阅读说明：本技术 一种防治香蕉枯萎病的复合精油微囊制剂及其制备方法 (Compound essential oil microcapsule preparation for preventing and treating banana wilt and preparation method thereof ) 是由 周闯 谢江辉 李普旺 杨子明 何祖宇 王超 焦静 吕明哲 宋书会 刘运浩 于 2020-06-05 设计创作，主要内容包括：本发明公开了一种防治香蕉枯萎病的复合精油微囊制剂及其制备方法,属于生物质有机高分子功能材料技术领域。通过对壳聚糖进行化学改性,在其结构上接枝(4-羧丁基)三苯基溴化磷、N-乙酰-L-苯丙氨酸,得到防治香蕉枯萎病的两亲性季膦盐壳聚糖衍生物,然后以两亲性季膦盐壳聚糖衍生物为壁材,以抗香蕉枯萎病的复合精油为芯材,采用复凝聚的方法,通过壁材分子间作用力和静电引力使芯材包埋于壁材内,得到具有核壳结构的复合精油微囊。本发明所公开的防治香蕉枯萎病的复合精油微囊不仅利用壳聚糖、植物精油的抗菌性,而且可以实现植物精油的缓慢释放,同时所制备的复合精油微囊制剂具有环保、无污染、可再生的特点。(The invention discloses a composite essential oil microcapsule preparation for preventing and treating banana vascular wilt and a preparation method thereof, belonging to the technical field of biomass organic polymer functional materials. The preparation method comprises the steps of chemically modifying chitosan, grafting (4-carboxybutyl) triphenyl phosphorus bromide and N-acetyl-L-phenylalanine on the structure of the chitosan to obtain an amphiphilic quaternary phosphonium salt chitosan derivative for preventing and treating banana vascular wilt, then taking the amphiphilic quaternary phosphonium salt chitosan derivative as a wall material, taking compound essential oil for resisting banana vascular wilt as a core material, adopting a complex coacervation method, and embedding the core material in the wall material through the intermolecular force of the wall material and the electrostatic attraction to obtain the compound essential oil microcapsule with a core-shell structure. The composite essential oil microcapsule for preventing and treating banana vascular wilt disclosed by the invention not only utilizes the antibacterial property of chitosan and plant essential oil, but also can realize the slow release of the plant essential oil, and meanwhile, the prepared composite essential oil microcapsule preparation has the characteristics of environmental protection, no pollution and reproducibility.)

1. An amphiphilic quaternary phosphonium salt chitosan derivative is characterized in that the structural formula is shown as the formula (I):

wherein x, y and z are natural numbers more than or equal to 1.

2. A method for preparing the amphiphilic quaternary phosphonium salt chitosan derivative of claim 1, comprising the steps of:

(1) dropwise adding an activating agent into the chitosan acetic acid aqueous solution, then adding (4-carboxybutyl) triphenyl phosphonium bromide and a condensing agent, stirring for reaction, dialyzing after the reaction is finished, and freeze-drying to obtain quaternary phosphonium salt chitosan;

(2) and (2) adding the quaternary phosphonium salt chitosan obtained in the step (1) and an activating agent into water, uniformly mixing and stirring to obtain a homogeneous transparent solution, then adding N-acetyl-L-phenylalanine and a condensing agent, stirring for reaction, dialyzing after the reaction is finished, and freeze-drying to obtain the amphiphilic quaternary phosphonium salt chitosan derivative.

3. The preparation method of the amphiphilic quaternary phosphonium salt chitosan derivative according to claim 2, wherein the activating agent is at least one of 1-hydroxy-benzotriazole, benzotriazole-N, N, N ', N' -tetramethyluronium hexafluorophosphate, O-benzotriazole-N, N, N ', N' -tetramethyluronium tetrafluoroborate;

the condensing agent is at least one of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, dicyclohexylcarbodiimide and diisopropylcarbodiimide.

4. The method for preparing amphiphilic quaternary phosphonium salt chitosan derivative according to claim 2, wherein the temperature of the stirring reaction in the step (1) and the step (2) is 20-30 ℃ and the time is 12-36 h; the dialysis time in the step (1) and the step (2) is 2-3 days.

5. The use of the amphiphilic quaternary phosphonium salt chitosan derivative of claim 1 as a carrier of drugs for preventing and treating banana vascular wilt.

6. A composite essential oil microcapsule preparation, wherein the wall material of the composite essential oil microcapsule preparation is a complex of the amphiphilic quaternary phosphonium salt chitosan derivative of claim 1 and sodium alginate; the core material of the compound essential oil microcapsule preparation is plant essential oil.

7. The composite essential oil microcapsule preparation according to claim 6, wherein the mass ratio of the wall material to the core material is (1-4): 1: 2; the particle size of the composite essential oil microcapsule preparation is 4-6 um;

the plant essential oil is at least one of geranium oil, lavender oil, blumea oil, lemongrass oil, eucalyptus oil, citronella oil, peppermint oil, cinnamon oil, blumea oil, lemon eucalyptus oil, basil oil, rosemary oil, clove oil and tea tree oil.

8. A method for preparing the composite essential oil microcapsule formulation according to any one of claims 6 to 7, comprising the steps of:

(1) solution A: dissolving the amphiphilic quaternary phosphonium salt chitosan derivative in water to prepare a polymer solution with the concentration of 0.5-2.0 wt%;

solution B: dissolving sodium alginate in water to prepare a polymer solution with the concentration of 0.5-2.0 wt%, and then adding tween-80 to form a uniform solution;

(2) uniformly mixing the plant essential oil and span-80, adding the mixture into the solution B, and then carrying out high-speed shearing emulsification for 5-10min at the speed of 1000-3000r/min to obtain an oil-in-water emulsion;

(3) dropwise adding the oil-in-water emulsion into the solution A at a stirring speed of 500-;

(4) slowly dripping a curing agent, and carrying out curing reaction for 0.5-1.0h under the ice bath condition to obtain the compound essential oil microcapsule preparation.

9. The method for preparing the composite essential oil microcapsule formulation according to claim 8, wherein the curing agent is at least one of calcium nitrate, magnesium sulfate and calcium chloride; the mass fraction of the curing agent is 0.3-0.9 w/v%.

10. Use of the composite essential oil microcapsule formulation of any one of claims 6 to 7 for preventing and treating banana vascular wilt.

Technical Field

The invention relates to the technical field of biomass organic polymer functional materials, in particular to a composite essential oil microcapsule preparation for preventing and treating banana vascular wilt and a preparation method thereof.

Background

The banana vascular wilt is a soil-borne disease caused by fungus infecting the vascular bundle of banana plants and is caused by the special infection of fusarium oxysporum cubeba. The banana wilt is a soil-borne vascular bundle disease, the banana seedlings with the disease and diseased soil are the initial infection source, pathogenic bacteria invade the banana from the root and spread to tubers through vascular bundle tissues, the vascular bundle tissues at the infected parts are obviously browned, and the phenomena of inward longitudinal cracking of pseudostem bases, tuber rot and the like occur. The banana wilt is remotely spread by the allocation and the movement of banana seedlings with bacteria, soil, agricultural machines and the like; the short-distance diffusion is carried out through water and conidia with bacteria. The conventional chemical pesticide dosage application method is spraying or sprinkling irrigation, only the surface of the plant can be treated, and the inhibition and killing effect on pathogenic bacteria invading into the vascular bundle of the plant is difficult to generate directly. Because the transportation of water in banana plants is fast, the vascular bundle diseases are difficult to control by the existing pesticide formulations and pesticide application methods, the control effect is not ideal, and the pesticide resistance is easy to cause by long-term use of chemical pesticides, so that the ecological environment is destroyed, and the quality of bananas is greatly influenced.

The Chinese patent with publication number CN104054699A discloses hymexazol aqueous solution and a preparation method thereof and application thereof in preventing and treating banana wilt, the hymexazol aqueous solution is obtained by homogenizing hymexazol original drug, pesticide adjuvant 06301, water and defoamer, the hymexazol aqueous solution has the characteristics of environmental protection, safety, excellent performance and the like, but the hymexazol belongs to chemical pesticide, and is easily influenced by the external environment due to no protection of wall materials. In addition, chinese patent publication No. CN107027824B discloses a synergistic composition of banana vascular wilt containing traditional Chinese medicine extract and pesticide, the composition includes clove extract, coptis extract, prochloraz, carbendazim, thiram, etc., the synergistic composition has synergistic effect through combination of multiple components, and can be used for preventing and treating banana vascular wilt, but the traditional Chinese medicine extract and pesticide are only simple composite synergy, and have no protection of wall materials, and are easily interfered by external environment.

The microcapsule is a micro capsule which is prepared by embedding solid or liquid medicines into natural or synthetic polymer materials and has the diameter of l-5000 microns (usually 5-250 microns), and has the functions of high bioavailability, slow release and delayed effect and the like. The chitosan is a product of natural polysaccharide chitin with partial acetyl removed, has various physiological functions of biodegradability, biocompatibility, nontoxicity, bacteriostasis and the like, and is widely applied to food additives, textiles, agriculture, environment-friendly cosmetics, antibacterial agents and the like. The plant essential oil is extracted from flowers, leaves, roots, barks, fruits, seeds and the like of herbaceous plants by distillation and squeezing, and has antibacterial, antimicrobial and antiviral properties due to the antibacterial and antiseptic components.

The antibacterial property of the chitosan plant essential oil composite microcapsule is mainly due to the antibacterial property of chitosan and carried components and the synergistic effect of the chitosan and the carried components, the antibacterial activity of chitosan is due to the interaction between amino groups carrying positive electricity and carboxylate groups carrying negative electricity on the surface of a microorganism, the structure of the microorganism is damaged or physiological imbalance is possibly caused by the electrochemical combination, so that the microorganism is killed, and the plant essential oil is a good natural antibacterial material, has broad-spectrum and efficient antibacterial activity, is taken from natural plants, has wide sources, is green and environment-friendly, and has great potential application value in the antibacterial field.

Therefore, aiming at the problems of single function of the existing carrier material, the drug resistance of the conventional chemical pesticide formulation to the banana vascular wilt and the damage to the environment, the new carrier material is provided, and the important significance of solving the drug resistance of the conventional chemical pesticide formulation to the banana vascular wilt and the damage to the environment is realized.

Disclosure of Invention

The invention aims to provide a compound essential oil microcapsule preparation for preventing and treating banana vascular wilt and a preparation method thereof, which are used for solving the problems in the prior art, solving the problem of single functionality of the existing carrier material, and solving the problems of drug resistance of the conventional chemical pesticide formulation to banana vascular wilt and environmental damage.

In order to achieve the purpose, the invention provides the following scheme:

the invention aims to provide an amphiphilic quaternary phosphonium salt chitosan derivative, which has a structural formula shown in a formula (I):

wherein x, y and z are natural numbers more than or equal to 1.

The invention also aims to provide a preparation method of the amphiphilic quaternary phosphonium salt chitosan derivative, which comprises the following steps:

(1) dropwise adding an activating agent into the chitosan acetic acid aqueous solution, then adding (4-carboxybutyl) triphenyl phosphonium bromide and a condensing agent, stirring for reaction, dialyzing after the reaction is finished, and freeze-drying to obtain quaternary phosphonium salt chitosan;

(2) and (2) adding the quaternary phosphonium salt chitosan obtained in the step (1) and an activating agent into water, uniformly mixing and stirring to obtain a homogeneous transparent solution, then adding N-acetyl-L-phenylalanine and a condensing agent, stirring for reaction, dialyzing after the reaction is finished, and freeze-drying to obtain the amphiphilic quaternary phosphonium salt chitosan derivative.

Further, the activating agent is at least one of 1-hydroxy-benzotriazole, benzotriazole-N, N, N ', N' -tetramethylurea hexafluorophosphate and O-benzotriazole-N, N, N ', N' -tetramethylurea tetrafluoroborate;

the condensing agent is at least one of 1- (3-dimethylaminopropyl) -3-ethylcarbodiimide, dicyclohexylcarbodiimide and diisopropylcarbodiimide;

in the step (1), the molar ratio of the activating agent to the (4-carboxybutyl) triphenyl phosphonium bromide is (1-2):1, the molar ratio of the condensing agent to the (4-carboxybutyl) triphenyl phosphonium bromide is (1-2) to 1;

in the step (2), the molar ratio of the activating agent to the N-acetyl-L-phenylalanine is (1-2):1, and the molar ratio of the condensing agent to the N-acetyl-L-phenylalanine is (1-2): 1;

taking the amount of chitosan amino as a calculation standard, wherein the molar ratio of the (4-carboxybutyl) triphenyl phosphonium bromide to the amount of the chitosan amino is (1-2): 1;

the molar ratio of the N-acetyl-L-phenylalanine to the chitosan amino amount is (1-2):1 by taking the chitosan amino amount as a calculation standard.

Further, the temperature of the stirring reaction in the step (1) and the step (2) is 20-30 ℃, and the time is 12-36 h; the dialysis time in the step (1) and the step (2) is 2-3 days.

The third purpose of the invention is to provide the application of the amphiphilic quaternary phosphonium salt chitosan derivative as a carrier of a medicine for preventing and treating banana vascular wilt.

The fourth purpose of the invention is to provide a composite essential oil microcapsule preparation, the wall material of which is a composite of the amphiphilic quaternary phosphonium salt chitosan derivative of claim 1 and sodium alginate; the core material of the compound essential oil microcapsule preparation is plant essential oil.

Further, the mass ratio of the wall material to the core material is (1-4) to (1: 2); the particle size of the composite essential oil microcapsule preparation is 4-6 um;

the plant essential oil is at least one of geranium oil, lavender oil, blumea oil, lemongrass oil, eucalyptus oil, citronella oil, peppermint oil, cinnamon oil, blumea oil, lemon eucalyptus oil, basil oil, rosemary oil, clove oil and tea tree oil.

The fifth purpose of the invention is to provide a preparation method of the composite essential oil microcapsule preparation, which comprises the following steps:

(1) solution A: dissolving the amphiphilic quaternary phosphonium salt chitosan derivative in water to prepare a polymer solution with the concentration of 0.5-2.0 wt%;

solution B: dissolving sodium alginate in water to prepare a polymer solution with the concentration of 0.5-2.0 wt%, and then adding tween-80 to form a uniform solution;

(2) uniformly mixing the plant essential oil and span-80, adding the mixture into the solution B, and then carrying out high-speed shearing emulsification for 5-10min at the speed of 1000-3000r/min to obtain an oil-in-water emulsion;

(3) dropwise adding the oil-in-water emulsion into the solution A at a stirring speed of 500-;

(4) slowly dripping a curing agent, and carrying out curing reaction for 0.5-1.0h under the ice bath condition to obtain the compound essential oil microcapsule preparation.

Further, the curing agent is at least one of calcium nitrate, magnesium sulfate and calcium chloride; the mass fraction of the curing agent is 0.3-0.9 w/v%.

The invention further aims to provide application of the compound essential oil microcapsule preparation in preventing and treating banana vascular wilt.

The invention discloses the following technical effects:

1. the amphiphilic quaternary phosphonium salt chitosan derivative is used for preventing and treating banana wilt, and can solve the problems of drug resistance and environmental damage of conventional chemical pesticides in the treatment of banana wilt.

2. The invention takes natural alkaline polysaccharide-chitosan quaternary phosphonium salt derivative as a composite wall material and plant essential oil as a core material, and utilizes a complex coacervation method to coat the natural alkaline polysaccharide-chitosan quaternary phosphonium salt derivative, so that the core material is embedded in the wall material through the intermolecular force and the electrostatic attraction of the wall material to obtain the spherical microcapsule with a core-shell structure and a regular shape, thereby solving the problem of single functionality of the existing carrier material. The hydrophobic groups on the wall materials inwards form an inner core which is a combined part of the hydrophobic plant essential oil; meanwhile, strong hydrogen bond effect exists between hydrophilic groups on the wall material and water, a compact shell can be formed around the kernel, and the plant essential oil is better wrapped in the shell, so that the plant essential oil in the kernel can be slowly released.

3. The composite essential oil microcapsule for preventing and treating banana vascular wilt disclosed by the invention not only utilizes the antibacterial properties of chitosan and plant essential oil, but also can realize the slow release of the plant essential oil, and meanwhile, the prepared composite essential oil microcapsule preparation has the characteristics of environmental protection, no pollution and reproducibility, and meanwhile, the preparation method is simple, and can meet the requirements of industrial production.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a Fourier infrared spectrum of various materials of example 1 wherein (a) is quaternary phosphonium salt chitosan; (b) is amphiphilic quaternary phosphonium salt chitosan derivative; (c) is (4-carboxybutyl) triphenyl phosphonium bromide; (d) is N-acetyl-L-phenylalanine and (e) is chitosan;

FIG. 2 is a Scanning Electron Microscope (SEM) image of the microcapsules of the compound essential oil of example 1;

FIG. 3 is a particle size distribution diagram of the microcapsules of complex essential oil of example 1;

FIG. 4 is the slow release profile of the composite essential oil microcapsules of example 1;

FIG. 5 is a graph comparing the effect of the composite essential oil microcapsules of example 1 on Fusarium oxysporum.

Detailed Description

Reference will now be made in detail to various exemplary embodiments of the invention, the detailed description should not be construed as limiting the invention but as a more detailed description of certain aspects, features and embodiments of the invention.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Further, for numerical ranges in this disclosure, it is understood that each intervening value, between the upper and lower limit of that range, is also specifically disclosed. Every smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in a stated range is encompassed within the invention. The upper and lower limits of these smaller ranges may independently be included or excluded in the range.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference herein for the purpose of disclosing and describing the methods and/or materials associated with the documents. In case of conflict with any incorporated document, the present specification will control.

It will be apparent to those skilled in the art that various modifications and variations can be made in the specific embodiments of the present disclosure without departing from the scope or spirit of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification. The specification and examples are exemplary only.

As used herein, the terms "comprising," "including," "having," "containing," and the like are open-ended terms that mean including, but not limited to.

The "parts" in the present invention are all parts by mass unless otherwise specified.

The structural formula of the amphiphilic quaternary phosphonium salt chitosan derivative prepared by the invention is shown as the formula (I):

the preparation process comprises the following steps: