Compound mosquito-repelling essential oil and preparation method thereof

Abstract

The invention provides compound mosquito-repelling essential oil with spanishneedles herb, elsholtzia and eupatorium adenophorum extracts as main active ingredients and a preparation method of the compound mosquito-repelling essential oil. According to the essential oil, through scientific proportioning, the synergistic effect of various mosquito-repelling active ingredients in the plant extracts is fully exerted, and the efficient and lasting mosquito-repelling performance is shown. The product takes natural plants as raw materials, is safe and environment-friendly, has no irritation to human bodies, and is suitable for mosquito protection in occasions such as families and outdoor activities. The invention also elaborates the preparation process of the compound essential oil in detail, and ensures the stability and consistency of the product quality.

Description

Technical Field

[0001] The present invention belongs to the field of prevention and control of hygienic pests, and particularly relates to a compound mosquito repellent essential oil and a preparation method thereof. Background Art

[0002] Mosquitoes can transmit diseases such as Japanese encephalitis, dengue fever and malaria, and are pests that pose great harm to human health. Humans have taken various preventive measures against the harm of mosquitoes for a long time. Among them, chemical mosquito control, biological mosquito control and genetic engineering mosquito control are technologies developed in recent decades. Chemical mosquito control: For example, during the use of some chemical mosquito repellents (especially aerosol sprays, mosquito coils, etc.), harmful gases or particles will be released, and direct inhalation may irritate the human respiratory tract, especially for sensitive groups such as the elderly, children and asthma patients. When using mosquito repellent lotions, creams, etc. directly applied to the skin, if they contain irritating or allergic components, they may cause skin discomfort and allergic reactions, especially for people allergic to chemical components such as N,N-diethyl-3-methylbenzamide (DEET). Chemical mosquito repellents may also be toxic to non-target organisms (such as beneficial insects and aquatic organisms like bees, butterflies, fish, amphibians, etc.), affecting the ecological balance. For example, insecticides containing pyrethroids are highly toxic to fish. If they accidentally flow into water bodies, they may damage the aquatic ecosystem. In addition, the long-term use of chemical mosquito repellents will also cause mosquitoes to develop drug resistance.

[0003] Biological mosquito control mainly uses organisms or biological products existing in nature to control the number of mosquitoes and reduce the threat to human life and health. Some organisms such as mosquito fish and dragonfly larvae can prey on mosquitoes; using biological pheromones to interfere with the communication between male and female mosquitoes and reduce the mating success rate. However, its effect is affected by factors such as environmental conditions, mosquito population dynamics, and the survival rate of natural enemies, and the control effect may not be as immediate as chemical methods, and regular replenishment or maintenance is required.

[0004] Genetic engineering for mosquito control involves using modern biotechnology to genetically modify the mosquito genome to create mosquitoes with specific genetic traits (such as sterility, reduced resistance to pathogens, and sex ratio imbalance), which are then released into the environment to spread through the mosquito population through genetic dominance, aiming to control or even eliminate the target mosquito species. For example, using genetic engineering techniques, male mosquitoes can be made to carry genes that prevent the development of germ cells (such as the I-PpoI system, tTAV system, etc.). After release, when they mate with wild female mosquitoes, sterile offspring are produced. Using gene editing tools such as CRISPR / Cas9, genetic elements that can self-replicate and rapidly spread in the mosquito population can be constructed, such as genes that make mosquitoes immune to pathogens like malaria or genes that cause female sterility. When the modified mosquitoes mate with wild mosquitoes, these genes can be efficiently passed on to the next generation, gradually replacing the wild population. However, the technology is complex, the implementation cost is high, and it involves complex ethical, legal, and social acceptance issues. The long-term ecological consequences are unknown and may affect the food chain, biodiversity, etc.

[0005] Bidens pilosa L. is an annual herbaceous plant of the genus Bidens in the Compositae family, also known as Chachaocao, Yajinbu, etc. This plant is often used as an ethnic medicine in China, with the whole herb used as medicine. It grows mostly on roadsides and in the wild and is very easy to collect. According to the "Compendium of Materia Medica", Bidens pilosa has the effects of clearing heat and detoxifying, dispersing stasis and reducing swelling. It is used by ethnic groups such as the Lahu, Bai, and Dai to treat jaundice hepatitis, infantile diarrhea, appendicitis, splenic hemorrhage, and snake bites. In 2023, researchers isolated (E)-7-phenyl-2-heptene-4,6-diyne-1-ol from the roots of Bidens pilosa and identified it as an anthelmintic. Its half-effective concentration is 0.20 μm, showing strong repellency.

[0006] Elsholtzia ciliata (Thunb.) Hyland., also known as coriander, is a plant of the genus Elsholtzia in the Lamiaceae family, mainly distributed in Yunnan, Guizhou, Sichuan, Tibet and other places. Elsholtzia ciliata has functions such as promoting diuresis and dissipating dampness, warming the stomach and regulating the middle energizer. The "Compendium of Materia Medica" records: "Physicians in the world treat summer diseases with Elsholtzia decoction as the first medicine." Elsholtzia ciliata contains various active ingredients such as volatile oils, flavonoids, and coumarins, and has pharmacological effects such as enhancing immune function, anti-inflammatory, and analgesic effects. The inflammatory response caused by mosquito bites is related to multiple cells and substances, and its mechanism of action is relatively complex. One aspect is that mosquitoes often carry pathogenic bacteria such as Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. When these pathogenic bacteria come into contact with the skin, they will also be regarded as allergens, thus triggering an immune response in the skin. Research by Ge Bing et al. shows that the volatile oil of Elsholtzia ciliata has strong inhibitory effects on Escherichia coli, Staphylococcus aureus, and Streptococcus. Therefore, the volatile oil of Elsholtzia ciliata can be used as a plant-derived mosquito bite antipruritic agent.

[0007] Eupatorium adenophorum is a poisonous plant of the genus Eupatorium in the Compositae family, commonly known as "broken horse grass", "black-stemmed grass", "stinking grass", "airplane grass", "tyrant grass", etc. It is a perennial robust herb. Its mature seeds can float everywhere with the wind. One plant can produce hundreds of thousands of seeds. It has a fast propagation speed and strong invasion ability, and is a harmful and poisonous plant worldwide. It is reported that it contains active substances such as epifriedelinol, stigmasterol, n-octacosanoic acid, daucosterol, o-hydroxycinnamic acid amide, ferulic acid, caffeic acid, 2-isopropenyl-5-acetyl-6-hydroxybenzofuran, and eupatilin. These active substances have a good killing effect on certain agricultural pests. In recent years, some scientific researchers have obtained Eupatorium adenophorum extract with 95% ethanol from Eupatorium adenophorum and carried out a mosquito repellent effect test according to the test method specified in the national standard GB / T13917.9—2009. It is found that the 100% protection time of the Eupatorium adenophorum extract at a dose of 1.5mg·cm-2 against Aedes albopictus is 3.63h. The repellent effect of the Eupatorium adenophorum extract against Aedes albopictus is slightly lower than the B-level standard (15% DEET) of the international repellent evaluation, indicating that Eupatorium adenophorum is a good mosquito repellent plant material and can be further developed and studied in depth.

[0008] The current research results on using plant essential oils for mosquito repellent show that the essential oils of Bidens pilosa, Elsholtzia ciliata, and Eupatorium adenophorum have a certain repellent effect on mosquitoes, and there are certain differences in their mosquito repellent effects. However, there is no report on the mosquito repellent essential oil prepared by compounding the three. Moreover, as substances of plant origin, due to their characteristics such as small environmental pollution, low tendency to produce drug resistance, and safety to human health, they have broad development space for use in the preparation of mosquito repellent preparations. Summary of the Invention

[0009] The invention aim of the present invention is to provide a compounded mosquito repellent essential oil. The whole formula of the compounded essential oil of the present invention is rationally formulated, and the components play a synergistic role, having a good mosquito repellent and insect avoidance effect. While achieving the mosquito repellent and insect avoidance effect, there are no adverse reactions such as allergies, and it is safe to human health.

[0010] The technical solution provided by the present invention is as follows: A compounded mosquito repellent essential oil and its preparation method, characterized in that the essential oil comprises the following weight percentages: 30-50% of Bidens pilosa extract, 20-40% of Elsholtzia ciliata extract, 10-30% of Eupatorium adenophorum extract, and the balance is at least one of carrier oils: olive oil, coconut oil, grape seed oil, sweet almond oil, jojoba oil.

[0011] The preparation method of the mosquito repellent essential oil comprises the following steps:

[0012] S1. Compounding: Mix the essential oils of Bidens pilosa, Elsholtzia ciliata, and Eupatorium adenophorum evenly according to a predetermined ratio, add an appropriate amount of carrier oil as a carrier, and heat and stir until completely dissolved;

[0013] S2. Refine and then perform vacuum degassing and filtration to remove any possible solid particles and air bubbles, obtaining a clear and transparent compounded mosquito repellent essential oil.

[0014] As a further improvement to the technical solution of the preparation method of the present invention, preferably, the carrier oil of the mosquito repellent essential oil is selected from one or more of olive oil, coconut oil, grape seed oil, sweet almond oil, and jojoba oil.

[0015] As a further improvement to the technical solution of the preparation method of the present invention, preferably, the mixing ratio of the compounded essential oils in S1 is: Bidens pilosa extract: Elsholtzia ciliata extract: Eupatorium adenophorum extract = 3:2:1 - 5:4:3.

[0016] As a further improvement to the technical solution of the preparation method of the present invention, preferably, the heating temperature in S1 is 40°C and stirring is carried out for 30 min.

[0017] As a further improvement to the technical solution of the preparation method of the present invention, preferably, in S2, the pressure for vacuum degassing is 0.05 MPa and degassing is carried out for 30 min.

[0018] Compared with the prior art, the beneficial effects of the present invention are mainly reflected in: the mosquito repellent essential oil of the present invention has a fresh fragrance, a reasonable overall formula, and the components work synergistically. When used at room temperature (26 - 30°C), the mosquito repellent effect lasts for about 4 weeks, having a good mosquito repellent effect. At the same time, there are no adverse reactions such as allergies. In addition, the preparation process of the compounded essential oil of the present invention is simple, which is conducive to the realization of industrialization. Specific Embodiments

[0019] The present invention will be further described below in conjunction with specific embodiments.

[0020] Example 1

[0021] The mosquito repellent essential oil is prepared by the following method:

[0022] Weigh 4 g of Bidens pilosa, 3 g of Elsholtzia ciliata, and 1 g of Eupatorium adenophorum essential oils and mix them evenly. Add 2 g of carrier oil, heat and stir at 40°C for 30 min until completely dissolved. Then degas under a vacuum of 0.05 MPa for 30 min, and filter to remove solid particles and air bubbles, obtaining a clear mosquito repellent essential oil.

[0023] Example 2

[0024] The mosquito repellent essential oil is prepared by the following method:

[0025] Weigh 2 g of Bidens pilosa, 3 g of Elsholtzia ciliata, and 3 g of Eupatorium adenophorum essential oils and mix them evenly. Add 2 g of carrier oil, heat and stir at 40°C for 30 min until completely dissolved. Then degas under a vacuum of 0.05 MPa for 30 min, and filter to remove solid particles and air bubbles, obtaining a clear mosquito repellent essential oil.

[0026] Example 3

[0027] The following method was used to prepare the mosquito repellent essential oil:

[0028] Weigh 3 g of Bidens pilosa, 3 g of Elsholtzia ciliata, and 2 g of Eupatorium adenophorum essential oil, mix them evenly, add 2 g of carrier oil, and heat and stir at 40 °C for 30 min until completely dissolved. Then degas for 30 min under a vacuum of 0.05 MPa, and filter to remove solid particles and air bubbles to obtain a clear mosquito repellent essential oil.

[0029] Comparative Examples 1-6 were prepared according to the proportions described in Table 1 below, and the preparation method was the same as that of the above examples.

[0030]

[0031]

[0032] Test Example

[0033] Determination of the mosquito-killing effect of the compound plant essential oil

[0034] Detection conditions: The laboratory temperature was 26 °C and the relative humidity was 60%.

[0035] Test mosquito species: Aedes albopictus, a normal strain reared indoors, and female adult mosquitoes 4-5 days after eclosion were used for determination.

[0036] Test agents: The essential oils prepared in Examples 1-3, the essential oils prepared in Comparative Examples 1-6, Liushen mosquito repellent, and Runben mosquito repellent ointment.

[0037] Detection device: Two glass square boxes with dimensions of 70 cm × 70 cm × 70 cm were connected by an organic glass pipe with a diameter of 20 cm × 180 cm. A mosquito-releasing hole was provided in the center of the channel, and movable partitions were provided on both sides.

[0038] Indoor test: Place the electric heater through the small door at the lower corner of the glass device into the middle corner of the test glass box, turn on the power supply. When the temperature of the filter paper on the heater reaches about 50 °C, drop 1 ml of the mosquito repellent essential oil composition on the filter paper, and immediately seal the entire glass device. Use a mosquito suction tube to suck 100 test mosquitoes from the breeding cage, put them in through the mosquito-releasing hole, open the channel partition, and start timing. After 30 minutes, cut off the channel, and record the number of mosquitoes and the number of knocked-down mosquitoes in the glass box. The test was repeated three times. After each test, clean the entire experimental device and then conduct the next test.

[0039] Statistical method: Mosquito-killing rate = number of killed mosquitoes / total number of test mosquitoes × 100%.

[0040] Test results: As shown in Table 2

[0041] Table 2 Mosquito control effect of compound plant essential oils

[0042]

[0043] As can be seen from Table 2, the mosquito-repellent compound plant essential oils of Bidens pilosa, Elsholtzia ciliata and Eupatorium adenophorum have good mosquito control effects, and the mosquito control rate is as high as 90-95%.

[0044] Conclusion: The mosquito control rate of this product is as high as 90-95%, and this product does not contain DEET. All components are natural extracts, which are highly efficient and safe. Therefore, it is very suitable for the prevention and control of household sanitary pests such as mosquitoes and has great application and promotion value.

[0045] Although the present invention has been described in detail above with general descriptions and specific embodiments, on the basis of the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A compound mosquito repellent essential oil and a preparation method thereof, characterized in that: The essential oil comprises the following weight percentages: Composition: Bidens pilosa essential oil: 30-50%, Elsholtzia ciliata essential oil: 20-40%, Eupatorium adenophorum essential oil: 10-30%, and the balance is at least one of the carrier oils: olive oil, coconut oil, grape seed oil, sweet almond oil, jojoba oil. The preparation method of the mosquito repellent essential oil comprises the following steps: S1. Compounding: Evenly mix Bidens pilosa, Elsholtzia ciliata, and Eupatorium adenophorum essential oils in a predetermined ratio, add appropriate amount of vegetable oil as a carrier, and heat and stir until completely dissolved; S2, refining, vacuum degassing and filtering are then performed to remove possible solid particles and bubbles to obtain a clear and transparent compound mosquito repellent essential oil.

2. A compound mosquito repellent essential oil and a preparation method thereof as claimed in claim 1, characterized in that: The carrier oil is selected from one or more of olive oil, coconut oil, grape seed oil, sweet almond oil and jojoba oil.

3. A compound mosquito repellent essential oil and a preparation method thereof as claimed in claim 1, characterized in that: The mixing ratio of the compound essential oil is: Bidens pilosa essential oil: Elsholtzia ciliata essential oil: Eupatorium adenophorum essential oil = 3:2:1-5:4:

3.

4. A compound mosquito repellent essential oil and a preparation method thereof as claimed in claim 1, characterized in that: In S1, the heating temperature is 40°C and the stirring time is 30 min.

5. A compound mosquito repellent essential oil and a preparation method thereof as claimed in claim 1, characterized in that: The vacuum degassing pressure in S2 is 0.05 MPa and the degassing time is 30 min.

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