Use of 2-chloro-n-(4-chlorophenyl)acetamide for controlling plant nematodes
The insecticide and drug composition developed by using 2-chloro-N(4-chlorophenyl)acetamide has solved the problems of toxicity and environmental pollution of traditional nematicides, and achieved highly efficient and low-toxicity control of root-knot nematodes, especially the rapid killing effect on southern root-knot nematodes.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YUNNAN UNIV
- Filing Date
- 2026-01-29
- Publication Date
- 2026-05-15
AI Technical Summary
Existing chemical nematicides pose risks of high toxicity, low specificity, environmental pollution, and carcinogenicity in the control of root-knot nematodes, necessitating the development of novel, highly effective, and low-toxic nematicidal compounds.
Using 2-chloro-N(4-chlorophenyl)acetamide and its pesticide-acceptable salts as active ingredients, an insecticide and drug composition for controlling plant root-knot nematodes has been developed with an effective concentration ≥4 μg/mL. The formulations include aqueous solutions and emulsions, and it is used for the control of root-knot nematodes in southern regions.
2-Chloro-N(4-chlorophenyl)acetamide exhibits high efficacy and low toxicity against southern root-knot nematodes, with an LC50 of 2.31 μg/mL at 24 h and 2.17 μg/mL at 48 h. It can rapidly and effectively control nematodes and maintains excellent killing activity even after 72 h.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of plant root-knot nematode control technology, and relates to the application of 2-chloro-N(4-chlorophenyl)acetamide in the control of plant root-knot nematodes. Background Technology
[0002] Root-knot nematodes ( Meloidogyne (Illicium spp.) is a plant-parasitic nematode that primarily hosts vegetables such as melons, solanaceous fruits, and legumes. Typical symptoms of infection include the formation of root knots of varying sizes and densities at the plant's roots, leading to root damage and impaired absorption of water and nutrients from the soil. Consequently, the plant's leaves wither and turn yellow, flowering decreases or flowers become dry, and the number of fruits decreases or the fruits become smaller. In addition, wounds created after infection allow other bacteria and fungi to infect the plant, causing even greater damage.
[0003] Traditional chemical nematicides were once the main means of controlling root-knot nematodes. However, due to their high toxicity, low specificity, potential carcinogenic risks, and severe environmental pollution, their use has been restricted or banned. Current research and development of nematicides is shifting towards in-depth exploration of the biological characteristics of root-knot nematodes, their mechanisms of plant infection, and the mechanisms by which they develop resistance, in order to create novel, highly effective, and low-toxic nematicidal compounds. Therefore, the development of highly effective and low-toxic pesticides to kill plant root-knot nematodes has practical value and broad application prospects. Summary of the Invention
[0004] The first objective of this invention is to provide the application of 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salts in the control of plant root-knot nematodes; the second objective is to provide a plant root-knot nematode insecticide; and the third objective is to provide a pharmaceutical composition for the control of plant root-knot nematodes.
[0005] The first objective of this invention is achieved by the application of 2-chloro-N(4-chlorophenyl)acetamide and / or its agrochemically acceptable salts in the control of plant root-knot nematodes, wherein the structural formula of the 2-chloro-N(4-chlorophenyl)acetamide is shown in Formula I:
[0006] Ⅰ;
[0007] The LC50 of 2-chloro-N(4-chlorophenyl)acetamide against southern root-knot nematodes over 24 hours 50 The concentration was 2.31 μg / mL, and the LC50 concentration at 48 h was... 50 It is 2.17 μg / mL.
[0008] The second objective of the present invention is achieved in that the insecticide for controlling plant root-knot nematodes uses 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salt as an active ingredient or one of the active ingredients.
[0009] The third object of the present invention is achieved in that the pharmaceutical composition for controlling plant root-knot nematodes uses 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salt as an active ingredient or one of the active ingredients.
[0010] The 2-chloro-N-(4-chlorophenyl)acetamide described in this invention is sourced from MCE (MedChem Express). Chloramide compounds are already used in herbicides or antibacterial agents in the prior art. This invention is the first to discover that 2-chloro-N-(4-chlorophenyl)acetamide has strong toxic activity against southern root-knot nematodes, with a 24-hour median lethal concentration (LC50). 50 The median lethal concentration (LC50) was 2.31 μg / mL at 48 h. 50 With a concentration of 2.17 μg / mL, it exhibits high specificity, high efficiency, and low toxicity, providing a new lead compound for the development of pesticides to kill plant root-knot nematodes. Attached Figure Description
[0011] Figure 1 The structural formula of 2-chloro-N(4-chlorophenyl)acetamide in this invention is shown below.
[0012] Figure 2 The results show the toxicity of 2-chloro-N(4-chlorophenyl)acetamide to *Rhizoctonia solani* in the experimental example. Detailed Implementation
[0013] The present invention will be further described in detail below with reference to experimental examples and embodiments, but this does not limit the present invention in any way. Any modifications or improvements made based on the teachings of the present invention shall fall within the protection scope of the present invention.
[0014] The application of 2-chloro-N(4-chlorophenyl)acetamide and / or its agrochemically acceptable salts in the control of plant root-knot nematodes, wherein the structural formula of 2-chloro-N(4-chlorophenyl)acetamide is shown in Formula I:
[0015] Ⅰ;
[0016] The LC50 of 2-chloro-N(4-chlorophenyl)acetamide against southern root-knot nematodes over 24 hours 50 The concentration was 2.31 μg / mL, and the LC50 concentration at 48 h was... 50 It is 2.17 μg / mL.
[0017] The insecticide for controlling plant root-knot nematodes of the present invention uses 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salt as an active ingredient or one of the active ingredients.
[0018] Furthermore, the effective concentration of 2-chloro-N(4-chlorophenyl)acetamide and / or its phytochemically acceptable salts in the insecticide is ≥4 μg / mL.
[0019] Furthermore, the insecticide is applied when the southern root-knot nematode has developed into a second-instar larva.
[0020] Furthermore, the insecticide is formulated as an aqueous solution, an emulsion, a wettable powder, a soluble powder, a soluble granule, a suspension, a tablet, or an effervescent granule.
[0021] Furthermore, the solvent for the aqueous solution or water emulsion is a dimethyl sulfoxide solution with a mass fraction concentration ≤ 5%.
[0022] The pharmaceutical composition for controlling plant root-knot nematodes of the present invention uses 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salt as an active ingredient or one of the active ingredients.
[0023] The 2-chloro-N(4-chlorophenyl)acetamide described in this invention is derived from the 50K Diversity Library, a drug-like diversity compound library containing 50,000 compounds developed by MCE (MedChem Express). The Library ID is F1791-1505, the CAS Number is 3289-75-6, and the relative molecular mass is 204.05.
[0024] Test Example 2: Activity of 2-chloro-N-(4-chlorophenyl)acetamide against plant root-knot nematodes
[0025] 1. Sample preparation
[0026] 1-1. Test solutions: Dissolve 0.5~1.5 mg of 2-chloro-N-(4-chlorophenyl)acetamide in DMSO (dimethyl sulfoxide), and dilute with a 4% (w / w) aqueous solution of DMSO to prepare test solutions with concentrations of 0.2 μg / mL, 0.4 μg / mL, 1 μg / mL, 2 μg / mL, 4 μg / mL, 8 μg / mL, 16 μg / mL, and 32 μg / mL. The concentration of DMSO in each test solution is 0.4% (w / w).
[0027] 1-2. Blank control sample solution: 0.4% DMSO aqueous solution;
[0028] 1-3. Southern root-knot nematode used in the experiment: The surface mud and sand of the tomato roots infected with southern root-knot nematode were washed off with water. Then, the egg sacs of the root-knot nematode were picked up with a dissecting needle and placed in a 5 mL centrifuge tube containing 0.4 M KCl solution. The nematode was washed three times with 4 mL of sterile water, once with 1 mL of sterile penicillin-streptomycin solution, and once with 3 mL of 0.1% NaClO aqueous solution. After each wash, the nematode was briefly centrifuged at 8000 rpm for 30 seconds and the supernatant was removed to achieve the purpose of cleaning and disinfection. The washed eggs were incubated in 0.4 M ZnCl2 solution for 48 h. The second-instar larvae were collected in a 1.5 mL centrifuge tube with a pipette and enriched by briefly centrifuging at 5000 rpm for 30 seconds for later use.
[0029] 2. Test methods
[0030] 2-1. Experimental group: 100 μL of each concentration of the test drug solution was injected into a 20-well plate. 50-100 second-instar larvae of Southern Root-knot Nematodes were added to each well. The plates were treated at 25℃ for 24h, 48h, and 72h, respectively. The mortality rate of the nematodes was then observed and calculated under an optical microscope. The method for identifying nematode mortality was as follows: 1-5 drops of 5% NaCl aqueous solution were added to the well of the treatment plate. After 2 minutes, the nematodes were observed. Dead nematodes were stiff and showed no reaction when stimulated with a needle, while live nematodes curled up or twisted.
[0031] 2-2. Blank control group: 100 μL of blank control sample solution was injected into a 20-well plate. 50-100 second-instar larvae of Southern Root-knot Nematode were added to each well. The plates were then treated at 25°C for 24 h, 48 h, and 72 h, respectively. The mortality rate of the nematodes was then observed and calculated under an optical microscope.
[0032] 2-3. Both trials were repeated three times, and the average value was taken. The mortality rate of each group and the corrected mortality rate of the experimental group were calculated using the following formula:
[0033] Mortality rate % = (Number of dead nematodes / (Number of dead nematodes + Number of surviving nematodes)) × 100%;
[0034] Corrected mortality rate % = Mortality rate of the experimental group – Mortality rate of the blank control group.
[0035] 3. Test Results
[0036] 3-1. At 24h, 48h, and 72h of treatment, the mortality rates of second-instar larvae of *Strombus heterophylla* in the blank control group were 1.5%, 1.7%, and 1.7%, respectively.
[0037] 3-2. The corrected mortality rates of *Strombus heterophylla* at different concentrations of the test drug in the experimental groups at 24h, 48h, and 72h of treatment are shown in Table 1:
[0038] Table 1 Corrected mortality rate of test drug solutions at different concentrations in the experimental group
[0039]
[0040] Table 1 shows that the corrected mortality rate of 2-chloro-N(4-chlorophenyl)acetamide at a concentration of 1 μg / mL for 24 h was 13.5%, while the corrected mortality rate reached 52% at a concentration of 4 μg / mL. Figure 2 The median lethal concentration (LC50) of 2-chloro-N(4-chlorophenyl)acetamide against southern root-knot nematodes was determined. 50 The median lethal concentration (LC50) was 2.31 μg / mL at 48 h. 50 The concentration was 2.17 μg / mL; clearly, an insecticide containing 2-chloro-N(4-chlorophenyl)acetamide at a concentration ≥4 μg / mL is effective in controlling southern root-knot nematodes and exhibits rapid efficacy at low concentrations; simultaneously, Figure 2 The curves at 24h, 48h, and 72h almost overlapped, indicating that the killing activity of 2-chloro-N(4-chlorophenyl)acetamide against southern root-knot nematodes only slightly decreased after 24h of application, and it still showed excellent killing activity even at 72h.
[0041] The following are examples of preparation methods for plant root-knot nematode insecticides.
[0042] Example 1
[0043] The insecticide was prepared using a 4% (mass fraction) DMSO aqueous solution as a solvent, and the concentration of 2-chloro-N-(4-chlorophenyl)acetamide in the insecticide was 30 μg / mL.
[0044] Example 2
[0045] The insecticide was prepared using a 5% (mass fraction) DMSO aqueous solution as a solvent, and the concentration of 2-chloro-N(4-chlorophenyl)acetamide in the insecticide was 20 μg / mL.
[0046] Example 3
[0047] The insecticide was prepared using a 3% (mass fraction) DMSO aqueous solution as a solvent, and the concentration of 2-chloro-N(4-chlorophenyl)acetamide in the insecticide was 10 μg / mL.
[0048] Example 4
[0049] The insecticide was prepared using a 4% (mass fraction) DMSO aqueous solution as a solvent, and the concentration of 2-chloro-N-(4-chlorophenyl)acetamide in the insecticide was 4 μg / mL.
[0050] The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.
Claims
1. The application of 2-chloro-N(4-chlorophenyl)acetamide and / or its pesticide-acceptable salts in the control of plant root-knot nematodes, characterized in that, The structural formula of the 2-chloro-N(4-chlorophenyl)acetamide is shown in Formula I: Ⅰ； The LC50 of 2-chloro-N(4-chlorophenyl)acetamide against southern root-knot nematodes over 24 hours 50 The concentration was 2.31 μg / mL, and the LC50 concentration at 48 h was... 50 It is 2.17 μg / mL.
2. An insecticide for controlling plant root-knot nematodes, characterized in that, The active ingredient in the insecticide includes 2-chloro-N(4-chlorophenyl)acetamide as described in claim 1 and / or its pesticide-acceptable salt.
3. The insecticide according to claim 2, characterized in that, The effective concentration of 2-chloro-N(4-chlorophenyl)acetamide and / or its phytochemically acceptable salts in the insecticide is ≥4 μg / mL.
4. The insecticide according to claim 2 or 3, characterized in that, The insecticide is applied when the southern root-knot nematode has developed into a second-instar larva.
5. The insecticide according to claim 2 or 3, characterized in that, The insecticide is formulated as an aqueous solution, emulsion, wettable powder, soluble powder, soluble granules, suspension concentrate, tablet, or effervescent granules.
6. The insecticide according to claim 5, characterized in that, The solvent for the aqueous solution or water emulsion is a dimethyl sulfoxide solution with a mass fraction concentration ≤ 5%.
7. A pharmaceutical composition for controlling plant root-knot nematodes, characterized in that, The active ingredient in the pharmaceutical composition includes 2-chloro-N(4-chlorophenyl)acetamide as described in claim 1 and / or a pesticide-acceptable salt thereof.