A compound containing a selenosulfide structure and its uses in medicine and pesticides

Abstract

The present invention relates to a compound containing a selenosulfide structure and its uses in medicine and pesticides. The compound containing a selenosulfide structure of the present invention has strong inhibition against a variety of 3C proteins, has good anti-CVB3 myocarditis virus activity, has good anti-agricultural plant virus activity, insecticidal activity and anti-agricultural pathogenic fungal activity. It can be used to prepare medical antiviral drugs, as well as agricultural plant antiviral agents, agricultural insecticides or agricultural fungicides.

Description

Technical Field

[0001] The present invention relates to a compound containing a selenosulfide structure and its use in the preparation of pharmaceuticals and pesticides, and more particularly to a compound containing a selenosulfide structure and its use in the preparation of pharmaceuticals for preventing virus infections caused by 3C proteins, as well as its use in the preparation of agricultural antiviral agents, agricultural insecticides, and agricultural fungicides. Technical Background

[0002] Among the Group VIA elements, sulfur has been widely used in human production and life. Among them, organic sulfur compounds play an important role in the fields of medicine and pesticides. Due to its long research history, the synthesis methods and biological effects of organic sulfur compounds are relatively clear. Compounds containing a disulfide structure, such as Compound A, exhibit herbicidal effects by inhibiting plant acetolactate synthase AHAS (Wang WM, et al. Bioorg. Med. Chem. Lett., 2013, 23, 3723 - 3727). Compound B shows strong inhibitory effects on the main protease of SARS-CoV (Wang L, et al., Eur. J. Med. Chem., 2017, 137, 450 - 461). Compound C shows inhibitory effects on myocarditis virus (Zhang Lixin, Wang Jianguo, et al., Chinese Invention Patent, CN 105640951B).

[0003]

[0004] However, for selenium, another Group VIA element, due to its low abundance in the earth's crust (five parts per hundred million), there is relatively little research on selenium-containing compounds, especially on organoselenium compounds. In recent years, the excellent biological activities of organoselenium compounds have been gradually discovered, and their important research value has also been gradually revealed (Jain and Priyadarsini, Organoselenium Compounds in Biology and Medicine, Royal Society of Chemistry, 2018, PDF eISBN: 978 - 1 - 78801 - 190 - 7). In 2020, Rao Zihe and others found that ebselen and disulfiram exhibited anti-SARS-CoV-2 virus activity by inhibiting the main protease of the new coronavirus (Jin Z, et al.. Nature, 2020, 582(7811), 1 - 9), which further stimulated the research on selenium-containing drugs. The simultaneous introduction of selenium and sulfur elements into the molecular skeleton by forming an ether bond between a selenium atom and a sulfur atom has rarely been reported in the literature. Therefore, compounds containing a selenosulfide structure have extremely broad research space in the fields of medicine and pesticides. Summary of the Invention

[0005] The object of the present invention is to provide a compound containing a selenosulfide structure and its uses in the preparation of pharmaceuticals and pesticides, particularly its use in the preparation of pharmaceuticals for combating virus infections by 3C proteins, as well as its uses in the preparation of antiviral agents for agricultural plants, agricultural insecticides, and agricultural fungicides.

[0006] A kind of compound containing a selenosulfide structure of the present invention is

[0007]

[0008]

[0009]

[0010]

[0011] The compound containing a selenosulfide structure of the present invention is obtained through the following reaction formula

[0012] For condition A, it refers to the condition where ebselen and its derivatives or analogs are used as raw material 1, and substituted benzenethiol (or naphthalenethiol) is used as raw material 2. In this case, raw material 1 is dissolved in dichloromethane or diethyl ether, and then raw material 2 is added for stirring at room temperature. The reaction is completed in about 30 minutes to 1 hour, and the target compound 3 is obtained through purification by column chromatography.

[0013] For condition B, it refers to the condition where selenocyanate is used as raw material 1, and substituted benzenethiol (or naphthalenethiol) is used as raw material 2. In this case, raw material 1 is dissolved in dichloromethane solution, a trace amount of Al2O3 is added, and then raw material 2 is added for stirring at room temperature. The reaction is completed in about 30 minutes, and the target compound 3 is obtained through purification by column chromatography.

[0014] Through in vitro enzyme inhibition activity research, the compound containing a selenosulfide structure of the present invention has good inhibitory effects on coxsackievirus B3 3C protease CVB3-3C, enterovirus 71 3C protease EV71-3C, SARS-CoV main protease SARS-CoV-Mpro, and SARS-CoV-2 main protease SARS-CoV-2-Mpro, and its IC 50 value can reach 0.11 μM.

[0015] Through antiviral activity research on cell models, the compound containing a selenosulfide structure of the present invention has good inhibitory effects on coxsackievirus B3 CVB3, and its IC 50 value can reach 1.8 μM, and it has low normal cell toxicity. The selectivity index (i.e., the IC 50 value for inhibiting normal cells and the IC for inhibiting CVB3 virus-infected cells50 The ratio of the values) is relatively high, and it has biosafety.

[0016] Through the research on agricultural antiviral activity, the compound with a selenium sulfide structure in the present invention has a good in-vivo inactivation effect on tobacco mosaic virus (TMV) at a concentration of 500 μg / mL, and its inhibition rate can reach 47.3%.

[0017] Through the experimental research on agricultural insecticidal activity, the compound with a selenium sulfide structure in the present invention has a good control effect on Mythimna separata and Ostrinia furnacalis at a concentration of 200 μg / mL, and its insecticidal activity can reach 100%. It has a good prevention effect on mosquito larvae at a concentration of 5 g / mL, and its insecticidal activity can reach 100%.

[0018] Through the research on the in-vitro inhibitory activity against agricultural fungi, the compound with a selenium sulfide structure in the present invention has a good control effect on Alternaria solani, Gibberella zeae, Magnaporthe oryzae, Phytophthora capsici, Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum f. sp. cucumerinum, Cercospora arachidicola, Physalospora piricola, Rhizoctonia cerealis, Bipolaris maydis, Colletotrichum orbiculare and Gibberella fujikuroi at a concentration of 50 μg / mL, and its bactericidal activity can reach 83.3%.

[0019] Through the research on the in-vivo control activity against Puccinia sorghi, the compound with a selenium sulfide structure in the present invention has an in-vivo control efficacy of 70% against Puccinia sorghi at a concentration of 200 μg / mL.

[0020] The present invention also provides a drug for preventing and treating infections of Coxsackievirus B3 (CVB3), Enterovirus 71 (EV71), Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This drug exerts its effect by inhibiting the 3C protease or main protease of the relevant virus.

[0021] This medical antiviral drug may contain the above-mentioned compound with a selenium sulfide structure and one or more pharmaceutically acceptable carriers. The carriers include conventional diluents, excipients, fillers, binders, wetting agents, disintegrants, absorption promoters, surfactants, adsorption carriers, lubricants and synergists in the pharmaceutical field, etc. This drug can be used in the form of injections, tablets, pills, capsules, suspensions or emulsions.

[0022] The present invention also provides an agricultural insecticide, which can control agricultural pests, especially Mythimna separata, mosquito larvae and Ostrinia furnacalis, at an effective dose.

[0023] The present invention also provides an agricultural fungicide, which has good control efficacy against agricultural pathogenic bacteria at an effective dose, especially good control efficacy against early blight of tomato, scab of wheat, rice blast, Phytophthora blight of pepper, sclerotinia rot of rape, gray mold of cucumber, sheath blight of rice, fusarium wilt of cucumber, brown spot of peanut, apple ring rot, sheath blight of wheat, southern leaf blight of maize, anthracnose of watermelon, and bakanae disease of rice.

[0024] The present invention also provides an agricultural antiviral agent, which has good control efficacy against tobacco mosaic virus (TMV) at an effective dose.

[0025] The agricultural insecticide, agricultural fungicide or agricultural antiviral agent may contain the compound with the above selenium sulfide structure, as well as one or more agriculturally acceptable carriers and salts. Its dosage form is emulsifiable concentrate, wettable powder, soluble powder, emulsion in water, microemulsion, aqueous solution, suspending agent, microcapsule or water dispersible granule. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1A is the single crystal structure diagram of compound WHL-16 (a mixed crystal), Figure 1B is the single crystal structure diagram of compound WHL-88. DETAILED DESCRIPTION OF THE INVENTION

[0027] The substantial features of the present invention can be embodied in the following examples, but these examples are only for illustration and do not limit the present invention.

[0028] The raw material 1 used in the present invention is the following compound (the numbers below are the corresponding CAS numbers):

[0029]

[0030] The compounds listed in raw material 1 are purchased from Aurora Chemicals Company in the United States and Chemhere Chemicals Company in Hong Kong, China.

[0031] The raw material 2 used in the present invention is the following compound (the numbers below are the corresponding CAS numbers):

[0032]

[0033] The compounds listed in raw material 2 are purchased from Tianjin Prisbio Technology Co., Ltd., Tianjin Solomon Biotechnology Co., Ltd., Shanghai Titan Technology Co., Ltd., Guangzhou Jiangshun Chemical Technology Co., Ltd., Beijing Innochem Technology Co., Ltd. and Tianjin Nankai District An Zaisheng Laboratory Equipment Distribution Center.

[0034] Example 1. Synthesis of Compound WHL-1

[0035]

[0036] Add ebselen (CAS No. 60940-34-3, 0.275 g, 1.0 mmol) to a 25 mL round-bottom flask, then add 5 mL of dichloromethane as the solvent. Subsequently, add p-fluorothiophenol (CAS No. 371-42-6, 0.128 g, 1.0 mmol), and stir at room temperature for 1 hour (monitored by TLC). Purify by column chromatography, eluting with n-hexane / ethyl acetate (v / v = 10 / 1) to obtain a total of 0.17 g of the light yellow target compound, with a yield of 41.9%.

[0037] Similarly, compounds WHL-2, WHL-3, WHL-4, WHL-5, WHL-6, WHL-7, WHL-8, WHL-9, WHL-10, WHL-11, WHL-12, WHL-13, WHL-14, WHL-15, WHL-16, WHL-17, WHL-18, WHL-19, WHL-20, WHL-21, WHL-25, WHL-26, WHL-27, WHL-28, WHL-29, WHL-30, WHL-31, WHL-32, WHL-33, WHL-34, WHL-35, WHL-36, WHL-37, WHL-38, WHL-39, WHL-40, WHL-41, WHL-42, WHL-43, WHL-44, WHL-45, WHL-46, WHL-47, WHL-48, WHL-49, WHL-50, WHL-51, WHL-52, WHL-53, WHL-54, WHL-55, WHL-56, WHL-57, WHL-58, WHL-59, WHL-60, WHL-61, WHL-62, WHL-63, WHL-64, WHL-65 and WHL-66 can be synthesized.

[0038] Example 2. Synthesis of Compound WHL-22

[0039]

[0040] Add p-methoxy-substituted ebselen (CAS No. 81943-91-1, 0.305 g, 1.0 mmol) to a 25 mL round-bottom flask, then add 5 mL of ether as the solvent. Subsequently, add p-fluorothiophenol (CAS No. 371-42-6, 0.128 g, 1.0 mmol), and stir at room temperature for 30 minutes (monitored by TLC). A precipitate forms in the solution, and filtering gives 0.238 g of the white target product, with a yield of 55.4%.

[0041] Similarly, compounds WHL-23 and WHL-24 can be synthesized.

[0042] Example 3. Synthesis of Compound WHL-67

[0043]

[0044] Add o-cyanobenzoate (CAS No. 78337-05-6, 0.241 g, 1.0 mmol) to a 25 mL flask and dissolve it in 5 mL of dichloromethane. Add a trace amount of aluminum oxide and p-methylthiophenol (CAS No. 10486-08-5, 0.124 g, 1.0 mmol). Stir at room temperature for 30 minutes (monitored by TLC). After the reaction is completed, purify it by column chromatography and elute with n-hexane / ethyl acetate (v / v = 100 / 1) to obtain 0.172 g of the white target compound with a yield of 52.9%.

[0045] Similarly, compounds WHL-68, WHL-69, WHL-70, WHL-71, WHL-72, WHL-73, WHL-74, WHL-75, WHL-76, WHL-77, WHL-78, WHL-79, WHL-80, WHL-81, WHL-82, WHL-83, WHL-84, WHL-85, WHL-86, WHL-87, WHL-88, WHL-89, WHL-90 and WHL-91 can be synthesized.

[0046] The physical and chemical data and structural characterization data of compounds WHL-1 to WHL-91 are shown in Table 1.

[0047] Table 1. Physical and Chemical Data and Spectral Characterization of WHL-1 to WHL-91

[0048]

[0049]

[0050]

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058]

[0059]

[0060]

[0061]

[0062]

[0063]

[0064]

[0065]

[0066] Example 4. Determination of the inhibitory activity of the compound against the 3C protease of coxsackievirus B3 (CVB3)

[0067] The total volume of each well in this test model is 50 μL, including CVB3 3C protease solution (final concentration 2.3 μM), substrate solution (final concentration 25 μM), and PBS-BSA buffer (2×PBS buffer supplemented with 2 mg / mL BSA and 5.85 mg / mL NaCl). The concentration of each compound is in a two-fold gradient, and the final concentration of the compound is 0 - 200 μM. At the same time, a negative control (without CVB3 3C protease) and a blank group (DMSO) are set, and positive controls AG7088 and rupintrivir are also set. Each group has 3 parallels. After mixing, incubate at 37 °C for 60 minutes, and then read the fluorescence value with a Spectra max GEMINI xps fluorescence microplate reader. The excitation wavelength is 340 nm, and the emission wavelength is 490 nm. Subtract the value of the blank group from the value of each well to obtain the true value, and calculate the inhibition rate of the compound against the 3C protease. The inhibition rate calculation formula is inhibition rate (%) = 100 × (negative control - value of the test compound group) / negative control. At the same time, calculate its IC 50 value.

[0068] Similarly, the inhibitory activities of enterovirus EV71 3C protease, SARS-CoV 3C protease, and SARS-CoV-2 3C protease can be determined, and the control drugs used are AG7088, ML18, GC376, and ebselen respectively.

[0069] The inhibitory activity data of the compound against the 3C enzyme are shown in Table 2.

[0070] Table 2. IC 50 values (μM) of some compounds inhibiting four 3C proteases such as CVB3 3C

[0071]

[0072]

[0073]

[0074] As can be seen from Table 2, the compounds containing selenoether structure provided by the present invention exhibit inhibitory activity against several 3C proteases, and some compounds have strong inhibitory effects, and the strongest IC 50 reaches 0.11 μM.

[0075] Example 5. Determination of the inhibitory activity of the compound against coxsackievirus B3 (CVB3) and the selectivity index

[0076] Compound pretreatment:

[0077] (1) The test compound and the positive compound are prepared into a 100 mM solution with DMSO.

[0078] (2) The test compound is serially diluted with the virus growth medium to concentrations of 200 μM, 66.7 μM, 22.2 μM, 7.4 μM, 2.5 μM, 0.8 μM, 0.3 μM, and 0.1 μM.

[0079] Virus preparation:

[0080] CVB3 virus is a recombinant virus generated by the 12-plasmid system using reverse genetics method, and the virus is stored in the Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences.

[0081] HeLa cells are cultured in DMEM medium containing 10% (v / v) fetal bovine serum and 1% antibiotics, and the culture conditions are normal culture in a 37 °C, 5% CO2 incubator, and passaged every other day.

[0082] Determination of the cytotoxic activity of the compound:

[0083] The cytotoxic activity of the compound is tested by the cell proliferation inhibition assay method. The principle is that dehydrogenase in the mitochondria of living cells can metabolically reduce yellow 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide to purple-blue water-insoluble formazan, and the amount of formazan can be determined by measuring its absorbance with an enzyme-linked immunosorbent assay (ELISA) reader. The amount of formazan is proportional to the number of living cells, so the number of living cells can be calculated according to its absorbance, thereby obtaining the ability of the drug to kill cells.

[0084] Using the MTT method, HeLa cells in the logarithmic growth phase are digested with trypsin to prepare a cell suspension containing 2×10 5A single-cell suspension of cells was inoculated into a 96-well plate (100 μL per well), and 3 parallel tests were set for each group. After reacting at 37 °C for 24 hours, 1 μL of the compound sample solution at different concentrations above (dissolved in DMSO, drug administration group) was added and cultured for 48 hours. At the same time, a blank control group was set (blank control: 1 μL DMSO). Then, 20 μL of DMEM solution containing MTT (5 mg·L -1 ) was added, and after culturing for another 4 hours, 150 μL of DMSO was added to dissolve the formazan after removing the culture medium, and its absorbance was measured at 490 nm to calculate the inhibition rate (%) of the target compound.

[0085] Formula for calculating the inhibition rate (%): (1 - OD value of the drug administration group / OD value of the blank control group) × 100%.

[0086] Calculate the IC 50 value: IC 50 = [C L (I H - 50) + C H (50 - I L )] / (I H - I L )

[0087] C L : Low concentration value; C H : High concentration value; I H : Inhibition rate at high concentration; I L : Inhibition rate at low concentration.

[0088] Screening for antiviral activity of compounds:

[0089] Take Hela cells in the logarithmic growth phase, digest them with trypsin, and prepare a single-cell suspension containing 2×10 5 cells per milliliter. Inoculate it into a 96-well plate (100 μL per well), and set 3 parallel tests for each group. After culturing at 37 °C for 24 hours, the test compound was diluted according to a 3-fold dilution gradient, and the virus growth solution was diluted to concentrations of 200 μM, 66.7 μM, 22.2 μM, 7.4 μM, 2.5 μM, 0.8 μM, 0.3 μM, and 0.1 μM, a total of 8 concentrations. Remove the culture medium from the 96-well plate, and then add 100 μl of high-glucose DMEM medium containing 2% FBS to each group. Take out the virus seed stock stored at -80 °C, equilibrate it at room temperature, and then dilute the virus seed stock to 100 TCID 50, Take 50 μL of each sample and add it to the cells in the above 96-well plate, and add an equal volume of virus growth medium as the control group. Take 50 μL of each concentration of the compound and add it to the 96-well plate respectively to make the final volume in the well 200 μL. At the same time, add an equal volume of virus growth medium to the cell and virus control groups. Incubate at 37 °C for a certain period of time, and record the cytopathic effect every day. Under light-proof conditions, mix the chemiluminescent cell viability detection reagent Buffer with the substrate. Discard the culture medium. After the plate is dry, add 100 μL of the detection reagent to the detection wells and shake for 5 min to induce cell lysis. After stabilizing for 2 min in the dark, measure the chemiluminescence units using the preset program.

[0090] Compound anti-encephalomyocarditis virus CVB3 plaque assay:

[0091] Digest the Hela cells in the logarithmic growth phase with trypsin to prepare a single-cell suspension containing 2×10 5 cells per milliliter, and inoculate it into a 96-well plate (100 μL per well), with 3 parallel tests set for each group. After culturing at 37 °C for 24 hours, add CVB3 solution (MOI = 0.2, MOI: the ratio of virus to cells during infection), and do not add virus to the blank control wells. Absorb for one hour. Then add 1 μL of the above different concentration target compound solutions (dissolved in DMSO, drug administration group) for culture. At the same time, set up a blank control group (1 μL DMSO, blank control group) and a positive control ribavirin group. Take the supernatant of each well at different time points for hemagglutination test. Add 50 μL of the above-mentioned supernatant taken out to the first column of the 96-well V-bottom hemagglutination plate, serially dilute it with PBS, and then add 25 μL of 1% red blood cell suspension. Shake and mix well on a micro oscillator and place it at room temperature for 30 - 45 minutes, and observe and record the results. Result representation: The hemagglutination titer is the reciprocal of the highest dilution at which complete hemagglutination occurs.

[0092] Normal cells can uptake vital dyes during metabolism; when infected with a virus, the cells will lose the ability to uptake the dye and become colorless cell plaques, commonly known as "plaques". In this experiment, the plaque method was used to determine the virus titer: After the Hela cells reached 95% density, they were transfected with different concentrations of CVB3 virus for 1 h, washed with PBS, and added with DMEM containing 1.5% low melting point agarose and 2 mg·L -1 of TPCK-treated trypsin, and the plaques were counted after culturing for 3 days, and the PFU / mL of the virus was calculated. PFU / Ml = average number of plaques / (dilution factor * amount of virus used).

[0093] Selectivity index (SI) = IC 50 value of cytotoxicity / IC 50 value of anti-CVB3. The data on the anti-CVB3 activity and cytotoxicity of the compounds are shown in Table 3.

[0094] Table 3. IC of compounds against CVB3 50 Value (μM) and selectivity index SI

[0095]

[0096]

[0097]

[0098] It can be seen that many compounds of the present invention show better inhibitory effects on CVB3 than ribavirin, and the selectivity index SI is also higher. The most representative compound is WHL-71, which has an activity 6.83 times higher than ribavirin, but its SI is 15.1 (close to ribavirin).

[0099] It is reasonable to speculate that the compounds of the present invention will also have anti-enterovirus EV71 activity, anti-SARS virus SARS-CoV activity and anti-new coronavirus SARS-CoV-2 activity.

[0100] Example 6. Determination of the Anti-Tobacco Mosaic Virus TMV Activity of Compounds

[0101] Virus purification and concentration determination were carried out in accordance with the SOP specification for tobacco mosaic virus compiled by the Laboratory of the Institute of Element Analysis of Nankai University. The crude virus extract was centrifuged twice with polyethylene glycol, the concentration was determined, and refrigerated at 4°C for later use. After weighing the target compound, the original drug was added to DMF to dissolve and 1×10 5 μg / mL mother solution, and then diluted to 500μg / mL with 1‰ Tween 80 aqueous solution; Ningnanmycin preparations were directly diluted with water. Select Sansi tobacco with uniform growth at the 3-5 leaf stage, mix the agent with an equal volume of virus juice and passivate for 30 minutes, then rub and inoculate, the virus concentration is 20μg / mL, rinse with running water after inoculation, repeat 3 times, set 1‰ Tween 80 aqueous solution as control. Count the number of lesions after 3 days to calculate the in vivo passivation effect.

[0102] Inhibition rate (%) = [(number of control necrosis spots - number of treated necrosis spots) / number of control necrosis spots] × 100%

[0103] The anti-TMV activity results of the compound and the control drugs ribavirin and ningnanmycin are shown in Table 4.

[0104] Table 4. In vivo passivation control effect of some compounds on TMV at 500 μg / mL

[0105]

[0106]

[0107] It can be seen that the compounds of the present invention have good in vivo inactivation control effects against tobacco mosaic virus TMV. Among them, the control effects of compounds WHL-6, WHL-13, WHL-33, WHL-44, WHL-47, WHL-50, WHL-53, WHL-56, WHL-57, WHL-58 and WHL-74 are better than that of the commercial agent ribavirin at a concentration of 500 μg / mL.

[0108] Example 7. Determination of insecticidal activity of compounds

[0109] The test insects were Mythimna separata Walker, Culex pipiens pallens and Ostrinia nubilalis Hubner.

[0110] A) Insecticidal activity against Mythimna separata: A normal population of Mythimna separata reared in the laboratory. By the leaf-dipping method, the corn leaves were dipped in the liquid medicine prepared with acetone. After the liquid medicine dried, the 3rd instar Mythimna separata larvae were introduced. It mainly has stomach poisoning and contact killing effects, and the feeding phenomenon of Mythimna separata larvae was observed. The mortality was checked after 72 hours. The lethality of the test target compound against Mythimna separata larvae was evaluated in the form of percentage (0-100%), where 0% indicates no insecticidal effect on Mythimna separata, and 100% means complete killing.

[0111] B) Insecticidal activity against Culex pipiens pallens larvae: A normal population of Culex pipiens pallens larvae reared in the laboratory. Ten 3rd instar Culex pipiens pallens larvae were selected and placed in the solution with the required concentration of the target compound. The treatment placed in a 100 mL beaker was put into the standard treatment room, and the mortality was checked after 72 hours. The blank control was an aqueous solution containing 1 mL of the test solvent. The lethality of the test target compound against Culex pipiens pallens larvae was evaluated in the form of percentage (0-100%), where 0% indicates no insecticidal effect, and 100% means complete killing.

[0112] C) Insecticidal activity against Ostrinia nubilalis: A normal population of Ostrinia nubilalis reared in the laboratory. The test method was also the leaf-dipping method.

[0113] The insecticidal activity results of some compounds are shown in Table 5.

[0114] Table 5. Insecticidal activities of some compounds against mosquito larvae, Mythimna separata and Ostrinia nubilalis

[0115]

[0116]

[0117]

[0118] *NT indicates no test.

[0119] It can be seen that the compounds of the present invention have good insecticidal activity, especially good effects on mosquito larvae and armyworms. Among them, the insecticidal effects of compounds WHL-4, WHL-25, WHL-36, WHL-67 and WHL-79 on mosquito larvae can reach 100% at a concentration of 5 μg / mL. The insecticidal effect of compound WHL-2 on armyworms is 100% at a concentration of 2005 μg / mL.

[0120] Example 8. Determination of bactericidal activity of compounds

[0121] The test fungi are Alternaria solani Sorauer., Phytophthora capsica., Sclerotinia sclerotiorum., Botrytis cinerea., Physalospora piricola., Rhizoctonia cerealis., Fusarium graminearum schw., Fusarium oxysporum (Schl.) F. sp cucumerinum Owen., Cercosporaarachidicola., Helminthosporium maydis., Thanatephorus cucumeris (Frank) Donk., Pyricularia oryzae Cav., Fusarium moniliforme Sheld., Colletotrichumorbiculare., and Puccinia sorghi.

[0122] Except for the Puccinia sorghi, the in vitro antibacterial activity of the target compounds was determined, with chlorothalonil as the control, and the room temperature was maintained at 25 ± 1°C.

[0123] The in vitro antibacterial activity was tested by the mycelial growth rate method. The target compound was dissolved in DMSO to prepare a solution with a concentration of 3.0×10 4 mg·L -1 and then diluted to 50 mg·L with Tween solution -1Test solution of concentration. Under aseptic conditions, take 1.0 mL of the test solution to be measured and add it to 9 mL of PDA medium. Inoculate the test strain, and set the medium with 1 mL of sterilized water added as a blank control. After culturing the medium in a constant temperature incubator at 25 ± 1 °C for 72 h, measure the colony diameter (D), and calculate the inhibition rate according to the following formula.

[0124]

[0125] Test method for corn rust: The experiment adopted the spray method on living corn seedlings. Weigh each compound, dissolve it with a quantitative amount of DMSO, and then add a 1‰ Tween 80 solution to prepare a test solution of the target compound with the required concentration. The test corn seedlings were cultured in the phytotron of Nankai University. When they reached the 3 - 4 leaf stage, the whole plant was sprayed. The spraying volume per time was 3 mL, and the treatment was repeated 3 times. The spraying pressure was set at 0.7 kg·cm -2 , and the spraying distance was 15 cm.

[0126] After 24 h of treatment with the medicament, spray inoculate a spore suspension of 5×10 5 per mL until the whole corn leaf shows a water - soaked state. Culture it under dark and humidity - maintaining conditions for 24 h, and then transfer it to the greenhouse environment for normal cultivation. After 6 - 7 d, when the disease develops significantly, investigate the results.

[0127] The results of the investigation were recorded using a grading method, with "100" representing no disease and "0" representing the most severe disease severity.

[0128] The bactericidal activities of the compounds are shown in Table 6 and Table 7.

[0129] Table 6. Inhibitory effects (%) of target compounds on agricultural disease - causing fungi at a concentration of 50 μg / mL

[0130]

[0131]

[0132] In the table, A represents cucumber fusarium wilt, B represents peanut brown spot, C represents apple ring rot, D represents wheat sheath blight, E represents corn southern leaf blight, F represents watermelon anthracnose, G represents rice bakanae disease, H represents tomato early blight, I represents wheat scab, J represents rice blast, K represents pepper phytophthora blight, L represents rape sclerotinia rot, M represents cucumber gray mold, N represents rice sheath blight. NT indicates not tested.

[0133] It can be seen that most of the compounds of the present invention have good inhibitory effects on crop disease - causing fungi, and the bactericidal rate of some compounds at a concentration of 50 μg / mL > 75%. Accordingly, we determined the EC 50 values of the bacteriostasis of some highly active compounds, and the results are shown in Table 7.

[0134] Table 7. EC50 values (μg / mL) of antibacterial activity of some highly active compounds

[0135]

Claims

1. A compound containing a selenosulfide structure, characterized in that The compound is 2. Use of a compound with a selenosulfide structure as described in claim 1 in the preparation of a drug for preventing infection by myocarditis virus CVB3, enterovirus EV71, SARS virus SARS-CoV, and novel coronavirus SARS-CoV-2.

3. Use of a compound with a selenosulfide structure as described in claim 1 in the preparation of an antiviral agent for agricultural plants.

4. Use of a compound with a selenosulfide structure as described in claim 1 in the preparation of an agricultural insecticide.

5. Use of a compound with a selenosulfide structure as described in claim 1 in the preparation of an agricultural fungicide.

6. A medical antiviral drug, characterized in that It contains a compound with a selenosulfide structure as described in claim 1 and one or more pharmaceutically acceptable carriers; the carriers include conventional diluents, excipients, fillers, binders, wetting agents, disintegrants, absorption promoters, surfactants, adsorption carriers, lubricants, or synergists in the pharmaceutical field.

7. An antiviral agent for agricultural plants, characterized in that It contains a compound with a selenosulfide structure as described in claim 1 and one or more pesticide-acceptable carriers; the carriers include conventional diluents, excipients, fillers, binders, wetting agents, disintegrants, absorption promoters, surfactants, adsorption carriers, lubricants, or synergists in the pharmaceutical field.

8. An agricultural insecticide, characterized in that It contains a compound with a selenosulfide structure as described in claim 1 and one or more pesticide-acceptable carriers; the carriers include conventional diluents, excipients, fillers, binders, wetting agents, disintegrants, absorption promoters, surfactants, adsorption carriers, lubricants, or synergists in the pharmaceutical field.

9. An agricultural fungicide, characterized in that It contains a compound with a selenosulfide structure as described in claim 1 and one or more pesticide-acceptable carriers; the carriers include conventional diluents, excipients, fillers, binders, wetting agents, disintegrants, absorption promoters, surfactants, adsorption carriers, lubricants, or synergists in the pharmaceutical field.

10. The medical antiviral drug according to claim 6, characterized in that It is an injection, tablet, pill, capsule, suspension, or emulsion containing the above-mentioned medical antiviral drug.

11. The agricultural plant antiviral agent according to claim 7, characterized in that Its dosage form is emulsifiable concentrate, wettable powder, soluble powder, emulsion in water, microemulsion, aqueous solution, suspension, microcapsule, or water-dispersible granule.

12. The agricultural insecticide according to claim 8, wherein Its dosage form is emulsifiable concentrate, wettable powder, soluble powder, emulsion in water, microemulsion, aqueous solution, suspension, microcapsule, or water-dispersible granule.

13. The agricultural fungicide according to claim 9, characterized in that Its dosage form is emulsifiable concentrate, wettable powder, soluble powder, emulsion in water, microemulsion, aqueous solution, suspension, microcapsule, or water-dispersible granule.

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