A plant-derived pesticide solvent with a high killing rate and its preparation method

Abstract

The present invention discloses a plant-derived pesticide solvent with a high killing rate and a preparation method thereof, relating to the technical field of pesticide formulations; the plant-derived pesticide solvent with a high killing rate is composed of drug-loaded porous calcium carbonate microspheres and a pH-responsive shell material; the drug-loaded porous calcium carbonate microspheres are composed of glycine-modified calcium carbonate, ferric trichloride, traditional Chinese medicine components, and plant-derived glycerides; the pH-responsive shell material is composed of sodium carboxymethylcellulose, pleurotus eryngii polysaccharide, epichlorohydrin, and tannic acid; the surface of the drug-loaded porous calcium carbonate microspheres is coated with the pH-responsive shell material to form a dual pH-responsive drug release system, which improves the stability of the active pharmaceutical ingredients, reduces the decomposition of the plant-derived pesticide by light, temperature, and humidity, and the constructed drug-loaded coating structure can adhere to the leaf surface of crops for release, reducing the loss caused by the rolling and rebounding of pesticides on the leaf surface, significantly improving the utilization rate, and achieving the pest control effect with a high killing rate.

Description

Technical Field

[0001] The present invention belongs to the technical field of pesticide formulations, and specifically refers to a plant-derived pesticide solvent with a high killing rate and a preparation method thereof. Background Art

[0002] Crop pests and diseases are one of the main agricultural disasters in China. They are characterized by a large variety, great impact, and frequent outbreaks. Their occurrence range and severity often cause significant losses to China's national economy, especially agricultural production. Common crop pests and diseases in China include the following types: rice planthoppers, powdery mildew, corn borers, cotton bollworms, wheat rust, rice sheath blight, aphids, spider mites, locusts, wheat scab, black mold, Erwinia amylovora, etc.

[0003] Pesticides are important agricultural means in agricultural production. They can kill various diseases and pests during the crop production process, ensuring crop growth and yield. However, with the rapid development of agrochemical enterprises and the unreasonable use of chemical pesticides, a large amount of toxic substances have entered the soil, water bodies, and the atmosphere, causing serious environmental pollution. It has also led to excessive pesticide residues on grains, vegetables, fruits, and tea leaves, affecting the food safety of consumers and further resulting in poisoning incidents and the occurrence of various diseases. Therefore, the emergence of Chinese herbal medicine pesticides meets the requirements of new pesticides and is a green and environmentally friendly plant-derived pesticide. It is developed through scientific compatibility and has the functions of insecticidal, bactericidal, or herbicidal. It can not only strongly damage the digestive system and metabolic functions of pests but also damage the vagus nerve of pests and inhibit their respiration. Moreover, it has no toxin residues in water quality, soil, agricultural products, fruits, vegetables, etc., and does not harm human health.

[0004] Currently, the following main problems exist in the prior art:

[0005] Since the active ingredients of plant-derived pesticides are mostly natural compounds, they are easily affected by light, heat, and humidity, resulting in poor stability and difficulty in ensuring continuous and effective control effects. Summary of the Invention

[0006] In view of the above situation, to overcome the defects of the prior art, the present invention provides a plant-derived pesticide solvent with a high killing rate, which comprises the following components in parts by weight: 30 - 40 parts of drug-loaded porous calcium carbonate microspheres and 20 - 30 parts of pH-responsive shell materials.

[0007] The drug-loaded porous calcium carbonate microspheres comprise the following components in parts by weight: 20 - 40 parts of glycine-modified calcium carbonate, 10 - 20 parts of ferric trichloride, 8 - 12 parts of traditional Chinese medicine components, and 8 - 12 parts of plant-derived glycerides.

[0008] The pH-responsive shell material comprises the following components in parts by weight: 10-20 parts of sodium carboxymethylcellulose, 10-20 parts of Pleurotus eryngii polysaccharide, 5-8 parts of epichlorohydrin, and 10-15 parts of tannic acid.

[0009] The traditional Chinese medicine component, and its raw materials comprise the following components in parts by weight: 8-10 parts of Tripterygium wilfordii Hook. f., 8-10 parts of Strychnos nux-vomica L., 8-10 parts of Heracleum hemsleyanum Diels, 8-10 parts of Picrasma quassioides (D. Don) Benn., 8-10 parts of Chrysanthemum morifolium Ramat., and 5-8 parts of alum.

[0010] The preparation method of the drug-loaded porous calcium carbonate microspheres specifically comprises the following steps:

[0011] (1) Add 1.0 g of soluble starch into 80-100 mL of deionized water, heat to 70-80 °C, stir for 30 min, after cooling to room temperature, add 80-100 mL of calcium acetate with a concentration of 0.1 mol / L to the solution, stir for 30 min, then add 80-100 mL of ammonium carbonate with a concentration of 0.1 mol / L, stir for 30 min, and then add glycine, and introduce CO 2 gas, continue to stir until the pH of the reaction solution is 7.0-7.5, control the temperature during the reaction process to be carried out at 25 °C. Glycine participates in the formation process of calcium carbonate in the form of complexing calcium ions. The obtained product has a complete sphericity, uniform size, and a large number of wrinkled surfaces, which not only improves the drug loading and sustained release performance of calcium carbonate, but also improves the biocompatibility of the material. Centrifuge and separate the solid product at a centrifugal speed of 8000-10000 rpm for 3-5 min, and wash it 3-5 times with deionized water, and then freeze-dry it. The drying temperature is -40 °C to -30 °C, and the drying time is 6-10 h to obtain glycine-modified calcium carbonate;

[0012] (2) First, pre-crush Tripterygium wilfordii Hook. f., Strychnos nux-vomica L., Heracleum hemsleyanum Diels, Picrasma quassioides (D. Don) Benn., Chrysanthemum morifolium Ramat., and alum through a 60-80 mesh sieve, and then ultra-finely crush the mixed coarse powder through a 500-800 mesh sieve. Take 2-3 g of the traditional Chinese medicine fine powder and add it to 50 mL of an ethanol solution with a mass fraction of 60-80%. The traditional Chinese medicine herb is rich in biologically active compounds such as alkaloids and terpenoid compounds, and has significant insecticidal and antibacterial effects. Multiple components act on the nervous system, muscle system, midgut enterocyte cells and other parts of pests through multiple pathways, effectively destroying the cell structure of pests, inhibiting their growth and population reproduction, playing the role of poisoning and anesthesia, and ultimately causing their death. Among them, alum has broad-spectrum antibacterial properties and can also release the smell liked by pests to prompt pests to eat, and then generate high temperature to kill them. Stir for 10-20 min, add 2-3 g of plant-derived glyceride, and continue to stir for 20-30 min. The plant-derived glyceride is compounded with the traditional Chinese medicine fine powder to play the role of emulsification and synergistic enhancement to obtain a plant-derived medicinal liquid;

[0013] (3) Add 5 - 10 g of glycine - modified calcium carbonate described in step (1) into 80 mL of an ethanol solution with a mass fraction of 60 - 80%, then add the plant - derived medicinal liquid described in step (2) and stir - mix. The stirring speed is 500 - 1000 rpm, and the stirring time is 5 - 10 min. Add 125 mL of ferric chloride ethanol solution, continue stirring, the stirring speed is 500 - 1000 rpm, and the stirring time is 20 - 30 min. Centrifuge the suspension at a centrifugal speed of 8000 - 10000 rpm for 3 - 5 min. Collect the precipitate, wash it 3 - 5 times with an ethanol solution with a mass fraction of 60 - 80%, and freeze - dry it. The drying temperature is - 40°C to - 30°C, and the drying time is 8 - 12 h. The medicinal components composed of plant - derived glycerides and fine traditional Chinese medicine powder can adhere and adsorb at the pores on the surface of the porous calcium carbonate carrier, having a certain sustained - release property. At the same time, the porous calcium carbonate carrier also plays a role in protecting the medicinal components, reducing the adverse effects of environmental factors such as light and temperature. Also, because calcium carbonate can decompose under acidic conditions, the carrier is given pH responsiveness, thereby improving the stability, persistence, and efficiency of the plant - derived pesticide, and obtaining drug - loaded porous calcium carbonate microspheres;

[0014] Preferably, in step (1), the addition amount of glycine is 0.2 - 0.5 g. The amino and carboxyl groups of glycine can interact with calcium ions, promoting the rapid growth and aggregation of amorphous nanoparticles, thus forming vaterite - type calcium carbonate and inhibiting the growth of calcite crystals;

[0015] Preferably, in step (3), in the ferric chloride ethanol solution, the mass fraction of ferric chloride is 2 - 4%. Ferric chloride makes the surface of glycine - modified calcium carbonate more pitted and rough, which is beneficial to improving the loading capacity and the adsorption ability of the drug, and also beneficial to enhancing the adhesion performance with the crop leaf surface, thus improving the utilization rate and achieving an efficient insecticidal and bacteriostatic effect.

[0016] The present invention also provides a preparation method of a plant - derived pesticide solvent with a high killing rate, which specifically includes the following steps:

[0017] S1. Place the fresh Pleurotus ferulae Lenzi in a dry room-temperature environment, lay it flat to dry until completely dehydrated, and then crush it into powder using a high-speed multi-functional pulverizer. Weigh 20 g of Pleurotus ferulae Lenzi powder, add it to 500 mL of water, stir evenly, place it in an ultrasonic oscillator for 50 - 60 min, centrifuge at a rotational speed of 6000 - 8000 rpm for 10 - 15 min, take the supernatant, concentrate it under reduced pressure. The concentrated Pleurotus ferulae Lenzi extract paste is dissolved in 100 mL, add 700 - 900 mL of absolute ethanol, refrigerate at 4°C for 24 h, filter by suction, and then wash the precipitate with absolute ethanol 3 - 5 times. After the precipitate is dried, it is dissolved in 100 mL of water, and the protein is removed by the Sevag method 3 - 5 times. Pleurotus ferulae Lenzi polysaccharide has good inhibitory activity against plant pathogenic bacteria, can also increase adhesiveness, reduce losses caused by the rolling and rebounding of pesticides, improve utilization rate, and thus is conducive to increasing the killing rate, obtaining Pleurotus ferulae Lenzi polysaccharide;

[0018] S2. Dissolve sodium carboxymethylcellulose in 80 mL of water, stir at a rotational speed of 500 - 600 rpm until completely dissolved, then add the Pleurotus ferulae Lenzi polysaccharide described in step S1, stir for 5 - 10 min, add epichlorohydrin, and perform ultrasonic treatment with an ultrasonic power of 60 - 100 W and an ultrasonic time of 20 - 30 min. Using sodium carboxymethylcellulose as the substrate, a network structure with antibacterial properties is formed under the cross-linking action of epichlorohydrin and Pleurotus ferulae Lenzi polysaccharide. Then immerse the prepared cellulose composite gel in 100 mL of tannic acid solution with a mass fraction of 1.1 - 3.3%, place it in a constant-temperature shaker at 37°C, with a shaking speed of 100 - 150 rpm and a shaking time of 1 - 2 h. The addition of tannic acid can form hydrogen bond connections with sodium carboxymethylcellulose, further cross-link inside the gel, and more fine pores appear, making the gel network structure more regular and perfect, enhancing the mechanical properties and antibacterial properties of the shell material, and further strengthening the pH responsiveness, reducing the adverse effects of factors such as light and temperature on drug release, obtaining a pH-responsive shell material;

[0019] S3. Transfer the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying device, spray the pH-responsive shell material described in step S2. During the fluidized bed drying process, the spraying pressure is 0.6 - 1.0 MPa, the feeding speed is 10 - 20 mL / min, the inlet air temperature is 40 - 50°C, and the drying time is 20 - 30 min. The drug-loaded porous calcium carbonate microspheres are coated with a pH-responsive shell material, constructing a drug release system with dual pH responsiveness, effectively reducing the decomposition of plant-derived pesticides by light, temperature, and humidity, improving the stability of the active ingredients. Moreover, the structure of the rough calcium carbonate spheres coated with a gel film layer on the surface can effectively adhere to the leaf surface of crops and slowly release the insecticidal and antibacterial active ingredients therein, reducing the loss of plant-derived pesticides and prolonging the effective period of action, thus significantly increasing the killing rate of pests and diseases, obtaining a plant-derived pesticide solvent with a high killing rate;

[0020] Preferably, in step S2, in the sodium carboxymethyl cellulose solution, the mass fraction of sodium carboxymethyl cellulose is 1.4-5.5%. Among them, a large number of carboxyl groups are contained on the carboxymethyl cellulose, endowing the material with certain pH-responsive properties.

[0021] The beneficial effects achieved by the present invention are as follows:

[0022] In the present invention, by coating the surface of the drug-loaded porous calcium carbonate microspheres with a pH-responsive shell material, a plant-derived pesticide solvent with a high killing rate is prepared, which has a dual pH-responsive drug release system, improves the stability of the active ingredient of the drug, effectively reduces the decomposition of the plant-derived pesticide by light, temperature, and humidity. At the same time, the constructed drug-loaded coating structure can adhere to the leaf surface of crops for release, reducing the loss caused by the rolling and rebounding of pesticides on the leaf surface, significantly improving the utilization rate, prolonging the effective period, and achieving the pest control effect with a high killing rate; in the drug-loaded porous calcium carbonate microspheres, a spherical structure with pitted and rough surfaces is formed under the action of ferric chloride, which can load more plant-derived active ingredients of the drug, enhance the adsorption capacity for the active ingredient of the drug, and also improve the adhesion and sticking properties to the leaf surface of crops. Calcium carbonate endows the microsphere carrier with certain pH-responsive properties, which is beneficial for precise and slow release, reducing the adverse effects of temperature, light, and humidity on the active ingredient of the drug, and enhancing the stability, effectiveness, and persistence of the active ingredient of the drug, thus being beneficial for the improvement of the killing rate; in the pH-responsive shell material, after sodium carboxymethyl cellulose and Pleurotus eryngii polysaccharide are crosslinked, under the action of tannic acid, a more perfect gel network structure containing fine pores is further formed. The introduction of sodium carboxymethyl cellulose and tannic acid endows the shell material with stable and effective pH-responsive properties, enhances the release precision of the shell material, and also has strong antibacterial ability, which is beneficial for synergistically exerting the insecticidal and sterilizing effects with the plant-derived active ingredient of the drug, thus improving the killing rate. Pleurotus eryngii polysaccharide has good inhibitory effects on a variety of pathogenic bacteria, which is beneficial for the expansion of the sterilization range, and also synergistically acts with tannic acid to enhance the adhesion of the shell material, reducing the loss caused by pesticide rolling, rebounding, etc., and improving the utilization rate; the pH-responsive shell material forms a protective film on the surface of the drug-loaded porous calcium carbonate microspheres, effectively protecting a large number of pores exposed on the surface of the microspheres, reducing the sudden release of the loaded plant-derived active ingredient of the drug, and improving the stability of the drug-loaded microspheres. The drug-loaded porous calcium carbonate microspheres provide an internal support for the pH-responsive shell material and also enhance the stability of the shell material. The two complement each other to ensure the effective and lasting function of the dual pH-responsive drug release system and achieve excellent pest control effects; the present invention uses drug-loaded porous calcium carbonate microspheres and a pH-responsive shell material to make a plant-derived pesticide solvent with a high killing rate, which has a dual pH-responsive drug release system, enhances the stability and persistence of the active ingredient of the drug, improves the killing rate, and achieves significant insecticidal and bactericidal effects. Description of the Drawings

[0023] Figure 1 Scanning electron micrograph of the drug-loaded porous calcium carbonate microspheres prepared in Example 1 of the present invention;

[0024] Figure 2 Scanning electron micrograph of the pH-responsive shell material prepared in Example 1 of the present invention;

[0025] Figure 3 Graph showing the release rate results of Examples 1-4 and Comparative Examples 1-3 and the control group of the present invention for 10-50 h;

[0026] Figure 4 Graph showing the leaf retention results of Examples 1-4 and Comparative Examples 1-3 of the present invention;

[0027] Figure 5 Graph showing the killing rate results of Examples 1-4 and Comparative Examples 1-3 of the present invention. Detailed Description of the Invention

[0028] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments; based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] Unless otherwise defined, all professional and scientific terms used herein have the same meaning as those familiar to those skilled in the art. In addition, any methods and materials similar or equivalent to the described content can be applied to the present invention. The preferred methods and materials described herein are only for illustrative purposes and do not limit the content of this application.

[0030] The experimental methods in the following embodiments are all conventional methods unless otherwise specified; the test materials used in the following embodiments are all obtained from commercial channels unless otherwise specified.

[0031] The sources of the reagents used in the examples are as follows:

[0032] Soluble starch, CAS No: 9005-84-9, brand Innochem, product number A48874;

[0033] Calcium acetate, CAS No: 62-54-4, brand Innochem, product number A59459;

[0034] Ammonium carbonate, CAS No: 10361-29-2, brand Innochem, product number A70855;

[0035] Glycine, CAS No: 56-40-6, Brand: Innochem, Item No: A00711;

[0036] Plant-derived glyceride, supervised by the Institute of Zoology, Guangdong Academy of Sciences, produced by Guangzhou Oulian Biotechnology Co., Ltd.;

[0037] Ferric trichloride, CAS No: 7705-08-0, Brand: Innochem, Item No: A03391;

[0038] Sodium carboxymethyl cellulose, CAS No: 9004-32-4, Brand: Innochem, Item No: A05925;

[0039] Epichlorohydrin, CAS No: 106-89-8, Brand: Innochem, Item No: A18396;

[0040] Tannic acid, CAS No: 1401-55-4, Brand: Innochem, Item No: A08870;

[0041] Absolute ethanol, CAS No: 64-17-5, Brand: Innochem, Item No: G00004.

[0042] Example 1

[0043] This example presents a plant-derived pesticide solvent with a high killing rate, comprising the following components in parts by weight: 40 parts of drug-loaded porous calcium carbonate microspheres and 30 parts of pH-responsive shell material.

[0044] The drug-loaded porous calcium carbonate microspheres comprise the following components in parts by weight: 40 parts of glycine-modified calcium carbonate, 20 parts of ferric trichloride, 12 parts of traditional Chinese medicine components, and 12 parts of plant-derived glyceride.

[0045] The pH-responsive shell material comprises the following components in parts by weight: 20 parts of sodium carboxymethyl cellulose, 10 parts of Pleurotus eryngii polysaccharide, 8 parts of epichlorohydrin, and 15 parts of tannic acid.

[0046] The traditional Chinese medicine components, whose raw materials comprise the following components in parts by weight: 10 parts of Tripterygium wilfordii, 10 parts of Strychnos nux-vomica, 10 parts of Heracleum hemsleyanum, 10 parts of Picrasma quassioides, 10 parts of Chrysanthemum morifolium, and 8 parts of alum.

[0047] The preparation method of the drug-loaded porous calcium carbonate microspheres specifically comprises the following steps:

[0048] (1) Add 1.0 g of soluble starch to 100 mL of deionized water, heat to 80 °C, stir for 30 min. After cooling to room temperature, add 100 mL of calcium acetate with a concentration of 0.1 mol / L to the solution, stir for 30 min, then add 100 mL of ammonium carbonate with a concentration of 0.1 mol / L, stir for 30 min, and then add glycine. Then introduce CO 2 gas, and continue stirring until the pH of the reaction solution is 7.5. Control the temperature during the reaction process to be carried out at 25 °C. The addition amount of glycine is 0.5 g. The amino and carboxyl groups of glycine can form interactions with calcium ions, promoting the rapid growth and aggregation of amorphous nanoparticles, thereby forming vaterite-type calcium carbonate and inhibiting the growth of calcite crystals. Glycine participates in the formation process of calcium carbonate in the way of complexing calcium ions. The obtained product has a complete sphericity, uniform size, and a large number of wrinkled surfaces, which not only improves the drug loading capacity and sustained-release performance of calcium carbonate, but also improves the biocompatibility of the material. Centrifuge to separate the solid product at a centrifugal speed of 10,000 rpm for 5 min, and wash it 5 times with deionized water, and then freeze-dry at a drying temperature of -40 °C for 10 h to obtain glycine-modified calcium carbonate;

[0049] (2) First, pre-crush Tripterygium wilfordii, Strychnos nux-vomica, Heracleum hemsleyanum, Picrasma quassioides, Chrysanthemum morifolium, and alum through an 80-mesh sieve, and then ultra-finely crush the mixed coarse powder through an 800-mesh sieve. Take 3 g of the fine traditional Chinese medicine powder and add it to 50 mL of an ethanol solution with a mass fraction of 80%. The traditional Chinese medicine herbs are rich in biologically active compounds such as alkaloids and terpenoids, and have significant insecticidal and antibacterial effects. The multi-components act on the nervous system, muscle system, midgut enterocyte cells and other parts of pests through multiple pathways, effectively destroying the cell structure of pests, inhibiting their growth and the reproduction of the population, playing the role of poisoning and anesthesia, and ultimately causing their death. Among them, alum has broad-spectrum antibacterial properties and can also release the smell liked by pests to prompt pests to eat, and then generate high temperature to kill them. Stir for 20 min, add 3 g of plant-derived glyceride, and continue stirring for 30 min. The plant-derived glyceride is compounded with the fine traditional Chinese medicine powder to play the role of emulsification and synergistic enhancement to obtain the plant-derived liquid medicine;

[0050] (3) Add 10 g of glycine-modified calcium carbonate described in step (1) to 80 mL of an ethanol solution with a mass fraction of 80%, and then add the plant-derived medicinal liquid described in step (2) thereto and stir and mix. The stirring speed is 1000 rpm and the stirring time is 10 min. Then add 125 mL of an iron(III) chloride ethanol solution and continue stirring. The stirring speed is 1000 rpm and the stirring time is 30 min. In the iron(III) chloride ethanol solution, the mass fraction of iron(III) chloride is 4%. Iron(III) chloride makes the surface of glycine-modified calcium carbonate more pitted and rough, which is beneficial to improving the loading capacity and the adsorption capacity for drugs, and is also beneficial to enhancing the adhesion performance with the leaf surface of crops. Therefore, the utilization rate is improved and an efficient insecticidal and bacteriostatic effect is achieved. Centrifuge the suspension at a centrifugal speed of 10000 rpm for 5 min, collect the precipitate, wash it 5 times with an ethanol solution with a mass fraction of 80%, and freeze-dry it. The drying temperature is -40 °C and the drying time is 12 h. The active pharmaceutical ingredients composed of plant-derived glycerides and fine powder of traditional Chinese medicine can adhere to and adsorb at the pores on the surface of the porous calcium carbonate carrier, having a certain sustained-release property. At the same time, the porous calcium carbonate carrier also plays a role in protecting the active pharmaceutical ingredients, reducing the adverse effects of environmental factors such as light and temperature. Also, because calcium carbonate can decompose under acidic conditions, the carrier is given pH responsiveness, thereby improving the stability, persistence and high efficiency of the plant-derived pesticide, and obtaining drug-loaded porous calcium carbonate microspheres.

[0051] This example provides a preparation method of a plant-derived pesticide solvent with a high killing rate, which specifically includes the following steps:

[0052] S1. Place fresh Pleurotus ferulae Lenzi in a dry room temperature environment, spread it out to dry until completely dehydrated, and use a high-speed multi-functional pulverizer to pulverize it into powder. Weigh 20 g of Pleurotus ferulae Lenzi powder and add it to 500 mL of water. After stirring evenly, place it in an ultrasonic oscillator for 60 min, centrifuge it at a centrifugal speed of 8000 rpm for 15 min, take the supernatant, concentrate it under reduced pressure. The concentrated Pleurotus ferulae Lenzi extract paste is dissolved in 100 mL, add 900 mL of absolute ethanol, refrigerate it at 4 °C for 24 h, filter it by suction, and then wash the precipitate 5 times with absolute ethanol. After the precipitate is dried, it is dissolved in 100 mL of water, and the protein is removed 5 times by the Sevag method. Pleurotus ferulae Lenzi polysaccharide has good inhibitory activity against plant pathogens, can also increase the adhesiveness, reduce the losses caused by the rolling and rebounding of pesticides, improve the utilization rate, and thus is beneficial to improving the killing rate, obtaining Pleurotus ferulae Lenzi polysaccharide;

[0053] S2. Dissolve sodium carboxymethylcellulose in 80 mL of water. In the sodium carboxymethylcellulose solution, the mass fraction of sodium carboxymethylcellulose is 5.5%. Among them, a large number of carboxyl groups are contained on the carboxymethylcellulose, endowing the material with certain pH-responsive properties. Stir at a rotation speed of 600 rpm until completely dissolved, then add the Pleurotus eryngii polysaccharide described in step S1, stir for 10 min, add epichlorohydrin, and perform ultrasonic treatment. The ultrasonic power is 100 W and the ultrasonic time is 30 min. Using sodium carboxymethylcellulose as the substrate, a network structure with antibacterial properties is formed with Pleurotus eryngii polysaccharide under the cross-linking action of epichlorohydrin. Then immerse the prepared cellulose composite gel in 100 mL of tannic acid solution with a mass fraction of 3.3%, place it in a constant temperature shaker at 37 °C, with a shaking speed of 150 rpm and a shaking time of 2 h. The addition of tannic acid can form hydrogen bond connections with sodium carboxymethylcellulose, and further cross-linking occurs inside the gel, resulting in more fine pores, making the gel network structure more regular and perfect, enhancing the mechanical properties and antibacterial properties of the shell material, further strengthening the pH responsiveness, reducing the adverse effects of factors such as light and temperature on drug release, and obtaining a pH-responsive shell material;

[0054] S3. Transfer the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying device, and spray the pH-responsive shell material described in step S2. During the fluidized bed drying process, the spraying pressure is 1.0 MPa, the feeding speed is 20 mL / min, the inlet air temperature is 50 °C, and the drying time is 30 min. The drug-loaded porous calcium carbonate microspheres are coated with a pH-responsive shell material, constructing a drug release system with dual pH responsiveness, effectively reducing the decomposition of plant-derived pesticides by light, temperature, and humidity, improving the stability of the active ingredients. Moreover, the structure of the rough calcium carbonate spheres coated with a gel film layer can effectively adhere to the leaf surface of crops and slowly release the insecticidal and antibacterial active ingredients therein, reducing the loss of plant-derived pesticides and prolonging the effective period of action, thereby significantly increasing the killing rate of pests and diseases, and obtaining a plant-derived pesticide solvent with a high killing rate.

[0055] In this example, scanning electron microscopy was performed on the prepared drug-loaded porous calcium carbonate microspheres and pH-responsive shell material to observe their microtopographies. Figure 1 It is a SEM image of the drug-loaded porous calcium carbonate microspheres prepared in Example 1 magnified 1000 times. Figure 2 It is a SEM image of the pH-responsive shell material prepared in Example 1 magnified 1000 times. As Figure 1 , the surface of the drug-loaded porous calcium carbonate microspheres prepared in this example presents a rough structure. As Figure 2 , the pH-responsive shell material prepared in this example is a gel network structure containing fine pores.

[0056] Example 2

[0057] This embodiment provides a plant-derived pesticide solvent with a high killing rate, comprising the following components in parts by weight: 30 parts of drug-loaded porous calcium carbonate microspheres and 20 parts of pH-responsive shell material.

[0058] The drug-loaded porous calcium carbonate microspheres comprise the following components in parts by weight: 20 parts of glycine-modified calcium carbonate, 10 parts of ferric trichloride, 8 parts of traditional Chinese medicine components, and 8 parts of plant-derived glycerides.

[0059] The pH-responsive shell material comprises the following components in parts by weight: 10 parts of sodium carboxymethylcellulose, 20 parts of pleurotus eryngii polysaccharide, 5 parts of epichlorohydrin, and 10 parts of tannic acid.

[0060] The traditional Chinese medicine components are prepared from the following raw materials in parts by weight: 8 parts of tripterygium wilfordii, 8 parts of strychnos nux-vomica, 8 parts of angelica pubescens, 8 parts of picrasma quassioides, 8 parts of chrysanthemum, and 5 parts of alum.

[0061] The preparation method of the drug-loaded porous calcium carbonate microspheres specifically comprises the following steps:

[0062] (1) Add 1.0 g of soluble starch to 80 mL of deionized water, heat to 70 °C, stir for 30 min, cool to room temperature, then add 80 mL of calcium acetate with a concentration of 0.1 mol / L to the solution, stir for 30 min, add 80 mL of ammonium carbonate with a concentration of 0.1 mol / L, stir for 30 min, then add glycine, and introduce CO 2 gas, continue stirring until the pH of the reaction solution is 7.0, control the temperature during the reaction to be 25 °C, the addition amount of glycine is 0.2 g, the amino and carboxyl groups of glycine can form interactions with calcium ions, promoting the rapid growth and aggregation of amorphous nanoparticles, thus forming vaterite-type calcium carbonate, inhibiting the growth of calcite crystals, glycine participates in the formation process of calcium carbonate in the form of complexing calcium ions, the obtained product has a complete sphericity, uniform size, and a large number of wrinkled surfaces, which not only improves the drug loading and slow-release performance of calcium carbonate, but also improves the biocompatibility of the material. Centrifuge to separate the solid product at a centrifugal speed of 8000 rpm for 3 min, wash 3 times with deionized water, and freeze-dry at a drying temperature of -30 °C for 6 h to obtain glycine-modified calcium carbonate;

[0063] (2) First, pulverize Tripterygium wilfordii, Strychnos nux-vomica, Heracleum hemsleyanum, Picrasma quassioides, Chrysanthemum morifolium, and alum through a 60-mesh sieve for pre-pulverization. Then, pulverize the mixed coarse powder through a 500-mesh sieve for ultrafine pulverization. Take 2 g of the fine traditional Chinese medicine powder and add it to 50 mL of an ethanol solution with a mass fraction of 60%. The traditional Chinese medicine herbs are rich in bioactive compounds such as alkaloids and terpenoids, and have significant insecticidal and antibacterial effects. Multiple components act on the nervous system, muscle system, midgut enterocyte cells, and other parts of pests through multiple pathways, effectively destroying the cell structure of pests, inhibiting their growth and population reproduction, and playing a role in poisoning and anesthetizing them, ultimately leading to their death. Among them, alum has broad-spectrum antibacterial properties and can also release the smell that pests like to encourage pests to eat, and then generate high temperature to kill them. Stir for 10 min, add 2 g of plant-derived glyceride, and continue to stir for 20 min. The plant-derived glyceride is compounded with the fine traditional Chinese medicine powder to play an emulsifying and synergistic role, and a plant-derived liquid medicine is obtained;

[0064] (3) Add 5 g of glycine-modified calcium carbonate described in step (1) to 80 mL of an ethanol solution with a mass fraction of 60%. Then, add the plant-derived liquid medicine described in step (2) and stir to mix. The stirring speed is 500 rpm, and the stirring time is 5 min. Add 125 mL of ferric chloride ethanol solution and continue to stir. The stirring speed is 500 rpm, and the stirring time is 20 min. In the ferric chloride ethanol solution, the mass fraction of ferric chloride is 2%. Ferric chloride makes the surface of glycine-modified calcium carbonate more pitted and rough, which is beneficial to improving the loading capacity and the adsorption ability of drugs, and is also beneficial to enhancing the adhesion performance with the leaf surface of crops, thus improving the utilization rate and achieving an efficient insecticidal and bacteriostatic effect. Centrifuge the suspension at a centrifugal speed of 8000 rpm for 3 min, collect the precipitate, wash it 3 times with an ethanol solution with a mass fraction of 60%, and freeze-dry it. The drying temperature is -30 °C, and the drying time is 8 h. The active pharmaceutical ingredients composed of plant-derived glyceride and fine traditional Chinese medicine powder can adhere and adsorb at the pores on the surface of the porous calcium carbonate carrier, having a certain sustained-release property. At the same time, the porous calcium carbonate carrier also plays a role in protecting the active pharmaceutical ingredients, reducing the adverse effects of environmental factors such as light and temperature. Also, because calcium carbonate can decompose under acidic conditions, the carrier is given pH responsiveness, thereby improving the stability, persistence, and efficiency of the plant-derived pesticide, and a drug-loaded porous calcium carbonate microsphere is obtained.

[0065] This example provides a preparation method of a plant-derived pesticide solvent with a high killing rate, which specifically includes the following steps:

[0066] S1. Place the fresh Pleurotus ferulae Lenzi in a dry room-temperature environment, lay it flat to dry until completely dehydrated, and crush it into powder using a high-speed multi-functional pulverizer. Weigh 20 g of Pleurotus ferulae Lenzi powder, add it to 500 mL of water, stir evenly, place it in an ultrasonic oscillator for 50 min, centrifuge at a rotational speed of 6000 rpm for 10 min, take the supernatant, concentrate it under reduced pressure. The concentrated Pleurotus ferulae Lenzi extract paste is dissolved in 100 mL, add 700 mL of absolute ethanol, refrigerate at 4 °C for 24 h, filter by suction, and then wash the precipitate with absolute ethanol 3 times. After the precipitate is dried, it is dissolved in 100 mL of water, and the protein is removed 3 times by the Sevag method. Pleurotus ferulae Lenzi polysaccharide has good inhibitory activity against plant pathogens, can also increase adhesiveness, reduce losses caused by the rolling and rebounding of pesticides, etc., improve the utilization rate, and thus is conducive to increasing the killing rate to obtain Pleurotus ferulae Lenzi polysaccharide;

[0067] S2. Dissolve sodium carboxymethyl cellulose in 80 mL of water. In the sodium carboxymethyl cellulose solution, the mass fraction of sodium carboxymethyl cellulose is 1.4%. Among them, a large number of carboxyl groups are contained on the sodium carboxymethyl cellulose, endowing the material with certain pH-responsive properties. Stir at a rotational speed of 500 rpm until completely dissolved, then add the Pleurotus ferulae Lenzi polysaccharide described in step S1, stir for 5 min, add epichlorohydrin, and perform ultrasonic treatment with an ultrasonic power of 60 W and an ultrasonic time of 20 min. Using sodium carboxymethyl cellulose as the substrate, a network structure with antibacterial properties is formed under the cross-linking action of epichlorohydrin and Pleurotus ferulae Lenzi polysaccharide. Then immerse the prepared cellulose composite gel in 100 mL of a tannic acid solution with a mass fraction of 1.1%, place it in a constant-temperature oscillator at 37 °C, with an oscillation speed of 100 rpm and an oscillation time of 1 h. The addition of tannic acid can form hydrogen bond connections with sodium carboxymethyl cellulose, and further cross-linking occurs inside the gel, resulting in more fine pores, making the gel network structure more regular and perfect, enhancing the mechanical properties and antibacterial properties of the shell material, and further strengthening the pH responsiveness, reducing the adverse effects of factors such as light and temperature on drug release to obtain a pH-responsive shell material;

[0068] S3. Transfer the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying equipment, and spray the pH-responsive shell material described in step S2. During the fluidized bed drying process, the spraying pressure is 0.6 MPa, the feeding rate is 10 mL / min, the inlet air temperature is 40 °C, and the drying time is 20 min. The drug-loaded porous calcium carbonate microspheres are coated with the pH-responsive shell material, constructing a drug release system with dual pH responsiveness, effectively reducing the decomposition of plant-derived pesticides by light, temperature, and humidity, improving the stability of the active ingredients. Moreover, the structure of the rough calcium carbonate spheres coated with a gel film layer can effectively adhere to the leaf surface of crops and slowly release the insecticidal and antibacterial active ingredients therein, reducing the loss of plant-derived pesticides and prolonging the effective period of action, thereby significantly increasing the killing rate of pests and diseases, and obtaining a plant-derived pesticide solvent with a high killing rate.

[0069] Example 3

[0070] This example presents a plant-derived pesticide solvent with a high killing rate, which includes the following components in parts by weight: 35 parts of drug-loaded porous calcium carbonate microspheres and 25 parts of pH-responsive shell material.

[0071] The drug-loaded porous calcium carbonate microspheres include the following components in parts by weight: 30 parts of glycine-modified calcium carbonate, 15 parts of ferric trichloride, 10 parts of traditional Chinese medicine components, and 10 parts of plant-derived glycerides.

[0072] The pH-responsive shell material includes the following components in parts by weight: 15 parts of sodium carboxymethylcellulose, 15 parts of Pleurotus eryngii polysaccharide, 6.5 parts of epichlorohydrin, and 12.5 parts of tannic acid.

[0073] The traditional Chinese medicine components, and its raw materials include the following components in parts by weight: 9 parts of Tripterygium wilfordii, 9 parts of Strychnos nux-vomica, 9 parts of Angelica pubescens, 9 parts of Picrasma quassioides, 9 parts of Chrysanthemum morifolium, and 6.5 parts of alum.

[0074] The preparation method of the drug-loaded porous calcium carbonate microspheres specifically includes the following steps:

[0075] (1) Add 1.0 g of soluble starch to 90 mL of deionized water, heat to 75 °C, stir for 30 min, cool to room temperature, then add 90 mL of calcium acetate with a concentration of 0.1 mol / L to the solution, stir for 30 min, add 90 mL of ammonium carbonate with a concentration of 0.1 mol / L, stir for 30 min, and then add glycine, and introduce CO 2The gas was added, and stirring was continued until the pH of the reaction solution reached 7.3. The temperature during the reaction was controlled at 25 °C. The addition amount of glycine was 0.3 g. The amino and carboxyl groups of glycine could form interactions with calcium ions, promoting the rapid growth and aggregation of amorphous nanoparticles, thereby forming vaterite-type calcium carbonate and inhibiting the growth of calcite crystals. Glycine participated in the formation process of calcium carbonate by chelating calcium ions. The obtained product had a complete sphericity, uniform size, and a large number of wrinkled surfaces. It not only improved the drug loading and slow-release performance of calcium carbonate but also enhanced the biocompatibility of the material. The solid product was separated by centrifugation at a rotational speed of 9000 rpm for 4 min, washed 4 times with deionized water, and freeze-dried at a drying temperature of -35 °C for 8 h to obtain glycine-modified calcium carbonate;

[0076] (2)Tripterygium wilfordii, Strychnos nux-vomica, Heracleum hemsleyanum, Picrasma quassioides, Chrysanthemum morifolium, and alum were first pre-crushed through a 70-mesh sieve, and the mixed coarse powder was then ultra-finely crushed through a 650-mesh sieve. 2.5 g of the fine traditional Chinese medicine powder was added to 50 mL of an ethanol solution with a mass fraction of 70%. The traditional Chinese medicine herbs were rich in bioactive compounds such as alkaloids and terpenoids and had significant insecticidal and antibacterial effects. The multi-components acted on the nervous system, muscle system, midgut enterocyte cells, and other parts of pests through multiple pathways, effectively destroying the cell structure of pests, inhibiting their growth, and the reproduction of the population, playing the roles of poisoning and anesthetizing, and ultimately leading to their death. Among them, alum had broad-spectrum antibacterial properties and could also release the smell liked by pests to prompt pests to eat and then kill them by generating high temperature. Stir for 15 min, add 2.5 g of plant-derived glycerol ester, and continue stirring for 25 min. The plant-derived glycerol ester was compounded with the fine traditional Chinese medicine powder to play an emulsifying and synergistic effect, obtaining a plant-derived medicinal solution;

[0077] (3) Add 7.5 g of glycine-modified calcium carbonate described in step (1) to 80 mL of an ethanol solution with a mass fraction of 70%, then add the plant-derived medicinal liquid described in step (2) and stir to mix. The stirring speed is 750 rpm and the stirring time is 7.5 min. Then add 125 mL of ferric chloride ethanol solution and continue stirring. The stirring speed is 750 rpm and the stirring time is 25 min. In the ferric chloride ethanol solution, the mass fraction of ferric chloride is 3%. Ferric chloride makes the surface of glycine-modified calcium carbonate more pitted and rough, which is beneficial to improving the loading capacity and the adsorption ability of the drug, and also beneficial to enhancing the adhesion performance with the leaf surface of crops, thus improving the utilization rate and achieving an efficient insecticidal and bacteriostatic effect. Centrifuge the suspension at a centrifugal speed of 9000 rpm for 4 min, collect the precipitate, wash it 4 times with an ethanol solution with a mass fraction of 70%, and freeze-dry it. The drying temperature is -35 °C and the drying time is 10 h. The active pharmaceutical ingredients composed of plant-derived glycerides and fine powder of traditional Chinese medicine can adhere and adsorb at the pores on the surface of the porous calcium carbonate carrier, having a certain sustained-release property. At the same time, the porous calcium carbonate carrier also plays a role in protecting the active pharmaceutical ingredients, reducing the adverse effects of environmental factors such as light and temperature. Also, because calcium carbonate can decompose under acidic conditions, the carrier is given pH responsiveness, thereby improving the stability, persistence, and efficiency of the plant-derived pesticide, and obtaining drug-loaded porous calcium carbonate microspheres.

[0078] This example provides a preparation method of a plant-derived pesticide solvent with a high killing rate, which specifically includes the following steps:

[0079] S1. Place fresh Pleurotus ferulae in a dry room temperature environment, lay it flat and air-dry until completely dehydrated, then use a high-speed multi-functional pulverizer to crush it into powder. Weigh 20 g of Pleurotus ferulae powder and add it to 500 mL of water. After stirring evenly, place it in an ultrasonic oscillator for 55 min, then centrifuge at a centrifugal speed of 7000 rpm for 12.5 min. Take the supernatant, concentrate it under reduced pressure. The concentrated Pleurotus ferulae extract paste is dissolved in 100 mL, add 800 mL of absolute ethanol, refrigerate at 4 °C for 24 h, filter by suction, and then wash the precipitate 4 times with absolute ethanol. After the precipitate is dried, it is dissolved in 100 mL of water, and the protein is removed 4 times by the Sevag method. Pleurotus ferulae polysaccharide has good inhibitory activity against plant pathogens, can also increase the adhesiveness, reduce the losses caused by the rolling and rebounding of pesticides, improve the utilization rate, and thus is beneficial to improving the killing rate, obtaining Pleurotus ferulae polysaccharide;

[0080] S2. Dissolve sodium carboxymethylcellulose in 80 mL of water. In the sodium carboxymethylcellulose solution, the mass fraction of sodium carboxymethylcellulose is 2.8%. Among them, a large number of carboxyl groups are contained on the carboxymethylcellulose, endowing the material with certain pH-responsive properties. Stir at a rotation speed of 550 rpm until completely dissolved, then add the Pleurotus eryngii polysaccharide described in step S1, stir for 7.5 min, add epichlorohydrin, and perform ultrasonic treatment. The ultrasonic power is 80 W and the ultrasonic time is 25 min. Using sodium carboxymethylcellulose as the substrate, a network structure with antibacterial properties is formed under the cross-linking action of epichlorohydrin and Pleurotus eryngii polysaccharide. Then immerse the prepared cellulose composite gel in 100 mL of tannic acid solution with a mass fraction of 1.8%, place it in a constant temperature oscillator at 37 °C, with an oscillation speed of 125 rpm and an oscillation time of 1.5 h. The addition of tannic acid can form hydrogen bond connections with sodium carboxymethylcellulose, further cross-link inside the gel, and more fine pores appear, making the gel network structure more regular and perfect, enhancing the mechanical properties and antibacterial properties of the shell material, further strengthening the pH responsiveness, reducing the adverse effects of factors such as light and temperature on drug release, and obtaining a pH-responsive shell material;

[0081] S3. Transfer the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying device, and spray the pH-responsive shell material described in step S2. During the fluidized bed drying process, the spraying pressure is 0.8 MPa, the feeding speed is 15 mL / min, the inlet air temperature is 45 °C, and the drying time is 25 min. The drug-loaded porous calcium carbonate microspheres are coated with a pH-responsive shell material, constructing a drug release system with dual pH responsiveness, effectively reducing the decomposition of plant-derived pesticides by light, temperature, and humidity, improving the stability of the active ingredients, and moreover, the structure of the rough calcium carbonate spheres coated with a gel film layer can effectively adhere to the leaf surface of crops and slowly release the insecticidal and antibacterial active ingredients therein, reducing the loss of plant-derived pesticides and prolonging the effective period of action, thereby significantly increasing the killing rate of pests and diseases, and obtaining a plant-derived pesticide solvent with a high killing rate.

[0082] Example 4

[0083] This example proposes a plant-derived pesticide solvent with a high killing rate, which includes the following components in parts by weight: 40 parts of drug-loaded porous calcium carbonate microspheres and 20 parts of pH-responsive shell material.

[0084] The drug-loaded porous calcium carbonate microspheres include the following components in parts by weight: 40 parts of glycine-modified calcium carbonate, 10 parts of ferric trichloride, 12 parts of traditional Chinese medicine components, and 8 parts of plant-derived glycerides.

[0085] The pH-responsive shell material includes the following components in parts by weight: 20 parts of sodium carboxymethylcellulose, 10 parts of Pleurotus eryngii polysaccharide, 5 - 8 parts of epichlorohydrin, and 15 parts of tannic acid.

[0086] Traditional Chinese medicine composition, the raw materials of which include the following components in parts by weight: 10 parts of Tripterygium wilfordii Hook. f., 10 parts of Strychnos nux-vomica L., 10 parts of Heracleum hemsleyanum Diels, 10 parts of Picrasma quassioides (D. Don) Benn., 10 parts of Chrysanthemum morifolium Ramat., and 5 parts of alum.

[0087] Preparation method of drug-loaded porous calcium carbonate microspheres, specifically including the following steps:

[0088] (1) Add 1.0 g of soluble starch to 100 mL of deionized water, heat to 80 °C, stir for 30 min, cool to room temperature, then add 100 mL of calcium acetate with a concentration of 0.1 mol / L to the solution, stir for 30 min, then add 100 mL of ammonium carbonate with a concentration of 0.1 mol / L, stir for 30 min, then add glycine, and introduce CO 2 gas, continue to stir until the pH of the reaction solution is 7.5, control the temperature during the reaction to be carried out at 25 °C, the addition amount of glycine is 0.2 g, the amino and carboxyl groups of glycine can form interactions with calcium ions, promoting the rapid growth and aggregation of amorphous nanoparticles, thereby forming vaterite-type calcium carbonate, inhibiting the growth of calcite crystals, glycine participates in the formation process of calcium carbonate in the way of complexing calcium ions, the obtained product has a complete sphericity, uniform size, and a large number of wrinkled surfaces, which not only improves the drug loading capacity and sustained release performance of calcium carbonate, but also improves the biocompatibility of the material, centrifuge to separate the solid product, the centrifuge speed is 10,000 rpm, the centrifuge time is 3 min, and wash with deionized water 5 times, freeze-dry, the drying temperature is -40 °C, the drying time is 6 h, to obtain glycine-modified calcium carbonate;

[0089] (2) First, pre-crush Tripterygium wilfordii Hook. f., Strychnos nux-vomica L., Heracleum hemsleyanum Diels, Picrasma quassioides (D. Don) Benn., Chrysanthemum morifolium Ramat., and alum through an 80-mesh sieve, and then ultra-finely crush the mixed coarse powder through an 800-mesh sieve. Take 3 g of the fine traditional Chinese medicine powder and add it to 50 mL of an ethanol solution with a mass fraction of 80%. The traditional Chinese medicine grass is rich in bioactive compounds such as alkaloids and terpenoids, and has significant insecticidal and antibacterial effects. Multiple components act on the nervous system, muscle system, midgut enterocyte cells and other parts of pests through multiple pathways, effectively destroying the cell structure of pests, inhibiting their growth and the reproduction of the population, playing a role in poisoning and anesthesia, and ultimately leading to their death. Among them, alum has broad-spectrum antibacterial properties, and can also release the smell liked by pests to promote pests to eat, and then generate high temperature to kill them. Stir for 10 min, add 2 g of plant-derived glyceride, and continue to stir for 20 - 30 min. The plant-derived glyceride is compounded with the fine traditional Chinese medicine powder to play an emulsifying and synergistic role, and obtain a plant-derived medicinal liquid;

[0090] (3) Add 10 g of glycine-modified calcium carbonate described in step (1) to 80 mL of an ethanol solution with a mass fraction of 80%, then add the plant-derived medicinal liquid described in step (2) and stir to mix. The stirring speed is 1000 rpm and the stirring time is 5 min. Then add 125 mL of ferric chloride ethanol solution and continue stirring. The stirring speed is 1000 rpm and the stirring time is 20 min. In the ferric chloride ethanol solution, the mass fraction of ferric chloride is 2%. Ferric chloride makes the surface of glycine-modified calcium carbonate more pitted and rough, which is beneficial to improving the loading capacity and the adsorption capacity for drugs, and also beneficial to enhancing the adhesion performance with the crop leaf surface, thus improving the utilization rate and achieving an efficient insecticidal and bacteriostatic effect. Centrifuge the suspension at a centrifugal speed of 10000 rpm for 3 min, collect the precipitate, wash it 5 times with an ethanol solution with a mass fraction of 80%, and freeze-dry it. The drying temperature is -40 °C and the drying time is 8 h. The active pharmaceutical ingredients composed of plant-derived glycerides and fine powder of traditional Chinese medicine can adhere to and adsorb at the pores on the surface of the porous calcium carbonate carrier, having a certain sustained-release property. At the same time, the porous calcium carbonate carrier also plays a role in protecting the active pharmaceutical ingredients, reducing the adverse effects of environmental factors such as light and temperature. Also, because calcium carbonate can decompose under acidic conditions, the carrier is given pH responsiveness, thereby improving the stability, persistence, and efficiency of the plant-derived pesticide, and obtaining drug-loaded porous calcium carbonate microspheres.

[0091] This example provides a preparation method of a plant-derived pesticide solvent with a high killing rate, which specifically includes the following steps:

[0092] S1. Place fresh Pleurotus ferulae Lenzi in a dry room temperature environment, lay it flat and air-dry until completely dehydrated, then use a high-speed multi-functional pulverizer to crush it into powder. Weigh 20 g of Pleurotus ferulae Lenzi powder and add it to 500 mL of water. After stirring evenly, place it in an ultrasonic oscillator for 50 min, then centrifuge at a centrifugal speed of 8000 rpm for 10 min. Take the supernatant, concentrate it under reduced pressure. The concentrated Pleurotus ferulae Lenzi extract paste is dissolved in 100 mL, add 900 mL of absolute ethanol, refrigerate at 4 °C for 24 h, filter by suction, and then wash the precipitate 5 times with absolute ethanol. After the precipitate is dried, it is dissolved in 100 mL of water, and the protein is removed 5 times by the Sevag method. Pleurotus ferulae Lenzi polysaccharide has good inhibitory activity against plant pathogens, can also increase the adhesiveness, reduce the losses caused by the rolling and rebounding of pesticides, improve the utilization rate, and thus is beneficial to improving the killing rate, obtaining Pleurotus ferulae Lenzi polysaccharide;

[0093] S2. Dissolve sodium carboxymethyl cellulose in 80 mL of water. In the sodium carboxymethyl cellulose solution, the mass fraction of sodium carboxymethyl cellulose is 5.5%. Among them, a large number of carboxyl groups are contained on the sodium carboxymethyl cellulose, endowing the material with certain pH-responsive properties. Stir until completely dissolved at a rotation speed of 600 rpm, then add the pleurotus eryngii polysaccharide described in step S1, stir for 5 min, add epichlorohydrin, and perform ultrasonic treatment. The ultrasonic power is 100 W and the ultrasonic time is 20 min. Using sodium carboxymethyl cellulose as the substrate, a network structure with antibacterial properties is formed under the cross-linking action of epichlorohydrin and pleurotus eryngii polysaccharide. Then immerse the prepared cellulose composite gel in 100 mL of tannic acid solution with a mass fraction of 3.3%, place it in a constant temperature oscillator at 37 °C, with an oscillation speed of 150 rpm and an oscillation time of 1 h. The addition of tannic acid can form hydrogen bond connections with sodium carboxymethyl cellulose, and further cross-linking occurs inside the gel, resulting in more fine pores, making the gel network structure more regular and perfect, enhancing the mechanical properties and antibacterial properties of the shell material, further strengthening the pH responsiveness, reducing the adverse effects of factors such as light and temperature on drug release, and obtaining a pH-responsive shell material;

[0094] S3. Transfer the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying device, and spray the pH-responsive shell material described in step S2. During the fluidized bed drying process, the spraying pressure is 1.0 MPa, the feeding speed is 20 mL / min, the inlet air temperature is 50 °C, and the drying time is 20 min. The drug-loaded porous calcium carbonate microspheres are coated with a pH-responsive shell material, constructing a drug release system with dual pH responsiveness, effectively reducing the decomposition of plant-derived pesticides by light, temperature, and humidity, improving the stability of the active ingredients. Moreover, the structure of the rough calcium carbonate spheres coated with a gel film layer can effectively adhere to the leaf surface of crops and slowly release the insecticidal and antibacterial active ingredients therein, reducing the loss of plant-derived pesticides and prolonging the effective period of action, thereby significantly increasing the killing rate of pests and diseases, and obtaining a plant-derived pesticide solvent with a high killing rate.

[0095] Comparative Example 1

[0096] This comparative example provides a plant-derived pesticide solvent with a high killing rate, which is different from Example 1 in that the plant-derived pesticide solvent with a high killing rate does not contain a pH-responsive shell material; the preparation method of the drug-loaded porous calcium carbonate microspheres is the same as that in Example 1; the preparation method of the plant-derived pesticide solvent with a high killing rate does not include steps S1 and S2.

[0097] Comparative Example 2

[0098] This comparative example provides a plant-derived pesticide solvent with a high killing rate, which is different from Example 1 in that the drug-loaded porous calcium carbonate microspheres do not contain glycine-modified calcium carbonate and ferric trichloride; the preparation method of the drug-loaded porous calcium carbonate microspheres does not include steps (1) and (3); the preparation method of the plant-derived pesticide solvent with a high killing rate is the same as that in Example 1.

[0099] Comparative Example 3

[0100] This comparative example provides a plant-derived pesticide solvent with a high killing rate, which is different from Example 1 in that the plant-derived pesticide solvent with a high killing rate does not contain glycine-modified calcium carbonate, ferric trichloride, and pH-responsive shell material; the preparation method of the drug-loaded porous calcium carbonate microspheres does not include steps (1) and (3); the preparation method of the plant-derived pesticide solvent with a high killing rate does not include steps S1 and S2.

[0101] Experimental Example 1

[0102] Release experiment

[0103] Test samples: The plant-derived pesticide solvents with a high killing rate prepared in Examples 1-4 and Comparative Examples 1-3.

[0104] Test method: Accurately weigh 1 g / mL of the plant-derived medicinal liquid and dilute it to 20 mg / mL. Using distilled water as the blank, scan it with a UV spectrophotometer in the wavelength range of 200-800 nm, and there is a maximum absorption at 415 nm; then dilute the traditional Chinese medicine components into a drug solution with a concentration of 0-20 mg / mL, measure the absorbance A at 415 nm, and obtain the standard curve equation A = 0.0325C + 0.0256 through regression, r 2 = 0.9993, and the best linear range is 4-20 mg / mL; add 5 mg of the test sample into a dialysis bag, then add 1 mL of PBS solution with a pH of 5, and use the release of Example 1 in PBS solution with a pH of 7 as the control group. Immerse the sealed dialysis bag in 100 mL of PBS solution and place it on a shaker to oscillate. The fixed interval time is 10 h. Take 3 mL of the diluted solution and supplement an equal amount of PBS solution. Finally, use a UV-visible spectrophotometer to measure the absorbance of the taken-out solution, calculate the drug concentration based on the standard curve, and then calculate the release rate (%) from 10 to 50 h according to the following formula:

[0105] Release rate (%) = (C i V 1 +V 2 ∑C i-1 ) / m 1 ×100%

[0106] Among them, Ci is the drug concentration in the i-th taken-out solution, mg / mL; V 1is the total volume of the solution, 100 mL; V 2 is the volume of each sampling, 3 mL; m 1 is the drug content, mg.

[0107] Figure 3 is the release rate result graph of 10 - 50 h for Examples 1 - 4, Comparative Examples 1 - 3 and the control group; as shown in the figure, the release rates of 10, 20, 30, 40, 50 h for Examples 1 - 4 are 38.8 - 43.6%, 46.1 - 52.8%, 57.8 - 63.7%, 61.6 - 71.2%, 62.9 - 72.5% respectively, and the cumulative release rate at 50 h reaches up to 72.5% at most, indicating excellent pH-responsive release performance; the release rates of 10, 20, 30, 40, 50 h for Comparative Examples 1 - 3 are 22.5 - 35.1%, 26.7 - 42.5%, 30.6 - 52.8%, 33.8 - 55.3%, 35.0 - 56.7% respectively, and the cumulative release rate at 50 h reaches only 56.7% at most, indicating weak pH-responsive release performance; the cumulative release rate at 50 h for the control group reaches only 31.8%, indicating no responsive release performance under the condition of pH = 7; the high-kill-rate plant-derived pesticide solvent in Comparative Example 1 does not contain a pH-responsive shell material and cannot synergistically play a pH-responsive release role with the drug-loaded porous calcium carbonate microspheres, resulting in weak pH-responsive release performance; the drug-loaded porous calcium carbonate microspheres in Comparative Example 2 do not contain glycine-modified calcium carbonate and ferric trichloride, only contain the plant-derived liquid medicine, and do not contain a drug-loaded carrier, thus unable to form a dual pH-responsive drug release system with the pH-responsive shell material, resulting in weak pH-responsive release performance; the high-kill-rate plant-derived pesticide solvent in Comparative Example 3 does not contain glycine-modified calcium carbonate, ferric trichloride and pH-responsive shell material, and cannot form a pH-responsive drug release system, resulting in weak pH-responsive release performance.

[0108] Experimental Example 2

[0109] Adhesion experiment

[0110] Test samples: High-kill-rate plant-derived pesticide solvents prepared in Examples 1 - 4 and Comparative Examples 1 - 3.

[0111] Test method: Prepare the test samples into a suspension with a concentration of 50 mg / L, ultrasonically treat for 30 min, collect fresh broad bean leaves, and use a punch to prepare regular square leaves (2 cm × 2 cm), weigh the initial weight M of the leaves 0 , soak the clean leaves in the test sample suspension for 15 s, vertically take them out and hang for 30 s, wait until the liquid drops no longer fall, and weigh the weight M of the leaves after soaking 1 , calculate the leaf retention amount of the liquid medicine according to the following formula:

[0112] Leaf retention amount (mg / cm 2 ) = (M 1 - M 0 ) / 4

[0113] Figure 4 Figure 4 shows the leaf retention amount results of Examples 1 - 4 and Comparative Examples 1 - 3; as shown in the figure, the leaf retention amount of Examples 1 - 4 is 14.3 - 16.2 mg / cm 2 , indicating good adhesiveness; the leaf retention amount of Comparative Examples 1 - 3 is 8.0 - 12.1 mg / cm 2 , indicating poor adhesiveness; the plant - derived pesticide solvent with a high killing rate in Comparative Example 1 does not contain a pH - responsive shell material and cannot form a gel structure, resulting in poor adhesiveness; the drug - loaded porous calcium carbonate microspheres in Comparative Example 2 do not contain glycine - modified calcium carbonate and ferric trichloride and cannot form a spherical structure with a rough surface, resulting in poor adhesiveness; the plant - derived pesticide solvent with a high killing rate in Comparative Example 3 does not contain glycine - modified calcium carbonate, ferric trichloride, and pH - responsive shell material, and neither can it form a spherical structure with pitted and rough surfaces, which is not conducive to adhesion and attachment to the leaf surface of crops, nor can it exert the adhesion effect of the gel shell, resulting in poor adhesiveness.

[0114] Experimental Example 3

[0115] Pharmacodynamic experiment

[0116] Test samples: The plant - derived pesticide solvents with a high killing rate prepared in Examples 1 - 4 and Comparative Examples 1 - 3.

[0117] Test method: The field pharmacodynamic test was carried out in the test plot of the Citrus Innovation Center of the Environmental Entomology Research Center, Guangdong Academy of Sciences. Each citrus tree was marked at five positions: east, west, south, north, and middle. A total of 25 leaves were investigated for the number of active spider mites. The leaf surface was directly observed with a hand - held magnifying glass to count the number of spider mites. A knapsack manual sprayer was used for spraying, and the spraying was carried out evenly until the leaf surface dripped water; the test samples were diluted 200 times with water and then sprayed. Each treatment was repeated 5 times, and 2 L of the liquid medicine was sprayed on each citrus tree. The base number of spider mites was investigated before spraying, and the number of spider mites was investigated 2 days after spraying. The killing rate (%) was calculated according to the following formula:

[0118] Killing rate (%) = (Number of live spider mites before spraying - Number of live spider mites after spraying) / Number of live spider mites before spraying × 100%

[0119] Figure 5Graph of the killing rate results for Examples 1-4 and Comparative Examples 1-3; as shown in the figure, the killing rates of Examples 1-4 were 99.5-100.0%, indicating a relatively high killing rate and better drug efficacy; the killing rates of Comparative Examples 1-3 were 75.7-91.6%, indicating a relatively low killing rate and poor drug efficacy; the plant-derived pesticide solvent with a high killing rate in Comparative Example 1 did not contain a pH-responsive shell material, and thus could not form a protective film on the surface of the drug-loaded porous calcium carbonate microspheres, which was not conducive to the stability, precise release of the pesticide, and also reduced the adhesion, resulting in a relatively low killing rate and poor drug efficacy; the drug-loaded porous calcium carbonate microspheres in Comparative Example 2 did not contain glycine-modified calcium carbonate and ferric trichloride, and thus could not form a carrier with a rough surface and certain pH responsiveness, reducing the pesticide loading amount and also decreasing the stability, effectiveness, and persistence of the drug efficacy components, resulting in a relatively low killing rate and poor drug efficacy; the plant-derived pesticide solvent with a high killing rate in Comparative Example 3 did not contain glycine-modified calcium carbonate, ferric trichloride, and pH-responsive shell material, and thus could not form a dual pH-responsive drug release system, and thus could not achieve precise release, nor could it form a structure that could reduce the rolling and rebounding of the pesticide, which was not conducive to adhesion on the crop leaves to play a role, resulting in a relatively low killing rate and poor drug efficacy.

[0120] The above experimental results show that the release, adhesion, and drug efficacy of Examples 1-4 of the present invention are significantly better than those of the samples of Comparative Examples 1-3. Among them, Example 1 using drug-loaded porous calcium carbonate microspheres and pH-responsive shell material has better pH release, stronger adhesion, and better drug efficacy. The drug-loaded porous calcium carbonate microspheres are a spherical structure with a pitted and rough surface, which can load more plant-derived drug efficacy components, improve the adhesion and attachment performance to the crop leaves, have a certain pH responsiveness, are conducive to precise and slow release, reduce the adverse effects of temperature, light, and humidity on the drug efficacy components, and enhance the stability, effectiveness, and persistence of the drug efficacy components, thereby being conducive to the improvement of the killing rate; in the pH-responsive shell material, a more perfect gel network structure containing small pores is formed, the shell material has a stable and effective pH-responsive performance, and the synergistic effect of pleurotus eryngii polysaccharide and tannic acid enhances the adhesion of the shell material, reducing the losses caused by the rolling and rebounding of the pesticide; the dual pH-responsive drug release system formed by the two plays an effective and persistent role, achieving the pest control effect with a high killing rate.

[0121] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention.

[0122] The above describes the present invention and its implementation manners. Such description is not restrictive. What is shown in the drawings is only one of the implementation manners of the present invention, and the actual application is not limited thereto. Generally speaking, if those of ordinary skill in the art are inspired by it and, without departing from the gist of the present invention, design in a non-creative way similar ways and embodiments to this technical solution, they shall fall within the protection scope of the present invention.

Claims

1. A plant-derived pesticide solvent with a high killing rate, characterized in that: The high-killing-rate botanical pesticide solvent comprises the following components in parts by weight: 30-40 parts of drug-loaded porous calcium carbonate microspheres and 20-30 parts of pH-responsive shell materials; the drug-loaded porous calcium carbonate microspheres comprise the following components in parts by weight: 20-40 parts of glycine-modified calcium carbonate, 10-20 parts of ferric chloride, 8-12 parts of traditional Chinese medicine ingredients, and 8-12 parts of plant-derived glycerides; the pH-responsive shell material comprises the following components in parts by weight: 10-20 parts of sodium carboxymethyl cellulose, 10-20 parts of Pleurotus ferulae polysaccharides, 5-8 parts of epichlorohydrin, and 10-15 parts of tannic acid; the raw materials of the traditional Chinese medicine ingredients comprise the following components in parts by weight: 8-10 parts of Tripterygium wilfordii, 8-10 parts of Strychnos nux vomica, 8-10 parts of Angelica dahurica, 8-10 parts of Quassima, 8-10 parts of Chrysanthemum, and 5-8 parts of Alum; The method for preparing the botanical pesticide solvent with a high killing rate specifically comprises the following steps: S1. Place fresh Pleurotus ferulae in a dry room temperature environment, lay it flat and dry it until it is completely dehydrated, use a high-speed multifunctional grinder to grind it into powder, weigh 20g of Pleurotus ferulae powder and add it to 500mL of water, stir it evenly, place it in an ultrasonic oscillator for 50-60min, centrifuge it at a speed of 6000-8000rpm, and centrifuge it for 10-15min. Take the supernatant, concentrate it under reduced pressure, dissolve the concentrated Pleurotus ferulae extract in 100mL, add 700-900mL of anhydrous ethanol, refrigerate it at 4℃ for 24h, filter it, wash the precipitate with anhydrous ethanol for 3-5 times, dry the precipitate and dissolve it in 100mL of water, remove protein by Sevag method for 3-5 times, and obtain Pleurotus ferulae polysaccharide; S2, dissolving sodium carboxymethyl cellulose in 80 mL of water, stirring at a speed of 500-600 rpm until completely dissolved, then adding the Pleurotus ferulae polysaccharide described in step S1, stirring for 5-10 min, adding epichlorohydrin, and performing ultrasonic treatment, with an ultrasonic power of 60-100 W and an ultrasonic time of 20-30 min, then immersing the prepared cellulose composite gel in 100 mL of a tannic acid solution with a mass fraction of 1.1-3.3%, placing it in a constant temperature oscillating box at 37°C, with an oscillation speed of 100-150 rpm and an oscillation time of 1-2 h, to obtain a pH-responsive shell material; S3, transferring the drug-loaded porous calcium carbonate microspheres to a fluidized bed drying device, spraying the pH-responsive shell material described in step S2, and during the fluidized bed drying process, the spraying pressure is 0.6-1.0 MPa, the feed rate is 10-20 mL / min, the inlet air temperature is 40-50° C., and the drying time is 20-30 min to obtain a botanical pesticide solvent with a high killing rate; The method for preparing the drug-loaded porous calcium carbonate microspheres specifically comprises the following steps: (1) Add 1.0 g of soluble starch to 80-100 mL of deionized water, heat to 70-80° C., stir for 30 min, cool to room temperature, add 80-100 mL of 0.1 mol / L calcium acetate to the solution, stir for 30 min, then add 80-100 mL of 0.1 mol / L ammonium carbonate, stir for 30 min, then add glycine, and introduce CO2 gas, continue stirring until the pH of the reaction solution is 7.0-7.5, control the temperature during the reaction at 25° C., separate the solid product by centrifugation at a centrifugal speed of 8000-10000 rpm for 3-5 min, wash with deionized water for 3-5 times, freeze-dry at a drying temperature of -40° C. to -30° C. for 6-10 h, and obtain glycine-modified calcium carbonate; (2) Pre-crushing tripterygium wilfordii, strychnos nux vomica, angelica pubescens, bitter wood, chrysanthemum and alum through a 60-80 mesh sieve, and then ultrafine grinding the mixed coarse powder through a 500-800 mesh sieve. Add 2-3 g of the fine powder of the traditional Chinese medicine into 50 mL of an ethanol solution with a mass fraction of 60-80%, stir for 10-20 min, add 2-3 g of plant-derived glyceride, and continue stirring for 20-30 min to obtain a plant-derived medicinal solution. (3) Add 5-10 g of the glycine-modified calcium carbonate described in step (1) to 80 mL of an ethanol solution having a mass fraction of 60-80%, and then add the plant-derived medicinal solution described in step (2) thereto and stir and mix at a stirring speed of 500-1000 rpm for 5-10 min. Add 125 mL of ferric chloride ethanol solution and continue stirring at a stirring speed of 500-1000 rpm for 20-30 min. Centrifuge the suspension at a centrifugal speed of 8000-10000 rpm for 3-5 min. Collect the precipitate, wash it 3-5 times with an ethanol solution having a mass fraction of 60-80%, and freeze-dry it at a drying temperature of -40°C to -30°C for 8-12 h to obtain drug-loaded porous calcium carbonate microspheres.

2. The method for preparing a botanical pesticide solvent with a high killing rate according to claim 1, characterized in that: In step S2, in the sodium carboxymethyl cellulose solution, the mass fraction of sodium carboxymethyl cellulose is 1.4-5.5%.

3. The method for preparing a botanical pesticide solvent with a high killing rate according to claim 2, characterized in that: In step (1), the amount of glycine added is 0.2-0.5 g.

4. The method for preparing a botanical pesticide solvent with a high killing rate according to claim 3, characterized in that: In step (3), the mass fraction of ferric chloride in the ferric chloride ethanol solution is 2-4%.

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