A modified eugenol mixture for the knockdown of spider mites and a method for its preparation

Abstract

The application belongs to the field of fine chemical industry, and particularly discloses a modified eugenol mixture for contact killing of spider mites and a preparation method thereof. The modified eugenol mixture is prepared by addition reaction of nonamethyltrihydrogen pentasiloxane, allyl polyether, eugenol and olefin under the condition of a platinum catalyst at normal pressure to obtain a novel structure siloxane grafted with eugenol; and then the product is mixed with a double-branched ethoxylated siloxane and a rhamnolipid surfactant according to a mass ratio to obtain the modified eugenol mixture for contact killing of spider mites. The novel structure siloxane is a novel eugenol compound for contact killing of spider mites, and the long-chain alkyl on the organic silicon chain can dissolve the sebum layer of the mites, and at the same time, the eugenol can penetrate below the sebum layer due to the low surface tension of silicon, so that the contact killing effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of fine chemical technology, and more specifically to a modified eugenol mixture for contact killing of spider mites and its preparation method. Background Technology

[0002] Currently, eugenol, as a bactericidal compound, is widely used in medicine and pesticides. Plant-derived eugenol is obtained by distilling the crude clove volatile oil from the flower buds of the clove plant (family Myrtaceae), then extracting and separating the phenolic and non-phenolic oils, followed by further distillation. Industrially, it can be isolated from natural clove volatile oil or synthesized using guaiacol.

[0003] Eugenol, as a plant-derived extract, is mainly used for its bactericidal effect in practical applications. For example, eugenol is emulsified into microcapsules using a double emulsion encapsulation method for the control of tomato yellow leaf curl virus ("Development of microcapsules and field application technology of plant-derived antiviral agent eugenol", Zhang Xiaoyan et al., Chinese Journal of Biological Control, 2015, 31(1): 139-147); eugenol water emulsion is used for the field control of strawberry gray mold ("Field control effect of 20% eugenol water emulsion, a plant-derived fungicide, on strawberry gray mold", Zhang Meng, Jiangsu Agricultural Sciences, 2015, 43(1). 1): 132-133); Prevention and treatment of tobacco mosaic virus by eugenol (“A preliminary study on the mechanism of action of natural compound eugenol against tobacco mosaic virus disease”, Wang Chunmei et al., Pesticides, 2012, 51(1): 29-31); and research on reducing drug resistance by synthesizing eugenol with pyrethroids (“Design, synthesis and preliminary activity test of novel insecticide eugenol ester”, Xu Xiaowei et al., Chemical Research and Application, 2009, 21(1): 110-112).

[0004] However, eugenol, as a phenol analogue, has low hydrophobicity and weak lipid solubility, resulting in poor penetration into the cell epidermis of pests. This limits its activity as an insecticide and its application range.

[0005] In addition, the inventors noted that the eugenol-terminated polysiloxane mentioned in the patent (application number 201480041460.7) is similar to this patent, but the two substances have different chemical structures and the resulting compounds have drastically different properties.

[0006] Therefore, the preparation of a highly penetrating insecticide using eugenol is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] In view of this, the present invention provides a modified eugenol mixture for contact killing of spider mites and a method for preparing the same. The modified eugenol mixture is obtained by mixing several surfactants, including conventional organosilicon low-surface-tension penetrants such as the eugenol-modified alkylsiloxane (Formula I) and the bibranched ethoxylated siloxane (Formula II) prepared in this invention, as well as rhamnolipid surfactants.

[0008] To achieve the above objectives, the present invention provides an eugenol-modified alkylsiloxane, wherein the general formula of the eugenol-modified alkylsiloxane is:

[0009]

[0010] Where R = -CH3 or -H; n = 8-20; a = 5-12; b = 0-5.

[0011] Furthermore, in order to achieve the above objectives, the present invention provides a method for preparing eugenol-modified alkylsiloxanes, characterized in that it specifically includes: reacting nonamethyltrihydropentasiloxane, allyl polyether, eugenol and α-olefin under atmospheric pressure with a catalyst and stirring to obtain eugenol-modified alkylsiloxanes.

[0012] Preferably, the mass ratio of the nonamethyltrihydropentasiloxane, allyl polyether, eugenol, and olefin is 20-35%: 30-50%: 5-20%: 5-15%.

[0013] Preferably, the catalyst is a platinum-based catalyst, and the addition amount is 0.001-0.002%.

[0014] Preferably, the catalyst is chloroplatinic acid hexahydrate.

[0015] Preferably, the reaction temperature is 90-120℃, the reaction time is 1.5-4 hours, and the stirring speed is 70-150 r / min.

[0016] This invention provides a modified eugenol mixture for contact killing of spider mites, comprising the following raw materials in the following mass ratio: 30-50% eugenol-modified alkylsiloxane, 45-68% bibranched ethoxylated modified siloxane, and 2-5% rhamnolipid surfactant.

[0017] Preferably, the general formula of the dibranched ethoxylated modified siloxane is:

[0018]

[0019] Where c = 4-12; R1 = -CH3 or -H.

[0020] Furthermore, to achieve the above objectives, the present invention also provides a method for preparing a modified eugenol mixture for contact killing of spider mites, the specific steps of which are as follows:

[0021] Eugenol-modified alkylsiloxane, bibranched ethoxy-modified siloxane, and rhamnose surfactant were mixed in a certain mass ratio and stirred under normal pressure to obtain a mixture.

[0022] Preferably, the stirring speed is 50-100 r / min and the stirring time is 0.5-2 hours.

[0023] This technical solution involves the addition reaction (Formula III) of nonamethyltrihydropentasiloxane containing silane-hydrogen bonds with allyl polyether, eugenol, and α-olefins under the action of a platinum-based catalyst. Adjusting the values ​​of n, a, and b yields compounds with different degrees of polymerization. The final product is obtained by uniformly mixing the above compounds with a bibranched ethoxylated modified siloxane and a rhamnolipid surfactant.

[0024]

[0025] As can be seen from the above technical solution, compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] (1) The eugenol-modified alkyl siloxane described in this invention is a novel modified eugenol compound that can kill spider mites by contact. The long-chain alkyl group on the silicon chain can dissolve the sebum layer of the mite, and the low surface tension of silicon allows eugenol to penetrate below the sebum layer to achieve the contact killing effect.

[0027] (2) The modified eugenol mixture prepared by the present invention exhibits good insecticidal activity in laboratory tests and practical applications when its highly diluted solution is diluted with water. This can reduce the use of pesticides and is beneficial to environmental protection. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 The attached figure is a schematic diagram of the reaction process provided by the present invention.

[0030] Figure 2 The attached figure shows the contact angle between Embodiment 1 of the present invention and a commercially available competing product. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1:

[0033] 20 kg of nonamethyltrihydropentasiloxane, 50 kg of allyl polyether (a=6, b=1, R=CH3), 20 kg of eugenol, and 10 kg of olefin (n=10) were reacted at atmospheric pressure under a 0.0011 kg chloroplatinic acid hexahydrate catalyst at 90 °C for 1.5 hours, with a stirring speed of 70 r / min. 30 kg of the above product (I 1) was then mixed with 68 kg of a dibranched ethoxylated (c=10, R1=H) modified siloxane (II 1) and 2 kg of rhamnolipid surfactant (6FA) to obtain the final mixture. This mixture was then physically stirred at atmospheric pressure at 50 r / min for 0.5 hours.

[0034]

[0035]

[0036] Example 2:

[0037] 35 kg of nonamethyltrihydropentasiloxane, 50 kg of allyl polyether (a=8, b=0, R=H), 5 kg of eugenol, and 10 kg of olefin (n=12) were reacted at atmospheric pressure under a 0.0015 kg chloroplatinic acid hexahydrate catalyst at 120 °C for 3 hours, with a stirring speed of 90 r / min. 50 kg of the above product (I₂) was then mixed with 45 kg of a dibranched ethoxylated (c=12, R₁=CH₃) modified siloxane (II₂) and 5 kg of rhamnolipid surfactant (6FA) to obtain the final mixture. This mixture was then physically stirred at atmospheric pressure at 90 r / min for 1 hour.

[0038]

[0039]

[0040] Example 3:

[0041] 28 kg of nonamethyltrihydropentasiloxane, 47 kg of allyl polyether (a=12, b=5, R=CH3), 10 kg of eugenol, and 15 kg of olefin (n=20) were reacted under normal pressure with 0.002 kg of chloroplatinic acid hexahydrate catalyst at 100°C for 3 hours, with a stirring speed of 150 r / min. 45 kg of the above product (I3) was then mixed with 52.5 kg of a dibranched ethoxylated (c=10, R1=CH3) modified siloxane (II3) and 2.5 kg of rhamnolipid surfactant (6FA) to obtain the final mixture. This mixture was then physically stirred under normal pressure at 80 r / min for 45 minutes.

[0042]

[0043]

[0044] Example 4:

[0045] 25 kg of nonamethyltrihydropentasiloxane, 40 kg of allyl polyether (a=10, b=0, R=H), 20 kg of eugenol, and 15 kg of olefin (n=16) were reacted at atmospheric pressure under a 0.0017 kg chloroplatinic acid hexahydrate catalyst at 120°C for 3 hours, with a stirring speed of 90 r / min. 32 kg of the above product (I4) was then mixed with 66 kg of a dibranched ethoxylated (c=4, R1=H) modified siloxane (II4) and 2 kg of rhamnolipid surfactant (6FA) to obtain the final mixture. This mixture was then physically stirred at atmospheric pressure at a stirring speed of 75 r / min for 50 minutes.

[0046]

[0047]

[0048]

[0049] Of the above embodiments, Embodiment 1 is the most effective.

[0050] To further verify the technical effectiveness of this product, Example 1 was compared with similar competing products on the market in terms of basic properties. The specific results are shown in Table 1 and Appendix. Figure 2 .

[0051] Table 1. Physicochemical properties of this product compared to commercially available competitors.

[0052]

[0053] As can be seen, the physicochemical properties of the product obtained in Example 1 are significantly different from those of commercially available competing products. In particular, the surface tension and contact angle are smaller than those of commercially available competing products, indicating that this product has better permeability, can efficiently penetrate the sebum layer of mites, and has a better contact killing effect than commercially available competing products.

[0054] Meanwhile, laboratory acaricide tests were conducted on the product of Example 1 and two competing products (test results are shown in Table 2). Data shows that the physicochemical properties of Example 1 prepared by this patent are comparable to, and in some aspects even superior to, those of the competing products. In actual acaricide tests, it was observed that the product prepared in Example 1 was superior to the competing products. Specific testing methods and procedures are described below.

[0055] Two-spotted spider mite source:

[0056] Natural populations were collected from greenhouse strawberry leaves and then further cultured on strawberry plants in the laboratory. Environmental conditions: temperature 25±1℃, relative humidity 85%, light-dark cycle 15h-9h.

[0057] Determine the product dilution ratio:

[0058] The slide immersion method was used, with the tested examples 1 to 4 diluted 1000 to 3000 times. Each concentration treatment was repeated three times, with a water treatment serving as a control. One hundred healthy adult mites were placed on each slide with double-sided tape, covered with a petri dish lid, and placed in a light incubator at (25±1)℃, (65±5)% relative humidity, and a light-dark cycle of 15-9 hours. The results were checked after 24, 48, and 72 hours. The mites were considered dead if their appendages did not move noticeably when gently touched with a soft thread multiple times. Specific results are shown in Table 2, determining the optimal dilution factor for this application.

[0059] Calculate the corrected mortality rate using the following formula:

[0060] Corrected mortality rate (%) = (treatment mortality rate - control mortality rate) / (1 - control mortality rate) * 100%

[0061] Table 2

[0062]

[0063]

[0064]

[0065] As can be seen from the results in Table 2, Example 1 showed the best overall contact kill effect, with the optimal dilution factor being 2000 times.

[0066] Acaricide testing of this product compared to competing products:

[0067] Using the slide immersion method, Example 1, Competitor A, and Competitor B were diluted 2000-fold, with three replicates for each concentration treatment. A water treatment served as a control. The same experimental and calculation methods were used to detect spider mite mortality at 24h, 48h, and 72h, and the average and corrected mortality rates were calculated. The specific results are shown in Table 3.

[0068] Table 3

[0069]

[0070]

[0071] Tables 2 and 3 show the use of different compounds to test the two-spotted spider mite. The results indicate that at the same dilution (2000 times), Examples 1 to 4 showed significant acaricidal effects, while competitor A was slightly less effective, and competitor B was very ineffective. Example 1, at a 2000-fold dilution, achieved a corrected mortality rate of 99% after 72 hours, demonstrating its obvious insecticidal activity against the two-spotted spider mite. Furthermore, tests revealed that Examples 1 to 4 remained more effective than competitors A and B at different dilutions (1000-3000 times), with Example 1 achieving a 100% corrected mortality rate at a 1000-fold dilution.

[0072] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0073] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An eugenol-modified alkylsiloxane for contact killing of spider mites, characterized in that, The general formula is: ； Where R = -CH3 or -H; n = 8-20; a = 5-12; b = 0-5.

2. The method for preparing eugenol-modified alkylsiloxane for contact killing of spider mites according to claim 1, characterized in that, Specifically, it includes: Nonmethyltrihydropentasiloxane, allyl polyether, eugenol and α-olefin were reacted under normal pressure with a catalyst and stirred to obtain eugenol-modified alkylsiloxane.

3. The method for preparing eugenol-modified alkylsiloxane for contact killing of spider mites according to claim 2, characterized in that, The mass ratio of the nonamethyltrihydropentasiloxane, allyl polyether, eugenol, and α-olefin is 20-35%: 30-50%: 5-20%: 5-15%.

4. The method for preparing eugenol-modified alkylsiloxane for contact killing of spider mites according to claim 2, characterized in that, The catalyst is a platinum-based catalyst, and the addition amount is 0.001-0.002%.

5. The method for preparing eugenol-modified alkylsiloxane for contact killing of spider mites according to claim 4, characterized in that, The catalyst is chloroplatinic acid hexahydrate.

6. The method for preparing eugenol-modified alkylsiloxane for contact killing of spider mites according to claim 2, characterized in that, The reaction temperature is 90-120℃, the reaction time is 1.5-4 hours, and the stirring speed is 70-150 r / min.

7. A modified eugenol mixture for contact killing of spider mites, characterized in that, The raw materials include the following mass ratios: 30-50% eugenol-modified alkylsiloxane as described in claim 1, 45-68% bibranched ethoxylated siloxane, and 2-5% rhamnolipid surfactant.

8. A modified eugenol mixture for contact killing of spider mites according to claim 7, characterized in that, The general formula of the dopally branched ethoxylated modified siloxane is: ； Where c = 4-12; R1 = -CH3 or -H.

9. A method for preparing a modified eugenol mixture for contact killing of spider mites according to claim 7, characterized in that, The specific steps are as follows: Eugenol-modified alkylsiloxane, bibranched ethoxy-modified siloxane, and rhamnose surfactant were mixed in a certain mass ratio and stirred under normal pressure to obtain a mixture.

10. The method for preparing a modified eugenol mixture for contact killing of spider mites according to claim 9, characterized in that, The stirring speed is 50-100 r / min, and the stirring time is 0.5-2 hours.

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