Pyrone Compounds Derived from Endophytic Fungi, Preparation Methods Thereof and Applications

Abstract

The present invention discloses a pyranone compound derived from endophytic fungi, its preparation method and application. The pyranone compound is derived from the endophytic fungus Ascomycota sp. FAE17 strain of Scutellaria violacea. The pyranone compound is prepared from the strain fermentation product. After the fermentation product is extracted with ethyl acetate, the extract is concentrated under reduced pressure to obtain an ethyl acetate extraction extract. The pyranone compound is obtained by column chromatography separation and purification, and is respectively compound 1, compound 2, compound 3 and / or compound 4. The results of various in vitro activity evaluations of the pyranone compound show that the above pyranone compound has antibacterial and anti-inflammatory activities, can be further developed into an anti-inflammatory drug, and has the prospect of being developed into an anti-inflammatory drug, especially in the application of anti-inflammatory drugs for inhibiting nitric oxide production.

Description

Technical Field

[0001] The present invention belongs to the field of natural product applications, and relates to a pyrone compound, a preparation method and an application thereof, and particularly relates to a pyrone compound derived from an endophytic fungus of Scutellaria baicalensis, a preparation method and an application thereof. Background Art

[0002] There are approximately 360 species of Scutellaria in the Lamiaceae family, most of which grow in Asia, but are also distributed in Europe, North America, and East Asia. There are 102 species and 50 varieties of Scutellaria recorded in the Flora of China, most of which are medicinal plants with the effects of clearing heat and dampness, purging fire and detoxifying. Among them, Scutellaria baicalensis and Scutellaria barbata were included in the 2020 edition of the Chinese Pharmacopoeia. Modern pharmacological studies have shown that Scutellaria plants have antioxidant, anti-tumor, hepatoprotective, anti-inflammatory, anticonvulsant, antibacterial, and antiviral effects.

[0003] Scutellaria formosana is primarily distributed in southern Hainan, eastern and southern Guangdong, Jiangxi, southern Fujian, and southern Yunnan. It primarily grows in shaded areas under forests at altitudes of 450-550 meters. Its unique habitat makes it exceptionally rare and difficult to find, resulting in limited production. Due to limited production, harvesting Scutellaria formosana plants for drug development is difficult to commercialize and poses a threat to the preservation of this rare natural medicinal plant. Therefore, there is an urgent need to develop alternative sources of Scutellaria formosana for medicinal purposes.

[0004] Endophytic fungi in Scutellaria baicalensis are symbiotic microorganisms that live within their host plant, Scutellaria baicalensis. They participate in the biosynthesis of secondary metabolites and, during their long-term adaptation to the natural environment, produce a rich array of structurally distinct metabolites. Importantly, these fungi can be produced on a large scale through fermentation technology, facilitating industrialization without destroying the scarce Scutellaria baicalensis plant resource. Therefore, research on the secondary metabolites of Scutellaria baicalensis endophytes and their pharmacological activities has both theoretical and practical significance. Summary of the Invention

[0005] The purpose of the present invention is to provide a pyrone compound based on an endophytic fungus from Scutellaria baicalensis, which has antibacterial and anti-inflammatory activities and can be further developed into an anti-inflammatory drug. It has the prospect of being developed into an anti-inflammatory drug, especially in the application of anti-inflammatory drugs in inhibiting nitric oxide production.

[0006] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0007] A pyrone compound, wherein the pyrone compound is Compound 1, Compound 2, Compound 3 and / or Compound 4, and their chemical structures are as follows:

[0008]

[0009] Another object of the present invention is to provide a method for preparing the pyrone compounds derived from the endophytic fungus of Scutellaria baicalensis, comprising the following steps:

[0010] S1: preparing a fermentation product of Ascomycota sp. FAE17; the Ascomycota sp. FAE17 is deposited in the China Center for Type Culture Collection, Wuhan University, Wuhan, Hubei Province, with the accession number CCTCC NO: M20231778;

[0011] S2: extracting the fermented product obtained in step S1 with an equal volume of ethyl acetate, and concentrating the extract under reduced pressure to obtain an ethyl acetate extract;

[0012] S3: The ethyl acetate extract obtained in step S2 is subjected to column chromatography separation and purification to obtain Compound 1, Compound 2, Compound 3 and Compound 4.

[0013] Furthermore, step S1 includes the following steps: transferring the Ascomycota sp. FAE17 strain to a PDA culture medium for culture, then transferring it to a conical flask containing a potato glucose liquid medium, shaking and culturing to obtain a seed bacterial liquid, and transferring the seed bacterial liquid to a high-temperature sterilized rice culture medium conical flask for static fermentation to obtain a fermentation product.

[0014] Furthermore, step S3 includes the following steps:

[0015] (1) The ethyl acetate extract was crudely separated by silica gel column chromatography, and petroleum ether-ethyl acetate gradient elution was performed at a volume ratio of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7, 2:8, 1:9, and 0:1, and ethyl acetate-methanol gradient elution was performed at a volume ratio of 9:1, 8:2, 7:3, 6:4, 5:5, and 1:1, and the ethyl acetate-methanol eluate with a volume ratio of 9:1, 8:2, and 7:3 was collected;

[0016] (2) combining the ethyl acetate-methanol eluates with a volume ratio of 9:1, 8:2, and 7:3 and performing reverse-phase silica gel column chromatography, eluting with a methanol-water gradient with a volume ratio of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, and 10:0, and collecting the methanol-water eluate with a volume ratio of 1:9;

[0017] (3) Subject the obtained methanol - water eluate to normal - phase silica gel column chromatography, and perform gradient elution with ethyl acetate - methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7. Collect the ethyl acetate - methanol eluates at volume ratios of 9:1 and 8:2 respectively and concentrate them;

[0018] (4) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 9:1 and separate it by semi - preparative high - performance liquid chromatography. The mobile phase is acetonitrile - water with a volume ratio of 8:92 to obtain Compound 1, Compound 3, and Compound 4;

[0019] (5) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 8:2 and perform reverse - phase silica gel column chromatography. Perform gradient elution with methanol - water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, 10:0, and collect the methanol - water eluate with a volume of 3:7;

[0020] (6) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 3:7 and separate it by semi - preparative high - performance liquid chromatography. The mobile phase is acetonitrile - water with a volume ratio of 13:87 to obtain Compound 2.

[0021] Another object of the present invention is to provide the application of the pyranone compounds (Compound 1, Compound 2, Compound 3, and / or Compound 4) in anti - inflammation, especially in the preparation of anti - inflammatory drugs, and more specifically in the application of anti - inflammatory drugs for inhibiting nitric oxide production.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] The present invention uses the fermentation product of endophytic fungi of Scutellaria baicalensis Georgi var. longituba as the raw material to prepare an ethyl acetate extraction extract, and then separates and identifies four novel pyranone compounds, namely Compound 1, Compound 2, Compound 3, and Compound 4. The results of various in vitro activity evaluations show that Compound 1, Compound 2, Compound 3, and Compound 4 have antibacterial and anti - inflammatory activities, can be further developed into anti - inflammatory drugs, and have the prospect of being developed into anti - inflammatory drugs, especially in the application of anti - inflammatory drugs for inhibiting nitric oxide production. Brief Description of the Drawings

[0024] Figure 1 They are the 1H - 1H COSY and HMBC correlation diagrams of Compound 1, Compound 2, Compound 3, and Compound 4 of the present invention.

[0025] Figure 2 They are the NOESY correlation diagrams of Compound 1, Compound 2, Compound 3, and Compound 4 of the present invention.

[0026] Figure 3 It is the ECD diagram of Compound 1 of the present invention.

[0027] Figure 4 This is the ECD diagram of Compound 2 of the present invention.

[0028] Figure 5 These are the experimental results of the anti-inflammatory activities of Compound 1, Compound 2, Compound 3, and Compound 4 of the present invention. Detailed implementation manners

[0029] To better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention. The following embodiments are used to illustrate the present invention but not to limit the scope of the present invention. For the experimental methods without specific conditions noted in the following embodiments, they are usually in accordance with conventional experimental conditions.

[0030] Example 1. Preparation method of pyranone compounds

[0031] The endophytic fungus Ascomycota sp. FAE17 of Scutellaria violacea of the present invention was collected from the flower part of the rare medicinal plant Scutellaria violacea in Bawangling National Nature Reserve, Changjiang Li Autonomous County, Hainan Province. The endophytic fungus strain of Scutellaria violacea was identified by a sequencing company (Qingdao Pengxiang Biotechnology Co., Ltd.). The obtained base sequence was compared for similarity in the GenBank database, and then the BLAST program was used to search for homologous sequences for comparison. The sequence similarity was 99%, and it was determined that the FAE-17 strain was a fungus of the genus Ascomycota (Ascomycota sp.).

[0032] The Ascomycota sp. FAE17 strain was taken out from the 4°C refrigerator and activated at room temperature, then transferred onto a PDA medium and placed in an incubator at 28°C for cultivation. After 2 - 3 days, its growth situation was observed. Then the strain was transferred to a triangular flask containing potato dextrose liquid medium and placed on a shaker at room temperature for shaking cultivation for 2 - 3 days to observe the growth situation of the seed bacterial liquid; the seed bacterial liquid was transferred to a conical flask of high-temperature sterilized rice medium in a laminar flow hood, inoculating 150 flasks, and standing at room temperature for cultivation for 5 weeks to obtain a fermentation product; the rice solid medium was: 90 g of rice per flask, 120 mL of water per flask, and a conical flask with a volume of 1000 mL, with a total of 150 flasks inoculated.

[0033] The fermentation product was extracted 3 - 5 times with an equal volume of ethyl acetate. After combining the extraction solutions, it was concentrated under reduced pressure to obtain 160.0 g of an ethyl acetate extraction extract.

[0034] The ethyl acetate extraction extract was roughly separated by silica gel column chromatography, and gradient elution with petroleum ether-ethyl acetate was carried out at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7, 2:8, 1:9, and 0:1 respectively, and gradient elution with ethyl acetate-methanol was carried out at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, and 1:1. The ethyl acetate-methanol eluates with volume ratios of 9:1, 8:2, and 7:3 were collected;

[0035] The ethyl acetate-methanol eluates with volume ratios of 9:1, 8:2, and 7:3 were combined and then subjected to reverse-phase silica gel column chromatography, and gradient elution with methanol-water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, and 10:0 was carried out, and the methanol-water eluate with a volume of 1:9 was collected.

[0036] The methanol-water eluate with a volume of 1:9 was taken for normal-phase silica gel column chromatography, and gradient elution with ethyl acetate-methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, and 3:7 was carried out, and the ethyl acetate-methanol eluates with volume ratios of 9:1 and 8:2 were collected respectively for concentration;

[0037] The concentrated ethyl acetate-methanol eluate with a volume ratio of 9:1 was separated by semi-preparative high-performance liquid chromatography, and the mobile phase was acetonitrile-water with a volume ratio of 8:92, and compound 1 (20.1 mg), compound 3 (1.2 mg), and compound 4 (1.7 mg) were obtained;

[0038] The concentrated ethyl acetate-methanol eluate with a volume ratio of 8:2 was subjected to reverse-phase silica gel column chromatography, and gradient elution with methanol-water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, and 10:0 was carried out, and the methanol-water eluate with a volume of 3:7 was collected.

[0039] The concentrated ethyl acetate-methanol eluate with a volume ratio of 3:7 was separated by semi-preparative high-performance liquid chromatography, and the mobile phase was acetonitrile-water with a volume ratio of 13:87, and compound 2 (4.6 mg) was obtained.

[0040] Structure determination: Through comprehensive analysis using a variety of modern spectroscopic techniques such as optical rotation spectroscopy, ultraviolet (UV) spectroscopy, infrared (IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS), as well as quantum chemical ECD calculation methods, the obtained 1 HNMR and 13 The \(^{1}H\) NMR and

[0041] Compound 1: Pale yellow oily substance; UV(MeOH)λ max[logε / (L·mol -1 ·cm -1 )]: 249(2.30) nm; IR(KBr) ν max : 1710 cm -1 , 1622 cm -1 ; HR-ESI-MS m / z 251.0877 [M+Na] + (calcd for C 11 H 16 O5Na, 251.0890). The two-dimensional carbon-hydrogen correlation signals are as shown in Figure 1 (1H-1HCOSY, HMBC spectra). The relative configuration is as shown in Figure 2 . The relative configuration of compound 1 was determined by the correlation between H-5 and H-10 in compound 1, and its absolute configuration was determined by CD test and ECD calculation. By comparing the CD test spectrum and ECD calculation spectrum of compound 1 ( Figure 3 ), it was found that the Cotton effect was in good agreement, that is, the absolute configuration of compound 1 was 5R, 8R and named ascomycopyrone A.

[0042] Compound 2: Yellow oil; UV(CH3OH) λ max [logε / (L·mol -1 ·cm -1 )]: 249(2.66), 300(0.43) nm; IR(KBr) ν max : 1710 cm -1 , 1621 cm -1 ; HR-ESI-MS m / z 391.1349 [M+Na] + (calcd for C 18 H 24 O8Na, 391.1349). The two-dimensional carbon-hydrogen correlation signals are as shown in Figure 1 (1H-1HCOSY, HMBC spectra). The relative configuration is as shown in Figure 2 . It was speculated that there were four relative configurations of compound 2 by the correlation between H-5 (δH 2.49) and H-10 (δH 0.93), and H-5′ (δH 2.86 / 4.38) and H-10′ (δH 15.7) in compound 2. Structure DP4+ calculation was carried out on it, and the results showed that the 5R, 8R, 5R, 8R-20 configuration was in complete agreement. Further, the absolute configuration of compound 2 was determined by the ECD calculation spectrum ( Figure 4 ) and named ascomycopyrone B.

[0043] Compound 3: Colorless oil; UV (MeOH) λ max [logε / (L·mol -1 ·cm -1 )]: 241 (2.45) nm; IR (KBr) ν max : 3446 cm -1 , 1622 cm -1 ; HR-ESI-MS m / z 337.1608 [M+Na] + (calcd for C 16 H 26 O6Na, 337.1622). The two-dimensional carbon-hydrogen correlation signals are as Figure 1 (1H-1HCOSY, HMBC spectra) shown. The relative configuration is as Figure 2 shown. By the correlation of H-5 (δH 2.44) with H-10 (δH 0.89) in compound 3, H-6′ (δH 0.97) with H-2′ (δH 4.58), H-4′ (δH 1.59), and H-3′ (δH 1.80) with H-7′ (δH 3.54), the relative configuration of compound 3 was determined and named ascomycopyrone C.

[0044] Compound 4: Colorless oil; UV (MeOH) λ max [logε / (L·mol -1 ·cm -1 )]: 248 (2.29) nm; IR (KBr) ν max : 3453 cm -1 , 1620 cm -1 ; HR-ESI-MS m / z 337.1604 [M+Na] + (calcd for C 16 H 26 O6Na, 337.1622). The two-dimensional carbon-hydrogen correlation signals are as Figure 1 (1H-1HCOSY, HMBC spectra) shown. The relative configuration is as Figure 2 shown. By the correlation of H-5 (δH 2.44) with H-10 (δH 0.91) in compound 4, H-3′ (δH 1.57) with H-6′ (δH 1.34), and H-8′ (δH 0.99) with H-6′ (δH 1.34), the relative configuration of compound 4 was determined and named ascomycopyrone D.

[0045] Table 1 1H NMR and 1 of compounds 1 and 2 and 1313C NMR (400 / 100 MHz, DMSO-d6) data

[0046]

[0047] Table 2 1 1H NMR and 13 13C NMR (400 / 100 MHz, DMSO-d6) data

[0048]

[0049]

[0050] Example 2. Preparation method of pyrone compounds

[0051] Take out the Ascomycota sp. FAE17 strain from the 4°C refrigerator and activate it at room temperature. Transfer it onto a potato dextrose solid medium and place it in an incubator at 28°C for cultivation. Observe its growth after 2 - 3 days. Then transfer the strain to an Erlenmeyer flask containing potato dextrose liquid medium and place it on a shaker at room temperature for shaking cultivation for 2 - 3 days to observe the growth of the seed culture solution. Transfer the seed culture solution under a laminar flow hood to a sterilized Erlenmeyer flask containing rice medium, inoculate 300 flasks, and let it stand at room temperature for 5 weeks to obtain the fermented product. Among them, the rice solid medium is: 90 g of rice per flask, 120 mL of water per flask, and Erlenmeyer flasks with a capacity of 1000 mL, with a total of 300 flasks inoculated.

[0052] Extract the obtained fermented product with an equal volume of ethyl acetate 3 - 5 times. After combining the extraction solutions, concentrate them under reduced pressure to obtain 310.0 g of an ethyl acetate extraction extract.

[0053] Crudely separate the ethyl acetate extraction extract by silica gel column chromatography, and perform gradient elution of petroleum ether - ethyl acetate at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7, 2:8, 1:9, 0:1 and gradient elution of ethyl acetate - methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 1:1, and collect the ethyl acetate - methanol eluates with volume ratios of 9:1, 8:2, 7:3.

[0054] After combining the ethyl acetate - methanol eluates with volume ratios of 9:1, 8:2, 7:3, perform reverse - phase silica gel column chromatography, and perform gradient elution with methanol - water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, 10:0, and collect the methanol - water eluate with a volume ratio of 1:9.

[0055] Take the methanol-water eluate with a volume ratio of 1:9 for normal-phase silica gel column chromatography, and perform gradient elution with ethyl acetate-methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, and 3:7. Collect the ethyl acetate-methanol eluates with volume ratios of 9:1 and 8:2 respectively for concentration;

[0056] Take the concentrated ethyl acetate-methanol eluate with a volume ratio of 9:1 and separate it by semi-preparative high-performance liquid chromatography. The mobile phase is acetonitrile-water with a volume ratio of 8:92 to obtain Compound 1 (40.6 mg), Compound 3 (2.3 mg), and Compound 4 (3.5 mg) (the structure confirmation data is the same as in Example 1);

[0057] Take the concentrated ethyl acetate-methanol eluate with a volume ratio of 8:2 for reverse-phase silica gel column chromatography, and perform gradient elution with methanol-water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, and 10:0. Collect the methanol-water eluate with a volume of 3:7.

[0058] Take the concentrated ethyl acetate-methanol eluate with a volume ratio of 3:7 and separate it by semi-preparative high-performance liquid chromatography. The mobile phase is acetonitrile-water with a volume ratio of 13:87 to obtain Compound 2 (9.5 mg) (the structure confirmation data is the same as in Example 1).

[0059] Study on the anti-inflammatory activity of the pyranone compounds obtained in Example 1 of the present invention:

[0060] Experimental method:

[0061] (1) Use the MTT colorimetric method to screen the cytotoxic activity of mouse macrophages RAW 264.7. Take 10 μL of RAW cells in the logarithmic growth phase and place them in a counting plate for counting to make the number of cells per well about 5000 - 10000. Add 100 μL of PBS solution to the outer circle of a 96-well plate. In each of the remaining wells, inoculate 100 μL of cell suspension and incubate for 24 hours to allow the cells to adhere and grow. Add the prepared sample solutions in order from high concentration to low concentration, with final concentrations of 100 μmol / L, 10 μmol / L, and 1 μmol / L in each well. The blank group is added with PBS solution, and then placed in a constant-temperature carbon dioxide incubator for � hours. Take out the cultured cells, add 10 μL of MTT pre-thawed at room temperature to each well, put it back into the incubator for 4 hours, then take out the 96-well plate, pour out the supernatant, and blot the excess liquid on a paper towel. Add 150 μL of DMSO to each well, shake it in the dark to dissolve the formazan purple crystals, remove the plate cover, and use an enzyme-linked immunosorbent assay (ELISA) reader to measure the absorbance values at 490, 570, and 630 nm. Calculate the cell inhibition rate according to the formula 1 - (OD sample / OD Control) × 100%.

[0062] (2) Take the cells in the logarithmic growth phase, prepare a cell suspension and count them. Inoculate 2x10 5 cells / well into a 96-well plate, and place it in a 5% CO2, 37°C incubator for 24 h. The next day, replace each well with a monomeric compound (final concentration 6.25 - 50 μM) and dexamethasone that are non-toxic to RAW cells, and an equal volume of DMSO for pretreatment for 1 h. Then, except for the blank control group, add LPS (2 μg / mL) for stimulation and continue culturing for 24 h. Collect the cell supernatant at the end of the culture.

[0063] Detect the NO release amount by the Griess method: Before measuring the NO content, restore Griess Reagent I and II to room temperature. Dilute the standard products with serum-free DMEM medium, and their concentrations are: 0, 1, 2, 5, 10, 20, 40, 60, and 100 μM. Take 50 μL of each standard product and the supernatant of the sample to be tested, add them to a new 96-well plate, and set three replicates for each sample in the standard product group, blank group, LP group, sample group, and positive drug group. Add 50 μL of griess Reagent I to each well in the dark, gently tap the 96-well plate to mix well, and after reacting for 5 min, add Griess Reagent II and gently shake to mix the liquid in the wells evenly. Measure the absorbance at 540 nm with an enzyme-linked immunosorbent assay (ELISA) reader. Substitute into the nitrite standard curve to calculate the NO content and calculate the inhibition rate of the compound on the production of NO by LPS-activated RAW264.7 cells. The results are shown in Figure 5 .

[0064] NO production inhibition rate % = (LPS group - sample group) / (LPS group - blank group) × 100%.

[0065] The results of the anti-inflammatory activity test show that at 50 μM, Compounds 1, 2, 3, and 4 all have varying degrees of inhibitory effects on the NO produced by LPS-induced RAW 264.7 cells, and have a certain anti-inflammatory activity.

[0066] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A pyrone compound, characterized in that, The pyranone compounds are Compound 1, Compound 2, Compound 3 and / or Compound 4, and their chemical structures are as follows:

2. The method for preparing the pyrone compound according to claim 1, characterized in that, It includes the following steps: S1: Prepare the fermentation product of Ascomycota sp. FAE17; Ascomycota sp. FAE17 is preserved in the China Center for Type Culture Collection, with the preservation address being Wuhan University, Wuhan, Hubei Province, and the preservation number being CCTCC NO: M20231778; S2: Extract the fermentation product obtained in step S1 with an equal volume of ethyl acetate, and concentrate the extract under reduced pressure to obtain an ethyl acetate extraction extract; S3: Subject the ethyl acetate extraction extract obtained in step S2 to column chromatography separation and purification to obtain Compound 1, Compound 2, Compound 3 and Compound 4; The steps are as follows: (1) Coarsely separate the ethyl acetate extraction extract by silica gel column chromatography, and perform gradient elution of petroleum ether - ethyl acetate at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7, 2:8, 1:9, 0:1 and gradient elution of ethyl acetate - methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 1:1, and collect the ethyl acetate - methanol eluates at volume ratios of 9:1, 8:2, 7:3; (2) Combine the ethyl acetate - methanol eluates at volume ratios of 9:1, 8:2, 7:3 and then perform reverse - phase silica gel column chromatography, and perform gradient elution with methanol - water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, 10:0, and collect the methanol - water eluate at a volume ratio of 1:9; (3) Subject the obtained methanol - water eluate to normal - phase silica gel column chromatography, and perform gradient elution with ethyl acetate - methanol at volume ratios of 9:1, 8:2, 7:3, 6:4, 5:5, 3:7, and collect and concentrate the ethyl acetate - methanol eluates at volume ratios of 9:1 and 8:2 respectively; (4) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 9:1 and separate it by semi - preparative high - performance liquid chromatography, with the mobile phase being acetonitrile - water at a volume ratio of 8:92, to obtain Compound 1, Compound 3 and Compound 4; (5) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 8:2 and perform reverse - phase silica gel column chromatography, and perform gradient elution with methanol - water at volume ratios of 1:9, 2:8, 3:7, 4:6, 6:4, 8:2, 10:0, and collect the methanol - water eluate at a volume ratio of 3:7; (6) Take the concentrated ethyl acetate - methanol eluate at a volume ratio of 3:7 and separate it by semi - preparative high - performance liquid chromatography, with the mobile phase being acetonitrile - water at a volume ratio of 13:87, to obtain Compound 2.

3. The preparation method of the pyrone compound according to claim 2, characterized in that, The step S1 includes the following steps: taking out the Ascomycota sp. FAE17 strain from a 4°C refrigerator and activating it at room temperature, transferring it onto a PDA medium, culturing it in a 28°C constant temperature incubator, observing its growth condition after 2-3 days, then transferring the strain into a triangular flask containing potato dextrose liquid medium, placing it in a room temperature shaker and culturing it by shaking for 2-3 days, observing the growth condition of the seed bacterial solution; transferring the seed bacterial solution in a laminar flow hood into a conical flask of high-temperature sterilized rice medium, and culturing it statically at room temperature for 5 weeks to obtain a fermented product; the rice solid medium is: 90 g of rice per bottle, 120 mL of water per bottle, and a conical flask with a capacity of 1000 mL.

4. Use of the pyranone compound according to claim 1 in the preparation of an anti-inflammatory drug.

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