Application of compound in prevention and control of plant pathogenic fungus fusarium oxysporum

Abstract

The invention discloses application of a compound to prevention and control of plant pathogenic fungus fusarium oxysporum, and belongs to the technical field of agricultural disease prevention and control. The compound is 3-[1-(1H-benzimidazole-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl] ethyl propionate. According to the invention, it is found for the first time that the 3-[1-(1H-benzimidazole-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl] ethyl propionate has a relatively strong inhibition effect on plant pathogenic fungus fusarium oxysporum; experiments show that the compound has a median inhibitory concentration IC50 of 25.2 [mu] g / mL on fusarium oxysporum, and compared with other bactericides, the compound has the advantages of high efficiency, low toxicity and low residue, has better environmental compatibility, and meets the requirements of green plant protection and sustainable agricultural production and the needs of development.

Description

Technical Field

[0001] This invention belongs to the field of agricultural disease control technology, specifically relating to the application of a compound in the control of plant pathogenic fungus Fusarium oxysporum. Background Technology

[0002] Fusarium oxysporum ( Fusarium oxysporum Fusarium oxysporum is a filamentous fungus widely found in soil, possessing extremely strong adaptability and genetic diversity, and is one of the most important plant pathogens worldwide. This fungus can invade plants through the roots, rapidly multiplying in the vascular bundles, causing vascular blockage and systemic wilting, earning it the nickname "vascular bundle killer." It is currently known to infect more than 200 plant species, including many important economic crops such as tomatoes, cucumbers, watermelons, bananas, and soybeans. Because its chlamydospores can survive for extended periods in the soil, coupled with its strong genetic variation and rapid development of drug resistance, it poses a significant challenge to traditional agricultural and chemical control methods. Therefore, finding novel, highly effective, and low-toxicity compounds to kill Fusarium oxysporum has become a crucial direction urgently needed in the field of plant disease control. Summary of the Invention

[0003] The first objective of this invention is to provide an application of a compound in controlling the plant pathogenic fungus Fusarium oxysporum; the second objective is to provide a composition for controlling the plant pathogenic fungus Fusarium oxysporum; and the third objective is to provide a fungicide for controlling the plant pathogenic fungus Fusarium oxysporum.

[0004] The first objective of this invention is achieved by providing the application of a compound in controlling the plant pathogenic fungus *Fusarium oxysporum*, wherein the compound is ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate, and its chemical structural formula is as follows: ; The compound has an IC50 effect on Fusarium oxysporum. 50 It is 25.2 μg / mL.

[0005] The second objective of this invention is achieved by providing a composition for controlling the plant pathogenic fungus Fusarium oxysporum, wherein the composition uses ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate as an active ingredient or one of the active ingredients.

[0006] The third objective of this invention is achieved by providing a fungicide for controlling the plant pathogenic fungus Fusarium oxysporum, wherein the fungicide is a compound of the above-mentioned composition and conventional pesticide adjuvants.

[0007] The compound ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate was purchased from MCE (MedChem Express). This invention is the first to discover that ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate exhibits strong inhibitory activity against the plant pathogenic fungus *Fusarium oxysporum*. Experiments showed that the half-maximal inhibitory concentration (IC50) of this compound against *Fusarium oxysporum* was [value missing]. 50 With a concentration of 25.2 μg / mL, it has the advantages of high efficiency, low toxicity and low residue compared with other fungicides, and better environmental compatibility, meeting the requirements and needs of green plant protection and sustainable agricultural production. Attached Figure Description

[0008] Figure 1 The chemical structural formula of ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate; Figure 2 The results show the inhibition of Fusarium oxysporum by ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate in the experimental example. Detailed Implementation

[0009] The present invention will be described in more detail below with reference to experimental examples and embodiments. However, the present invention is not limited thereto. Any modifications or improvements based on the present invention should be covered within the protection scope of the present invention.

[0010] The application of the compound of this invention in the control of plant pathogenic fungus Fusarium oxysporum, wherein the compound is ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate, and its chemical structural formula is as follows: ; The compound has an IC50 effect on Fusarium oxysporum. 50 It is 25.2 μg / mL.

[0011] The composition for controlling the plant pathogenic fungus Fusarium oxysporum of the present invention uses ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate as an active ingredient or one of the active ingredients.

[0012] Furthermore, the effective concentration of ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl]propionate in the composition is ≥30 μg / mL.

[0013] Furthermore, the composition includes cyclohexanone and water or dimethyl sulfoxide and water.

[0014] Furthermore, the composition contains 4% to 20% cyclohexanone or dimethyl sulfoxide by mass fraction.

[0015] The fungicide for controlling plant pathogenic fungus Fusarium oxysporum of the present invention is composed of the above-mentioned composition and conventional pesticide adjuvants.

[0016] Furthermore, the bactericide is available in the form of an aqueous solution, an emulsion, a wettable powder, a soluble powder, a soluble granule, a suspension, a tablet, or an effervescent granule.

[0017] The compound described in this invention, ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propanoate, is derived from the 50K Diversity Library (Catalog Number HY-Q09245), a drug-likeness diversity library containing 50,000 compounds developed by MedChem Express. It has no CAS number yet. Its relative molecular mass is 314.35, and its mass-to-charge ratio (m / z) is 314.14 (100.0%), 315.14 (17.6%), 316.14 (2.3%), and 315.13 (1.5%). Its chemical structure is as follows: Figure 1 As shown; the following tests were conducted based on ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate: Test case 1. Preparation of test solution 1-1. Test solutions for the experimental groups: 0.5 mg to 1.5 mg of ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl]propionate (hereinafter referred to as technical grade) was dissolved in DMSO and diluted with water to obtain test solutions of different concentrations. The concentrations of technical grade in the test solutions of each experimental group were 7.858 μg / mL, 15.717 μg / mL, 31.434 μg / mL, 62.868 μg / mL, 125.736 μg / mL, 241.472 μg / mL, and 502.944 μg / mL, respectively. The content of DMSO in the test solutions of each experimental group was 20% (mass fraction). 1-2. Control group solution: 20% DMSO aqueous solution.

[0018] 2. Preparation of bacterial suspension for experiment 2-1. Preparation of PDA solid culture medium and PDB liquid culture medium: Take 200g of potatoes, add 1L of water and boil for 30min. Filter the extract through four layers of gauze, add 20g of glucose and 20g of agar powder, mix and add water to make up to 1L. Stir well and put it into an autoclave at 121℃ for 30min for autoclaving. After sterilization, dispense 20mL of culture medium liquid into sterile petri dishes and cool to room temperature to obtain PDA solid culture medium (i.e., PDA plates). When preparing PDA solid culture medium according to the above method, without adding agar powder, PDB liquid culture medium is obtained. 2-2. Preparation of experimental bacterial suspension: Take a PDA plate from step 2-1, and use an inoculation loop to take a small amount of *Fusarium oxysporum* suspension. Use the streak plating method to draw 3-4 consecutive parallel lines on the surface of the solid medium. Then, invert the plate and incubate it in a constant temperature incubator at 28-30℃. After 24 hours of incubation, check the PDA plate for contamination. If there is no contamination, take a well-grown mycelial block, invert it, and inoculate it onto a new PDA plate. Incubate at 28-30℃ in the dark until the hyphae evenly spread to about half the surface area of ​​the PDA plate. Take a small amount of activated *Fusarium oxysporum* hyphae and inoculate them into PDB liquid medium. Incubate for 3 days in a constant temperature shaker at 28℃ and 150 rpm. After incubation, filter out the hyphae with sterile gauze, and then dilute the fungal spore suspension to 1×10⁻⁶ using a hemocytometer. 7 The bacterial solution was obtained by dispersing cfu / mL.

[0019] 3. Test methods 3-1. Experimental Groups: Take 10 μL of each of the different concentrations of the test drug solution and place them in different wells of a 96-well plate. Add 90 μL of the test bacterial culture to each well, and then incubate at 28℃ for 24 h. Observe the absorbance (OD) at 600 nm using a microplate reader. 600 At this time, the concentrations of the original drug in the experimental groups were 0.7858 μg / mL, 1.5717 μg / mL, 3.1434 μg / mL, 6.2868 μg / mL, 12.5736 μg / mL, 24.1472 μg / mL, and 50.2944 μg / mL, respectively. 3-2. Control group: Place 10 μL of control group solution into the wells of a 96-well plate, add 90 μL of experimental bacterial culture, and incubate at 28℃ for 24 h. Observe the absorbance (OD) at 600 nm using a microplate reader. 600 ; 3-3. Blank group: 100 μL of PDB liquid culture medium was placed in the wells of a 96-well plate, and then incubated at 28℃ for 24 h. The absorbance (OD) at 600 nm was then measured using a microplate reader. 600 ; 3-4. The entire experiment was set up in triplicate, and the average value of the three trials was taken. The inhibition rate was calculated using the following formula: Inhibition rate = 1 - ((experimental group OD) 600 - Blank group OD 600 ) / (Control group OD 600 - Blank group OD 600 ))× 100% 4. Test Results The inhibitory effects of different concentrations of the original drug on Fusarium oxysporum in the experimental group are shown in Table 1. Figure 2 As shown: Table 1. Inhibition rate of different concentrations of the original drug against Fusarium oxysporum

[0020] Combination Figure 2 The IC50 of compound 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate against Fusarium oxysporum was determined. 50 The effective concentration of this compound was 25.2 μg / mL, and the inhibition rate reached about 68% when the effective concentration was 50 μg / mL. It can be seen that this compound has a strong inhibitory effect on Fusarium oxysporum, and it can effectively inhibit Fusarium oxysporum when the effective concentration of the compound is ≥30 μg / mL.

[0021] Example 1: Preparation of a composition for controlling the plant pathogenic fungus Fusarium oxysporum The composition contains ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate at an effective concentration of 50 μg / mL, DMSO at 20% (mass fraction), and the remainder being water.

[0022] Example 2: Preparation of a composition for controlling the plant pathogenic fungus Fusarium oxysporum The composition contains ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate at an effective concentration of 40 μg / mL, DMSO at 4% (mass fraction), and the remainder being water.

[0023] Example 3: Preparation of a composition for controlling the plant pathogenic fungus Fusarium oxysporum The composition contains ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate at an effective concentration of 45 μg / mL, cyclohexanone at 20% (mass fraction), and the remainder is water.

[0024] Example 4: Preparation of a composition for controlling the plant pathogenic fungus Fusarium oxysporum The composition contains ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate at an effective concentration of 30 μg / mL, cyclohexanone at 4% (mass fraction), and the remainder is water.

[0025] Example 5: Preparation of a fungicide for controlling the plant pathogenic fungus Fusarium oxysporum The compositions in Examples 1-4 are prepared into aqueous solutions, emulsions, wettable powders, soluble powders, soluble granules, suspensions, tablets, or effervescent granules by conventional pesticide adjuvants using known methods.

Claims

1. The application of a compound in the control of plant pathogenic fungus *Fusarium oxysporum*, characterized in that, The compound is ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazol-4-yl]propionate, and its chemical structural formula is as follows: ； The compound has an IC50 effect on Fusarium oxysporum. 50 It is 25.2 μg / mL.

2. A composition for controlling the plant pathogenic fungus *Fusarium oxysporum*, characterized in that, The composition uses ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl]propionate as an active ingredient or one of the active ingredients as described in claim 1.

3. The composition according to claim 2, characterized in that, The effective concentration of ethyl 3-[1-(1H-benzimidazol-2-yl)-5-hydroxy-3-methyl-1H-pyrazole-4-yl]propionate in the composition is ≥30 μg / mL.

4. The composition according to claim 2 or 3, characterized in that, The composition includes cyclohexanone and water or dimethyl sulfoxide and water.

5. The composition according to claim 4, characterized in that, The composition contains 4% to 20% cyclohexanone or dimethyl sulfoxide by mass fraction.

6. A fungicide for controlling the plant pathogenic fungus *Fusarium oxysporum*, characterized in that, The fungicide is a compound of the composition described in claim 2 and conventional pesticide adjuvants.

7. The bactericide according to claim 6, characterized in that, The bactericide is available in the form of an aqueous solution, an emulsion, a wettable powder, a soluble powder, a soluble granule, a suspension, a tablet, or an effervescent granule.

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