Diazole thioformate compound as well as preparation method and application thereof

Abstract

The invention relates to a diazole thioformate compound as well as a preparation method and application thereof. The compound has a structure as shown in (I): # imgabs0 #, an oxadiazole (thiadiazole) structure is taken as a basis, a thioformate structure with biological activity is introduced into the structure, a series of novel oxadiazole (thiadiazole) thioformate compounds are synthesized, and the compound has a wide application prospect on various common fungal diseases of crops, such as crop diseases, crop diseases and crop diseases. The composition has obvious prevention and treatment effects on cucumber gray mold, sclerotinia rot of colza, rice blast and the like. The compound disclosed by the invention shows wide antibacterial activity and has a remarkable inhibition effect on various bacteria.

Description

Technical Field

[0001] The present invention relates to the technical field of medicinal chemistry, and in particular to an oxa(thia)diazole compound containing a thiocarboxylate fragment, and a preparation method and application thereof. Background Art

[0002] With the development of global agriculture, the occurrence of microbial diseases of crops has become increasingly serious, causing huge losses to agricultural production. Although traditional agricultural fungicides can control the occurrence of diseases to a certain extent, long-term and large-scale use is likely to lead to problems such as the generation of drug resistance in pathogens, excessive pesticide residues, and environmental pollution. Therefore, the development of new, highly efficient, low-toxic, and environmentally friendly agricultural fungicides has become a research hotspot in the field of agricultural pest control. Laccase is a copper-containing polyphenol oxidase that widely exists in fungi and participates in processes such as the growth, development, metabolism, and pathogenicity of fungi. Research shows that inhibiting the activity of laccase can effectively interfere with the normal physiological metabolism of fungi, thereby achieving the purpose of sterilization. Therefore, the development of new laccase inhibitors as new agricultural fungicides has broad application prospects.

[0003] The research progress of laccase inhibitors is as follows:

[0004] In 2023, Yang et al. [Z. Yang, X. Sun, Y. Qiu, D. Jin, Y. Zheng, J. Li, W. Gu, J. Agric. Food Chem. 2023, 71, 14151.] optimized compound 4b based on Todiscovery natural products and showed the most effective inhibitory activity (EC 50 = 1.28 mg / L), which is much higher than the positive control chlorothalonil. In addition, compound 4b showed potential laccase inhibitory effect with an IC 50 value of 11.3 μM, which is better than the positive control cysteine. Molecular binding studies showed that compound 4b forms multiple interactions through key residues in the laccase pocket, which can effectively inhibit the activity of laccase. Compound 4b has great potential to be developed into a new laccase-targeted fungicide.

[0005] In 2023, Wu et al. [H. Wu, X. Lu, J. Xu, X. Zhang, H. Xu, Z. Li, C. Hou, X. Yang, Y. Ling, J. Agric. Food Chem. 2023, 71, 11026.] designed and synthesized a series of N-acyl-1,2,3,4-tetrahydroquinoline (NATHQ) derivatives, which were formed by connecting the active substructure NATHQ part in aspergillin with the O-benzyl oxime ether scaffold in commercial agrochemicals. Compound 3j showed good laccase inhibitory activity (73.2% at 200 mg / L). Molecular docking indicated that the dicyano oxime ether part of compound 3j exhibited an excellent binding mode with the laccase target protein and could serve as a lead compound for the development of laccase inhibitors. The structural features of these NATHQ derivatives will provide inspiration for the development of laccase inhibitors and the discovery of more effective fungicides to control agricultural diseases.

[0006] In 2023, Chang et al. [J. Chang, Y. Liu, T. Zhang, Z. Chen, H. Fang, X. Hua, J. Agric. Food Chem. 2023, 71, 8297.] reviewed the applications of the structures of targeted inhibitors and their derivative structures in the field of agricultural sterilization. It mainly involved laccase inhibitors, succinate dehydrogenase inhibitors, and targeting the plasma membrane. Finally, based on the structural analysis of novel fungicidal lead compounds, the structure-activity relationship of the derivatives was constructed, and the development trend of the structure in fungicidal applications was prospected. This review can provide some meaningful guidance for the future development of novel laccase inhibitors.

[0007] In 2022, Zhang et al. [X. Zhang, H. Xu, H. Su, X. Yang, T. Sun, ×. Lu, F. Shi, H. Duan, X. Liu, Y. Ling, J. Agric. Food Chem. 2022, 70, 1776.] reported that laccase is a new target for fungicides. We previously developed a new fungicide, 4-chlorocinnamaldehyde thiosemicarbazide (PMDD-5Y), as a laccase inhibitor. Introducing the active groups of natural products into the framework of the pesticide molecular structure is an effective method for discovering active lead compounds and has applications in the discovery of new pesticides. In this work, PMDD-5Y was selected as the lead compound, and a series of novel sulfonylhydrazide derivatives containing the natural product scaffold 1,2,3,4-tetrahydroquinoline were designed and synthesized. The new compounds exhibited antifungal activities against several fungi, especially Valsa mali and Sclerotinia sclerotiorum. One compound (4b1) showed very good in vitro activities against Sclerotinia sclerotiorum and Valsa mali, EC 50The values were 3.32 and 2.78 μg / mL respectively. The results of enzyme activity assay showed that the inhibitory activity against laccase was the best at 48 h, and the EC50 value was 14.85 μg / mL. This was more active than the lead compound PMDD-5Y and the positive control cysteine. By the molecular docking method, we studied the binding mode of the title compound with laccase. The structural features of these novel laccase inhibitors as fungicides will advance the research and influence the field of discovering more effective fungicides to control agricultural diseases. SUMMARY OF THE INVENTION

[0008] One object of the present invention is to provide an oxa(thia)diazole compound or its stereoisomer, or its salt or its solvate.

[0009] Another object of the present invention is to provide intermediate compounds for preparing the above-mentioned compound or its stereoisomer, or its salt or its solvate and their preparation methods.

[0010] Another object of the present invention is to provide a composition containing the above-mentioned compound or its stereoisomer, or its salt or its solvate.

[0011] Another object of the present invention is to provide the use of the above-mentioned compound or its stereoisomer, or its salt or its solvate, or the said composition.

[0012] Another object of the present invention is to provide a method for controlling agricultural pests and diseases by using the above-mentioned compound or its stereoisomer, or its salt or its solvate, or the said composition.

[0013] To achieve the above objects, the present invention adopts the following technical solutions:

[0014] An oxa(thia)diazole compound or its stereoisomer, or its salt or its solvate, and the compound has a structure shown in the general formula (I):

[0015]

[0016] Among them, the general formula compound (I) can be represented by the following structure:

[0017]

[0018] Wherein A is selected from oxygen or sulfur, and Q is a single bond, methylene or -A-CH2-;

[0019] R1 is selected from one or more of hydrogen, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, hydroxy, amino, cyano, nitro, aryl, heteroaryl.

[0020] Preferably, A is selected from oxygen or sulfur; R1 is selected from one or more of hydrogen, halogen, methyl, ethyl, propyl, n-butyl, sec-butyl, isobutyl, tert-butyl, methoxy, ethoxy, methylthio, ethylthio, trifluoromethyl, and trifluoromethoxy.

[0021] By adopting the above technical solution, based on the oxadiazole (thiadiazole) compounds, the thiocarboxylate unit capable of improving the biological activity of the target compound is introduced into this system, and a series of oxadiazole (thiadiazole) compounds containing thiocarboxylate are synthesized. The application of the compound shown in Formula I is its application in the preparation of fungicides or in the preparation of laccase inhibitors. And it is found that this compound has good inhibitory effects on phytopathogenic fungi, and has good inhibitory effects on pathogenic fungi such as Aspergillus flavus, Botrytis cinerea of cucumber, Colletotrichum gloeosporioides of blueberry, Sclerotinia sclerotiorum of rapeseed, Magnaporthe oryzae of rice, and Alternaria solani of tomato, providing an important scientific basis for the research and development of new pesticides. Examples

[0022] The present invention will be further described below through examples. It should be understood that the methods described in the embodiments of the present invention are only used to illustrate the present invention, rather than limiting the present invention. Any simple improvement of the preparation method of the present invention under the premise of the concept of the present invention belongs to the scope protected by the present invention. All raw materials and solvents used in the examples are commercially available products of corresponding purity.

[0023] Example 1: Preparation of 5-(4-fluorophenyl)-1,3,4-oxadiazole-2-thiol

[0024] Weigh p-fluorobenzohydrazide (1.00 g, 6.49 mmol), add it to 20 mL of absolute ethanol, add carbon disulfide (0.74 g, 9.73 mmol), stir at room temperature for 5 h, and then heat to 85 °C and react for 8 h. Filter and purify, wash with ethanol, collect the solid, and dry it to obtain 5-(4-fluorophenyl)-1,3,4-oxadiazole-2-thiol.

[0025] Example 2: Preparation of 5-(4-fluorophenyl)-1,3,4-oxadiazol-2-yl dimethylcarbamoyl dithiocarboxylate (IA-10)

[0026] Dissolve 5-(4-fluorophenyl)-1,3,4-oxadiazole-2-thiol (0.5 g, 2.77 mmol) in 20 mL of acetonitrile, add dimethylaminothiocarbonyl chloride (0.51 g, 4.16 mmol), stir at room temperature for 8 hours, then cool to 0 °C for crystallization, and filter to obtain 0.58 g of white solid, with a yield of 78.19%.

[0027] Structure confirmation data: 1H NMR (600 MHz, CDCl3) δ 8.12 (dd, J = 8.9, 5.2 Hz, 2H), 7.24 - 7.20 (m, 2H), 3.52 (d, J = 6.6 Hz, 6H). 13C NMR (151 MHz, CDCl3) δ 188.59, 167.68, 165.99, 164.31, 157.83, 129.70, 129.64, 119.88, 116.59, 116.44, 45.41, 42.93. 19F NMR (565 MHz, CDCl3) δ -105.81.

[0028] 1 1H NMR spectral data are listed in Table 1, and the appearance, melting point and yield of some compounds of Formula I are listed in Table 2.

[0029] For the synthesis of other target compounds, the corresponding raw materials or substituents were selected and prepared with reference to Examples 1 - 2.

[0030] Table 1 NMR data of the compounds of the present application

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] Table 2 Physicochemical properties of the compounds of the present application

[0039]

[0040]

[0041] Pharmacological Example 1:

[0042] The mycelial growth rate method was used for the primary screening to test the inhibition rate of the target compounds against plant pathogenic bacteria. The test objects were Aspergillus flavus, Botrytis cinerea, Colletotrichum gloeosporioides, Sclerotinia sclerotiorum, Magnaporthe oryzae, and Alternaria solani. The pathogen fungus cakes were inoculated into PDA medium and cultured in an incubator at 28 °C for 48 h before use. The compounds were dissolved in dimethyl sulfoxide to prepare a drug solution with a concentration of 20000 μg / mL for standby. Take 0.5 mL of the standby drug solution and mix it with 199 mL of PDA medium to prepare a toxic medium with a concentration of 50 μg / mL. Pour it into a petri dish with a diameter of 90 cm, about 15 - 20 mL per dish. After it solidifies, inoculate the activated pathogenic fungal cake and place it in an incubator at 25 °C for culture. Dimethyl sulfoxide was used as the solvent control, and sterile water was used as the blank control. Each sample was repeated 3 times. The above operations were strictly aseptic. After the blank control colony grew fully, the colony diameter of each treatment was measured by the cross method, and the average value was taken. Calculate the mycelial growth inhibition rate according to the following formula. The experimental results of the target compounds are shown in Table 3:

[0043] Mycelial growth inhibition rate (%) = [(control colony growth diameter - treated colony growth diameter) / control colony growth diameter] × 100%

[0044] Table 3 In vitro bactericidal activity data of some compounds of this application (50 μg / mL)

[0045]

[0046]

[0047] Table 4 EC of in vitro antifungal activity data of the compounds of this application 50

[0048]

[0049] As can be seen from Tables 3 and 4, some of the compounds of Formula I provided by the present invention have certain inhibitory activities against the 6 plant pathogenic bacteria tested. At a concentration of 50 μg / mL, the inhibition rates of multiple compounds against Aspergillus flavus, Botrytis cinerea, Colletotrichum gloeosporioides, Sclerotinia sclerotiorum, Magnaporthe oryzae, and Alternaria solani exceed 80%. The inhibition rates of compounds IA - 8, IA - 10, and IA - 11 against Aspergillus flavus are 100%; the inhibition rates of compounds IA - 1, IA - 4, IA - 8, IA - 10, and IA - 11 against Botrytis cinerea are 100%. Compound IA - 8 showed good inhibitory activity against Botrytis cinerea (B.c), and the EC 50 is 0.33 μg / mL, which is close to the commercial drug thiram. For Aspergillus flavus (A.f), compound IA - 4 has good activity, and the EC 50 is 1.55 μg / mL. For Magnaporthe oryzae (Mo), compound IA - 8 has significant activity, and the EC50 was 1.44 μg / mL, superior to the control drug isoprothiolane (EC 50 = 15.71 μg / mL). Based on the significant antibacterial activity of this class of compounds, they can be used to develop and manage agricultural diseases.

[0050] Pharmacological Example 2:

[0051] Inhibitory activity of the compounds of this application against laccase:

[0052] Pure laccase from Coriolus versicolor was purchased from Sigma-Aldrich to determine the inhibition rate of the target compounds against laccase. 120 μL of citric acid-phosphate buffer was added to a 96-well plate at one time, 20 μL of DMSO / PMDD-5Y / target compound with concentration gradients of 50 μg / mL, 40 μg / mL, 35 μg / mL, 25 μg / mL, 20 μg / mL, and 12.5 μg / mL in sequence, 40 μL of pure laccase with an enzyme activity of 0.02 U / mL, and 20 μL of 2,6-dimethoxyphenol (a specific substrate of laccase) with a concentration of 2 mmol / L; at 25 °C, oscillated at 468 nm, and the change value of absorbance within 20 minutes was measured. Each sample was repeated 3 times, and the inhibition rate was calculated. The inhibition rate was calculated according to the following formula:

[0053] Inhibition rate (%) = (△ODn - △ODi) / △ODn × 100%

[0054] Among them, △ODn is the change value of absorbance within 20 minutes of the blank control, and △ODi is the change value of optical density within 20 minutes after treatment with the inhibitor.

[0055] Table 4 Laccase activity of some compounds of this application

[0056]

[0057] As shown by the results in Table 4, some of the formula IA and IB compounds provided by the present invention have good inhibitory activity against the tested laccase from Coriolus versicolor. The IC 50 values of all tested compounds in the IA-10 series against the laccase from Coriolus versicolor are superior to those of the lead PMDD and cysteine, indicating that IA-10 has the best ability to inhibit laccase, providing a new idea for the development of new targeted laccase inhibitors to manage agricultural diseases.

Claims

1. A diazole compound, or a salt, stereoisomer, solvate thereof, characterized in that: The compound has a structure shown in general formula (I): Wherein, A is selected from oxygen or sulfur, and Q is a single bond, methylene or -A-CH2-; R1 is selected from one or more of hydrogen, alkyl, alkoxy, alkylthio, haloalkyl, haloalkoxy, hydroxyl, amino, cyano, nitro, aryl, heteroaryl.

2. The 1,2,4-oxadiazole compound according to claim 1, or a salt, stereoisomer, or solvate thereof, characterized in that: A is selected from oxygen or sulfur; R1 is selected from one or more of hydrogen, halogen, methyl, ethyl, propyl, n-butyl, sec-butyl, isobutyl, tert-butyl, methoxy, ethoxy, methylthio, ethylthio, trifluoromethyl, trifluoromethoxy, hydroxyl, amino, cyano, nitro.

3. The 1,2,4-oxadiazole compound according to claim 1, or a salt, stereoisomer, or solvate thereof, characterized in that Selected from the following specific compounds:

4. An intermediate compound for preparing the 1,2,4-oxadiazole compound or its stereoisomer, or its salt or its solvate as claimed in claim 1, characterized in that As shown below: Wherein A, Q and R1 are as described in any one of claims 1-3.

5. A process for preparing the diazole compound or its stereoisomer, or its salt or its solvate according to claim 1, characterized in that Including: Compound Steps for preparing the compound shown in general formula (I) with dimethylaminothiocarbonyl chloride; Further, it further includes: Steps for preparing carbon disulfide ; Most preferably, the following steps are further included: Wherein A, Q and R1 are as described in any one of claims 1-3.

6. A composition, characterized in that Containing the oxadiazole compound or its stereoisomer, or its salt or its solvate as claimed in claim 1, and an agriculturally acceptable adjuvant or fungicide, insecticide or herbicide; the dosage form of the composition is selected from emulsifiable concentrate, powder, wettable powder, granule, aqueous solution, suspension, ultra-low volume spray, soluble powder, microcapsule, smoke agent, emulsion in water, water dispersible granule.

7. Use of the oxadiazole compound or its stereoisomer, or its salt or its solvate as claimed in any one of claims 1-3, or the composition as claimed in claim 6 in controlling agricultural diseases, wherein the agricultural pests and diseases are plant fungal and bacterial diseases; most preferably, the agricultural pests and diseases are Botrytis cinerea of cucumber, Sclerotinia sclerotiorum of rape, Magnaporthe oryzae of rice, Xanthomonas oryzae pv. oryzae of rice, Colletotrichum gloeosporioides of blueberry, Alternaria solani of tomato, Aspergillus flavus, Rhizoctonia solani of rice, Xanthomonas campestris pv. cucurbitae of cucumber, Xanthomonas campestris pv. conglutinans of konjac, Xanthomonas axonopodis pv. citri of citrus, Neofusicoccum parvum of grape, Clavibacter michiganensis subsp. michiganensis of tomato, Pseudomonas syringae pv. actinidiae of kiwifruit, Pseudomonas syringae pv. mali of apple, Pseudomonas syringae pv. mangiferaeindicae of mango, Fusarium oxysporum f. sp. vasinfectum of pepper, Gibberella zeae of wheat, Phytophthora infestans of potato, Phytophthora cinnamomi of blueberry.

8. A method for preventing and controlling agricultural pests and diseases, characterized in that: To make the oxadiazole compound or its stereoisomer, or its salt or its solvate as claimed in any one of claims 1-3, or the composition as claimed in claim 6 act on the harmful substances or their living environment; the agricultural pests and diseases are plant fungal diseases and plant bacterial diseases; the agricultural diseases are Botrytis cinerea of cucumber, Sclerotinia sclerotiorum of rape, Magnaporthe oryzae of rice, Xanthomonas oryzae pv. oryzae of rice, Colletotrichum gloeosporioides of blueberry, Alternaria solani of tomato, Aspergillus flavus, Rhizoctonia solani of rice, Xanthomonas campestris pv. cucurbitae of cucumber, Xanthomonas campestris pv. conglutinans of konjac, Xanthomonas axonopodis pv. citri of citrus, Neofusicoccum parvum of grape, Clavibacter michiganensis subsp. michiganensis of tomato, Pseudomonas syringae pv. actinidiae of kiwifruit, Pseudomonas syringae pv. mali of apple, Pseudomonas syringae pv. mangiferaeindicae of mango, Fusarium oxysporum f. sp. vasinfectum of pepper, Gibberella zeae of wheat, Phytophthora infestans of potato, Phytophthora cinnamomi of blueberry.

9. A method for protecting plants from agricultural diseases, which includes a method step of bringing the plants into contact with the oxadiazole compound or its stereoisomer, or its salt or its solvate as claimed in any one of claims 1-3, or the composition as claimed in claim 6.

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