Carvacrol modified compound as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of agriculture, and discloses a carvacrol modified compound and a preparation method and application thereof, and the preparation method comprises the following specific steps: (1) carvacrol and halogenated cyclohexene oxide are subjected to a ring-opening reaction to obtain modified carvacrol; (2) catalyzing the modified carvacrol to generate elimination reaction to obtain modified carvacrol containing unsaturated groups; and (3) carrying out addition reaction on the modified carvacrol containing the unsaturated group, low-molecular-weight hydrogen-containing siloxane and allyl polyether to obtain a carvacrol modified compound, namely the carvacrol modified organic silicon. According to the invention, carvacrol is chemically grafted to polysiloxane and is mixed with ethyoxyl modified polysiloxane to obtain a substance capable of assisting in killing insects, and the substance has an obvious effect on assisting in killing spider mites, aphids, thrips, plant hoppers, borer and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of agriculture, and specifically relates to a carvacrol modified compound and a preparation method and application thereof. Background Art

[0002] Essential oil is a kind of aromatic volatile oil obtained from the flowers, leaves, bark, fruit and seed buds of plants through fermentation extraction or distillation. Ordinary squeezed essential oil is a complex mixture, generally containing olefins, aldehydes, ketones, ethers and phenols. Such substances have been widely used in medicine, perfumes and cosmetics, and are sometimes added to food as spices. There are about 3,000 known essential oils, of which more than 300 varieties have commercial value, mainly used in the spices and flavors market.

[0003] Data from the past decade show that carvacrol essential oil has a significant inhibitory effect on multiple bacterial species such as Escherichia coli, Salmonella, Pasteurella, Staphylococcus, etc., and also has antioxidant properties. For example, in the prior art "Preparation and Antibacterial Activity of Carvacrol-Chitosan Nanoparticles" (Food and Fermentation Industries, 2022, 48(22): 82-88), carvacrol-chitosan nanoparticles were prepared by emulsification cross-linking method and the antibacterial stability against Fusarium graminearum was tested; "Antibacterial Agents and Dosage Screening of Addition-type Silicone Rubber Oral Impression Materials" (Chemistry and Engineering, 2022, 39(4): 29-32) also mentioned that thymol can be added to silicone rubber to inhibit gingival bacteria, which are all antibacterial technologies of phenolic substances.

[0004] In the process of agricultural insecticide, carvacrol generally only plays an auxiliary role, and as a volatile oil, carvacrol has a special smell and is easy to cause disgust during use. For example, the technology used in the existing invention patents CN115226715A, CN115418333A, CN113475523B, etc. is just to add phenolic substances into the system by physical means, but there are few related studies on the chemical modification of carvacrol.

[0005] Therefore, it is an urgent problem for those skilled in the art to provide a carvacrol-modified compound and a preparation method and application thereof. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a carvacrol-modified compound and a preparation method and application thereof.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] A carvacrol-modified compound, wherein the carvacrol-modified compound is carvacrol-modified organosilicon, and has the following structural formula:

[0009]

[0010] Wherein, R is at least one of hydroxyl, methyl, butyl and hydrogen, and a is an integer of 3-20.

[0011] The method for preparing the carvacrol-modified compound described above comprises the following specific steps:

[0012] (1) subjecting carvacrol and halogenated epoxycyclohexane to a ring-opening reaction to obtain modified carvacrol;

[0013] (2) catalyzing the modified carvacrol to undergo an elimination reaction to obtain a modified carvacrol containing an unsaturated group;

[0014] (3) subjecting the modified carvacrol containing an unsaturated group, a low molecular weight hydrogen-containing siloxane and an allyl polyether to an addition reaction to obtain a carvacrol-modified compound, i.e., a carvacrol-modified silicone;

[0015] The process is as follows:

[0016]

[0017]

[0018] Preferably, in step (1), the molar ratio of carvacrol to the halogenated epoxycyclohexane is 1.1:1-1.3;

[0019] The base is potassium hydroxide and / or tetramethylethylenediamine, and the pH value of the solution is adjusted to 8-10;

[0020] The heating temperature is 90-120° C. and the heating time is 3-12 hours.

[0021] Preferably, the preparation method of the halogenated epoxycyclohexane in step (1) is:

[0022] Allyl cyclohexyl oxide and halogen are subjected to addition reaction to obtain halogenated cyclohexyl oxide;

[0023] The process is as follows:

[0024]

[0025] Preferably, the halogen is Br2 or I2;

[0026] The molar ratio of the allyl cyclohexene oxide to the halogen is 1:1 to 1.3;

[0027] The parameters of the addition reaction are: reaction at below 5° C. for 2-4 hours.

[0028] Preferably, the mass ratio of the modified carvacrol to the catalyst in step (2) is 1:1-15;

[0029] The catalyst is zinc and / or magnesium powder;

[0030] The parameters of the elimination reaction are: reaction at 70-130° C. for 2-12 hours.

[0031] Preferably, a dehalogenation aid is also added in the elimination reaction.

[0032] Preferably, the dehalogenation aid is zinc bromide or magnesium bromide, and the added ratio is 1-5% of the total system mass.

[0033] Preferably, in step (3), the molar ratio of the modified carvacrol containing an unsaturated group, the low molecular weight hydrogen-containing siloxane and the allyl polyether is 0.6-1:1:0.6-1;

[0034] The structure of the allyl polyether is as follows:

[0035]

[0036] Wherein, R is at least one of hydroxyl, methyl, butyl and hydrogen, and a is an integer of 2-12.

[0037] The catalyst is chloroplatinic acid catalyst, and the addition amount is 3-10ppm

[0038] The parameters of the addition reaction are: reaction at 120-135° C. for 6-7.5 h.

[0039] Application of the carvacrol-modified compound or the carvacrol-modified compound obtained by the above-mentioned preparation method in the field of insecticide.

[0040] Preferably, the carvacrol-modified compound and ethoxy-modified polysiloxane are mixed and used as an insecticide adjuvant.

[0041] Preferably, the insect is at least one of spider mites, aphids, thrips, planthoppers and borers. Compared with the prior art, the present invention has the following beneficial effects:

[0042] The invention provides a carvacrol modified compound and a preparation method and application thereof. The invention obtains a substance capable of assisting in killing insects by chemically grafting carvacrol onto polysiloxane and mixing the compound with ethoxy modified polysiloxane. The ethoxy modified polysiloxane is an organic silicon substance with super strong spreading and penetration effects. After the compound is added, the spreading and penetration of the insecticide on the surface of the insect pest can be significantly enhanced, and the absorption of the insect pest to the drug can be promoted, reflecting the synergistic effect of the two. The addition amount of the compound is controlled at 10-20%. The compound has obvious effect in assisting in killing insects such as spider mites, aphids, thrips, planthoppers, and heart borers. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0044] Figure 1 This is a graph showing the test results of the insecticide adjuvant prepared in an embodiment of the present invention on citrus spider mites (red spider);

[0045] Figure 2 This is a graph showing the test results of the insecticide adjuvant prepared in an embodiment of the present invention on corn aphids;

[0046] Figure 3 This is a test result diagram of the insecticide adjuvant prepared in an embodiment of the present invention against rose thrips;

[0047] Figure 4 The present invention is a flowchart of preparing an insecticide adjuvant according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] Example 1

[0050] The present invention provides a method for preparing a carvacrol-modified compound, comprising the following specific steps:

[0051] (1) In a three-necked flask, 4-vinyl cyclohexene oxide is added to carbon tetrachloride and stirred thoroughly, and then Br2 is added dropwise under low temperature, wherein the molar ratio of 4-vinyl cyclohexene oxide to Br2 is 1:1, and the volume of carbon tetrachloride accounts for 60% of the reaction system; the specific operation steps are as follows: after 4-vinyl cyclohexene oxide is fully dissolved in carbon tetrachloride, the reaction temperature is controlled below 5°C in an ice-water bath, and a mixed solution of Br2 and carbon tetrachloride is added dropwise. After sufficient shaking, the mixture is placed in a dark place and kept at 4°C for 2 hours. After the reaction is completed, the mixture is washed with water, the organic layer is dried, and the solvent is evaporated under reduced pressure to obtain white crystals, namely bromocyclohexene oxide;

[0052] (2) Add white crystalline bromoepoxycyclohexane and carvacrol in a molar ratio of 1:1.1 into a three-necked flask, fully dissolve with N,N-dimethylformamide, the mass ratio of bromoepoxycyclohexane, carvacrol and N,N-dimethylformamide is 284:165:146, adjust the pH of the reaction system to 8 with potassium hydroxide, the reaction temperature is about 100°C, the reaction time is 4h, and after the reaction is completed, modified carvacrol is obtained;

[0053] (3) Add 5 times the weight of zinc powder (the average particle size of zinc powder particles is controlled to be 6-9 um) to the above-mentioned modified carvacrol product, and add zinc bromide as a dehalogenation agent at the same time. Add anhydrous ethanol to the reaction system. The mass of anhydrous ethanol is the same as that of zinc powder. The amount of dehalogenation agent added is 3 wt %. The dehalogenation reaction temperature is 130° C. and the reaction time is 3 h. After the reaction is completed, modified carvacrol containing an unsaturated group is obtained.

[0054] (4) After mixing octamethyldihydrogentetrasiloxane, modified carvacrol containing an unsaturated group and allyl polyether in a molar ratio of 1:0.6:0.6, nitrogen protection is introduced, and after stirring for 30 minutes, 3 ppm of chloroplatinic acid catalyst is added, the reaction temperature is controlled at 135° C., the reaction time is 7.5 hours, and after the reaction is completed, a reaction product, carvacrol-modified silicone, is obtained; wherein the allyl polyether is a polyether in which R is a hydroxyl group and a is equal to 6;

[0055] (5) The obtained carvacrol-modified silicone and ethoxy-modified decamethyl pentasiloxane were mixed in a mass ratio of 8:2 to obtain an insecticide adjuvant (preparation process as shown in Figure 4 ).

[0056] Example 2

[0057] The present invention provides a method for preparing a carvacrol-modified compound, comprising the following specific steps:

[0058] (1) In a three-necked flask, 4-vinyl cyclohexene oxide is added to carbon tetrachloride and stirred thoroughly, and then Br2 is added dropwise under low temperature, wherein the molar ratio of 4-vinyl cyclohexene oxide to Br2 is 1:1.3, and the volume of carbon tetrachloride accounts for 50% of the reaction system; the specific operation steps are as follows: after 4-vinyl cyclohexene oxide is fully dissolved in carbon tetrachloride, the reaction temperature is controlled below 5°C in an ice-water bath, and a mixed solution of Br2 and carbon tetrachloride is added dropwise. After sufficient shaking, the mixture is placed in a dark place and kept at 3°C ​​for 4 hours. After the reaction is completed, the mixture is washed with water, the organic layer is dried, and the solvent is evaporated under reduced pressure to obtain white crystals, namely bromocyclohexene oxide;

[0059] (2) Add white crystalline bromoepoxycyclohexane and carvacrol in a molar ratio of 1:1.2 into a three-necked flask and dissolve them with N,N-dimethylformamide. The mass ratio of bromoepoxycyclohexane, carvacrol and N,N-dimethylformamide is 284:180:146. Use potassium hydroxide to adjust the pH of the system to 9.5. The reaction temperature is about 90°C and the reaction time is 8 hours. After the reaction, modified carvacrol is obtained.

[0060] (3) Add 4 times the mass of magnesium metal (magnesium strips need to be polished to treat surface oxides) to the above-mentioned modified carvacrol product, add 1.3 times the mass of anhydrous ethanol to the metal magnesium, and add 2.5% magnesium bromide at the same time. The dehalogenation reaction temperature is 110°C and the reaction time is 4 hours. After the reaction is completed, a modified carvacrol containing an unsaturated group is obtained;

[0061] (4) Octamethyldihydrogentetrasiloxane, modified carvacrol containing an unsaturated group and allyl polyether are mixed in a molar ratio of 1:1:1, wherein R of the allyl polyether is methyl and a is 4, and then nitrogen is introduced for protection. After stirring for 30 minutes, 6 ppm of chloroplatinic acid catalyst is added, the reaction temperature is controlled at 135° C., the reaction time is 6 hours, and after the reaction is completed, the reaction product carvacrol-modified silicone is obtained;

[0062] (5) The obtained carvacrol-modified silicone and ethoxy-modified decamethyl pentasiloxane were mixed in a mass ratio of 8.5:1.5 to obtain an insecticide adjuvant (preparation process as shown in Figure 4 ).

[0063] Example 3

[0064] The present invention provides a method for preparing a carvacrol-modified compound, comprising the following specific steps:

[0065] (1) In a three-necked flask, 4-vinyl cyclohexene oxide is added to carbon tetrachloride and stirred thoroughly, and then Br2 is added dropwise under low temperature, wherein the molar ratio of 4-vinyl cyclohexene oxide to Br2 is 1:1.2, and the volume of carbon tetrachloride accounts for 50% of the reaction system; the specific operation steps are as follows: 4-vinyl cyclohexene oxide is fully dissolved in carbon tetrachloride, the reaction temperature is controlled below 5°C with an ice-water bath, a mixed solution of Br2 and carbon tetrachloride is added dropwise, after sufficient shaking, the mixture is placed in a dark place, the temperature is maintained at 3°C ​​and the reaction is carried out for 3 hours, after the reaction is completed, the mixture is washed with water, the organic layer is dried, and the solvent is evaporated under reduced pressure to obtain white crystals, namely bromocyclohexene oxide;

[0066] (2) Add white crystalline bromocyclohexane and carvacrol in a molar ratio of 1.1:1.3 into a three-necked flask, and dissolve them with N,N-dimethylformamide. The mass ratio of bromocyclohexane, carvacrol and N,N-dimethylformamide is 284:195:146. Add potassium hydroxide and tetramethylethylenediamine to adjust the pH of the system to 9. The reaction temperature is 120°C and the reaction time is 3.5 hours. After the reaction is completed, modified carvacrol is obtained.

[0067] (3) Add 10 times the mass of magnesium metal (magnesium strips need to be polished to treat surface oxides) to the above-mentioned modified carvacrol product, add anhydrous ethanol of the same mass as the magnesium metal, the dehalogenation reaction temperature is 70°C, the reaction time is 12 hours, and after the reaction is completed, a modified carvacrol containing an unsaturated group is obtained;

[0068] (4) After mixing octamethyldihydrogen tetrasiloxane, modified carvacrol containing an unsaturated group and allyl polyether in a molar ratio of 1:0.8:1, nitrogen protection is introduced, and after stirring for 40 minutes, 6 ppm of chloroplatinic acid catalyst is added, the reaction temperature is controlled at 125° C., the reaction time is 7 hours, and after the reaction is completed, the reaction product carvacrol modified silicone is obtained; wherein the allyl polyether is selected from a polyether in which R is a hydroxyl group and a is equal to 6;

[0069] (5) The obtained carvacrol-modified silicone and ethoxy-modified decamethyl pentasiloxane were mixed in a ratio of 8:2 to obtain an insecticide adjuvant (preparation process as shown in Figure 4 ).

[0070] Example 4

[0071] The present invention provides a method for preparing a carvacrol-modified compound, comprising the following specific steps:

[0072] (1) In a three-necked flask, 4-vinyl cyclohexene oxide is added to carbon tetrachloride and stirred thoroughly, and then Br2 is added dropwise under low temperature, wherein the molar ratio of 4-vinyl cyclohexene oxide to Br2 is 1:1.2, and the volume of carbon tetrachloride accounts for 50% of the reaction system; the specific operation steps are: 4-vinyl cyclohexene oxide is fully dissolved in carbon tetrachloride, and the reaction temperature is controlled below 5°C in an ice-water bath, and a mixed solution of I2 and carbon tetrachloride is added dropwise. After sufficient shaking, the mixture is placed in a dark place and kept at 4°C for 2.5 hours. After the reaction is completed, the mixture is washed with water, and after the organic layer is dried, the solvent is evaporated under reduced pressure to obtain white crystals, namely bromocyclohexene oxide;

[0073] (2) Add white crystalline bromocyclohexane and carvacrol in a molar ratio of 1.1:1.3 into a three-necked flask, and dissolve them with N,N-dimethylformamide. The mass ratio of bromocyclohexane, carvacrol and N,N-dimethylformamide is 284:180:146. Add potassium hydroxide to adjust the pH of the system to 8.5. Control the reaction temperature at 110°C and react for 3 hours. After the reaction, obtain modified carvacrol.

[0074] (3) Add 5 times the mass of zinc powder (the average particle size of zinc powder particles is controlled to be 6-9 um) to the above-mentioned modified carvacrol, add anhydrous ethanol twice the mass of zinc powder, and add zinc bromide as a dehalogenation agent with a total system mass fraction of 1.2%. The dehalogenation reaction temperature is 125°C, and the reaction is carried out for 2 hours. After the reaction is completed, modified carvacrol containing unsaturated groups is obtained;

[0075] (4) After mixing octamethyldihydrogen tetrasiloxane, modified carvacrol containing an unsaturated group and allyl polyether in a molar ratio of 1:0.6:1, nitrogen protection is introduced, and after stirring for 30 minutes, 3 ppm of chloroplatinic acid catalyst is added, the reaction temperature is controlled at 120° C., the reaction time is 7.5 hours, and after the reaction is completed, the reaction product carvacrol modified silicone is obtained; wherein the allyl polyether is selected from a polyether in which R is butyl and a is equal to 4;

[0076] (5) The obtained carvacrol-modified silicone and ethoxy-modified decamethyl pentasiloxane were mixed in a mass ratio of 8.5:1 to obtain an insecticide adjuvant (preparation process as shown in Figure 4 ).

[0077] Application Examples

[0078] Test subject: Citrus spider mite (red spider)

[0079] Test time: insect population reduction rate 1-3 days after medication

[0080] Test agent: 20% Emamectin benzoate and Ethioxazole

[0081] Auxiliary agents: New substances in Examples 1 and 3 and commercially available Momentive Silwet 819

[0082] Test treatment ratio:

[0083] ① Example 1 diluted 2000 times

[0084] ② Example 1 diluted 2000 times + 20% Emamectin Benzoate·Ethioxazole SC diluted 2000 times

[0085] ③ Example 3 diluted 2000 times + 20% Emamectin Benzoate·Ethioxazole SC diluted 2000 times

[0086] ④ Momentive Silwet819 diluted 3000 times + 20% Emamectin Benzoate·Ethioprine SC diluted 2000 times

[0087] ⑤20% Emamectin Benzoate and Ethioxazole SC diluted 2000 times

[0088] ⑥Blank

[0089] Related results can be found in Figure 1 ;

[0090] Test subject: Corn aphid

[0091] Test time: insect population reduction rate 1-3 days after medication

[0092] Test agent: 10% imidacloprid

[0093] Auxiliary agents: New substances in Examples 1-4 and commercially available Momentive Silwet 819

[0094] Test treatment ratio:

[0095] ① Example 2 diluted 3000 times

[0096] ② Example 2 diluted 3000 times + 10% imidacloprid diluted 3000 times

[0097] ③ Example 4 diluted 3000 times + 10% imidacloprid diluted 3000 times

[0098] ④ Momentive Silwet819 diluted 3000 times + 10% imidacloprid diluted 3000 times

[0099] ⑤10% Imidacloprid diluted 3000 times

[0100] ⑥Blank

[0101] Related results can be found in Figure 2 ;

[0102] Test object: Rose thrips

[0103] Test time: insect population reduction rate 1-3 days after medication

[0104] Test agent: 25% thiamethoxam

[0105] Auxiliary agents: New substance in Example 4 and commercially available Momentive Silwet 819

[0106] Test treatment ratio:

[0107] ① Example 4 diluted 1000 times

[0108] ② Example 4 diluted 1000 times + 25% thiamethoxam diluted 1000 times

[0109] ③Momentive Silwet819 diluted 1000 times + 25% thiamethoxam diluted 1000 times

[0110] ④25% thiamethoxam diluted 1000 times

[0111] ⑤Blank

[0112] Related results can be found in Figure 3 ;

[0113] Depend on Figure 1-3 It can be seen that the product has a significant effect of reducing the insect population compared with the blank, and compared with the commercially available products, the drug effect of the present invention is more durable, and the drug effect is more durable as the dilution multiple increases.

[0114] The various embodiments are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to in detail.

[0115] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one 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 present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A carvacrol-modified compound, characterized in that: The carvacrol-modified compound is carvacrol-modified silicone, and the structural formula is as follows: Wherein, R is at least one of hydroxyl, methyl, butyl and hydrogen, and a is an integer of 3-20.

2. The method for preparing a carvacrol-modified compound according to claim 1, characterized in that: The specific steps include: (1) subjecting carvacrol and halogenated epoxycyclohexane to a ring-opening reaction to obtain modified carvacrol; (2) catalyzing the modified carvacrol to undergo an elimination reaction to obtain a modified carvacrol containing an unsaturated group; (3) subjecting the modified carvacrol containing an unsaturated group, a low molecular weight hydrogen-containing siloxane and an allyl polyether to an addition reaction to obtain a carvacrol-modified compound, i.e., a carvacrol-modified silicone; The process is as follows:

3. The method for preparing a carvacrol-modified compound according to claim 2, characterized in that: The molar ratio of carvacrol to the halogenated epoxycyclohexane in step (1) is 1.1:1-1.3; The base is potassium hydroxide and / or tetramethylethylenediamine, and the pH of the solution is adjusted to 8-10; The heating temperature is 90-120° C. and the heating time is 3-12 hours.

4. The method for preparing a carvacrol-modified compound according to claim 3, characterized in that: The preparation method of the halogenated epoxycyclohexane described in step (1) is: Allyl cyclohexyl oxide and halogen are subjected to addition reaction to obtain halogenated cyclohexyl oxide; The process is as follows:

5. The method for preparing a carvacrol-modified compound according to claim 4, characterized in that: The halogen is Br2 or I2; The molar ratio of the allyl cyclohexene oxide to the halogen is 1:1 to 1.3; The parameters of the addition reaction are: reaction at below 5° C. for 2-4 hours.

6. The method for preparing a carvacrol-modified compound according to claim 2, characterized in that: The mass ratio of the modified carvacrol to the catalyst in step (2) is 1:1-15; The catalyst is zinc and / or magnesium powder; The parameters of the elimination reaction are: reaction at 70-130° C. for 2-12 hours.

7. The method for preparing a carvacrol-modified compound according to claim 2, characterized in that: In step (3), the molar ratio of the modified carvacrol containing an unsaturated group, the low molecular weight hydrogen-containing siloxane and the allyl polyether is 0.6-1:1:0.6-1; The catalyst is a chloroplatinic acid catalyst, and the addition amount is 3-10ppm; The parameters of the addition reaction are: reaction at 120-135° C. for 6-7.5 h.

8. Use of the carvacrol-modified compound according to claim 1 or the carvacrol-modified compound obtained by the preparation method according to any one of claims 2 to 7 in the field of insecticide.

9. The use according to claim 8, characterized in that: The carvacrol modified compound and the ethoxy modified polysiloxane are mixed and used as an insecticide auxiliary agent.

10. The use according to claim 8, characterized in that: The insect is at least one of spider mites, aphids, thrips, plant hoppers and borers.

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