Syzygium aromaticum bud essential oil compound, preparation method thereof and application of syzygium aromaticum bud essential oil compound in repelling tephros asiaticum

Abstract

The invention relates to the technical field of tick repelling, in particular to a clove bud essential oil compound as well as a preparation method and application thereof in repelling ticks in Asia, the compound comprises an essential oil composition and a functional additive, the essential oil composition comprises clove bud essential oil and chrysanthemum artemisia essential oil in a volume ratio of 6: 4, and the functional additive is a functional additive. The functional additive comprises a synergist, a stabilizer and an emulsifier, the synergist is limonene, the stabilizer is vitamin E, and the emulsifier is polyglycerol fatty acid ester. According to the clove bud essential oil compound, the preparation method thereof and the application of the clove bud essential oil compound in repelling the Asia glass ticks, efficient and long-acting repelling of the Asia glass ticks is achieved, and meanwhile the clove bud essential oil compound has the advantages of being natural, safe, high in stability and wide in application scene.

Description

Technical Field

[0001] This invention relates to the field of tick repellency technology, and in particular to a compound of clove bud essential oil, its preparation method, and its application in repelling Asian water tick nymphs. Background Technology

[0002] Ticks, obligate blood-sucking ectoparasites, are widely distributed in temperate, subtropical, and some tropical regions worldwide. They are core vectors for the transmission of various zoonotic diseases such as tick-borne encephalitis, Lyme disease, and babesiosis, posing a serious threat to human health, livestock safety, and ecological stability. The Asian tick (Hyalomma asiaticum), a dominant tick species in arid and semi-arid regions of northern my country, has a life cycle encompassing four stages: egg, larva, nymph, and adult. The nymph stage is characterized by high activity, wide environmental adaptability, and high population density, and its exploratory biting behavior towards humans and livestock hosts is particularly active, making it a key link in the spread of tick-borne diseases. Therefore, effective repellency and control of Asian tick nymphs has become a key research direction in the field of public health.

[0003] Currently, the mainstream tick repellent products on the market are mainly chemically synthesized repellents, among which DEET is widely used due to its proven repellent effect. However, long-term application practice has shown that these chemical repellents have significant drawbacks: On the one hand, DEET has potential toxicity to the human nervous system, and long-term exposure can easily cause adverse reactions such as skin redness, swelling, allergies, and itching, especially posing a higher safety risk to children, pregnant women, and sensitive populations. On the other hand, chemical repellents are difficult to degrade naturally in the environment, and long-term, large-scale use can easily cause soil and water pollution, disrupting the ecological balance and contradicting the current green and environmentally friendly pest control concept.

[0004] With increasing health awareness and environmental demands, natural plant essential oils, with their advantages of good biocompatibility, environmental friendliness, and low toxicity, are gradually becoming a core focus of tick repellent research. Existing research confirms that some plant essential oils have certain repellent activity against ticks. For example, eugenol, the core component of clove bud essential oil, can interfere with the signal transduction of tick olfactory receptors, blocking its host localization process and demonstrating potential application value.

[0005] However, single-plant essential oil repellents still face several technical bottlenecks in practical applications: First, their repellency is limited; the half-maximal concentration (EC50) of a single essential oil is relatively high, making it difficult to achieve long-lasting protection. Second, they lack stability; the unsaturated active ingredients in essential oils are easily affected by environmental factors such as light and temperature, leading to oxidative degradation, resulting in a short product shelf life and rapid attenuation of repellency. Third, their application scenarios are limited; most natural essential oils are fat-soluble and have poor water compatibility, making it difficult to prepare water-based formulations suitable for skin application and animal body spraying, thus limiting their industrial application scope. Summary of the Invention

[0006] The purpose of this invention is to provide a compound of clove flower bud essential oil, its preparation method, and its application in repelling Asian water hyacinth nymphs, achieving efficient and long-lasting repellency against Asian water hyacinth nymphs, while possessing the advantages of being natural, safe, highly stable, and widely applicable.

[0007] To achieve the above objectives, the present invention provides a clove bud essential oil compound, the compound comprising an essential oil composition and functional additives. The essential oil composition comprises clove bud essential oil and chrysanthemum essential oil in a volume ratio of 6:4. The functional additives include a synergist, a stabilizer, and an emulsifier. The synergist is limonene, the stabilizer is vitamin E, and the emulsifier is polyglycerol fatty acid ester.

[0008] Preferably, limonene accounts for 3%-7% of the total mass of the essential oil composition, vitamin E accounts for 1%-3% of the total mass of the essential oil composition, and polyglycerol fatty acid esters account for 2%-6% of the total mass of the compound.

[0009] Preferably, limonene accounts for 5% of the total mass of the essential oil composition, vitamin E accounts for 2% of the total mass of the essential oil composition, and polyglycerol fatty acid esters account for 4% of the total mass of the compound.

[0010] The preferred varieties have clove bud essential oil with a purity of ≥98% and an active ingredient eugenol content of ≥67%; and wormwood essential oil with a purity of ≥98%, an active ingredient artemisinin content of ≥1.2%, and terpene compound content of 60%-85%.

[0011] Even more preferred are those with limonene purity ≥98%, vitamin E of food grade and α-tocopherol content ≥96%, and polyglycerol fatty acid esters of food grade.

[0012] This invention also provides a method for preparing the above-mentioned clove bud essential oil compound, comprising the following steps: S1. The clove bud essential oil and the artemisia essential oil are filtered through an organic filter membrane to remove impurities, and the pretreated clove bud essential oil and artemisia essential oil are obtained. S2. Mix the clove bud essential oil and wormwood essential oil after the pretreatment in step S1, and stir to form a uniform essential oil mixture. S3. Add limonene and vitamin E in sequence while stirring, and finally add polyglycerol fatty acid ester. Stir at high speed to form a stable and homogeneous compound mother liquor. S4. Dilute the mother liquor of the compound with food-grade anhydrous ethanol or deionized water to prepare an alcohol-based reagent or a water-based reagent, and seal it in a brown container to protect it from light for later use.

[0013] Preferably, the pore size of the organic filter membrane in S1 is 0.2-0.3 μm. The organic filter membrane removes mechanical impurities, insoluble particles, and trace amounts of moisture from the raw materials, ensuring the purity of the core components and preventing impurities from affecting the repellency effect and system stability.

[0014] Preferably, the mixing in S2 is carried out at 25-30℃ under light-protected conditions, and the stirring is carried out at a speed of 250-350r / min for 12-18min.

[0015] Preferably, when adding limonene and vitamin E to S3, the stirring speed is 250-350 r / min for 10-15 min, and the high-speed stirring speed is 500-600 r / min for 15 min.

[0016] Preferably, in S4, the amount of anhydrous ethanol is 8-10 times the volume of the mother liquor of the compound, and the amount of deionized water is 8-10 times the volume of the mother liquor of the compound.

[0017] This invention also provides an application of a clove bud essential oil compound in repelling Asian water tick nymphs. The alcohol-based preparation or water-based reagent made from the above-mentioned clove bud essential oil compound preparation method is used to repel Asian water tick nymphs in human protection, livestock breeding or environmental protection scenarios.

[0018] Preferably, the alcohol-based formulation is suitable for soaking clothing and spraying the environment. The soaking time for clothing is 10-15 minutes, and the spraying rate for the environment is 10-20 mL / m². 2 ; Water-based reagents are suitable for skin application and animal body spraying. For skin application, the dosage is 0.5-1 mL / 10 cm². 2 The amount of sprayed on the surface of the animal is 5-10 mL per head.

[0019] In this invention, the clove bud essential oil is a natural extract with a purity of ≥98%, and the core active ingredient, eugenol, has a content of ≥67%. Eugenol has a strong aromatic odor and can specifically interfere with the olfactory receptors of Asian water tick nymphs, blocking their host localization process.

[0020] Artemisia annua essential oil is made from natural extracts with a purity of ≥98%, containing the core active ingredient artemisinin at a content of ≥1.2%, along with terpenoids such as α-pinene and β-pinene. Artemisinin can disrupt the waxy layer on the tick's surface, enhancing the penetration of the essential oil components and forming a synergistic effect with eugenol, significantly improving repellency efficiency. Terpenoids can prolong the duration of repellency, compensating for the short duration of action of clove bud essential oil alone. The repellency rate is enhanced through the synergistic effect of clove bud essential oil and Artemisia annua essential oil.

[0021] The synergist selected is natural limonene with a purity of ≥98%. As a terpene compound, it enhances the volatility of the core essential oil's active ingredients, expands the repellent range, and penetrates the tick's cuticle, promoting the entry of active ingredients into the insect's body and improving the repellent effect. The dosage range is 3%-7% of the total mass of the essential oil composition. This range ensures the synergistic effect while avoiding the problem of a pungent odor caused by excessive dosage.

[0022] The stabilizer used is food-grade vitamin E (α-tocopherol content ≥96%), which has strong antioxidant properties and can inhibit the oxidative degradation of unsaturated active ingredients such as eugenol and artemisinin, thus extending the product's shelf life. The dosage range is 1%-3% of the total mass of the essential oil composition. This range effectively delays oxidation reactions without negatively impacting the repellent effect.

[0023] The emulsifier used is food-grade polyglycerol fatty acid ester (HLB value 10-12), which has good emulsifying and dispersing properties, improves the compatibility of essential oils with water, solves the technical problem of the poor water solubility of natural essential oils, and enables the development of water-based formulations. The dosage range is 2%-6% of the total mass of the compound. This range ensures stable emulsification of the system without layering or precipitation.

[0024] Therefore, the present invention, employing the above-mentioned clove bud essential oil compound, its preparation method, and its application in repelling Asian water flea tick nymphs, has the following beneficial effects: This invention utilizes a 6:4 volume ratio of clove bud essential oil and artemisia annua essential oil. Eugenol synergizes with artemisinin and terpenoids, and the addition of limonene as a synergist significantly enhances the repellency effect, resulting in repellency efficiency significantly superior to existing plant essential oil repellents. The addition of vitamin E as a stabilizer effectively inhibits the oxidative degradation of the core active ingredients, ensuring strong stability and a long shelf life. Polyglycerol fatty acid esters are used as emulsifiers, allowing the compound to be formulated into both alcohol-based and water-based formulations, facilitating a wide range of applications. The alcohol-based formulation is suitable for soaking clothing and environmental spraying, while the water-based formulation is suitable for skin application and animal body spraying, meeting the tick repellency needs of various scenarios such as outdoor work, livestock farming, and home camping, demonstrating strong adaptability.

[0025] All ingredients in this invention are natural plant extracts or food-grade additives, with no chemically synthesized substances. They are biodegradable in the environment, leaving no residual pollution, and are in line with the concept of green environmental protection.

[0026] The technical solution of the present invention will be further described in detail below through embodiments. Detailed Implementation

[0027] The present invention will be further described below with reference to embodiments. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art. The features mentioned above or in the specific examples mentioned in this invention can be combined arbitrarily, and these specific embodiments are only used to illustrate the invention and are not intended to limit the scope of the invention.

[0028] Example 1 This invention provides a clove bud essential oil compound, comprising an essential oil composition and functional additives. The essential oil composition includes clove bud essential oil and chrysanthemum essential oil, limonene, vitamin E, and polyglycerol fatty acid esters. Its preparation method includes the following steps: S1. The clove bud essential oil and the artemisia essential oil were filtered through a 0.2μm organic filter membrane to remove impurities, and the pretreated clove bud essential oil and artemisia essential oil were obtained.

[0029] S2. Accurately measure 60 mL of clove bud essential oil and 40 mL of wormwood essential oil from step S1 at a volume ratio of 6:4. Add the clove bud essential oil and wormwood essential oil to a sterile reaction vessel and stir at 250 r / min for 12 min at 25°C in the dark to form a 100 mL mixture of essential oils.

[0030] S3. Add 3g of limonene (3% of the total mass of the essential oil composition) to the mixture of essential oils and stir at 250r / min for 10min; then add 1g of vitamin E (1% of the total mass of the essential oil composition) and stir at 250r / min for 10min; finally add 2.2g of polyglycerol fatty acid ester (2% of the total mass of the compound) and stir at 500r / min for 15min to form 106.2mL of stable and homogeneous compound mother liquor.

[0031] S4.1 Alcohol-based reagent: Take 10 mL of the compound mother liquor, add 80 mL of anhydrous ethanol, stir for 8 min until the system is transparent to obtain the alcohol-based reagent, i.e., the alcohol-based repellent.

[0032] S4.2 Water-based reagent: Take 10 mL of the compound mother liquor, add 80 mL of deionized water, stir for 10 min until the system forms a uniform emulsion, and obtain the water-based reagent, i.e., water-based repellent.

[0033] Example 2 This invention provides a clove bud essential oil compound, comprising an essential oil composition and functional additives. The essential oil composition includes clove bud essential oil and chrysanthemum essential oil, limonene, vitamin E, and polyglycerol fatty acid esters. Its preparation method includes the following steps: S1. The clove bud essential oil and the artemisia essential oil were filtered through a 0.2μm organic filter membrane to remove impurities, and the pretreated clove bud essential oil and artemisia essential oil were obtained.

[0034] S2. Accurately measure 60 mL of clove bud essential oil and 40 mL of wormwood essential oil from step S1 at a volume ratio of 6:4. Add the clove bud essential oil and wormwood essential oil to a sterile reaction vessel and stir at 300 r / min for 15 min at 28°C in the dark to form a 100 mL mixture of essential oils.

[0035] S3. Add 5g limonene (5% of the total mass of the essential oil composition) to the mixture of essential oils and stir at 300r / min for 12min; then add 2g vitamin E (2% of the total mass of the essential oil composition) and stir at 300r / min for 12min; finally add 4.5g polyglycerol fatty acid ester (4% of the total mass of the compound) and stir at 550r / min for 15min to form 111.5mL of stable and homogeneous compound mother liquor.

[0036] S4.1 Alcohol-based reagent: Take 10 mL of the compound mother liquor, add 90 mL of anhydrous ethanol, stir for 8 min until the system is transparent to obtain the alcohol-based reagent, i.e., the alcohol-based repellent.

[0037] S4.2 Water-based reagent: Take 10 mL of the compound mother liquor, add 90 mL of deionized water, stir for 10 min until the system forms a uniform emulsion, and obtain the water-based reagent, i.e., water-based repellent.

[0038] Example 3 This invention provides a clove bud essential oil compound, comprising an essential oil composition and functional additives. The essential oil composition includes clove bud essential oil and chrysanthemum essential oil, limonene, vitamin E, and polyglycerol fatty acid esters. Its preparation method includes the following steps: S1. The clove bud essential oil and the artemisia essential oil were filtered through a 0.2μm organic filter membrane to remove impurities, and the pretreated clove bud essential oil and artemisia essential oil were obtained.

[0039] S2. Accurately measure 60 mL of clove bud essential oil and 40 mL of wormwood essential oil from step S1 at a volume ratio of 6:4. Add the clove bud essential oil and wormwood essential oil to a sterile reaction vessel and stir at 350 r / min for 18 min at 30°C in the dark to form a 100 mL mixture of essential oils.

[0040] S3. Add 7g limonene (7% of the total mass of the essential oil composition) to the mixture of essential oil compositions and stir at 350r / min for 15min; then add 3g vitamin E (3% of the total mass of the essential oil composition) and stir at 350r / min for 15min; finally add 7g polyglycerol fatty acid ester (6% of the total mass of the compound) and stir at 600r / min for 15min to form 117mL of stable and homogeneous compound mother liquor.

[0041] S4.1 Alcohol-based reagent: Take 10 mL of the compound mother liquor, add 100 mL of anhydrous ethanol, stir for 8 min until the system is transparent to obtain the alcohol-based reagent, i.e., the alcohol-based repellent.

[0042] S4.2 Water-based reagent: Take 10 mL of the compound mother liquor, add 100 mL of deionized water, stir for 10 min until the system forms a uniform emulsion, and obtain the water-based reagent, i.e., water-based repellent.

[0043] Comparative Example 1 Take 10 mL of clove bud essential oil from Example 2 and dilute it with 90 mL of anhydrous ethanol to obtain a single clove bud essential oil repellent.

[0044] Comparative Example 2 Take 10 mL of Artemisia annua essential oil from Example 2 and dilute it with 90 mL of anhydrous ethanol to obtain a single Artemisia annua essential oil repellent.

[0045] Comparative Example 3 Prepare the essential oil composition mixture according to steps S1-S2 of Example 2. Take 10 mL of the essential oil composition mixture and dilute it directly with 90 mL of anhydrous ethanol. Do not add limonene, vitamin E and polyglycerol fatty acid ester.

[0046] Comparative Example 4 Take 10 mL of 99.3% DEET and dilute it with 90 mL of anhydrous ethanol to obtain DEET repellent.

[0047] Comparative Example 5 Following the preparation method of Example 2, clove bud essential oil and artemisia essential oil were mixed at a volume ratio of 8:2, with 80 mL of clove bud essential oil and 20 mL of artemisia essential oil, and the rest were the same as in Example 2.

[0048] Comparative Example 6 The preparation method of Example 2 was followed, except that the synergist limonene was replaced with menthol (98% purity), the amount of which remained the same, and everything else was the same as in Example 2.

[0049] Performance testing Test subjects: Asian ticks, 3 weeks after molting, were cultured in a laboratory artificial climate chamber (temperature 26±1℃, relative humidity 75±5%, photoperiod 12L:12D). Individuals with uniform body size and strong mobility were selected. Ten ticks were used in each test group, and the test was repeated 3 times.

[0050] I. Repellency Effect Test (Filter Paper Ring Method) Three concentric circles were drawn on a 9cm diameter Waterman No. 4 filter paper, with radii of 0.8cm (central area), 1.6cm (drug application area), and 3cm (outer area). 20μL of test sample was taken from each group and evenly applied to the 1.6cm concentric circle on the filter paper. The samples were then allowed to air dry in a clean bench for 10 minutes to remove solvent interference. The filter paper was placed in a petri dish, and 10 starving ticks were gently placed in the central area. The petri dish was then covered and placed in an artificial climate chamber. The tick positions were observed and recorded at 1h, 6h, 12h, and 24h. The number of ticks effectively repelled (those leaving the central area, remaining between 1.6cm and 3cm, or returning after reaching the drug application area) was counted. The repellency rate was calculated as (number of effectively repelled ticks / total number of ticks) × 100%.

[0051] The results are shown in Table 1. The repellency rates of both alcohol-based and water-based reagents in Examples 1-3 were significantly higher than those in Comparative Examples 1-6, indicating that the 6:4 ratio of clove bud essential oil and artemisia essential oil, combined with limonene synergist, can achieve synergistic effects and significantly improve the repellency. Among them, Example 2 showed the best repellency effect, with a 24-hour sustained repellency rate of 68.3%-72.0%, which was better than other examples, indicating that the overall repellency performance of this adjuvant combination was optimal. The repellency rate of Example 2 was slightly higher than that of Comparative Example 4 (DEET), and the repellency duration was longer than that of DEET. Its safety was significantly better than that of chemical repellents, and it has the potential to replace them. The repellency effect of the alcohol-based formulations in each example was slightly better than that of the water-based reagents, but the difference was not significant, indicating that the polyglycerol fatty acid ester emulsifier improved water solubility without significantly affecting the repellency activity, and both formulations could meet the usage requirements.

[0052] Table 1. Test data on the repellency rate of different repellents

[0053] II. Half-maximum repellency concentration (EC50) test The alcohol-based and water-based reagents from Example 2 (optimal ratio) were selected, along with Comparative Examples 1 and 4. Each sample was diluted to five concentration gradients using anhydrous ethanol (alcohol-based samples) or deionized water (water-based samples). Using a membrane filtration method, 10 molting, 3-week-old *Ixodes asiaticus* nymphs (cultured in a laboratory artificial climate chamber at 26±1℃, 75±5% relative humidity, and a photoperiod of 12L:12D) were used for each concentration group, repeated three times. The sample was evenly spread on the filter membrane (per cm). 2Apply 0.1 mL of the solution, air dry for 5 min, and place it in the center of a petri dish. Place ticks on the edge of the dish. After standing for 1 h, record the number of ticks that did not come into contact with the filter membrane and calculate the repellency rate. Using SPSS 26.0 software, perform Probit regression analysis with the logarithm of concentration on the x-axis and the probability unit of repellency rate on the y-axis to fit the dose-response equation, calculate the EC50 value and 95% confidence interval.

[0054] The results are shown in Table 2. The EC50 of the alcohol-based reagent in Example 2 was lower than that of the water-based reagent, but both were significantly lower than those of Comparative Examples 1 and 4. This indicates that the synergistic effect of the essential oils and the synergistic effect of the functional additives significantly improved the repellent activity after compounding. The EC50 of the water-based reagent was slightly higher than that of the alcohol-based reagent, possibly because some active ingredients were encapsulated after emulsification of the polyglycerol fatty acid ester, resulting in a slightly lower volatilization efficiency than the alcohol-based system, but still maintaining a high repellent level. The R... 2 The values ​​are all ≥0.965, indicating that the dose-response equation has a high degree of fit and the EC50 measurement results have good reliability and repeatability.

[0055] Table 2. Results of the 50% antagonistic concentration (EC50) for different repellents.

[0056] Note: y is the probability unit of avoidance rate, x is the logarithm of sample concentration; R 2 The closer the value is to 1, the higher the goodness of fit of the regression equation.

[0057] III. Stability Testing Each product was sealed in a brown container and stored at room temperature away from light for 3 months. The 1-hour instantaneous repellency rate was then measured according to the above repellency rate test method and compared with the initial data.

[0058] The results are shown in Table 3. After 3 months of storage, the efficacy decay rate of Example 2 was only 3.36%-3.81%, which was much lower than that of the non-functional additive compound in Comparative Example 3 (15.29%) and DEET in Comparative Example 4 (8.89%). This indicates that the strong antioxidant properties of vitamin E effectively inhibited the oxidative degradation of unsaturated components such as eugenol and artemisinin, thus extending the shelf life and expiration date.

[0059] Table 3. Stability test data of different repellents

[0060] IV. Security Testing Referring to the "Toxicological Test Methods for Pesticide Registration", water-based reagent (skin-applicable type) was applied to the hairless skin on the back of rabbits and observed continuously for 72 hours, recording irritant reactions such as skin erythema and edema.

[0061] The results are shown in Table 4. The water-based reagent (skin-compatible) was tested and found to be non-irritating, with a safety profile superior to the mildly irritating DEET, making it more suitable for children, pregnant women, and sensitive individuals. The alcohol-based reagent (for clothing soaking and environmental spraying) and the water-based reagent (for skin application and animal body spraying) are suitable for different scenarios, meeting diverse needs in human protection, livestock farming, and environmental protection, thus solving the problem of limited application scenarios for traditional natural essential oils.

[0062] Table 4 Safety test data for different repellents

[0063] Therefore, the present invention adopts the above-mentioned clove bud essential oil compound and its preparation method and its application in repelling Asian water tick nymphs. The compound has significant advantages in repellency, stability, safety and application scenario adaptability. It can effectively replace traditional chemical repellents and has broad industrial application prospects in human protection, animal husbandry, environmental protection and other scenarios.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A compound of clove bud essential oil, characterized in that: The compound comprises an essential oil composition and functional additives. The essential oil composition comprises clove bud essential oil and chrysanthemum essential oil in a volume ratio of 6:

4. The functional additives include synergists, stabilizers, and emulsifiers. The synergist is limonene, the stabilizer is vitamin E, and the emulsifier is polyglycerol fatty acid ester.

2. The clove bud essential oil compound according to claim 1, characterized in that: Limonene accounts for 3%-7% of the total mass of the essential oil composition, vitamin E accounts for 1%-3% of the total mass of the essential oil composition, and polyglycerol fatty acid esters account for 2%-6% of the total mass of the compound.

3. The clove bud essential oil compound according to claim 1, characterized in that: Limonene accounts for 5% of the total mass of the essential oil composition, vitamin E accounts for 2% of the total mass of the essential oil composition, and polyglycerol fatty acid esters account for 4% of the total mass of the compound.

4. A method for preparing a clove bud essential oil compound as described in any one of claims 1-3, characterized in that: Includes the following steps: S1. The clove bud essential oil and the artemisia essential oil are filtered through an organic filter membrane to remove impurities, and the pretreated clove bud essential oil and artemisia essential oil are obtained. S2. Mix the clove bud essential oil and wormwood essential oil after the pretreatment in step S1, and stir to form a uniform essential oil mixture. S3. Add limonene and vitamin E in sequence while stirring, and finally add polyglycerol fatty acid ester. Stir at high speed to form a stable and homogeneous compound mother liquor. S4. Dilute the mother liquor of the compound with food-grade anhydrous ethanol or deionized water to prepare an alcohol-based reagent or a water-based reagent, and seal it in a brown container to protect it from light for later use.

5. The method for preparing a clove bud essential oil compound according to claim 4, characterized in that: The organic filter membrane in S1 has a pore size of 0.2-0.3 μm.

6. The method for preparing a clove bud essential oil compound according to claim 4, characterized in that: Mixing in S2 is carried out at 25-30℃ under dark conditions, and stirring is performed at a speed of 250-350r / min for 12-18min.

7. The method for preparing a compound of clove bud essential oil according to claim 4, characterized in that: When adding limonene and vitamin E to S3, stir at 250-350 rpm for 10-15 minutes, or at 500-600 rpm for 15 minutes.

8. The method for preparing a clove bud essential oil compound according to claim 4, characterized in that: In S4, the amount of anhydrous ethanol used is 8-10 times the volume of the mother liquor of the compound, and the amount of deionized water used is 8-10 times the volume of the mother liquor of the compound.

9. The application of a clove bud essential oil compound in repelling Asian water tick nymphs, characterized in that: An alcohol-based preparation or water-based reagent made by the preparation method of a clove bud essential oil compound according to any one of claims 4-8 is used to repel Asian glass tick nymphs in human protection, animal husbandry or environmental protection scenarios.

10. The application of the clove bud essential oil compound according to claim 9 in repelling Asian water tick nymphs, characterized in that: Alcohol-based formulations are suitable for soaking clothing and spraying the environment. Soaking time for clothing is 10-15 minutes, and the spraying rate for the environment is 10-20 mL / m². 2 ; Water-based reagents are suitable for skin application and animal body spraying. For skin application, the dosage is 0.5-1 mL / 10 cm². 2 The amount of sprayed on the surface of the animal is 5-10 mL per head.

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