biological active substances and a preparation method thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions: A pesticide composition based on marine bioactive substances comprises the following raw materials by weight percentage: 20-25% of sulfonated brown algae polyphenol microcapsules, 8-12% of sodium alginate, 0.1-1% of phosphatidylcholine, 2-3% of alkylphenol polyoxyethylene ether, 1-3% of fatty alcohol polyoxyethylene ether, 0.5-2% of azone, 2-5% of propylene glycol and 0.2-1% of organosilicon defoaming agent, and the balance is water.

[0007] Furthermore, the sulfonated brown algae polyphenol microcapsules are prepared by the following steps: S1. Crush the copper algae and sieve it, add ethanol and phytic acid, perform ultrasonic treatment, centrifuge at 8000 rpm for 10-15 min, collect the supernatant, and concentrate it by rotary evaporation to 1 / 10 of the original volume to obtain brown algae polyphenol extract; S2, mixing the brown algae polyphenol extract and 3'-phosphoadenosine-5'-phosphosulfate, and reacting under constant temperature and stirring in a phosphate buffer reaction environment with a pH value of 7.5. After the reaction is completed, centrifuging at a speed of 8000 rpm for 10-15 minutes in a water bath to collect the supernatant to obtain a sulfonated brown algae polyphenol solution; S3. Add the chitosan oligosaccharide solution to the primary emulsion, add the sulfonated brown algae polyphenol solution dropwise, add sodium tripolyphosphate, control the temperature and magnetic stirring, centrifuge at 8000 rpm for 10-15 min to collect the precipitate, wash, vacuum dry for 48 hours, and sieve through 200-400 mesh to obtain sulfonated brown algae polyphenol microcapsules.

[0008] Furthermore, in step S1, the mass ratio of copper algae, ethanol and phytic acid is (1-1.05): (16-19): (0.005-0.006), the power of ultrasonic treatment is 300-400 W, the power is 50-55 kHz, the temperature during ultrasonic treatment is 50-55° C., and the time during ultrasonic treatment is 20-30 min.

[0009] Furthermore, in step S2, the mass ratio of the brown algae polyphenol extract to 3'-phosphoadenosine-5'-phosphosulfate is (7-8): (0.95-1.05), the temperature is controlled at 60-65°C, the stirring speed is 60-100rpm, the reaction time is 8-10h, the water bath temperature is 90-95°C, and the water bath time is 10-20min.

[0010] Furthermore, in step S3, the mass ratio of the chitosan oligosaccharide solution, the primary emulsion, the sulfonated brown algae polyphenol solution and the sodium tripolyphosphate is 1: (20-22): (0.4-0.5): (0.2-0.3), the concentration of the chitosan oligosaccharide solution is 1.0-1.3% (w / v), the solvent is a 1% acetic acid solution with a pH value of 5.0, the temperature is controlled at 40°C, the speed of the magnetic stirring is 300-400 rpm, and the stirring time is 2-3h.

[0011] Further, the primary emulsion in step S3 is prepared through the following steps: A1. Add corn oil and vitamin E acetate into a container, heat in a water bath until completely melted, add Tween 80 and polyglycerol polyricinoleate, and stir magnetically until uniformly transparent to obtain an oil phase; A2. Add sodium hyaluronate into deionized water, perform ultrasonic treatment, add glycerol, stir magnetically until the solution is clear, and control the pH value to be 5.5 - 6.0 to obtain an aqueous phase; A3. Slowly pour the aqueous phase into the oil phase for mixing, homogenize and refine, transfer the emulsion to a water bath, stir magnetically and cool naturally to below 30°C, and adjust the pH value to 5.5 - 6.0 with citric acid or triethanolamine to obtain a primary emulsion.

[0012] Further, in step A1, the mass ratio of corn oil, vitamin E acetate, Tween 80, and polyglycerol polyricinoleate is (182 - 186):(1 - 1.1):(6 - 7):(0.09 - 0.11), the temperature of the water bath is 60 - 65°C, and the speed of magnetic stirring is 500 - 600 rpm.

[0013] Further, in step A2, the mass ratio of deionized water, sodium hyaluronate, and glycerol is (128 - 130):(1.3 - 1.5):(0.09 - 0.1), the temperature during ultrasonic treatment is 40 - 45°C, the power of ultrasonic treatment is 200 - 300 W, the frequency is 40 - 45 kHz, the time of ultrasonic treatment is 10 - 20 min, and the speed of magnetic stirring is 300 - 400 rpm.

[0014] Further, in step A3, the temperature of mixing is 70 - 75°C, the speed of homogenization is 5000 - 6000 rpm, the time of homogenization is 3 - 5 min, the temperature of the water bath is 45 - 47°C, and the speed of magnetic stirring is 100 - 200 rpm.

[0015] According to another aspect of the present invention, there is provided a preparation method of the above pesticide composition, including the following steps: Add water into a reaction kettle by weight percentage, heat to 50 - 55°C, then add sodium alginate, stir at a speed of 100 - 200 rpm until completely dissolved, add sulfonated brown algal polyphenol microcapsules, phosphatidylcholine, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether, stir at a speed of 300 - 400 rpm for 10 - 20 min, add azone and an organic silicon defoamer, and shear and emulsify at a speed of 3000 - 4000 rpm for 15 - 25 min to obtain a pesticide composition based on marine bioactive substances.

[0016] Advantages of the present invention: 1. In the technical solution of the present invention, the sulfonated modification of phlorotannins with 3'-phosphoadenosine-5'-phosphosulfate (PAPS) strengthens the interaction between phlorotannins and the cell membrane of pathogenic bacteria through charge density regulation and exposure of active sites. The electrostatic repulsion between sulfonic acid groups and the head of membrane phospholipids destroys membrane integrity, while the hydrophobic aromatic ring inserts into the membrane bilayer to cause perforation. In addition, the degradation products of chitosan oligosaccharides interfere with the formation of biofilms of pathogenic bacteria, forming a multi-target antibacterial synergistic effect with sulfonated phlorotannins.

[0017] 2. In the technical solution of the present invention, the core-shell heterogeneous structure of sulfonated phlorotannin microcapsules constructs a dense interfacial layer through the electrostatic interaction between chitosan oligosaccharides and sodium tripolyphosphate and the bonding between sulfonic acid groups and hydroxyl groups, forming a physical barrier. It not only blocks the damage to the inner-core polyphenols from the external environment, such as ultraviolet rays and oxidative free radicals, but also significantly delays the oxidative degradation of phlorotannins through the amino free radical scavenging ability and metal chelating effect of chitosan oligosaccharides, improving the stability and utilization efficiency of active ingredients, thereby enhancing the persistence and efficacy of pesticides.

[0018] 3. The pesticide composition prepared by the present invention has good environmental compatibility. The microcapsule shell layer is composed of chitosan oligosaccharides and sodium tripolyphosphate, which can be degraded by soil microorganisms into non-toxic products in the natural environment, avoiding the accumulation and pollution of chemical pesticides in the environment and helping to reduce the impact on the environment.

[0019] 4. In the technical solution of the present invention, the sulfonated phlorotannin microcapsules have a certain slow-release effect. In the alkaline environment of the plant leaf surface, the ionic cross-linked network of the shell layer dissociates to release active ingredients; while under neutral or weakly acidic storage conditions, the cross-linked structure remains stable to achieve long-term slow release. At the same time, the chitinase secreted by plant pathogenic bacteria can specifically hydrolyze the β-1,4 glycosidic bond of chitosan oligosaccharides, enabling the sulfonated phlorotannins to act precisely on the pathogenic bacteria enrichment area, improving the control efficiency and reducing the application frequency. Detailed implementation mode

[0020] Next, the technical solution of the present invention will be clearly and completely described in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0021] Unless otherwise specified, the raw materials used in the present invention are all conventional products purchased from the market.

[0022] Preparation Example 1 The primary emulsion is prepared through the following steps: A1. Add 182 g of corn oil and 1 g of vitamin E acetate into a container, heat in a water bath at 60 °C until completely melted, add 6 g of Tween 80 and 0.09 g of polyglyceryl polyricinoleate, and magnetically stir at a speed of 500 rpm until homogeneous and transparent to obtain the oil phase; A2. Add 1.3 g of sodium hyaluronate into 128 g of deionized water, perform ultrasonic treatment at 40 °C for 10 min, the power of ultrasonic treatment is 200 W, the power is 40 kHz, add 0.09 g of glycerol, and magnetically stir at a speed of 300 - 400 rpm until the solution is clear, control the pH value to be 5.5 to obtain the water phase; A3. Slowly pour the water phase into the oil phase and mix at 70 °C, homogenize and refine at a speed of 5000 rpm for 3 min, transfer the emulsion to a 45 °C water bath, magnetically stir at a speed of 100 rpm and cool naturally to 25 °C, and adjust the pH value to 5.5 with citric acid to obtain the primary emulsion.

[0023] The sulfonated fucoidan polyphenol microcapsules are prepared by the following steps: S1. Crush 10 g of Sargassum horneri and sieve it, add 160 g of ethanol and 0.05 g of phytic acid, perform ultrasonic treatment at 50 °C for 20 min, the power of ultrasonic treatment is 300 W, the power is 50 kHz, centrifuge at a speed of 8000 rpm for 10 min to collect the supernatant, and rotary evaporate and concentrate to 1 / 10 of the original volume to obtain the fucoidan polyphenol extract; S2. Mix 70 g of the fucoidan polyphenol extract and 9.5 g of 3'-phosphoadenosine-5'-phosphosulfate, react at a constant temperature of 60 °C and stir at a speed of 60 rpm for 8 h in a phosphate buffer reaction environment with a pH value of 7.5. After the reaction, perform a water bath at 90 °C for 10 min, centrifuge at a speed of 8000 rpm for 10 min to collect the supernatant to obtain the sulfonated fucoidan polyphenol solution; S3. Dissolve 0.1 g of chitosan oligosaccharide powder in 9.9 g of 1% acetic acid solution with a pH of 5.0 to prepare a chitosan oligosaccharide solution. Add 10 g of the chitosan oligosaccharide solution into 200 g of the above-prepared primary emulsion, dropwise add 4 g of the sulfonated fucoidan polyphenol solution, add 2 g of sodium tripolyphosphate, control the temperature to be 40 °C, magnetically stir at a speed of 300 rpm for 2 h, centrifuge at a speed of 8000 rpm for 10 min to collect the precipitate, wash it, vacuum dry it for 48 h, and sieve it through a 200-mesh sieve to obtain the sulfonated fucoidan polyphenol microcapsules.

[0024] Preparation Example 2 The primary emulsion is prepared by the following steps: A1. Add 184 g of corn oil and 1.05 g of vitamin E acetate into a container, heat in a water bath at 62 °C until completely melted, add 6.5 g of Tween 80 and 0.1 g of polyglyceryl polyricinoleate, and magnetically stir at a speed of 550 rpm until uniformly transparent to obtain an oil phase; A2. Add 1.4 g of sodium hyaluronate into 129 g of deionized water, perform ultrasonic treatment at 42 °C for 15 min, the power of ultrasonic treatment is 250 W, the frequency is 42 kHz, add 0.095 g of glycerol, magnetically stir at a speed of 350 rpm until the solution is clear, and control the pH value to 5.7 to obtain an aqueous phase; A3. Slowly pour the aqueous phase into the oil phase and mix at 72 °C, homogenize and refine at a speed of 5500 rpm for 4 min, transfer the emulsion to a water bath at 46 °C, magnetically stir at a speed of 150 rpm and naturally cool to 20 °C, and adjust the pH value to 5.8 with citric acid to obtain a primary emulsion.

[0025] The sulfonated fucoidan polyphenol microcapsules are prepared by the following steps: S1. Crush 10.2 g of Sargassum horneri and sieve it, add 180 g of ethanol and 0.055 g of phytic acid, perform ultrasonic treatment at 52 °C for 25 min, the power of ultrasonic treatment is 350 W, the frequency is 52 kHz, centrifuge at a speed of 8000 rpm for 12 min to collect the supernatant, and rotary evaporate and concentrate to 1 / 10 of the original volume to obtain a fucoidan polyphenol extract; S2. Mix 74 g of the fucoidan polyphenol extract and 10 g of 3'-phosphoadenosine-5'-phosphosulfate, react in a phosphate buffer reaction environment with a pH value of 7.5, stir at a constant temperature of 62 °C at a speed of 80 rpm for 9 h, after the reaction, perform a water bath at 92 °C for 15 min, centrifuge at a speed of 8000 rpm for 12 min to collect the supernatant to obtain a sulfonated fucoidan polyphenol solution; S3. Dissolve 0.12 g of chitosan oligosaccharide powder in 9.88 g of 1% acetic acid solution with a pH of 5.0 to prepare a chitosan oligosaccharide solution, add 10 g of the chitosan oligosaccharide solution to 210 g of the above-prepared primary emulsion, dropwise add 4.5 g of the sulfonated fucoidan polyphenol solution, add 2.3 g of sodium tripolyphosphate, control the temperature at 40 °C, magnetically stir at a speed of 350 rpm for 2.5 h, centrifuge at a speed of 8000 rpm for 12 min to collect the precipitate, wash it, vacuum dry it for 48 h, and sieve it through a 300-mesh sieve to obtain the sulfonated fucoidan polyphenol microcapsules.

[0026] Preparation Example 3 The primary emulsion is prepared by the following steps: A1. Add 186 g of corn oil and 1.1 g of vitamin E acetate into a container, heat in a water bath at 65 °C until completely melted, add 7 g of Tween 80 and 0.11 g of polyglyceryl polyricinoleate, and magnetically stir at a speed of 600 rpm until homogeneous and transparent to obtain the oil phase; A2. Add 1.5 g of sodium hyaluronate into 130 g of deionized water, perform ultrasonic treatment at 45 °C for 20 min, the power of ultrasonic treatment is 300 W, the frequency is 45 kHz, add 0.1 g of glycerol, magnetically stir at a speed of 400 rpm until the solution is clear, and control the pH value to 6.0 to obtain the aqueous phase; A3. Slowly pour the aqueous phase into the oil phase and mix at 75 °C, homogenize and refine at a speed of 6000 rpm for 5 min, transfer the emulsion to a water bath at 47 °C, magnetically stir at a speed of 200 rpm and cool naturally to 25 °C, and adjust the pH value to 6.0 with citric acid to obtain the primary emulsion.

[0027] The sulfonated fucoidan microcapsules are prepared by the following steps: S1. Crush 10.5 g of Sargassum horneri and sieve it, add 190 g of ethanol and 0.06 g of phytic acid, perform ultrasonic treatment at 55 °C for 30 min, the power of ultrasonic treatment is 400 W, the frequency is 55 kHz, centrifuge at a speed of 8000 rpm for 15 min to collect the supernatant, and rotary evaporate and concentrate to 1 / 10 of the original volume to obtain the fucoidan extract; S2. Mix 80 g of the fucoidan extract and 10.5 g of 3'-phosphoadenosine-5'-phosphosulfate, react in a phosphate buffer reaction environment with a pH value of 7.5, stir at a constant temperature of 65 °C at a speed of 100 rpm for 10 h, after the reaction, heat in a water bath at 95 °C for 20 min, centrifuge at a speed of 8000 rpm for 15 min to collect the supernatant to obtain the sulfonated fucoidan solution; S3. Dissolve 0.13 g of chitosan oligosaccharide powder in 9.87 g of 1% acetic acid solution with a pH of 5.0 to prepare a chitosan oligosaccharide solution, add 10 g of the chitosan oligosaccharide solution into 220 g of the above-prepared primary emulsion, dropwise add 5 g of the sulfonated fucoidan solution, add 3 g of sodium tripolyphosphate, control the temperature at 40 °C, magnetically stir at a speed of 400 rpm for 3 h, centrifuge at a speed of 8000 rpm for 15 min to collect the precipitate, wash, vacuum dry for 48 h, and sieve through a 400-mesh sieve to obtain the sulfonated fucoidan microcapsules.

[0028] Example 1 A preparation method of a pesticide composition based on marine bioactive substances, comprising the following steps: Add 59.5 g of water into a reaction kettle by weight percentage. After heating to 50 °C, add 8 g of sodium alginate and stir at a speed of 100 rpm until completely dissolved. Then add 20 g of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 1, 0.5 g of phosphatidylcholine, 3 g of alkylphenol polyoxyethylene ether, and 1 g of fatty alcohol polyoxyethylene ether. Stir at a speed of 300 rpm for 10 min, add 2 g of azone and 1 g of silicone defoamer, and shear and emulsify at 3000 rpm for 15 min to obtain a pesticide composition based on marine bioactive substances.

[0029] Example 2 A preparation method of a pesticide composition based on marine bioactive substances, comprising the following steps: Add 53.7 g of water into a reaction kettle by weight percentage. After heating to 52 °C, add 12 g of sodium alginate and stir at a speed of 150 rpm until completely dissolved. Then add 25 g of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 2, 0.3 g of phosphatidylcholine, 2 g of alkylphenol polyoxyethylene ether, and 3 g of fatty alcohol polyoxyethylene ether. Stir at a speed of 350 rpm for 15 min, add 0.5 g of azone and 0.5 g of silicone defoamer, and shear and emulsify at 3500 rpm for 20 min to obtain a pesticide composition based on marine bioactive substances.

[0030] Example 3 A preparation method of a pesticide composition based on marine bioactive substances, comprising the following steps: Add 59.8 g of water into a reaction kettle by weight percentage. After heating to 50 - 55 °C, add 10 g of sodium alginate and stir at a speed of 200 rpm until completely dissolved. Then add 22 g of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 3, 1 g of phosphatidylcholine, 2 g of alkylphenol polyoxyethylene ether, and 2 g of fatty alcohol polyoxyethylene ether. Stir at a speed of 400 rpm for 20 min, add 1 g of azone and 0.2 g of silicone defoamer, and shear and emulsify at 4000 rpm for 25 min to obtain a pesticide composition based on marine bioactive substances.

[0031] Comparative Example 1 The difference between this comparative example and Example 1 is that brown algal polyphenols are used instead of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 1, and the remaining steps are the same as those in Example 1.

[0032] Comparative Example 2 The difference between this comparative example and Example 2 is that chitosan oligosaccharide is used instead of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 2, and the remaining steps are the same as those in Example 2.

[0033] Comparative Example 3 The difference between this comparative example and Example 3 is that sodium tripolyphosphate is used instead of the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 3, and the remaining steps are the same as those in Example 3.

[0034] (Ⅰ)Indoor toxicity determination: Collect 3rd instar Plutella xylostella larvae, with a body weight of about 0.5 - 1.0 mg / larva, and subject them to starvation treatment for 4 h.

[0035] Respectively prepare 2% pesticide solutions to be tested from the pesticide compositions prepared in Examples 1 - 3 and Comparative Examples 1 - 3 according to mass fraction, using distilled water containing 0.05% Triton X - 100 as the solvent. Additionally, set up a blank control group of 0.05% Triton X - 100 solution and a positive control group of commercially available 5% abamectin emulsifiable concentrate.

[0036] Take fresh cabbage leaves, cut them into 3×5 cm leaf discs, immerse them in each pesticide solution for 10 s, air - dry naturally, place the leaf discs in a 9 - cm - diameter petri dish, line the bottom with moist filter paper for moisture retention, introduce 20 Plutella xylostella larvae into each dish for cultivation. The cultivation conditions are a temperature of 26±1℃, a relative humidity of 70%, and a light - dark ratio of 14:10 h. Gently touch the insect body with a writing brush, and those that cannot crawl normally or are completely immobile are considered dead. Set up 3 replicates. Calculate the corrected mortality after 24 h, 48 h, and 72 h. The corrected mortality (%) = (treatment mortality - control mortality) / (1 - control mortality)×100. The results are shown in Table 1: Table 1. Corrected mortalities of Examples 1 - 3, Comparative Examples 1 - 3, and the control group

[0037] (Ⅱ)Earthworm avoidance behavior test: Mix according to the ratio of 70% quartz sand, 20% kaolin, and 10% peat, control the pH value to be 6.0±0.5, and the organic matter content to be 2% to prepare artificial soil. Uniformly incorporate the pesticide compositions of Examples 1 - 3 and Comparative Examples 1 - 3 into the soil at a ratio of 1% (w / w), fully mix, and let it stand for 24 h. Prepare 6 groups of 20 cm×10 cm×5 cm transparent plastic boxes, divided into a polluted area, an intermediate isolation area, and a control area. The intermediate isolation area separates the polluted area and the control area through a partition board. The width of the intermediate isolation area is 2 cm, which is used for initially placing earthworms. The polluted area contains 200 g of soil containing 1% of the pesticide compositions prepared in each example and comparative example, and the control area contains 200 g of uncontaminated artificial soil. Set the environmental conditions as a temperature of 20±1℃, a humidity of 70%, and a dark and light - avoiding condition.

[0038] Selected adult healthy Eisenia fetida with a body weight of 300 - 500 mg were pre - adapted in artificial soil for 7 days and fed with cow dung during this period. The earthworms were randomly divided into 6 groups corresponding to Examples 1 - 3 and Comparative Examples 1 - 3, with 10 earthworms in each group and 4 replicates (n = 4). Another blank control group without the incorporation of the pesticide composition was set up.

[0039] The earthworms were placed in the middle isolation area, the isolation board was removed to allow them to move freely, and after 48 h, the number of earthworms in the contaminated area and the control area was counted, and the avoidance rate was calculated. The avoidance rate (%) = (the number of earthworms in the control area - the number of earthworms in the contaminated area) / total number of earthworms × 100. The results are shown in Table 2: Table 2. Distribution numbers of earthworms in Examples 1 - 3, Comparative Examples 1 - 3 and the blank control group

[0040] As can be seen from Table 1, the 24 - h corrected mortality rates of Examples 1 - 3 were 35 - 39%, and increased to 95 - 97.5% after 72 h, approaching the positive control (5% abamectin emulsifiable concentrate, 72 - h mortality rate 99.1%), indicating that the sulfonated fucoidan polyphenol microcapsule pesticide has both certain quick - acting and long - lasting effects. The 72 - h mortality rate of Comparative Example 1 was 65%, indicating that the non - microencapsulated fucoidan polyphenol may cause the attenuation of drug efficacy due to rapid degradation or photolysis. The 72 - h mortality rates of Comparative Example 2 and Comparative Example 3 were 50.2% and 42.3% respectively, indicating that the release of the active ingredient may be uncontrollable, resulting in a reduction in drug efficacy.

[0041] As can be seen from Table 2, the avoidance rates of Examples 1 - 3 were 15 - 22%, indicating that the sulfonated fucoidan polyphenol microcapsules have no significant repellent or toxic effects on earthworms and are environmentally friendly. The avoidance rates of Comparative Example 1 and Comparative Example 3 were 85 - 90%, indicating that free fucoidan polyphenol or sodium tripolyphosphate may stimulate the mucus layer or nerve receptors on the earthworm body surface, triggering strong avoidance behavior. The avoidance rate of Comparative Example 2 was 40%, which may be due to the cationic properties of chitosan oligosaccharide interfering with the osmotic regulation of earthworms.

[0042] In summary, the pesticide composition prepared by the present invention prolongs the long - lasting period and improves the bioavailability through slow release and targeted release. At the same time, it reduces the exposure of non - target organisms and lowers the ecological toxicity.

[0043] In the description of the specification, the descriptions referring to terms such as "preparation example", "example", "each example", etc. mean that the specific features, structures, materials or characteristics described in connection with that example or preparation example are included in at least one example or preparation example of the present invention. In this specification, the schematic representations of the above - mentioned terms do not necessarily refer to the same example or preparation example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more examples or preparation examples.

[0044] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. A pesticide composition based on marine bioactive substances, characterized in that: The raw materials include the following by weight percentage: 20-25% of sulfonated brown algae polyphenol microcapsules, 8-12% of sodium alginate, 0.1-1% of phosphatidylcholine, 2-3% of alkylphenol polyoxyethylene ether, 1-3% of fatty alcohol polyoxyethylene ether, 0.5-2% of azone, 2-5% of propylene glycol and 0.2-1% of silicone defoaming agent, and the balance is water.

2. A pesticide composition based on marine bioactive substances according to claim 1, characterized in that: The sulfonated brown algae polyphenol microcapsules are prepared by the following steps: S1. Crush the copper algae and sieve it, add ethanol and phytic acid, and perform ultrasonic treatment for 20-30 minutes. Collect the supernatant by centrifugation and concentrate it to obtain brown algae polyphenol extract; S2, mixing the brown algae polyphenol extract and 3'-phosphoadenosine-5'-phosphosulfate, controlling the temperature to keep constant and stirring for 8-10 hours, after the reaction is completed, water bathing for 10-20 minutes, centrifuging and collecting the supernatant to obtain a sulfonated brown algae polyphenol solution; S3. Add the chitosan oligosaccharide solution to the primary emulsion, add the sulfonated brown algae polyphenol solution dropwise, add sodium tripolyphosphate, stir magnetically for 2-3 hours, collect the precipitate by centrifugation, wash, dry and sieve to obtain the sulfonated brown algae polyphenol microcapsules.

3. A pesticide composition based on marine bioactive substances according to claim 2, characterized in that: In step S1, the mass ratio of copper algae, ethanol and phytic acid is (1-1.05): (16-19): (0.005-0.006), and the temperature during ultrasonic treatment is 50-55°C.

4. A pesticide composition based on marine bioactive substances according to claim 2, characterized in that: In step S2, the mass ratio of the brown algae polyphenol extract to 3'-phosphoadenosine-5'-phosphosulfate is (7-8): (0.95-1.05), the temperature is controlled at 60-65°C, and the temperature of the water bath is 90-95°C.

5. A pesticide composition based on marine bioactive substances according to claim 2, characterized in that: In step S3, the mass ratio of the chitosan oligosaccharide solution, the primary emulsion, the sulfonated brown algae polyphenol solution and sodium tripolyphosphate is 1: (20-22): (0.4-0.5): (0.2-0.3), the concentration of the chitosan oligosaccharide solution is 1.0-1.3% (w / v), and the solvent is a 1% acetic acid solution with a pH value of 5.

0.

6. A pesticide composition based on marine bioactive substances according to claim 2, characterized in that: The primary emulsion in step S3 is prepared by comprising the following steps: A1. Add corn oil and vitamin E acetate into a container, heat in a water bath until completely melted, add Tween 80 and polyglycerol polyricinoleate, and stir magnetically until uniform and transparent to obtain an oil phase; A2. Add sodium hyaluronate to deionized water, perform ultrasonic treatment for 10-20 min, add glycerol, stir magnetically until the solution is clear, and control the pH value to 5.5-6.0 to obtain an aqueous phase; A3. Slowly pour the water phase into the oil phase and mix, homogenize and refine, transfer the emulsion to a water bath, cool naturally to below 30°C with magnetic stirring, adjust the pH value to 5.5-6.0, and obtain a primary emulsion.

7. A pesticide composition based on marine bioactive substances according to claim 6, characterized in that: In step A1, the mass ratio of corn oil, vitamin E acetate, Tween 80 and polyglycerol polyricinoleate is (182-186): (1-1.1): (6-7): (0.09-0.11), and the temperature of the water bath is 60-65°C.

8. A pesticide composition based on marine bioactive substances according to claim 6, characterized in that: The mass ratio of deionized water, sodium hyaluronate and glycerol in step A2 is (128-130): (1.3-1.5): (0.09-0.1).

9. A pesticide composition based on marine bioactive substances according to claim 6, characterized in that: In step A3, the mixing temperature is 70-75°C, the homogenizing speed is 5000-6000 rpm, the homogenizing time is 3-5 min, and the temperature of the water bath is 45-47°C.

10. A method for preparing a pesticide composition based on marine bioactive substances according to any one of claims 1 to 9, characterized in that: The following steps are involved: Water is added into a reaction kettle according to weight percentage, and sodium alginate is added after the temperature is raised to 50-55° C., and the mixture is stirred at a speed of 100-200 rpm until it is completely dissolved, sulfonated brown algae polyphenol microcapsules, phosphatidylcholine, alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether are added, and the mixture is stirred at a speed of 300-400 rpm for 10-20 minutes, azone and an organosilicon defoamer are added, and the mixture is sheared and emulsified at 3000-4000 rpm for 15-25 minutes to obtain a pesticide composition based on marine biological active substances.

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