Use of a 1H-pyrrolo[3,4-c]quinoline-1,3(2H)-dione derivative for the control of plant fungi

Abstract

This invention relates to the field of plant disease control technology, specifically disclosing a 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The application of α-dione derivatives in the control of plant fungi: These derivatives exhibit varying degrees of inhibitory activity against plant fungi such as *Sclerotinia sclerotinia*, *Rhizoctonia solani*, *Botrytis cinerea*, *Botrytis cinerea*, *Fusarium graminearum*, *Fusarium graminearum*, and *Blastomyces oryzae*. Some compounds show higher activity than the positive control drug difenoconazole. The compounds involved in this invention have a simple preparation process, use inexpensive and readily available raw materials, and exhibit excellent activity, making them promising candidates for development into novel agricultural antibacterial agents.

Description

Technical Field

[0001] This invention relates to the field of plant disease control technology, and particularly to a method 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H Uses of )-dione derivatives in the control of plant fungi. Background Technology

[0002] Fungal diseases are a major cause of crop damage and agricultural slowdown, resulting in severe plant diseases and crop yield reductions worldwide. Examples include Fusarium head blight of wheat, gray mold of tomato, rice blast fungus, and Fusarium pseudobulb. Currently, chemical fungicides with different spectrums are mainly used to control plant diseases in agricultural production. However, with the long-term and increasing use of chemical pesticides, problems such as increased fungal resistance, environmental pollution, and excessive pesticide residues are emerging. Therefore, developing new applications for antimicrobial compounds is particularly important for controlling plant pathogens. Researching and developing new, highly effective, low-toxicity, and low-residue pesticides that can effectively control plant diseases has become one of the primary goals of pesticide development.

[0003] 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H 1)-Diketone compounds contain N-substituted cyclic imide structural units, an important structural backbone and molecular building blocks for drug synthesis. Drugs with cyclic imide structures include thalidomide and its analogues—lenalidomide, pomalidomide, and ipridomide—which are known as immunomodulatory drugs (IMiDs). They bind to the cereblon (CRBN) protein and promote the degradation of IKZF1 and IKZF3 via the ubiquitination-dependent proteasome pathway. These drugs can also regulate the function of T cells and NK cells by modulating the production of cytokines, including interleukin-2 and interferon-γ. Therefore, 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketones show promise, but there are no reports of this compound being used to control agricultural pathogenic fungi. Summary of the Invention

[0004] To address the above shortcomings, this invention provides a 1 H -pyrrolo[3,4- c Quinoline-1,3(2) HA novel application of α-dione derivatives in combating agricultural pathogenic fungi: This application can be used to control diseases caused by various agricultural pathogenic fungi, such as *Sclerotinia sclerotinia* (causal agent of rapeseed rot), *Rhizoctonia solani* (causal agent of rhizoctonia solani), *Fusarium graminearum* (causal agent of wheat scab), *Gyromitra esculenta* (causal agent of tomato gray mold), *Gyromitra esculenta* (causal agent of cucumber gray mold), *Blastophytes oryzae* (rice blast fungus), and *Fusarium pseudocarpa*. The specific technical solution is as follows: A type 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The use of )-dione derivatives in the control of plant fungi, wherein the 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives are selected from any of the following: , , , , , .

[0005] Preferably, the 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives are selected from any of the following: , , , .

[0006] Preferably, the plant fungus is *Sclerotinia sclerotiorum*, the causal agent of rapeseed disease. Sclerotinia sclerotiorum Rhizoctonia solani Rhizoctonia solani Fusarium head blight of wheat Fusarium graminearum Tomato gray mold Botrytis gray Gray mold of cucumber Botrytis cinerea Rice blast fungus Magnaporthe Rice and Fusarium pseudograss Fusarium pseudogramineum One or more of them.

[0007] Preferably, the plant fungus is *Fusarium graminearum*, the pathogen of wheat scab. Fusarium graminearum Tomato gray mold Botrytis cinerea Gray mold of cucumber Botrytis cinerea and Fusarium pseudograss Fusarium pseudograsses One or more of them.

[0008] The present invention also provides a pesticide composition, wherein the active ingredient is 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives, selected from any of the following: , , , , , .

[0009] Preferably, the pesticide composition is one of the following: granules, dry suspension, aqueous suspension, dispersible oil suspension, microcapsule suspension, wettable powder, emulsifiable concentrate, water emulsion, water-dispersible granules, or seed treatment agent.

[0010] Preferably, the pesticide composition further includes adjuvants selected from one or more of dispersants, wetting agents, fillers, emulsifiers, thickeners, dispersion media, disintegrants, preservatives, antifreeze agents, specific gravity regulators, defoamers, oil-phase wall materials, and aqueous-phase wall materials.

[0011] This invention relates to 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The )-dione underwent structural derivatization to obtain a series of compounds, which were then tested for their activity against plant pathogenic fungi. In vitro activity results showed that these compounds exhibited certain inhibitory activity against agricultural fungi such as *Fusarium graminearum*, with superior inhibitory effects against *Botrytis cinerea*. Some compounds showed significantly better inhibitory effects than the control drug difenoconazole, demonstrating the potential to be developed into novel antifungal drugs, particularly targeting *Botrytis cinerea*. This could fill the gap in the market for fungicides and address the current relative shortage of innovative agricultural drugs.

[0012] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention discovers 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The )-dione derivatives exhibit excellent inhibitory effects against agricultural pathogenic fungi, especially against gray mold, demonstrating excellent in vitro activity.

[0013] 2. The present invention 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives have simple structures, are easy to synthesize, and have readily available raw materials, making them potential for further development into novel agricultural fungicides. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 Intermediate I, 1 of the present invention H -pyrrolo[3,4- c Quinoline-1,3(2) H Synthetic routes for )-dione derivatives A-1~A-3, B-1~B-4, C-1~C-2. Detailed Implementation

[0016] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention are commercially available or can be prepared by existing methods.

[0017] Example 1: 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H Synthesis of )-diketone derivatives A-1~A-3, B-1~B-4, C-1~C-2 1. Synthesis of Intermediate I: Different substituted indigo was added to a reaction flask containing an aqueous solution of potassium hydroxide. The mixture was stirred until the solution became clear, and then ethyl acetoacetate was added dropwise. The mixture was stirred overnight at room temperature. After the reaction was complete, the pH of the solution was adjusted to 2 with hydrochloric acid, filtered, and dried to obtain Intermediate I as a white powder.

[0018] 2. Synthesis of A-1~A-3, B-1~B-4, and C-1~C-2: Intermediate I (1 eq), aryl amines or aliphatic amines with different substitutions (1.2 eq) were dissolved in 1,4-dioxane, and then p-toluenesulfonic acid monohydrate was added and refluxed with stirring overnight. After the reaction was complete, the reaction was quenched with water. The mixture was extracted twice with ethyl acetate, and the organic layers were combined, dried over anhydrous Na2SO4, and concentrated. The solutions were purified by silica gel (petroleum ether / AcOEt, 6 / 1v / v) column chromatography to give compounds A-1~A-3, B-1~B-4, and C-1~C-2 (yield: 50%~60%). (Reference for synthetic method:) Bioorganic Chemistry 147 (2024) 107359) 3.1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The structural characterizations of the )-dione derivatives A-1~A-3, B-1~B-4, and C-1~C-2 are shown in the table below: Table 1.1 H -pyrrolo[3,4- c Quinoline-1,3(2) H Structural characterization parameters of )-diketone derivatives A-1~A-3, B-1~B-4, C-1~C-2 Example 2: 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H Determination and Results of the Antibacterial Activity of α-dione Derivatives against Pathogenic Fungi 1. Test reagent: 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives A-1~A-3, B-1~B-4, C-1~C-2.

[0019] 2. Test strains: Fusarium graminearum (wheat scab), Botrytis cinerea (tomato gray mold), and Fusarium pseudograss (all provided by Gansu Academy of Agricultural Sciences).

[0020] 3. Antibacterial activity test: Test Method: Antibacterial activity was determined using potato dextrose agar (PDA) medium, prepared as follows: Wash and peel potatoes, weigh 200g, cut into small pieces, and boil until tender (20-30 minutes, until the potato pieces can be pierced with a glass rod). Filter through eight layers of gauze, heat, add 15g of agar, continue heating and stirring until dissolved. After the agar is completely dissolved, add 20g of glucose, stir well, cool slightly, and then add water to bring the volume to 1000ml. Dispense into Erlenmeyer flasks, stopper and seal, and sterilize at 115℃ for 2 hours. Dissolve the test reagents separately in DMSO, add them to the medium, and mix well to achieve a compound concentration of 50 μg / mL. Use an equal concentration of DMSO as a blank control, and the marketed drugs difenoconazole and isoprothiolane as positive controls. Pour plates into cool agar plates, inoculate with bacteria, and incubate at 23°C until the blank control mycelium completely covers the plates. Measure the inhibition rate of each compound. All experiments should be performed in triplicate or triplet. The inhibition rate should be calculated using the following formula: Antibacterial rate = 100% Table 2. At 50 μg / mL, 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives Inhibition rate against plant pathogenic fungi (%) Note: "-" indicates that the antibacterial activity of the compound was not determined.

[0021] As shown in Table 2, the 1 prepared by the present invention H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives all exhibited varying degrees of inhibitory activity against plant pathogenic fungi. Therefore, further activity tests were conducted on these compounds, and EC50 values ​​were calculated using SPSS software. 50 The test data for the half-maximal effective concentration (WMC) are shown in Table 3.

[0022] Table 3.1 H -pyrrolo[3,4- c Quinoline-1,3(2) H EC50 of α-dione derivatives against plant pathogenic fungi 50 Value (μg / mL) Note: "-" indicates that the antibacterial activity of the compound was not determined.

[0023] As shown in Tables 2 and 3, the portion 1 prepared by this invention... H -pyrrolo[3,4- c Quinoline-1,3(2) H The )-dione derivatives exhibited excellent inhibitory activity against *Botrytis cinerea* (tomato causal agent) and *Fusarium graminearum* (wheat scab), especially against *Botrytis cinerea*. Compounds A-3 and B-1 showed excellent inhibitory activity against *Botrytis cinerea* EC50. 50 The values ​​were 0.473 μg / mL and 0.09 μg / mL, respectively, significantly better than the positive control difenoconazole. Compound B-4 showed an EC50 value against *Botrytis cinerea*. 50 The concentration of 1.012 μg / mL is comparable to that of the positive control, difenoconazole. Therefore, this derivative has further research value and is expected to be developed into a novel antifungal drug against plant pathogens, especially against gray mold.

[0024] Example 3: 30% Compound A-3 Water Dispersible Granules Formula composition: 30% compound A-3, 8% alkyl naphthalene sulfonate formaldehyde condensate (wetting and dispersing agent), 2% sodium dodecyl sulfate (dispersing agent), 2% polycarboxylate (dispersing agent), 1% corn starch (binder), and kaolin to make up 100%.

[0025] Preparation method: Weigh each material according to the above formula, then mix the materials and pulverize them through an air jet mill. Stir evenly, granulate, dry, and sieve to obtain the water-dispersible granule product.

[0026] Example 4: 40% Compound A-3 Suspension Formulation composition: 40% Compound A-3, 8% Diisopropyl Naphthalene Sulfonate (wetting agent), 2% Sulfate Polyether Multi-component Complex (dispersant), 1% Alkylbenzene Sulfonate (dispersant), 3.5% Polymerized Carboxylate (wetting and dispersing agent), 2% Ethylene Glycol (antifreeze agent), 0.4% Magnesium Aluminum Silicate (thickener), 0.1% Xanthan Gum (thickener), 0.1% Kathon (preservative), 0.05% Organosilicon (defoamer), water to 100%.

[0027] Preparation method: Weigh each material according to the above formula. First, put compound A-3, wetting agent, dispersant and a certain amount of water into a high-speed shearing machine for shearing and mixing evenly to obtain a mixed liquid. Then, pump these mixed liquids into a sand mill ball mill and grind them with antifreeze, thickener, preservative, defoamer and the remaining water for 2 to 3 hours until the particle diameter meets the standard requirements, and the suspension product is obtained.

[0028] Example 5: 25% Compound B-4 Suspension Formulation composition: 25% Compound B-4, 5% polycarboxylate salt (wetting agent), 2% sodium lignosulfonate (dispersant), 2% phenylethyl phenylpropylphenol polyoxyethylene ether (dispersant), 1.6% block polyether (wetting and dispersing agent), 2% ethylene glycol (antifreeze agent), 0.4% magnesium aluminum silicate (thickener), 0.1% xanthan gum (thickener), 0.1% Kathon (preservative), 0.05% organosilicon (defoamer), water to 100%.

[0029] Preparation method: Same as in Example 4.

[0030] Example 6: 50% Compound B-1 Water Dispersible Granules Formulation composition: 50% compound B-1, 7.5% alkyl naphthalene sulfonate formaldehyde condensate (wetting and dispersing agent), 1% sodium dodecyl sulfate (dispersing agent), 4% modified polycarboxylate (dispersing agent), and kaolin to make up to 100%.

[0031] Preparation method: Same as in Example 3.

[0032] Example 7: 60% Compound A-2 Wettable Powder Formula composition: 60% compound A-2, 4% alkyl naphthalene sulfonate formaldehyde condensate (wetting and dispersing agent), 2% sodium dodecyl sulfate (dispersing agent), 4% modified lignosulfonate (wetting and dispersing agent), diatomaceous earth to make up 100%.

[0033] Preparation method: Weigh each material according to the above formula, then mix the materials and pulverize them through an air jet mill. Stir evenly and sieve to obtain the wettable powder product.

[0034] Example 8: Field efficacy trial 1. Experimental Design The experiment consisted of 6 treatments, each repeated 3 times, for a total of 18 plots, each plot having an area of ​​5m². 2 (1 ridge, 4m long, 1.25m wide), plots are randomly arranged, and the treatments are as follows: Treatment 1 was 30% compound A-3 water-dispersible granules (Example 3); Treatment 2 was 25% compound B-4 suspension (Example 5); Treatment 3 was 50% compound B-1 water-dispersible granules (Example 6); Treatment 4 was 60% compound A-2 wettable powder (Example 7); Treatment 5 was 10% difenoconazole water-dispersible granules (Registration Certificate PD20110749, Shandong Weifang Shuangxing Pesticide Co., Ltd.); Treatment 6 was a water control.

[0035] 2. Inoculation: On April 15, 2025, in a cucumber greenhouse at Beautiful South in Nanning, Guangxi, the cucumber leaf spraying method was used. First, the cucumber gray mold pathogen (provided by the Gansu Academy of Agricultural Sciences) was isolated and pre-cultured on PDA medium at 25℃ for 3 days. Then, 5×10⁶ spores were sprayed using a throat sprayer. 5 A conidial suspension of 1 spore / L was evenly sprayed onto the surface of cucumber leaves until the leaves were completely wetted. The temperature inside the greenhouse was 21–25℃, and the RH was >90%. Five sites were randomly selected from each plot, and 10 plants were inoculated at each site, with each site and plant labeled.

[0036] 3. Experimental method: Spraying was carried out 24 hours after inoculation. Spraying was carried out at 17:00 on April 16. The pesticide solution was prepared according to the designed dosage for each treatment (see Table 4) and the spraying volume of 30 kg per mu. The solution was sprayed evenly with a manual sprayer. Seven days later (April 23), the pesticide was sprayed a second time using the same method.

[0037] 4. Survey: Ten days after the second spraying, investigate the incidence of gray mold in cucumbers. Based on the inoculation tags, investigate 5 points in each plot, 4 plants at each point, and a total of 20 plants in each plot. 4 leaves are investigated on each plant. Record the number of diseased leaves at each level according to the following grading method, and calculate the disease index and relative control efficacy.

[0038] 5. Grading method for cucumber leaf damage (by leaf): Grade 0: No lesions; Grade 1: Three lesions on a single leaf; Grade 3: 4-6 lesions on a single leaf; Grade 5: 7-10 lesions on a single leaf; Grade 7: 11-20 lesions on a single leaf, some of which are densely clustered together; Level 9: Dense lesions on a single leaf covering more than a quarter of the leaf area.

[0039] Disease index = [∑(number of diseased leaves at each level × representative value at each level) / (total number of leaves surveyed × highest representative value)] × 100.

[0040] Relative efficacy (%) = (Control disease index - Treatment disease index) / Control disease index × 100.

[0041] Table 4. Experimental results for the control of gray mold in cucumbers As shown in the table above, the 50% compound B-1 water-dispersible granules showed the best control efficacy against cucumber gray mold at 83.01%. Following closely were the 30% compound A-3 water-dispersible granules, the 25% compound B-4 suspension concentrate, and the 60% compound A-2 wettable powder. These agents demonstrated significant advantages over the commercially available control agent, 10% difenoconazole water-dispersible granules, in controlling cucumber gray mold, and are worthy of development and application as fungicides.

[0042] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A kind of 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The use of )-dione derivatives in the control of plant fungi, characterized in that, The 1 mentioned H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives are selected from any of the following: 、 、 、 、 、 。 2. A method according to claim 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H The use of )-dione derivatives in the control of plant fungi, characterized in that, The 1 mentioned H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives are selected from any of the following: 、 、 、 。 3. A type of 1 according to claim 1 or 2 H -pyrrolo[3,4- c Quinoline-1,3(2) H The use of )-dione derivatives in the control of plant fungi, characterized in that, The plant fungi mentioned are one or more of the following: Fusarium graminearum, Botrytis cinerea, Botrytis cinerea, and Fusarium pseudograss.

4. A type of 1 according to claim 1 or 2 H -pyrrolo[3,4- c Quinoline-1,3(2) H The use of )-dione derivatives in the control of plant fungi, characterized in that, The plant fungus mentioned is gray mold.

5. A pesticide composition, characterized in that, The active ingredient is 1 H -pyrrolo[3,4- c Quinoline-1,3(2) H )-Diketone derivatives, selected from any of the following: 、 、 、 、 、 。 6. The pesticide composition according to claim 5, characterized in that, The pesticide composition is one of the following: granules, dry suspension, water suspension, dispersible oil suspension, microcapsule suspension, wettable powder, emulsifiable concentrate, water emulsion, water-dispersible granules, or seed treatment agent.

7. A pesticide composition according to claim 5 or 6, characterized in that, The pesticide composition further includes adjuvants selected from one or more of the following: dispersants, wetting agents, fillers, emulsifiers, thickeners, dispersion media, disintegrants, preservatives, antifreeze agents, specific gravity regulators, defoamers, oil-phase wall materials, and aqueous-phase wall materials.

Images