CN105123789A - Rhubarb free anthraquinone nanometer emulsion preparation for preventing and treating plant red spider disease - Google Patents

Abstract

The invention belongs to the technical field of biopesticides, and in particular relates to the prescription and preparation process of rhubarb free anthraquinone nanoemulsion preparation, and its application in preventing and treating plant red spider disease. The rhubarb free anthraquinone is extracted from the traditional Chinese medicine rhubarb palmatum, rhubarb tangutica or medicinal rhubarb. Based on the mass percentage of each component contained in the nanoemulsion, the free anthraquinone content of rhubarb in the nanoemulsion is 0.05-0.16%, the oil phase in the nanoemulsion accounts for 18-22%, the emulsifier 16-20%, and the co-emulsifier 4-6%, water 50-61%, stabilizer 1.0%, preservative 0.1%, adhesive 0.1%. The rhubarb free anthraquinone nanoemulsion preparation can be used for preventing and treating plant red spider disease. The free anthraquinone in the rhubarb free anthraquinone nanoemulsion disclosed by the present invention is derived from the traditional Chinese medicine rhubarb, the extraction process has strong applicability, the cost of raw material acquisition is low, the preparation of the nanoemulsion is spontaneously formed, the process is simple, the quality is controllable, and it is easy to produce Large-scale production, and showed excellent control effect on plant spider mite disease.

Description

A rhubarb free anthraquinone nanoemulsion preparation for preventing and treating plant red spider disease

technical field

The invention belongs to the field of pesticides, in particular to a rhubarb free anthraquinone nanoemulsion preparation for preventing and treating plant red spider disease.

Background technique

Plant spider mite disease widely exists on the stems and leaves of various crops, vegetables, flowers, trees and other plants, and mainly harms crops such as Solanaceae, Cucurbitaceae, Leguminosae, Liliaceae and Gramineae. The species of spider mite in my country is dominated by Tetranychus cinnabarinidae, belonging to Arachnida, Acaridae, and Tetranychidae. It has a wide distribution area and miscellaneous feeding habits, and can harm more than 110 kinds of plants. The red spider has a large reproduction rate, and the insects are small and difficult to find. Once the damage is found, the transfer speed is fast, the pest area is large, and the crops are repeatedly infested. The way of harm is that the mouthparts penetrate into the leaves to suck the juice, so that the chlorophyll is damaged, the leaves appear grayish-yellow spots or plaques, until the whole leaves are orange-yellow and fall off, which seriously hinders the normal growth and development of plants and causes huge economic losses. At present, the main pesticides used are dextate, dicofol, dimethoate, huachongjing, and sacdin, etc. to prevent and control plant spider mite disease. However, with the long-term use of chemical agents, red spiders have developed different degrees of resistance to them, and the control effect has been greatly reduced, and the disadvantages of environmental pollution and high residue of chemical agents have become increasingly apparent. Therefore, it is urgent to develop biopesticides with low toxicity, little pollution, less residue and the ability to avoid drug resistance.

Botanical fungicides have the advantages of being safe for humans and animals, environmentally friendly, and can be naturally degraded without residue. Rhubarb [including Rheum palmatum, followed by Rheumpalmatum var. etc., but there is no research on its inhibitory effect on plant spider mites. Drug dosage forms can have a significant impact on the control effect of drugs. For example, wettable powders and suspensions only exhibit inhibitory activity through the contact of solid drug particles with pathogenic microorganisms on the surface of plants, and the inhibitory effect on pathogenic microorganisms inside plants Poor; the adhesion and ductility of the EC on the plant surface are not good, and the effect of the drug cannot be exerted to the greatest extent; the particle size of the microemulsion is usually in the micron level, and it cannot effectively penetrate the epidermis of the plant stem and leaf to inhibit the internal tissue of the plant of pathogenic microorganisms. Due to its smaller particle size, nanoemulsion has good fluidity, can more effectively penetrate into plant leaves and stems, and exert the biological activity of drugs. Moreover, the preparation process is simple, and it can be mixed with water in any proportion without clogging the nozzle. Easy to use. So far, no technical publication has been found on the activity of rhubarb free anthraquinone nanoemulsion preparations against plant spider mite disease.

Contents of the invention

The purpose of the present invention is to address the deficiencies in the prior art, to provide a kind of rhubarb free anthraquinone (mainly containing emodin, aloe-emodin, chrysophanol, Methyl ether and rhein) are used as raw materials, and a nanoemulsion preparation specially used for the prevention and treatment of plant spider mite disease is developed.

Technical scheme of the present invention: a rhubarb free anthraquinone nanoemulsion preparation for preventing and treating plant red spider mite, made of the following raw materials: in terms of the mass percentage of each component contained in the nanoemulsion, the rhubarb free anthraquinone content is 0.05-0.16%, the oil phase in nanoemulsion accounts for 18-22%, emulsifier 16-20%, co-emulsifier 4-6%, water 50-61%, stabilizer 1.0%, preservative 0.1%, adhesive 0.1%.

The oil phase is selected from the group consisting of isopropyl myristate, propylene glycol monocaprylate, ethyl oleate, isopropyl palmitate, caprylic capric triglyceride, castor oil and combinations thereof. Among them, propylene glycol monocaprylate and its mixture with ethyl oleate are further preferred, and the oil phase concentration is less than 30%. The emulsifier is selected from the group consisting of polyoxyethylene-40-hydrogenated castor oil, caprylic capric macrogol glyceride, lauric macrogol glyceride, Tween-80, poloxamer-188 and combinations thereof. Among them, polyoxyethylene-40-hydrogenated castor oil is further preferred; the co-emulsifier is selected from diethylene glycol monoethyl ether, polyethylene glycol 600, polyethylene glycol 400, 1,2-propylene glycol, propane Triols and combinations thereof. Among them, diethylene glycol monoethyl ether is further preferred, and the amount of co-emulsifier is less than 20%; the mass ratio of emulsifier to co-emulsifier is 2:1. The water is a solvent, the stabilizer is oleic acid or sodium oleate or sodium citrate, preferably oleic acid; the antiseptic is sodium benzoate and ethylparaben, preferably sodium benzoate; the adhesive agent is silicon trioxide.

A kind of rhubarb free anthraquinone nanoemulsion preparation for preventing and treating plant red spider disease according to the present invention, its preparation method is: dissolving rhubarb free anthraquinone in the oil phase, adding stabilizer, emulsifier/co-emulsifier mixture , stir well. Add water dropwise, stir, and self-emulsify to form a clear and transparent nanoemulsion. After ultrasonic treatment for 15-30 minutes, adjust the pH of the system to 6.0-7.0 with 1mol/L NaOH, and then add preservatives and adhesives in proportion. The emulsifier needs to be heated and melted at 35-40°C before use, and the magnetic stirring speed is 200-300rpm. When the obtained nanoemulsion is packaged, it is directly filtered into a sterilized brown plastic container with a water-based microporous filter membrane with a pore size of 0.22 μm.

The particle diameter of the nanoemulsion of the present invention is between 20-100nm, the ξ potential is between -20--50mV, the viscosity is between 8-12cP, and the pH is between 6.0-7.0.

The rhubarb free anthraquinone nanoemulsion of the invention has the application of preventing and treating plant spider mite disease, and has excellent effect.

The beneficial effects of the present invention are:

One is that the raw material drug used in the product of the present invention is the free anthraquinone extract of rhubarb, a Chinese medicinal material, which is non-toxic, non-drug resistant, high in safety, and low in economic cost within the dosage range;

The second is that the product of the present invention can be mixed with any proportion of water to present a transparent and stable homogeneous system, the preparation process is simple, easy to produce in large quantities, the emulsion droplet size is small, the viscosity is small, the field spraying does not block the sprayer, and it is convenient to use;

The third is that the product of the present invention has significant control effect on spider mite disease of crops such as cucumber, eggplant, corn and flowers, and its effect is equal to or better than Huachongjing.

Description of drawings

Fig. 1 is the rhubarb free anthraquinone nanoemulsion transmission electron microscope photo (× 15000) of the embodiment of the present invention 2

Fig. 2 is the photograph of preventing and treating plant red spider disease of embodiment 4.

Detailed ways

The present invention will be further described below in conjunction with the examples, but not limited thereto. Among them, the emulsifier polyoxyethylene-40-hydrogenated castor oil is sold in BASF Chemical Co., Ltd.; Alcohol glycerides are available from Gattefosse, France; Poloxamer 188 is available from Adamas, Switzerland. All other raw material components can be purchased in the market.

Embodiment 1: the extraction of rhubarb free anthraquinone

Experimental conditions

Rhubarb was purchased from Lixian Xinshengyuan Biotechnology Development Co., Ltd. The crushed and sieved rhubarb powder was added to 20% sulfuric acid for acid hydrolysis, and the dregs were washed with water until neutral and then dried. Rhubarb hydrolyzed dry powder is mixed according to the raw material drug: 90% ethanol = 1:30 (w/v), ultrasonically extracted, suction filtered while hot, the filtrate is concentrated under reduced pressure until it has no alcohol smell, extracted with chloroform, and the chloroform extract is then 5% NaOH Extract until the supernatant is colorless, combine the alkaline extracts, adjust the pH to about 2, centrifuge to collect the precipitate, and wash with water until neutral to obtain the crude rhubarb free anthraquinone. After the crude product is dried, add methanol for ultrasonic dissolution according to the ratio of crude drug: methanol = 1:10, centrifuge the supernatant and spin dry under reduced pressure to obtain rhubarb free anthraquinones (the five free anthraquinones account for more than 98% of the total mass).

Embodiment 2: Prescription and preparation of rhubarb free anthraquinone nanoemulsion

Prescription one:

Rhubarb free anthraquinone 0.130g, oil phase 19.5g, emulsifier 16.5g, co-emulsifier 4.5g, stabilizer 1.0g, preservative 0.1g, adhesive agent 0.1g, purified water 58.4g, total weight about 100.0g.

Prescription two:

Rhubarb free anthraquinone 0.098g, oil phase 18.4g, emulsifier 16.0g, co-emulsifier 4.0g, stabilizer 1.0g, preservative 0.1g, adhesive agent 0.1g, purified water 60.5g, total weight about 100.0g.

In the prescription: rhubarb free anthraquinone is the main drug, the oil phase is propylene glycol monocaprylate (prescription 2) or its mixture with ethyl oleate (prescription 1), the emulsifier is polyoxyethylene-40-hydrogenated castor oil, The auxiliary emulsifier is diethylene glycol monoethyl ether, the stabilizer is oleic acid, the preservative is sodium benzoate, and the adhesive agent is silicon trioxide.

The preparation method is:

Dissolve the rhubarb free anthraquinone and stabilizer in the oil phase, add the mixture of emulsifier/co-emulsifier, and stir well. Add water drop by drop, stir at a constant speed, self-emulsify to form a clear and transparent nanoemulsion, and adjust the pH of the system to 6.0-7.0, and then add preservatives and adhesives. The emulsifier is solid at room temperature, so it needs to be melted at 35-40°C before use. When the obtained nanoemulsion is packaged, it is directly filtered into a sterilized brown plastic container with a water-based microporous filter membrane with a pore size of 0.22 μm.

Embodiment 3: Type, property, content determination and stability of rhubarb free anthraquinone nanoemulsion

Test condition: to the nanoemulsion that embodiment 2 prescription one obtains, carry out following test:

Identification of nanoemulsion type: the type of nanoemulsion is identified by dyeing method, and the type of nanoemulsion is judged by the diffusion speed of oil-soluble dye Sudan red and water-soluble dye methylene blue in nanoemulsion.

Nanoemulsion properties: appearance, light transmittance, pH value, viscosity, particle size and Zeta potential.

Content determination: take 1 ml of rhubarb free anthraquinone nanoemulsion, add 10 ml of methanol, ultrasonically break the emulsion, filter through a 0.45 μm microporous membrane, analyze with high performance liquid chromatography (HPLC), and calculate the total free anthraquinone in rhubarb free anthraquinone nanoemulsion. Anthraquinone content.

Stability investigation: (1) Influencing factor test: The nanoemulsion was sampled on the 5th and 10th day under strong light, high temperature and high temperature respectively, and observed whether the properties of rhubarb free anthraquinone nanoemulsion changed. (2) Centrifugal acceleration test: After centrifuging the nanoemulsion at 12000rpm for 30min, observe whether there is stratification or precipitation. (2) Sample test at room temperature: Rhubarb free anthraquinone nanoemulsion was placed at room temperature for 90 days, and samples were collected on the 30th day, 60th day, and 90th day to investigate the properties and drug content of the nanoemulsion. test results:

The type of rhubarb free anthraquinone nanoemulsion is O/W type. The emulsion droplets are spherical under the transmission electron microscope, the light transmittance is 99.0-99.9%, the pH is 6.4-6.7, the viscosity is 10.0-11.5cP, and the particle size is between 20-100nm, the ξ potential is -25.0～-35.0mV.

The content of free anthraquinone in rhubarb free anthraquinone nanoemulsion is 0.122% (w/w). The ratio of each component of rhubarb free anthraquinone determined by the nanoemulsion preparation is basically close to the range of the ratio of each component in the extract, and the error is mainly due to the same treatment of different batches of rhubarb, which is not the case for traditional Chinese herbal medicine extracts. is acceptable.

The stability test showed that the free anthraquinone nanoemulsion of rhubarb was placed under the above conditions, and the morphology was still clear and transparent without delamination or flocculation. In the centrifugal acceleration test, after the nanoemulsion was centrifuged at 12000rpm for 30min, it was still clear and homogeneous. The sample test at room temperature showed that the nanoemulsion had good physical stability when placed at room temperature for 90 days, and the content of free total anthraquinones and monomers in rhubarb remained basically unchanged.

Example 4 Rhubarb free anthraquinone nanoemulsion anti-plant spider mite test

Main target disease: Eggplant spider mite disease

Test field: ***vegetable field

Test grouping: blank control group without any reagent (respectively marked as E in the table below); three dilution groups of drug components: 100 times, 250 times and 500 times dilutions of rhubarb free anthraquinone nanoemulsion respectively (in the table below Respectively marked as A, B, C); The positive control group is the 800-fold dilution of Huachongjing per 10g (respectively marked as D in the table below).

Test plan: Eggplant (Liangjiao No. 2, bred by Wuwei Agricultural Science Research Institute), during the onset of spider mite disease, 3 repetitions per treatment, 5m ² for each repetition, 2 eggplants were randomly selected for each repetition before spraying, Before spraying, select 2 complete leaves with a moderate number of spider mites in different parts of each plant, hang tags and check the number of active mites. The number of active mites was investigated on the 2nd and 5th day after spraying, and the population reduction rate and control effect were calculated. Compared with the blank control group, the population reduction rate and control effect were calculated.

Insect population reduction rate % = [number of live insects before spraying - number of live insects after spraying] × 100 / number of live insects before spraying

Control effect% = [reduction rate of treatment area - reduction rate of control area] × 100/[100-reduction rate of insect population in control area]

Test result (table 1):

Table 1 Control test of different pesticides on eggplant red spider disease

It can be seen from the test results that the 100-fold dilution of rhubarb free anthraquinone nanoemulsion has the best control effect on red spider mite among the tested agents, and has a long drug effect time and strong control ability on red spider mite. An ideal agent for spiders; Rhubarb free anthraquinone nanoemulsion 250 times and Huachongjing 800 times dilution have similar control effects for 2 to 5 days, both above 85%, both of which can be popularized and used in production.

During the investigation of the control effect, it was found that although the 100-fold dilution of free anthraquinone nanoemulsion of rhubarb had an excellent control effect on eggplant spider mite, it accelerated the withering of eggplant leaves, showing certain phytotoxicity. However, the 250-fold dilution of rhubarb free anthraquinone nanoemulsion did not show obvious phytotoxicity and can be used safely. The best control period is about 5 days, and then spray according to the situation.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field of the present invention, without departing from the premise of the present invention, some simple deduction or replacement can also be made, which should be regarded as belonging to the protection scope of the present invention.

Claims (4)

1. a free anthraquinones extracted from rheum composition, is characterized in that, described free anthraquinones extracted from rheum composition stems from the extract of traditional Chinese medicine sorrel, Rheum tanguticum Maxim or Rheum officinale.

2. a free anthraquinones extracted from rheum nano-emulsion preparation, it is made up of following raw material:

Free anthraquinones extracted from rheum 0.05 ~ 0.16%, Sefsol 218 13 ~ 16%, ethyl oleate 4 ~ 6%, polyoxyethylene-40-rilanit special 16 ~ 20%, TC 4 ~ 6%, oleic acid 1.0%, Sodium Benzoate 0.1%, disilicon trioxide 0.1%, purified water 50 ~ 61%.

3. a kind of free anthraquinones extracted from rheum nano-emulsion preparation as claimed in claim 2, prepare as follows: free anthraquinones extracted from rheum and stabilizing agent are dissolved in Sefsol 218 and ethyl oleate, add polyoxyethylene-40-rilanit special, TC, stir, dropwise add water, Keep agitation, until the liquid forming clear, 1mol/LNaOH regulating system pH6.0-7.0 after ultrasonic process 15-30min, then add Sodium Benzoate and disilicon trioxide.Polyoxyethylene-40-rilanit special needs 35-40 DEG C of heating and melting, magnetic agitation speed 200-300rpm before using.

4. a kind of free anthraquinones extracted from rheum nano-emulsion as described in claim 1-3 has the purposes of control plant two spotted spider mite disease.