A pesticide composition based on marine bioactive substances and a method for preparing the same

Abstract

The present application relates to the technical field of pesticides, and particularly relates to a pesticide composition based on marine bioactive substances and a preparation method thereof, which comprises the following raw materials in percentage by weight: sulfonated brown algae polyphenol microcapsules 20-25%, sodium alginate 8-12%, phosphatidylcholine 0.1-1%, alkylphenol polyoxyethylene ether 2-3%, fatty alcohol polyoxyethylene ether 1-3%, azone 0.5-2%, propylene glycol 2-5% and organic silicon defoaming agent 0.2-1%, and the rest is water. The pesticide composition prepared by the present application can achieve slow release and targeted release, prolong the effective period and improve the bioavailability. Meanwhile, the exposure of non-target organisms is reduced, and the ecological toxicity is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pesticides, in particular to a pesticide composition based on marine bioactive substances and a preparation method thereof. BACKGROUND

[0002] With the continuous development of global agricultural production, pesticides play a crucial role in ensuring crop yield and quality. Long-term use of traditional chemical pesticides leads to increased resistance of pathogenic bacteria and environmental pollution. In China alone, the annual loss of agricultural product exports due to pesticide residues reaches tens of billions of yuan. Marine organisms have evolved unique secondary metabolites in extreme environments such as high pressure and high salt, and their active substances have the advantages of good environmental compatibility, strong targeting and difficulty in inducing resistance. For example, chitosan derivatives can achieve high inhibition rate by destroying the cell membrane of pathogenic bacteria, and activate plant systemic resistance gene expression to increase crop yield. 3DTA compounds found in marine fungi not only inhibit a variety of plant pathogens, but also exhibit herbicidal activity.

[0003] Algae, as an important part of marine biological resources, contain rich bioactive substances. Flavonoids and alkaloids produced by marine algae exert antibacterial effects through mechanisms such as interfering with DNA synthesis and inhibiting histidine decarboxylase. Novel antibacterial peptides isolated from marine biofilms still have significant inhibitory effects on drug-resistant strains. For example, bis-indole pyrrole compounds isolated from marine actinomycetes have significant killing effect on lepidopteran pests. Alginic acid polysaccharides extracted from seaweed have multiple physiological activities such as anticoagulation, antithrombosis and blood lipid regulation.

[0004] In the prior art, marine active substances are diverse, traditional screening methods are inefficient, and most active ingredients are easily oxidized or degraded during extraction and processing, resulting in unstable effects in actual application. In addition, the enzymatic products of marine bioactive peptides have poor functional targeting, affecting the precision of the final pesticide formula. At the same time, the action range of single marine active ingredient is limited, resulting in lower than expected prevention and control effect. SUMMARY

[0005] To solve the problems mentioned in the background art, the present application provides a pesticide composition based on marine bioactive substances and a preparation method thereof.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] A pesticide composition based on marine bioactive substances, comprising the following raw materials by weight percentage: sulfonated brown algal polyphenol microcapsules 20-25%, sodium alginate 8-12%, phosphatidylcholine 0.1-1%, alkylphenol polyoxyethylene ether 2-3%, fatty alcohol polyoxyethylene ether 1-3%, azone 0.5-2%, propylene glycol 2-5%, and silicone defoaming agent 0.2-1%, with the balance being water.

[0008] Further, the sulfonated brown algal polyphenol microcapsules are prepared by the following steps:

[0009] S1, crushing the Sargassum horneri, adding ethanol and phytic acid, ultrasonic treatment, centrifuging at 8000 rpm for 10-15 min to collect the supernatant, rotary evaporation to concentrate to 1 / 10 of the original volume, to obtain a brown algal polyphenol extract;

[0010] S2, mixing the brown algal polyphenol extract and 3'-adenosine-5'-phosphosulfate, controlling the temperature to be constant under the reaction environment of a phosphate buffer with a pH value of 7.5, stirring, after the reaction, water bath, centrifuging at 8000 rpm for 10-15 min to collect the supernatant, to obtain a sulfonated brown algal polyphenol solution;

[0011] S3, adding the chitin oligosaccharide solution to the primary emulsion, adding the sulfonated brown algal polyphenol solution drop by drop, adding sodium tripolyphosphate, controlling the temperature to be constant by magnetic stirring, centrifuging at 8000 rpm for 10-15 min to collect the precipitate, washing, vacuum drying for 48 h, sieving through a 200-400 mesh sieve, to obtain sulfonated brown algal polyphenol microcapsules.

[0012] Further, in step S1, the mass ratio of Sargassum horneri, ethanol and phytic acid is (1-1.05):(16-19):(0.005-0.006), the ultrasonic treatment power is 300-400 W, the power is 50-55 kHz, the ultrasonic treatment temperature is 50-55℃, and the ultrasonic treatment time is 20-30 min.

[0013] Further, in step S2, the mass ratio of the brown algal polyphenol extract and 3'-adenosine-5'-phosphosulfate is (7-8):(0.95-1.05), the controlled temperature is 60-65℃, the stirring speed is 60-100 rpm, the reaction time is 8-10 h, the water bath temperature is 90-95℃, and the water bath time is 10-20 min.

[0014] Further, the mass ratio of the chitin oligosaccharide solution, the primary emulsion, the sulfonated phlorofuco-phenol solution and the sodium tripolyphosphate in step S3 is 1:(20-22):(0.4-0.5):(0.2-0.3), the concentration of the chitin oligosaccharide solution is 1.0-1.3% (w / v), the solvent is 1% acetic acid solution with pH value = 5.0, the temperature is controlled at 40°C, the speed of the magnetic stirring is 300-400 rpm, and the stirring time is 2-3 h.

[0015] Further, the primary emulsion in step S3 is prepared by the following steps:

[0016] A1, corn oil and vitamin E acetate are added into a container, heated to complete melting in a water bath, Tween 80 and polyglycerol polyricinoleate are added, and magnetic stirring is performed until uniform and transparent, to obtain an oil phase;

[0017] A2, sodium hyaluronate is added into deionized water, ultrasonic treatment is performed, glycerol is added, and magnetic stirring is performed until the solution is clear, and the pH value is controlled at 5.5-6.0, to obtain an aqueous phase;

[0018] A3, the aqueous phase is slowly poured into the oil phase for mixing, homogenization and refinement are performed, the emulsion is transferred to a water bath, magnetic stirring is performed for natural cooling to below 30°C, and the pH value is adjusted to 5.5-6.0 with citric acid or triethanolamine, to obtain a primary emulsion.

[0019] Further, the mass ratio of the corn oil, vitamin E acetate, Tween 80 and polyglycerol polyricinoleate in step A1 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 the magnetic stirring is 500-600 rpm.

[0020] Further, the mass ratio of the deionized water, sodium hyaluronate and glycerol in step A2 is (128-130):(1.3-1.5):(0.09-0.1), the temperature during ultrasonic treatment is 40-45°C, the power during ultrasonic treatment is 200-300 W, the power is 40-45 kHz, the ultrasonic treatment time is 10-20 min, and the speed of the magnetic stirring is 300-400 rpm.

[0021] Further, the temperature during mixing in step A3 is 70-75°C, the speed of the homogenization is 5000-6000 rpm, the homogenization time is 3-5 min, the temperature of the water bath is 45-47°C, and the speed of the magnetic stirring is 100-200 rpm.

[0022] According to another aspect of the present application, a preparation method of the above-mentioned pesticide composition is provided, comprising the following steps:

[0023] The water is added in the reaction kettle according to the percentage by weight, heated to 50-55 DEG C, then add sodium alginate, stirring at 100-200 rpm until completely dissolved, add sulfonated brown algal polyphenol microcapsule, phosphatidylcholine, alkylphenol polyoxyethylene ether and fatty alcohol polyoxyethylene ether, stirring at 300-400 rpm for 10-20 min, add a nitrogen ketone and silicone defoaming agent, shear emulsification at 3000-4000 rpm for 15-25 min, to obtain a pesticide composition based on marine active substances.

[0024] The beneficial effects of the present application are:

[0025] 1、In the technical scheme of the present application, the 3'-phosphoadenosine-5'-phosphosulfate (PAPS) sulfonated modification of brown algal polyphenol regulates the charge density and exposes the active site, strengthening the interaction of brown algal polyphenol with the cell membrane of pathogenic bacteria. The electrostatic repulsion of the sulfonic acid group with the head of the membrane phospholipid destroys the membrane integrity, and the hydrophobic aromatic ring inserts into the membrane bilayer to induce perforation. In addition, the chitooligosaccharide degradation product interferes with the formation of pathogenic bacterial biofilm, forming a multi-target synergistic effect with sulfonated brown algal polyphenol.

[0026] 2、In the technical scheme of the present application, the core-shell heterostructure of the sulfonated brown algal polyphenol microcapsule forms a dense interface layer through the electrostatic interaction of chitooligosaccharide and sodium tripolyphosphate and the bonding of the sulfonic acid group and the hydroxyl group, forming a physical barrier. Not only does it block the destruction of the inner core polyphenol by the external environment, such as ultraviolet light and oxidative free radicals, but also significantly delays the oxidative degradation of brown algal polyphenol through the amino radical scavenging ability and metal chelation of chitooligosaccharide, improving the stability and utilization efficiency of the active ingredient, thereby improving the persistence and effect of the pesticide.

[0027] 3、The pesticide composition prepared by the present application has good environmental compatibility. The microcapsule shell layer is composed of chitooligosaccharide 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.

[0028] 4、In the technical scheme of the present application, the sulfonated brown algal polyphenol microcapsule has a certain slow-release effect. In the alkaline environment of plant leaves, the shell ion crosslinking network dissociates, releasing the active ingredient; while in neutral or weakly acidic storage conditions, the crosslinking structure remains stable, achieving long-acting slow release. At the same time, chitinase secreted by plant pathogenic bacteria can specifically hydrolyze the beta-1,4 glycosidic bond of chitooligosaccharide, allowing the sulfonated brown algal polyphenol to act precisely on the pathogenic bacteria-rich area, improving the control efficiency and reducing the frequency of pesticide application. DETAILED DESCRIPTION

[0029] The technical solutions of the present application will be clearly and completely described below in combination with the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0030] Unless otherwise specified, the raw materials used in the present application are all obtained from market-purchased conventional products.

[0031] Preparation Example 1

[0032] The primary emulsion is prepared by the following steps:

[0033] A1, 182 g of corn oil and 1 g of vitamin E acetate are added to a container, heated to complete melting in a water bath at 60°C, 6 g of Tween 80 and 0.09 g of polyglycerol polyricinoleate are added, and magnetic stirring is performed at a speed of 500 rpm until uniform transparency is obtained, to obtain an oil phase;

[0034] A2, 1.3 g of sodium hyaluronate is added to 128 g of deionized water, ultrasonic treatment is performed at 40°C for 10 min, the ultrasonic treatment power is 200 W, the power is 40 kHz, 0.09 g of glycerol is added, and magnetic stirring is performed at a speed of 300-400 rpm until the solution is clear, the pH value is controlled to be 5.5, to obtain an aqueous phase;

[0035] A3, the aqueous phase is slowly poured into the oil phase and mixed at 70°C, homogenized and refined at a speed of 5000 rpm for 3 min, the emulsion is transferred to a 45°C water bath, magnetic stirring is performed at a speed of 100 rpm, and natural cooling is performed to 25°C, the pH value is adjusted to 5.5 with citric acid, to obtain a primary emulsion.

[0036] The sulfonated brown algal polyphenol microcapsule is prepared by the following steps:

[0037] S1, 10 g of Sargassum copper powder is crushed and sieved, 160 g of ethanol and 0.05 g of phytic acid are added, ultrasonic treatment is performed at 50°C for 20 min, the ultrasonic treatment power is 300 W, the power is 50 kHz, centrifugation is performed at a speed of 8000 rpm for 10 min to collect the supernatant, and rotary evaporation is performed to concentrate to 1 / 10 of the original volume, to obtain a brown algal polyphenol extract;

[0038] S2, 70 g of the brown algal polyphenol extract and 9.5 g of 3'-adenosine-5'-phosphosulfate are mixed, the reaction is performed in a phosphate buffer solution reaction environment with a pH value of 7.5 at 60°C for 8 h with constant temperature and stirring at a speed of 60 rpm, after the reaction is completed, 90°C water bath is performed for 10 min, centrifugation is performed at a speed of 8000 rpm for 10 min to collect the supernatant, to obtain a sulfonated brown algal polyphenol solution;

[0039] S3, 0.1 g of chitin oligosaccharide powder was dissolved in 9.9 g of 1% acetic acid solution with pH = 5.0 to prepare a chitin oligosaccharide solution, 10 g of the chitin oligosaccharide solution was added to 200 g of the primary emulsion prepared above, 4 g of sulfonated brown algal polyphenol solution was added dropwise, 2 g of sodium tripolyphosphate was added, the temperature was controlled at 40°C, and magnetic stirring was performed at a speed of 300 rpm for 2 h, and the precipitate was collected by centrifugation at a speed of 8000 rpm for 10 min, washed, vacuum dried for 48 h, and sieved through a 200 mesh screen to obtain sulfonated brown algal polyphenol microcapsules.

[0040] Preparation Example 2

[0041] The primary emulsion was prepared by the following steps:

[0042] A1, 184 g of corn oil and 1.05 g of vitamin E acetate were added to a container, heated to complete melting in a water bath at 62°C, 6.5 g of Tween 80 and 0.1 g of polyglycerol polyricinoleate were added, and magnetic stirring was performed at a speed of 550 rpm until uniform transparency was obtained to obtain an oil phase;

[0043] A2, 1.4 g of sodium hyaluronate was added to 129 g of deionized water, ultrasonically treated at 42°C for 15 min, the ultrasonic treatment power was 250 W, the power was 42 kHz, 0.095 g of glycerol was added, and magnetic stirring was performed at a speed of 350 rpm until the solution was clear, and the pH value was controlled at 5.7 to obtain an aqueous phase;

[0044] A3, the aqueous phase was slowly poured into the oil phase and mixed at 72°C, homogenized and refined at a speed of 5500 rpm for 4 min, the emulsion was transferred to a 46°C water bath, magnetic stirring was performed at a speed of 150 rpm, and the pH value was adjusted to 5.8 by citric acid to obtain a primary emulsion.

[0045] The sulfonated brown algal polyphenol microcapsules were prepared by the following steps:

[0046] S1, 10.2 g of Sargassum horneri was crushed and sieved, 180 g of ethanol and 0.055 g of phytic acid were added, ultrasonically treated at 52°C for 25 min, the ultrasonic treatment power was 350 W, the power was 52 kHz, the supernatant was collected by centrifugation at a speed of 8000 rpm for 12 min, and rotary evaporation was performed to concentrate to 1 / 10 of the original volume to obtain a brown algal polyphenol extract;

[0047] S2, 74 g of the brown algal polyphenol extract and 10 g of 3'-adenosine-5'-phosphosulfate were mixed, the reaction was carried out in a phosphate buffer solution reaction environment with a pH value of 7.5 at 62°C for 9 h with constant temperature and stirring at a speed of 80 rpm, after the reaction was completed, 92°C water bath for 15 min, centrifugation at a speed of 8000 rpm for 12 min to collect the supernatant to obtain a sulfonated brown algal polyphenol solution;

[0048] S3, 0.12 g of chitin oligosaccharide powder was dissolved in 9.88 g of 1% acetic acid solution with pH = 5.0 to prepare a chitin oligosaccharide solution, 10 g of the chitin oligosaccharide solution was added to 210 g of the primary emulsion prepared above, 4.5 g of sulfonated phlorofuco-phenone solution was added dropwise, 2.3 g of sodium tripolyphosphate was added, the temperature was controlled at 40°C, and magnetic stirring was carried out at a speed of 350 rpm for 2.5 h, and the precipitate was collected by centrifugation at a speed of 8000 rpm for 12 min, washed, vacuum dried for 48 h, and sieved through a 300 mesh sieve to obtain sulfonated phlorofuco-phenone microcapsules.

[0049] Preparation Example 3

[0050] The primary emulsion was prepared by the following steps:

[0051] A1, 186 g of corn oil and 1.1 g of vitamin E acetate were added to a container, heated to complete melting in a water bath at 65°C, 7 g of Tween 80 and 0.11 g of polyglycerol polyricinoleate were added, and magnetic stirring was carried out at a speed of 600 rpm until uniform transparency was obtained to obtain an oil phase;

[0052] A2, 1.5 g of sodium hyaluronate was added to 130 g of deionized water, ultrasonic treatment was carried out at 45°C for 20 min, the ultrasonic treatment power was 300 W, the power was 45 kHz, 0.1 g of glycerol was added, and magnetic stirring was carried out at a speed of 400 rpm until the solution was clear, and the pH value was controlled at 6.0 to obtain an aqueous phase;

[0053] A3, the aqueous phase was slowly poured into the oil phase and mixed at 75°C, homogenized and refined at a speed of 6000 rpm for 5 min, the emulsion was transferred to a 47°C water bath, magnetic stirring was carried out at a speed of 200 rpm, and the pH value was adjusted to 6.0 with citric acid to obtain a primary emulsion.

[0054] The sulfonated phlorofuco-phenone microcapsules were prepared by the following steps:

[0055] S1, 10.5 g of Sargassum horneri was crushed and sieved, 190 g of ethanol and 0.06 g of phytic acid were added, ultrasonic treatment was carried out at 55°C for 30 min, the ultrasonic treatment power was 400 W, the power was 55 kHz, centrifugation was carried out at a speed of 8000 rpm for 15 min to collect the supernatant, and rotary evaporation was carried out to concentrate to 1 / 10 of the original volume to obtain a phlorofuco-phenone extract;

[0056] S2, 80 g of the phlorofuco-phenone extract and 10.5 g of 3'-adenosine-5'-phosphosulfate were mixed, the reaction was carried out in a phosphate buffer solution reaction environment with a pH value of 7.5 at 65°C for 10 h with stirring at a speed of 100 rpm, after the reaction was completed, 95°C water bath was carried out for 20 min, centrifugation was carried out at a speed of 8000 rpm for 15 min to collect the supernatant, and a sulfonated phlorofuco-phenone solution was obtained.

[0057] S3, 0.13 g of chitin oligosaccharide powder was dissolved in 9.87 g of 1% acetic acid solution with pH = 5.0 to prepare a chitin oligosaccharide solution, 10 g of the chitin oligosaccharide solution was added to 220 g of the primary emulsion prepared above, 5 g of sulfonated brown algae polyphenol solution was added dropwise, 3 g of sodium tripolyphosphate was added, the temperature was controlled at 40°C, and magnetic stirring was performed at a speed of 400 rpm for 3 h, and the precipitate was collected by centrifugation at a speed of 8000 rpm for 15 min, washed, vacuum dried for 48 h, and sieved through a 400 mesh screen to obtain sulfonated brown algae polyphenol microcapsules.

[0058] Example 1

[0059] A method for preparing a pesticide composition based on marine bioactive substances, comprising the following steps:

[0060] In a reaction kettle, 59.5 g of water was added in percentage by weight, heated to 50°C, and then 8 g of sodium alginate was added, stirred at a speed of 100 rpm until completely dissolved, 20 g of sulfonated brown algae 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 were added, stirred at a speed of 300 rpm for 10 min, 2 g of azone and 1 g of silicone antifoaming agent were added, and emulsified at a speed of 3000 rpm for 15 min to obtain a pesticide composition based on marine bioactive substances.

[0061] Example 2

[0062] A method for preparing a pesticide composition based on marine bioactive substances, comprising the following steps:

[0063] In a reaction kettle, 53.7 g of water was added in percentage by weight, heated to 52°C, and then 12 g of sodium alginate was added, stirred at a speed of 150 rpm until completely dissolved, 25 g of sulfonated brown algae 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 were added, stirred at a speed of 350 rpm for 15 min, 0.5 g of azone and 0.5 g of silicone antifoaming agent were added, and emulsified at a speed of 3500 rpm for 20 min to obtain a pesticide composition based on marine bioactive substances.

[0064] Example 3

[0065] A method for preparing a pesticide composition based on marine bioactive substances, comprising the following steps:

[0066] In a reaction kettle, 59.8 g of water was added, and after being heated to 50-55°C, 10 g of sodium alginate was added. After stirring at 200 rpm until completely dissolved, 22 g of 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 were added. After stirring at 400 rpm for 20 min, 1 g of azone and 0.2 g of a silicone antifoaming agent were added. After shearing emulsification at 4000 rpm for 25 min, a pesticide composition based on marine active substances was obtained.

[0067] Comparative Example 1

[0068] This comparative example differs from Example 1 in that the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 1 were replaced with brown algal polyphenol, and the remaining steps were the same as in Example 1.

[0069] Comparative Example 2

[0070] This comparative example differs from Example 2 in that the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 2 were replaced with chitooligosaccharides, and the remaining steps were the same as in Example 2.

[0071] Comparative Example 3

[0072] This comparative example differs from Example 3 in that the sulfonated brown algal polyphenol microcapsules prepared in Preparation Example 3 were replaced with sodium tripolyphosphate, and the remaining steps were the same as in Example 3.

[0073] (Ⅰ) In vitro toxicity determination:

[0074] 3rd instar Plutella xylostella larvae with a body weight of about 0.5-1.0 mg per head were collected and starved for 4 h.

[0075] The pesticide compositions prepared in Examples 1-3 and Comparative Examples 1-3 were each formulated into a 2% test pesticide solution by mass fraction, with distilled water containing 0.05% Triton X-100 as the solvent. A group of 0.05% Triton X-100 solution was set as a blank control group, and a commercially available 5% abamectin EC was set as a positive control group.

[0076] Fresh cabbage leaves were cut into 3×5 cm leaf discs, immersed in each pesticide solution for 10 s, and naturally dried. The leaf discs were placed in a 9 cm diameter culture dish, with wet filter paper at the bottom to maintain moisture. Twenty Plutella xylostella larvae were introduced into each dish for culture. The culture conditions were a temperature of 26±1°C, a relative humidity of 70%, and a light-dark ratio of 14:10 h. The larvae were gently touched with a brush, and those that could not crawl normally or were completely immobile were considered dead. Three replicates were set. After 24 h, 48 h, and 72 h, the corrected mortality rate was calculated, and the results are shown in Table 1.

[0077] Table 1. Corrected mortality of Examples 1-3 and Comparative Examples 1-3 and the control group

[0078]

[0079] (II) Earthworm avoidance behavior test:

[0080] The artificial soil was prepared by mixing 70% quartz sand, 20% kaolin, and 10% peat, with a pH value of 6.0±0.5 and an organic matter content of 2%. The pesticide compositions of Examples 1-3 and Comparative Examples 1-3 were uniformly mixed into the soil at a ratio of 1% (w / w), and after thorough mixing, the soil was allowed to stand for 24 h. Six groups of 20 cm x 10 cm x 5 cm transparent plastic boxes were prepared, divided into a contaminated area, an intermediate isolation area, and a control area. The intermediate isolation area was separated from the contaminated area and the control area by a partition. The width of the intermediate isolation area was 2 cm, and it was used for initial placement of earthworms. The contaminated area contained 200 g of soil containing 1% of the pesticide compositions prepared in Examples 1-3 and Comparative Examples 1-3, and the control area contained 200 g of uncontaminated artificial soil. The environmental conditions were set to a temperature of 20±1°C, a humidity of 70%, and dark conditions.

[0081] Selected adult healthy Eisenia foetida, weighing 300-500 mg, were pre-acclimated in artificial soil for 7 days, during which they were fed cow dung. The earthworms were randomly divided into 6 groups corresponding to Examples 1-3 and Comparative Examples 1-3, with 10 earthworms per group and 4 replicates (n=4). Another group without the addition of pesticide compositions was set as a blank control group.

[0082] The earthworms were placed in the intermediate isolation area, and the partition was removed to allow them to move freely. After 48 h, the number of earthworms in the contaminated area and the control area was counted, and the avoidance rate was calculated as follows: avoidance rate (%) = (number of earthworms in the control area - number of earthworms in the contaminated area) / total number of earthworms x 100. The results are shown in Table 2:

[0083] Table 2. Number of earthworms distributed in Examples 1-3 and Comparative Examples 1-3 and the blank control group

[0084]

[0085] As shown in Table 1, the 24 h corrected mortality of Examples 1-3 was 35-39%, and after 72 h, it increased to 95-97.5%, close to the positive control (5% abamectin emulsion, 72 h mortality 99.1%), indicating that the sulfonated brown algal polyphenol microcapsule pesticide has both quick-acting and long-acting properties. The 72 h mortality of Comparative Example 1 was 65%, indicating that the non-microencapsulated brown algal polyphenol may have a rapid degradation or photolysis, resulting in a decrease in efficacy. The 72 h mortality of Comparative Examples 2 and 3 was 50.2% and 42.3%, respectively, indicating that the release of active ingredients may not be controllable, resulting in a decrease in efficacy.

[0086] As shown in Table 2, the avoidance rates of Examples 1-3 are 15-22%, indicating that the sulfonated brown algae polyphenol microcapsules have no significant repellency or toxicity to earthworms, and are environmentally friendly. The avoidance rates of Comparative Example 1 and Comparative Example 3 are 85-90%, indicating that free brown algae polyphenol or sodium tripolyphosphate can stimulate the cuticle layer or nerve receptors of earthworms, triggering strong avoidance behavior. The avoidance rate of Comparative Example 2 is 40%, which may be due to the cationic properties of chitooligosaccharides interfering with the osmotic pressure regulation of earthworms.

[0087] In summary, the pesticide composition prepared by the present application prolongs the effective period and improves the bioavailability through slow release and targeted release. At the same time, the exposure of non-target organisms is reduced, and the ecological toxicity is reduced.

[0088] In the description of the specification, the description of the terms "preparation example", "embodiment", "each embodiment" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or preparation example are included in at least one embodiment or preparation example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or preparation example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or preparation examples in a suitable manner.

[0089] The above description is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this. Any person skilled in the art, according to the technical solution and the inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, should be covered within the protection scope of the present application.

Claims

1. A pesticide composition based on marine bioactive substances, characterized in that: The raw materials include the following by weight percentage: 20-25% sulfonated brown algae polyphenol microcapsules, 8-12% sodium alginate, 0.1-1% phosphatidylcholine, 2-3% alkylphenol polyoxyethylene ether, 1-3% fatty alcohol polyoxyethylene ether, 0.5-2% azone, 2-5% propylene glycol and 0.2-1% organosilicon defoaming agent, and the balance is water; 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 ultrasonicate it for 20-30 minutes. Collect the supernatant by centrifugation and concentrate it to obtain a brown algae polyphenol extract; S2, mixing the brown algae polyphenol extract and 3'-adenosine 5'-phosphosulfate, controlling the temperature to react with stirring for 8-10 hours, and 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 sulfonated brown algae polyphenol microcapsules.

2. The pesticide composition based on marine bioactive substances according to claim 1, 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.

3. The pesticide composition based on marine bioactive substances according to claim 1, characterized in that: In step S2, the mass ratio of the brown algae polyphenol extract to 3'-adenosine 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.

4. The pesticide composition based on marine bioactive substances according to claim 1, 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.

5. The pesticide composition based on marine bioactive substances according to claim 1, characterized in that: The primary emulsion in step S3 is prepared by comprising the following steps: A1. Add corn oil and vitamin E acetate to a container and heat in a water bath until completely melted. Add Tween 80 and polyglycerol polyricinoleate and stir magnetically until the mixture is homogeneous and transparent to obtain an oil phase. A2. Sodium hyaluronate was added to deionized water, and the mixture was ultrasonically treated for 10-20 minutes. Glycerol was added and magnetically stirred until the solution was clear. The pH value was controlled at 5.5-6.0 to obtain an aqueous phase. A3. Slowly pour the aqueous phase into the oil phase and mix, homogenize and refine, transfer the emulsion to a water bath, stir magnetically and cool naturally to below 30°C, adjust the pH value to 5.5-6.0, and obtain a primary emulsion.

6. The pesticide composition based on marine bioactive substances according to claim 5, 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.

7. The pesticide composition based on marine bioactive substances according to claim 5, 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).

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

9. The method for preparing a pesticide composition based on marine bioactive substances according to any one of claims 1 to 8, characterized in that: The following steps are involved: Water is added to a reaction kettle according to weight percentage, and sodium alginate is added after heating to 50-55° C., and stirred at a speed of 100-200 rpm until completely dissolved. Sulfonated brown algae polyphenol microcapsules, phosphatidylcholine, alkylphenol polyoxyethylene ether, and fatty alcohol polyoxyethylene ether are added, and stirred at a speed of 300-400 rpm for 10-20 minutes. Azone and an organosilicon defoamer are added, and shear emulsification is performed at 3000-4000 rpm for 15-25 minutes to obtain a pesticide composition based on marine bioactive substances.

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