Pyrone natural product with antifungal activity as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of medicinal chemistry and agricultural biology, and particularly relates to a pyrone natural product with antifungal activity and a preparation method and application thereof. According to the invention, a novel pyrone natural product is separated from the plant endophytic fungus Diamorpha kushuensis ZMU-48-1 for the first time, and the novel pyrone natural product can be obtained. According to the present invention, the compound has significant inhibitory activity on colletotrichum musae (Colletotrichum gloeosporioides) and colletotrichum gloeosporioides (Colletotrichum gloeosporioides), and can be used for the preparation of the compound, such that the compound has significant inhibitory activity on colletotrichum musae (Colletotrichum gloeosporioides), compared with traditional chemical synthetic fungicides, the compound has the outstanding advantages of novel structure, strong targeting property, environmental friendliness, slow resistance development and the like, has a good prospect in the field of research and development of agricultural antifungal drugs, is particularly suitable for green control of plant fungal diseases, and has important scientific research value and application value.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of pharmaceutical chemistry and agricultural biotechnology, and particularly relates to a natural product with antifungal activity, and a preparation method and application thereof. BACKGROUND

[0002] Plant fungal diseases are ubiquitous in agricultural production, and seriously threaten the yield and quality of fruits, vegetables, grains and economic crops, becoming an important factor restricting the sustainable development of agriculture. At present, the prevention and control of plant fungal diseases still mainly relies on chemical synthetic fungicides. Although these fungicides can exhibit good control effect in the short term, they generally face the problems of environmental pollution, increasing drug resistance of pathogens, and high toxicity to non-target organisms. Therefore, the development of green, safe, low-toxic and high-efficiency natural antifungal agents has become an important direction of current pesticide research and development.

[0003] Microorganisms, especially secondary metabolites derived from fungi, are an important source of natural drugs and bioactive molecules. Secondary metabolites are non-essential metabolites produced by microorganisms under specific ecological or stress conditions, which do not directly participate in cell growth and reproduction, but play an important role in biological defense, signal transduction and ecological interaction. Compared with primary metabolites, secondary metabolites have the characteristics of complex structure, strong species specificity and diverse biological activities. In recent decades, many drugs such as antibiotics (penicillin and erythromycin) and antitumor drugs (trabectedin and rapamycin) have been developed from microbial secondary metabolites, which fully demonstrates their great application potential in the fields of medicine and agriculture.

[0004] Plant endophytic fungi are a group of fungi that parasitize or symbiotically exist in the internal tissues of plants and do not cause significant diseases to the host. In the process of long-term co-evolution with host plants, these fungi usually carry rich secondary metabolism gene clusters, and thus have the potential to produce a variety of natural products with pharmacological or agricultural value. Among them, the strategy of activating the expression of metabolites by setting multiple culture conditions (i.e., the so-called OSMAC strategy) is an effective means to tap the potential of active products of plant endophytic fungi.

[0005] Pyrones are a class of natural products with a typical 2H-pyrane-2-one core structure, which are widely distributed in fungi, actinomycetes and plants. Previous studies have shown that these compounds have anti-inflammatory, antibacterial, antitumor and other biological activities. However, there is still a lack of in-depth research and industrial development in the field of agricultural anti-plant pathogenic fungi. In particular, pyrone natural products with novel structure and targeting are very scarce. Compared with traditional chemical synthesis fungicides, these natural products have more significant advantages in structural diversity, biological targeting and ecological safety. At present, although the widely used synthetic fungicides have rapid and broad-spectrum effects, long-term and large-scale use has caused a series of problems that cannot be ignored. First, most synthetic fungicides have a single mechanism of action, which can easily promote the development of drug resistance in pathogenic bacteria and reduce the field control effect. Second, some fungicides have a long residual period in the environment, which can pollute the soil, water and other ecosystems. Third, some varieties have potential toxicity to humans, animals and non-target beneficial organisms, which threatens the quality and safety of agricultural products and ecological health. Therefore, it is urgent to develop new antifungal agents with a wide range of sources, environmental friendliness, novel mechanism of action and selectivity to targets. Among them, natural compounds are considered as one of the key paths to promote the green transformation of pesticides.

[0006] Under this background, mining new pyrone secondary metabolites from plant endophytic fungi and exploring their anti-plant pathogenic fungal activity and application prospect not only can expand the molecular resource library of natural product antifungal agents, but also can provide theoretical support and practical guidance for green, efficient and sustainable pesticide research and development, which has important scientific research value and industrial transformation potential. SUMMARY

[0007] In order to overcome the shortcomings of the prior art, the present application provides a novel pyrone natural product derived from plant endophytic fungi, which has clear anti-plant pathogenic fungal activity and can provide candidate molecules with novel structure and low toxicity for the development of new, green and safe agricultural fungicides.

[0008] In order to achieve the above purpose, the technical scheme adopted by the present application is: The first aspect of the present application provides a pyrone compound with antifungal activity, and the structure of the pyrone compound is as follows: .

[0009] Preferably, the pyrone compound is derived from endophytic fungi Diaporthe kyushuensisZMU-48-1, with accession number GDMCC No: 66577, is deposited at the Guangdong Provincial Microbial Culture Collection Center on June 23, 2025. This strain was isolated from *Acacia taiwanensis* (Taiwanese acacia) on Huanglvbei Mountain, Jinwan District, Zhuhai City, Guangdong Province. Acacia confusa Colletotrichum musae In the decaying leaves of Merr.

[0010] The second aspect of this invention also provides the pyranone compounds described in the first aspect for use in the preparation of preparations of fungi that inhibit banana anthracnose ( Colletotrichum gloeosporioides ) and / or Colletotrichum candida ( Colletotrichum musae Application in agricultural fungicides that promote proliferation.

[0011] The third aspect of the present invention also provides the pyranone compounds described in the first aspect in the preparation of a preparation for the prevention and control of anthracnose caused by *Bacillus anthracis* (banana anthracnose). Colletotrichum gloeosporioides ) and / or Colletotrichum candida ( Diaporthe kyushuensis Application of pesticides in treating plant diseases caused by ).

[0012] This invention uses plant endophytic fungi Colletotrichum musae Using ZMU-48-1 as the research object, the expression of its metabolites was regulated by the OSMAC strategy, and after fermentation on rice solid medium, a novel pyranone natural product was successfully isolated and purified. This compound is effective against *Anthracis bananaans* (…). Colletotrichum gloeosporioides ) and Colletotrichum anthracnose ( Diaporthe kyushuensis Both compounds exhibited significant inhibitory activity, with minimum inhibitory concentrations (MICs) of 100 μg / mL and 80 μg / mL, respectively. Compared to traditional chemically synthesized fungicides, these natural products possess outstanding advantages such as novel structure, strong targeting, environmental friendliness, and slow resistance development. Therefore, the pyranone compounds involved in this invention show promising prospects in the field of agricultural antifungal drug development, especially suitable for the green control of plant fungal diseases, possessing both significant scientific and practical value.

[0013] A fourth aspect of the present invention also provides a pesticide formulation, wherein the pesticide formulation uses the pyranone compounds described in the first aspect as the main active ingredient.

[0014] Preferably, the pesticide formulation further includes pesticide-acceptable excipients.

[0015] More preferably, the pesticide-acceptable excipient is selected from one or more of dispersants, wetting agents, disintegrants, binders, defoamers, antifreeze agents, thickeners, fillers, and solvents.

[0016] More preferably, the pesticide formulation is in the form of a wettable powder, a water-dispersible granule, an aqueous suspension, or a dispersible oil suspension.

[0017] Compared with the prior art, the application has the beneficial effects that: The application is the first time to isolate a novel pyrone natural product from plant endophytic fungi Colletotrichum A novel pyrone natural product is isolated from ZMU-48-1, and the compound has excellent antifungal activity, and shows significant inhibitory activity on Colletotrichum musae musae Colletotrichum gloeosporioides ) and Colletotrichum gloeosporioides Figure 1 ), and has good prospects in the field of agricultural antifungal drugs, especially for green prevention and control of plant fungal diseases, and has important scientific research value and application value.

[0018] Specifically, compared with the existing chemical synthesis fungicides or known natural products, the application has the following obvious advantages: (1) novel structure: the target compound is a novel pyrone skeleton, which has outstanding structural innovation; (2) natural source: derived from plant endophytic fungi, relying on biosynthetic pathway, having the characteristics of biological renewable; (3) stable preparation: using the optimized OSMAC+ fermentation extraction process, the product can be stably and repeatedly obtained; (4) low toxicity and environmental protection: as a natural product, its biological toxicity is significantly lower, and its environmental friendliness is higher; (5) clear activity: the activity has been verified in a variety of plant pathogenic fungi models, and the antifungal activity effect is accurate.

[0019] In summary, the pyrone compound obtained by the application shows certain inhibitory activity in some plant pathogenic fungi, which fully embodies its potential as a natural lead compound. Combined with the unique structural characteristics and microbial renewable source of the compound, it not only lays a research foundation for subsequent structure optimization, activity improvement and development of green agricultural fungicide, but also further expands the application space of plant endophytic fungi in the field of biological source pesticide research and development. BRIEF DESCRIPTION OF DRAWINGS

[0020] Diaporthe kyushuensis The plant endophytic fungus ZMU-48-1 is isolated from the roots of the plant Figure 2 HPLC detection chart of metabolites of ZMU-48-1 in different culture media; Figure 3 HPLC chart of compound I; Figure 4 UV absorption spectrum of compound I; Figure 5 MIC experimental result chart of pyrone compound I and carbendazim on common plant pathogenic fungi; Diaporthe kyushuensis MIC heat map of pyrone compound I and carbendazim on common plant pathogenic fungi. DETAILED DESCRIPTION

[0021] The specific embodiments of the present application are further described below. It is to be understood that the description of these embodiments is intended to help understand the present application and is not intended to limit the present application. In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0022] The experimental methods in the following examples are all conventional methods unless otherwise specified. The test materials used in the following examples are all commercially available unless otherwise specified.

[0023] Example 1: Strain isolation and identification Endophytic fungal strain used in the present application Acacia confusa ZMU-48-1 was isolated from the sample of leaf litter of Acacia confusa Merr. collected in Jinwan District, Zhuhai City, Guangdong Province. Diaporthe kyushuensis The specific isolation steps are as follows: (1) The surface of the leaf litter was first treated with 75% ethanol for 30 seconds, then disinfected with 5% sodium hypochlorite (NaClO) for 1 minute, and then washed with clean water three times; (2) The leaf litter was sliced under sterile conditions, then inoculated into PDA medium, and cultured at 28°C for 5-7 days. After the colonies grew, single colonies were selected for purification; (3) The purified strain was subjected to ITS sequence determination. After the sequencing results were analyzed by BLAST program comparison, it was confirmed that the strain was Figure 1 ; (4) The strain was inoculated into a 50 mL centrifuge tube containing PDB liquid medium for small-scale culture. After the culture was completed, the strain genome was extracted for whole genome sequencing. The sequencing results were analyzed by antiSMASH bioinformatics tool for gene cluster analysis, and it was speculated that the secondary metabolites of the strain were mainly polyketides; (5) Finally, the strain was preserved in the Guangdong Microbial Culture Collection Center, with the preservation number of GDMCC No:66577.

[0024] Example 2: Multi-medium screening under OSMAC strategy In order to induce ZMU-48-1 strain to express different secondary metabolites, 12 different culture media were set up using OSMAC strategy, including liquid and solid systems, specifically including the following culture media: A, P, COB, MMD, ME, Gao's, PDB+0.3% NaCl, PDB+3% NaCl, PDB+0.3% NaBr, PDB+3% NaBr, PDB+3% KI, rice medium; (1) A medium: 1 g soluble starch, 0.5 g yeast extract, 0.2 g peptone, 0.2 g CaCO3, 0.004 g Fez(SO4)4H2O, 0.01 g KBr and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0025] (2) P medium: 0.2 g yeast extract, 0.4 g mannitol, 0.2 g peptone and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0026] (3) COB medium: 0.5 g multivalent peptone, 0.5 g yeast extract, 0.1 g Mg2SO47H2O, 0.05 g KH2PO4, 3 g sucrose and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and the pH was adjusted to 5.5, and sterilized at 121°C for 30 min.

[0027] (4) MMD medium: 0.5 g peptone, 0.3 g fish peptone, 2 g sucrose, 0.1 g Mg2SO4, 0.2 g KH2PO4 and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min. (5) ME medium: 0.2 g malt extract, 2 g sucrose, 0.1 g peptone and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0028] (6) Gao's medium: 2 g soluble starch, 0.1 g KNO3, 0.05 g KHPO4, 0.05 g MgSO4·7H2O, 0.001 g FeSO4·7H2O and 3 g sea salt were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0029] (7) PDB+0.3% NaCl: 2.4 g potato dextrose broth (purchased from HuanKai Microorganism, item number: 021053) and 0.3 g NaCl were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0030] (8) PDB+3% NaCl: 2.4 g potato dextrose broth and 3 g NaCl were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0031] (9) PDB+0.3% NaBr: 2.4 g potato dextrose broth and 0.3 g NaBr were weighed respectively, deionized water was added to 100 mL, and sterilized at 121°C for 30 min.

[0032] (10) PDB + 3% NaBr: 2.4 g of potato dextrose broth and 3 g of NaBr were weighed respectively, and deionized water was added to 100 mL, sterilized at 121°C for 30 min.

[0033] (11) PDB + 3% KI: 2.4 g of potato dextrose broth and 3 g of KI were weighed respectively, and deionized water was added to 100 mL, sterilized at 121°C for 30 min.

[0034] (12) Rice medium: 50 g of rice and 50 mL of 3% (w / v) sea salt aqueous solution were weighed respectively, and sterilized at 121°C for 30 min.

[0035] Among them, 2 bottles of liquid medium were inoculated and fermented at 30°C, 200 rpm for 14 days; 3 bottles of solid medium were inoculated and fermented at 28°C for 43 days.

[0036] The culture was collected, extracted with ethyl acetate, concentrated under reduced pressure, and then detected and analyzed by HPLC; D. kyushuensis The results show that the metabolites in the rice solid medium are the most abundant, and the probability of producing novel pyrone compounds is greater.

[0037] Example 3: Solid fermentation and crude extract preparation (1) 50 g of rice and 50 mL of 3% (w / v) sea salt aqueous solution were weighed respectively, and sterilized at 121°C for 30 min. Figure 2 ZMU-48-1 was inoculated in rice solid medium (50 g of rice, 50 mL of water, and 3% of sea salt per bottle); (2) Incubate at 25°C for 43 days, and then take out the solid mycelium after incubation; (3) Add anhydrous ethanol to the solid substrate at the same volume, soak and extract for 3 times (5-6 days each time), and filter and concentrate under reduced pressure each time; (4) After the concentrated extract is combined, add an appropriate amount of distilled water to fully dissolve the concentrate into a clear liquid, and then extract with an equal volume of ethyl acetate three times; (5) After combining the organic phase, concentrate under reduced pressure to obtain 66.7 g of crude extract.

[0038] Example 4: Isolation and purification of target compounds (1) Mix the crude extract with 200-300 mesh silica gel powder at a ratio of 1:1 (w / w), pack into a silica gel column, and use petroleum ether-ethyl acetate system for gradient elution (v / v), with gradients of 100:0, 90:10, 70:30, 50:50, 30:70, 10:90 and 0:100, a total of seven gradient fractions; (2) Monitor and combine similar fractions by TLC, and preliminarily obtain 7 main fractions Fr.B1~Fr.B7; (3) The Fr.B5 component (6.88 g) was subjected to gradient elution with a dichloromethane-methanol system, and the gradient was 20:1, 15:1, 10:1, 8:1, 5:1, 3:1 and 2:1 (v / v) in sequence, and seven sub-components (Fr.B5-1~Fr.B5-7) were obtained according to the gradient; (4) The Fr.B5-3 (1.2 g) was subjected to Ultimate phenyl column HPLC purification (the mobile phase was acetonitrile-water, 21:79, v / v), and the target compound was obtained.

[0039] Example 5: Structure identification of the compound 1. The structure of the obtained compound was identified by the following spectral methods: (1) 1D NMR: 1 H NMR, 13 C NMR, DEPT; (2) 2D NMR: 1 H- 1 H COSY, HSQC, HMBC; (3) High resolution mass spectrometry (HR-ESI-MS); (4) Infrared spectroscopy (IR).

[0040] The results show that the obtained compound (denoted as compound I) has a 2H-pyrane-2-ketone core mother nucleus, is novel in structure, and has not been reported in known databases or literature. The HPLC spectrum and ultraviolet absorption spectrum thereof are shown in Bipolaris sorokiniana , 3 respectively. The structural formula of the compound (6-methyl-4-hydroxy-3-(4-methoxy-4-oxobutanoyl)-2H-pyrane-2-ketone) is as follows: .

[0041] At the same time, the compound I was subjected to structure nuclear magnetic analysis, and the obtained physicochemical property data are as follows: Compound I: Brown solid; UV (MeOH) λmax (log ε) 235.4 (3.00), 274.5 (1.10) nm; IR (KBr) vmax 3365 (OH), 2929, 2899, 2864 (C–H), 2505 (COOH), 2320, 2237 (C≡C / C≡N), 2077, 1770, 1734, 1716 (C=O), 1683, 1655 (C=C), 1585, 1564, 1506 (aromatic), 1489, 1471, 1456 (CH2 / CH3), 1338, 1116, 1082 (C–O), 972, 831, 667,603, 546, 518 cm -1 ; HR-ESI-MS m / z 227.0914 [M + H] + (calcd for C 11 H 15 O5,227.0911); 1 H NMR (CD3OD, 600 MHz) and 13 C NMR (CD3OD, 150 MHz); see Table 1 for specific data.

[0042] Table 1. Compound I 1 H NMR and 13 C NMR data

[0043] Example 6: Evaluation of activity against plant pathogenic fungi This experiment used the two-fold dilution method to evaluate the MIC of compound I against nine plant pathogenic fungi. The tested strains included *Cyclophorus spp.* Valsa mali ), Apple black rot fungus ( Botryosphaeria dothidea Miyabe & G. Yamada), Staphylococcus aureus ( Carbendazim All pathogenic fungi were purchased from Beijing Baosai Biotechnology Co., Ltd., and the positive control drug was carbendazim. Figure 4 All materials and reagents used in the experiment were autoclaved.

[0044] I. Preparation of Experimental Materials and Reagents 1. Consumables and equipment (autoclaved): (1) 15 mL centrifuge tubes, glass test tubes, 1000 μL / 200 μL / 10 μL pipette tips; (2) Sealing film, sterilized syringe (use cotton to plug the outlet as a filter).

[0045] 2. Reagents (autoclaved): (1) 5% DMSO aqueous solution (for sample dissolution and dilution); (2) PDB liquid medium; (3) Sterile water.

[0046] II. Activation culture of pathogenic fungi (1) Prepare PDA solid medium (2% agar + PDB powder), pour flat after autoclaving; (2) Inoculate the pathogenic fungi stored in the refrigerator to the PDA flat plate; (3) Place in a 30°C constant temperature incubator for 3-5 days for standby.

[0047] III. Preparation of sample solution and positive control solution (1) Accurately weigh the compound or carbendazim with a one-hundredth electronic balance; (2) In the clean bench, dissolve the sample with 5% DMSO aqueous solution, the initial concentration is 800 μg / mL; (3) Further dilute the above mother liquor to 200 μg / mL working solution; (4) The positive control (carbendazim) is treated in the same way.

[0048] IV. Preparation of spore suspension (1) Select a pathogenic strain with abundant spores and subculture to a new PDA flat plate; (2) Add an appropriate amount of sterile water, and use a surgical knife sterilized with alcohol lamp flame to scrape the surface of the mycelium to release spores; (3) Filter with a cotton plug syringe, receive liquid into a 15 mL sterile centrifuge tube, repeat 2 times, about 5 mL per tube; (4) Centrifuge at 5000 rpm for 10 min, discard the supernatant and retain the precipitate; (5) Add 3-5 mL PDB to resuspend, mix evenly by repeated pipetting, count under a microscope (10 5 CFU / mL), which is the spore suspension.

[0049] V. Setting of experimental and control groups (1) The control group is set as shown in the table below:

[0050] (2) Experimental group setting: A. Compound I working solution with concentration gradient of 200, 160, 120, 80, 40 μg / mL (200 μL) + spore suspension (200 μL); B. Set 1 glass test tube for each concentration; C. All groups set 3 parallel repeats.

[0051] Six, culture and MIC determination (1) All test tubes were incubated at 30°C for 24 hours; (2) Observe the clarity of the test tube solution and mycelium growth; (3) Record the MIC results of the compound and compare them with the control results of carbendazim.

[0052] Seven, MIC result analysis (see musae , 5 ) (1) Compound I showed good antibacterial activity in some pathogenic fungi, especially for Colletotrichum musae (C. musae) and Colletotrichum gloeosporioides (C. gloeosporioides), with MIC values of 80-100 μg / mL; C. C. gloeosporioides (2) For other pathogenic fungi such as Fusarium graminearum (F. graminearum) and Botryosphaeria dothidea (B. dothidea), compound I showed weak or no obvious antibacterial activity, with MIC values mostly in the range of >128 μg / mL; Fusarium graminearum (3) In comparison, the MIC of the positive drug carbendazim for most of the above strains was in the range of 1-12.5 μg / mL, which was only used as a control. Botryosphaeria dothidea ​ As can be seen from the above, the pyrone natural product (compound I) of the present application has certain antibacterial activity in some plant pathogenic fungi (Table 2), especially in the Colletotrichum and Botryosphaeria dothidea models, and after subsequent structure optimization or substituent modification, it is expected to further improve its activity level. The present application provides a research basis for subsequent development of natural product lead structure modification and agricultural bacteriostatic agent.

[0053] Although the pyrone compound isolated by the present application has weak in vitro antibacterial activity (MIC = 80-100 μg / mL) for the measured strains, which is weaker than the positive control carbendazim (MIC = 1-12.5 μg / mL), the compound is a newly reported natural product, which enriches the structural diversity of pyrone compounds. Its unique substitution mode provides a reference for subsequent structure-activity relationship analysis, which helps to determine the key structural features affecting the activity on the pyrone skeleton. At the same time, natural products often have good modifiability and safety basis, and subsequent structure optimization, formula improvement or synergistic drug use are expected to further improve its antifungal activity. Therefore, the compound has certain application value and potential development prospect.

[0054] Although the pyrone compound isolated by the present application has weak in vitro antibacterial activity (MIC = 80-100 μg / mL) for the measured strains, which is weaker than the positive control carbendazim (MIC = 1-12.5 μg / mL), the compound is a newly reported natural product, which enriches the structural diversity of pyrone compounds. Its unique substitution mode provides a reference for subsequent structure-activity relationship analysis, which helps to determine the key structural features affecting the activity on the pyrone skeleton. At the same time, natural products often have good modifiability and safety basis, and subsequent structure optimization, formula improvement or synergistic drug use are expected to further improve its antifungal activity. Therefore, the compound has certain application value and potential development prospect.

[0055] ​​​Table 2 Minimum inhibitory concentration (MIC, μg / mL) of pyrones I against 9 plant pathogenic fungi

[0056] The embodiments of the present application have been described in detail, but the present application is not limited to the described embodiments. Various changes, modifications, substitutions and variations of these embodiments can be made by those skilled in the art without departing from the principles and spirit of the present application, and still fall within the scope of the present application.

Claims

1. A pyranone compound with antifungal activity, characterized in that, The structural formula of the pyranone compounds is shown below: 。 2. A pyranone compound with antifungal activity according to claim 1, characterized in that, The pyranone compounds are derived from endophytic fungi. Diaporthe kyushuensis ZMU-48-1, the preservation number of this strain is: GDMCC No: 66577.

3. The pyranone compounds of claim 1 in the preparation of preparations of fungi that inhibit banana anthracnose ( Colletotrichum musae ) and / or Colletotrichum candida ( Colletotrichum gloeosporioides Application in agricultural fungicides that promote proliferation.

4. The pyranone compound of claim 1 in the preparation of a preparation for the prevention and control of anthracnose caused by *Bacillus anthracis* (banana anthracnose). Colletotrichum musae ) and / or Colletotrichum candida ( Colletotrichum gloeosporioides Application of pesticides in treating plant diseases caused by ).

5. A pesticide formulation, characterized in that, The pesticide formulation uses the pyranone compounds of claim 1 as the main active ingredient.

6. A pesticide formulation according to claim 5, characterized in that, The pesticide formulation also includes pesticide-acceptable excipients.

7. A pesticide formulation according to claim 5, characterized in that, The pesticide-acceptable excipients are selected from one or more of the following: dispersants, wetting agents, disintegrants, binders, defoamers, antifreeze agents, thickeners, fillers, and solvents.

8. A pesticide formulation according to claim 5, characterized in that, The pesticide formulation is in the form of wettable powder, water-dispersible granules, water suspension, or dispersible oil suspension.

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