A subplenodomus genus fungus, an antibacterial compound and a preparation method and application thereof

Abstract

The application discloses a Subplenodomus genus fungus, an antibacterial compound and a preparation method and application thereof. A Subplenodomus genus fungus is discovered by taking medicinal plant endophytic fungi as a research object, and a novel strong antibacterial compound is discovered in a fermentation product of the Subplenodomus genus fungus, especially has strong bacteriostatic activity on drug-resistant strains, has very good application prospect and research and development value, and provides a basis for subsequent antibacterial drug research and development.

Description

[0001] This application is a divisional application of Chinese patent application No. 202211291210.1, filed on October 17, 2022, entitled "A Subplenodomus fungus, an antibacterial compound and its preparation method and application". Technical Field

[0002] This invention relates to the field of chemical and pharmaceutical technology, specifically to a fungus of the genus Subplenodomus, an antibacterial compound, its preparation method, and its application. Background Technology

[0003] Bacterial infection is one of the major factors endangering human health. Bacterial infectious diseases refer to diseases caused by bacterial infection. Among the common pathogens in clinical practice, Gram-negative bacteria are more numerous, such as Escherichia coli, Enterobacter spp., and Pseudomonas spp., while Gram-positive bacteria, such as Staphylococcus spp. and Enterococcus spp., also exist.

[0004] Currently, most commonly used drugs for bacterial infections are antibiotics and broad-spectrum antibacterial agents, such as imipenem, vancomycin, and teicoplanin. These have significant side effects, and excessive use can lead to drug resistance, resulting in the emergence of superbugs, such as methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), and vancomycin-resistant enterococci (VRE), which have become important pathogens in hospital-acquired infections. Bacterial resistance makes the challenges to global public health even more severe.

[0005] The need to develop new antimicrobial drugs is particularly urgent in order to alleviate the public health crisis caused by antibiotic-resistant bacteria.

[0006] The genus *Subplenodomus* belongs to the phylum Ascomycota, class Ascomycota, order Leptosporales, family Subplenodomusaceae, and is mainly isolated from plants in the Gentianaceae family. Currently, there are no reports on the secondary metabolites of strains in this genus. Summary of the Invention

[0007] In view of this, the present invention provides a fungus of the genus Subplenodomus, an antibacterial compound, a method for preparing the same, and its application.

[0008] In a first aspect of the invention, a fungus of the genus Subplenodomus is provided.

[0009] Specifically, the ITS gene sequence of the Subplenodomus fungal strain is shown in SEQ ID NO: 1.

[0010] Specifically, the characteristics of the fungi of the genus Subplenodomus include: colonies growing on PDA medium with smooth edges and a raised center; white and well-developed aerial hyphae; light yellow to gray mycelium with a dull and dry surface; and white edges and brown to tan center on the reverse side.

[0011] In one embodiment of the present invention, the Subplenodomus fungus is an endophytic fungus derived from Gentiana straminea Maxim.; specifically, the Gentiana straminea Maxim. is Gentiana straminea from marshes, wet grasslands, riverbanks, hillsides, or forest edges; the Gentiana straminea Maxim. is Gentiana straminea from Tibet, Yunnan, Guizhou, Shanxi, Shaanxi, Gansu, Inner Mongolia, and other places.

[0012] Preferably, the ITS gene sequence of the *Subplenodomus* fungal strain shares 100% similarity with that of strain *Subplenodomus drobnjacensis* PRG11-03 in the ITS sequence; 89% similarity with that of *Comoclathris incompta isolate CH-12* in the tublin sequence; and 100% similarity with that of *Subplenodomus drobnjacensis* PRG11-03 in the LSU sequence. Based on the morphological characteristics and ITS gene sequence, the strain is identified as *Subplenodomus* sp. Most preferably, the Subplenodomus fungus is CPCC 401465, which was deposited at the China General Microbiological Culture Collection Center on April 25, 2022, with accession number CGMCC No. 40181.

[0013] In a second aspect of the invention, a composition is provided comprising the Subplenodomus fungi described in the first aspect and / or their metabolites.

[0014] Specifically, the metabolite can be a culture, suspension, or lysate of the aforementioned Subplenodomus fungi.

[0015] In some embodiments of the present invention, the culture is a fermentation product of the aforementioned Subplenodomus fungi, such as fermentation broth, clarified liquid of fermentation broth (e.g., supernatant, filtrate, etc., which no longer contains solid matter (e.g., bacterial cells) from the fermentation broth), concentrated fermentation broth, extract of fermentation broth, etc. Preferably, the fermentation product of the Subplenodomus fungi is obtained by the fermentation method described below.

[0016] In a third aspect of the invention, a fermentation method for the fungi of the genus Subplenodomus described in the first aspect is provided.

[0017] Specifically, the fermentation method includes the step of fermenting the Subplenodomus fungus in a culture medium.

[0018] Specifically, the culture medium is a fungal fermentation medium, which may be a solid culture medium, a semi-solid culture medium, or a liquid culture medium; more specifically, the culture medium may be a rice culture medium, a potato dextrose agar medium, or other fungal fermentation media well known to those skilled in the art.

[0019] Preferably, the rice culture medium comprises rice and water; more preferably, the rice culture medium further comprises one or more of inorganic salts and nitrogen sources.

[0020] Specifically, the rice culture medium can be made from rice and water, or from rice, water and inorganic salts, or from rice, water and a nitrogen source, or from rice, water, a nitrogen source and inorganic salts.

[0021] The rice mentioned can be either white rice or brown rice. Both white rice and brown rice are products of paddy rice. Paddy rice refers to the fruit of the rice plant with the husk intact, and it consists of the husk, pericarp, seed coat, outer endosperm, aleurone layer, endosperm, and embryo. Brown rice refers to paddy rice with the husk removed, retaining all other parts of the rice; white rice refers to paddy rice with only the endosperm retained, while all other parts of the rice have been removed.

[0022] Preferably, the potato dextrose agar medium comprises potatoes, glucose, and agar; more preferably, the potato dextrose agar medium further comprises one or more of water, inorganic salts, and a nitrogen source. Specifically, the potato glucose agar medium can be made from potatoes, glucose, agar and water, or from potatoes, glucose, agar, water and inorganic salts, or from potatoes, carbon source, agar, water and nitrogen source, or from potatoes, carbon source, agar, nitrogen source and inorganic salts.

[0023] Specifically, the other fungal fermentation media known to those skilled in the art may be made from one or more fast-acting or slow-acting carbon sources, one or more fast-acting or slow-acting nitrogen sources, water and / or inorganic salts.

[0024] In some embodiments of the present invention, the culture medium is a rice culture medium, particularly a rice culture medium.

[0025] Specifically, the mass ratio of rice to water in the rice culture medium can be 1:0.8-1.2 (e.g., 1:0.8, 1:0.9, 1:1, 1:1.1, 1:1.2), especially 1:1.

[0026] Specifically, the inoculum amount for fermentation can be 1-10% (e.g., 1%, 2%, 4%, 5%, 6%, 7%, 8%, 10%), especially 5-8%.

[0027] Specifically, the fermentation temperature can be 20-35℃ (e.g., 20, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35℃), especially 28-30℃.

[0028] Specifically, the fermentation time can be 1-40 days (e.g., 1, 5, 10, 15, 20, 25, 30, 35, 40 days), especially 25-35 days.

[0029] Specifically, the fermentation is a static culture fermentation.

[0030] Specifically, the above method may also include a step of expanding the strain (before fermentation), for example, expanding the strain activated by slant culture medium in seed culture medium.

[0031] Specifically, the temperature for extended cultivation can be 20-35℃ (e.g., 20, 22, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35℃), especially 28℃.

[0032] Specifically, the extended culture period can be 1-5 days, especially 1-3 days.

[0033] Specifically, the culture was carried out under oscillating conditions (e.g., 200 rpm).

[0034] Specifically, the seed culture medium can be any suitable fungal culture medium, such as Sabouraud dextrose agar, potato dextrose agar, etc. In one embodiment of the present invention, the seed culture medium is a potato glucose liquid culture medium, which is composed of potato extract powder, glucose and water, for example, it contains 4 g / L potato extract powder and 20 g / L glucose. Specifically, the pH value of the seed culture medium can be 5-7 (e.g., 5, 5.4, 5.6, 5.8, 6, 6.5, 7).

[0035] In a fourth aspect of the invention, a compound and its pharmaceutically acceptable salts, stereoisomers, prodrugs, or solvates are provided, the compound having the following structure: (I) in, Represents a single bond or a double bond; X and Y are selected independently from: , , , , ; R1 and R2 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 alkyl); R3 and R4 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 alkyl; R5 and R6 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 alkyl; R7 and R8 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 alkyl; R9 and R 10 Independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 alkyl; R 11 To R 14 Independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 Alkyl; or, R 11 and R 13 Together with the carbon atom it is attached to, it forms a heterocyclic group (e.g. ), and / or, R 12 and R 14 Together with the carbon atom it is attached to, it forms a heterocyclic group (e.g. ).

[0036] In one embodiment of the present invention, the compound has the following structure: (II) in, Represents a single bond or a double bond; X and Y are selected independently from: , ; R1 and R2 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 alkyl).

[0037] Specifically, the compound can have the following structure: .

[0038] Specifically, R1 can be selected from: H, -OH.

[0039] Specifically, R2 can be selected from: H, -OH.

[0040] Specifically, X can be selected from: , .

[0041] Specifically, Y can be selected from: , .

[0042] More specifically, the compound can have the following structure: .

[0043] In some embodiments of the present invention, the stereoisomers of the compound have the following structures:

[0044]

[0045]

[0046] In another embodiment of the present invention, the compound has the following structure: (III) in, Represents a single bond or a double bond; Y is selected from: , ; R2 is selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 alkyl); R5 is selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 Alkyl), C 1-3 alkyl.

[0047] Specifically, R2 can be selected from: H, -OH.

[0048] Specifically, R5 can be selected from: -OH, -OCH3, -OCO-CH3.

[0049] Specifically, the compound can have the following structure:

[0050] More specifically, the compound can have the following structure: .

[0051] In some embodiments of the present invention, the stereoisomers of the compound have the following structures: .

[0052] In another embodiment of the present invention, the compound has the following structure: (IV) in, R5 and R6 are independently selected from: H, -OH, -O-(C 1-3 alkyl), -OCO-(C 1-3 alkyl).

[0053] Specifically, R5 can be selected from: -OH, -OCH3, -OCO-CH3.

[0054] Specifically, R6 can be selected from: -OH, -OCH3, -OCO-CH3.

[0055] Specifically, the compound can have the following structure: .

[0056] More specifically, the compound can have the following structure: .

[0057] In a fifth aspect of the invention, compounds selected from A1 to A13 and their structural analogues are provided:

[0058]

[0059]

[0060]

[0061] .

[0062] Specifically, the above-mentioned structural analogs are compounds whose structures are modified and altered based on the basic parent nuclei of compounds A1 to A13, such as other compounds or stereoisomers covered by general formula I (excluding A1 to A13) as described in the fourth aspect of this invention. The structural modification and alteration methods can be methods well known to those skilled in the art.

[0063] In a sixth aspect of the invention, a method for preparing the compound described in the fifth aspect is provided, comprising the step of extracting and separating the fermentation product of the fungus genus Subplenodomus described in the first aspect.

[0064] Specifically, the fermentation product can be prepared using the fermentation method described in the third aspect of this invention.

[0065] Specifically, the extraction and separation includes: (1) The fermentation product was extracted with organic solvent I to obtain a crude extract; (2) Disperse the crude extract obtained in step (1) and extract it with organic solvent II to obtain the extract; (3) The extract obtained in step (2) is subjected to adsorption chromatography, and the eluent is collected; Optionally, (4) the eluent obtained in step (3) is extracted and separated.

[0066] In one embodiment of the present invention, the extraction in step (1) is ultrasonic extraction.

[0067] Specifically, the extraction temperature in step (1) is 20-30°C, for example, room temperature.

[0068] Specifically, the extraction time in step (1) can be 1-5 days, for example, 3 days.

[0069] Specifically, the extraction in step (1) can be done once or multiple times, for example, three times.

[0070] Specifically, the organic solvent II in step (2) can be selected from methanol, ethanol, or ethyl acetate; in one embodiment of the present invention, the organic solvent I in step (1) is methanol.

[0071] Specifically, step (1) further includes the step of filtering the extract; more specifically, step (1) further includes the step of concentrating the filtrate, at which point the crude extract obtained is a concentrated crude extract.

[0072] Specifically, the dispersing solvent in step (2) is immiscible with organic solvent II; in one embodiment of the present invention, the dispersing solvent in step (2) is water, such as deionized water.

[0073] Specifically, the organic solvent II in step (2) can be selected from: ethyl acetate, N,N-dimethylacetamide, isopropyl acetate, methyl acetate, methyl isobutyl ketone; in one embodiment of the present invention, the organic solvent II in step (2) is ethyl acetate.

[0074] Specifically, the extraction in step (2) can be done once or multiple times, for example, three times.

[0075] Specifically, the adsorbent (stationary phase) for the adsorption chromatography in step (3) is silica gel, especially silica gel H.

[0076] Specifically, the mobile phase of the adsorption chromatography in step (3) is dichloromethane and / or methanol, especially a mixture of dichloromethane and methanol, with a volume ratio of 100-0:0-100.

[0077] Specifically, the extraction and separation described in step (4) includes the steps of performing ODS column chromatography separation and preparative HPLC separation.

[0078] In a seventh aspect of the invention, a pharmaceutical composition is provided comprising the composition of the second aspect, the compound of the fourth aspect or a pharmaceutically acceptable salt, stereoisomer, prodrug, solvate thereof, or the compound of the fifth aspect or a structural analog thereof, and one or more pharmaceutically acceptable excipients.

[0079] In one embodiment of the invention, the pharmaceutical composition is used as an antibacterial drug, particularly an antimicrobial drug.

[0080] Specifically, the bacteria are pathogenic bacteria, such as, but not limited to, Staphylococcus aureus (including methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA) (e.g., vancomycin-intermediate resistant Staphylococcus aureus (VISA))), Staphylococcus epidermidis (including methicillin-sensitive Staphylococcus epidermidis (MSSE), methicillin-resistant Staphylococcus epidermidis (MRSE)), Enterococcus faecalis (including vancomycin-sensitive Enterococcus faecalis, vancomycin-resistant Enterococcus faecalis (VRE)), Enterococcus faecium (including vancomycin-sensitive Enterococcus faecium, vancomycin-resistant Enterococcus faecium (VRE)), and Streptococcus pneumoniae (including penicillin-sensitive Streptococcus pneumoniae). Cocci, penicillin-resistant Streptococcus pneumoniae (PRSP), Pseudomonas aeruginosa (including multidrug-resistant Pseudomonas aeruginosa (MDR-PA) and carbapenem-resistant Pseudomonas aeruginosa (CRPA)), Klebsiella pneumoniae (including third-generation cephalosporin-resistant Klebsiella pneumoniae (3GCRKP)), Escherichia coli (including third-generation cephalosporin-resistant Escherichia coli (3GCREC), fluoroquinolone-resistant Escherichia coli (FQREC), and polymyxin-resistant Escherichia coli (ColR-EC)), Acinetobacter baumannii (including multidrug-resistant Acinetobacter baumannii (MDR-AB) and carbapenem-resistant Acinetobacter baumannii (CRAB)), Clostridium difficile, Streptococcus pyogenes, Serratia marcescens, Micrococcus lysate, Micrococcus luteus, Salmonella, Pseudomonas aeruginosa, etc.

[0081] In particular, the bacteria are Gram-positive bacteria.

[0082] In particular, the bacteria are drug-resistant strains, such as, but not limited to, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant Enterococcus (VRE), penicillin-resistant Streptococcus pneumoniae (PRSP), multidrug-resistant Pseudomonas aeruginosa (MDR-PA), carbapenem-resistant Pseudomonas aeruginosa (CRPA), third-generation cephalosporin-resistant Klebsiella pneumoniae (3GCRKP), and third-generation cephalosporin-resistant Klebsiella pneumoniae. Enterobacteriaceae (3GCREC), fluoroquinolone-resistant Escherichia coli (FQREC), polymyxin-resistant Escherichia coli (ColR-EC), multidrug-resistant Acinetobacter baumannii (MDR-AB), carbapenem-resistant Acinetobacter baumannii (CRAB), and especially methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), vancomycin-resistant Enterococcus (VRE), and penicillin-resistant Streptococcus pneumoniae (PRSP).

[0083] In some embodiments of the present invention, the bacteria are Staphylococcus epidermidis, such as Staphylococcus epidermidis (ATCC12228, MSSE) or Staphylococcus epidermidis (19-1, MRSE).

[0084] In other embodiments of the present invention, the bacteria are Staphylococcus aureus, such as Staphylococcus aureus (ATCC 29213, MSSA), Staphylococcus aureus (ATCC 33591, MRSA), Staphylococcus aureus (ATCC 43300, MRSA), Staphylococcus aureus (ATCC 700698, MRSA, VISA), and Staphylococcus aureus (15, MSSA).

[0085] In other embodiments of the present invention, the bacteria are enterococci, such as Enterococcus faecalis (ATCC 29212, VSE), Enterococcus faecalis (ATCC 51299, VRE), Enterococcus faecium (ATCC 700221, VRE), and Enterococcus faecium (20-2, VSE).

[0086] Specifically, the pharmaceutical composition can be formulated in any suitable dosage form, such as, but not limited to, tablets, sugar-coated tablets, film-coated tablets, enteric-coated tablets, capsules, hard capsules, soft capsules, oral liquids, lozenges, granules, powders, pills, powders, ointments, elixirs, suspensions, powders, solutions, injections, suppositories, ointments, plasters, creams, sprays, drops, patches, etc., preferably injections.

[0087] Specifically, pharmaceutically acceptable excipients may include, for example, but not limited to, binders, fillers, diluents, tableting agents, lubricants, disintegrants, colorants, flavoring agents, and humectants; suitable fillers may include, for example, cellulose, mannitol, lactose, and other similar fillers; suitable disintegrants may include, for example, starch, polyvinylpyrrolidone, and starch derivatives, such as sodium glycolate starch; suitable lubricants may include, for example, magnesium stearate; and suitable humectants may include, for example, sodium dodecyl sulfate.

[0088] In an eighth aspect of the invention, the use of the fungi of the genus Subplenodomus described in the first aspect, the composition described in the second aspect, the compound described in the fourth aspect or a pharmaceutically acceptable salt, stereoisomer, prodrug, solvate thereof, and the compound described in the fifth aspect or a structural analog thereof in the preparation of an antibacterial agent are provided.

[0089] Specifically, the antibacterial agent can be used to kill or inhibit pathogens, particularly pathogenic bacteria, as described in the seventh aspect of the present invention.

[0090] In particular, the antibacterial agent can be used to kill or inhibit drug-resistant strains, as described in the seventh aspect of the present invention.

[0091] In one embodiment of the present invention, the antibacterial agent is a drug that can be used to prevent and / or treat diseases caused by pathogen infection.

[0092] In a ninth aspect of the invention, the use of the fungi of the genus Subplenodomus described in the first aspect, the composition described in the second aspect, the compound described in the fourth aspect or a pharmaceutically acceptable salt, stereoisomer, prodrug, solvate thereof, the compound described in the fifth aspect or a structural analog thereof, and the pharmaceutical composition described in the seventh aspect in the preparation of a medicament for the prevention and / or treatment of a disease is provided.

[0093] In one embodiment of the present invention, the disease is a disease caused by pathogen infection.

[0094] Specifically, pathogens can be microorganisms, parasites (protozoa, worms, etc.) or other vectors.

[0095] Specifically, the pathogenic microorganisms can be selected from one or more of the following: viruses, chlamydia, rickettsia, mycoplasma, bacteria, spirochetes, fungi, etc., especially bacteria.

[0096] Specifically, the bacteria are as described in the seventh aspect of this invention.

[0097] In particular, the bacteria are drug-resistant strains, as described in the seventh aspect of this invention.

[0098] In another embodiment of the present invention, the disease is a tumor, particularly a malignant tumor, such as lung cancer, breast cancer, liver cancer, pancreatic cancer, colorectal cancer, stomach cancer, gastroesophageal adenocarcinoma, esophageal cancer, small bowel cancer, cardia cancer, endometrial cancer, ovarian cancer, fallopian tube cancer, vulvar cancer, testicular cancer, prostate cancer, penile cancer, kidney cancer, bladder cancer, anal cancer, gallbladder cancer, bile duct cancer, myeloma, leukemia, lymphoma, melanoma, head and neck tumors, etc.

[0099] Specifically, the subjects of this drug can be mammals, such as humans, monkeys, pigs, cattle, horses, sheep, dogs, cats, rats, etc., especially humans.

[0100] In a tenth aspect of the invention, a method for preventing and / or treating a disease is provided, comprising the step of administering to a subject in need an effective amount of the compound of the fourth aspect or a pharmaceutically acceptable salt, stereoisomer, prodrug, solvate, the compound of the fifth aspect or a structural analog thereof, or a pharmaceutical composition of the seventh aspect.

[0101] Specifically, the disease is caused by pathogen infection, particularly bacterial infection (such as drug-resistant strains).

[0102] Specifically, the bacteria are as described in the seventh aspect of this invention.

[0103] Specifically, the subjects are as described in the ninth aspect of this invention.

[0104] This invention focuses on endophytic fungi of medicinal plants and has discovered a fungus of the genus Subplenodomus. Fermentation and isolation of this fungus yield a novel and potent antibacterial compound, which exhibits particularly high antibacterial activity against drug-resistant strains. This compound has excellent application prospects and research value, and provides a foundation for the development of subsequent antibacterial drugs.

[0105] The preservation information of the biomaterials of this invention is as follows: A fungus of the genus *Subplenodomus*, CPCC 401465, was deposited on April 25, 2022, at the China General Microbiological Culture Collection Center (Address: No. 3, Courtyard 1, Beichen West Road, Chaoyang District, Beijing, Institute of Microbiology, Chinese Academy of Sciences), with accession number CGMCC No. 40181 and classification name *Subplenodomus* sp. Attached Figure Description

[0106] Figure 1 This is a high-resolution mass spectrum of compound A1 described in this invention.

[0107] Figure 2 This is a high-resolution mass spectrum of compound A2 described in this invention.

[0108] Figure 3 This is a high-resolution mass spectrum of compound A3 described in this invention.

[0109] Figure 4 This is a high-resolution mass spectrum of compound A4 described in this invention.

[0110] Figure 5 This is a high-resolution mass spectrum of compound A5 described in this invention.

[0111] Figure 6 This is a high-resolution mass spectrum of compound A6 described in this invention.

[0112] Figure 7 This is a high-resolution mass spectrum of compound A7 described in this invention.

[0113] Figure 8 This is a high-resolution mass spectrum of compound A8 described in this invention.

[0114] Figure 9 This is a high-resolution mass spectrum of compound A9 described in this invention.

[0115] Figure 10 This is a high-resolution mass spectrum of compound A10 described in this invention.

[0116] Figure 11 This is a high-resolution mass spectrum of compound A11 described in this invention.

[0117] Figure 12 This is a high-resolution mass spectrum of compound A12 described in this invention.

[0118] Figure 13 This is a high-resolution mass spectrum of compound A13 described in this invention.

[0119] Figure 14 Compound A1 of the present invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0120] Figure 15 Compound A1 of the present invention is dissolved in CDCl3. 13 C-NMR spectrum Figure 16 Compound A2 of the present invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0121] Figure 17 Compound A2 of the present invention is dissolved in CDCl3. 13 C-NMR spectrum Figure 18 Compound A3 of the present invention is dissolved in DMSO-d6. 1 H-NMR spectrum.

[0122] Figure 19 Compound A3 of the present invention is dissolved in DMSO-d6. 13 C-NMR spectrum Figure 20 Compound A4 of the present invention is dissolved in CDCl3. 1 H-NMR spectrum Figure 21 Compound A4 of the present invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0123] Figure 22 Compound A5 of this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0124] Figure 23 Compound A5 of this invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0125] Figure 24 Compound A6 of this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0126] Figure 25 Compound A6 of this invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0127] Figure 26 Compound A7 of this invention is dissolved in DMSO-d6 1 H-NMR spectrum.

[0128] Figure 27 Compound A7 of this invention is dissolved in DMSO-d6 13 C-NMR spectrum.

[0129] Figure 28 Compound A8 of this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0130] Figure 29 Compound A8 of this invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0131] Figure 30 Compound A9 of the present invention is dissolved in DMSO-d6. 1 H-NMR spectrum.

[0132] Figure 31 Compound A9 of the present invention is dissolved in DMSO-d6. 13 C-NMR spectrum.

[0133] Figure 32 The compound A10 of this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0134] Figure 33 The compound A10 of this invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0135] Figure 34 The compound A11 described in this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0136] Figure 35 The compound A11 described in this invention is dissolved in CDCl3. 13 C-NMR spectrum.

[0137] Figure 36 The compound A12 described in this invention is dissolved in DMSO-d6. 1 H-NMR spectrum.

[0138] Figure 37The compound A12 described in this invention is dissolved in DMSO-d6. 13 C-NMR spectrum.

[0139] Figure 38 The compound A13 of this invention is dissolved in CDCl3. 1 H-NMR spectrum.

[0140] Figure 39 The compound A13 of this invention is dissolved in CDCl3. 13 C-NMR spectrum. Detailed Implementation

[0141] Unless otherwise defined, all scientific and technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art.

[0142] The term "culture" refers to a group of cells or growths of microorganisms within a certain time and space, especially liquid or solid culture media that have grown microbial communities (such as Subplenodomus fungi CPCC 401465 as described in this invention) after artificial inoculation and cultivation, such as slant cultures of microorganisms, fermentation products, etc.

[0143] The term "bacterial suspension" refers to a suspension obtained by dispersing microbial cells (such as Subplenodomus fungus CPCC 401465 as described in this invention) in a solvent (e.g., water).

[0144] The term "lysate" refers to the product obtained after the lysis of microbial cells (such as Subplenodomus fungus CPCC 401465 as described in this invention).

[0145] The term "carbon source" refers to a class of nutrients that contain carbon and can be utilized by microorganisms for growth and reproduction, including fast-acting and slow-acting carbon sources such as sugars, fats, organic acids and organic acid esters, and small molecule alcohols.

[0146] The term "nitrogen source" refers to substances that provide nitrogen for microbial nutrition, including readily available and slowly available nitrogen sources such as peanut meal, soybean meal, yeast powder, peptone, ammonia, ammonium salts, and nitrates.

[0147] The term "alkyl" refers to a straight-chain or branched hydrocarbon group that does not contain unsaturated bonds and is connected to the rest of the molecule by a single bond. Alkyl groups as used herein typically contain 1 to 10 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10) carbon atoms (i.e., C1-10 alkyl groups), preferably containing 1 to 3 carbon atoms (i.e., C1-10 alkyl groups). 1-3 Alkyl groups. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, etc.

[0148] The pharmaceutically acceptable salts described in this invention include acid addition salts and base addition salts.

[0149] The acid addition salts include, but are not limited to, salts from inorganic acids such as hydrochloric acid, nitric acid, phosphoric acid, sulfuric acid, hydrobromic acid, hydroiodic acid, and phosphonic acid, as well as salts from organic acids such as aliphatic monocarboxylic acids and dicarboxylic acids, phenyl-substituted alkanic acids, hydroxyalkanic acids, alkanedioic acids, aromatic acids, and aliphatic and aromatic sulfonic acids. Therefore, these salts include, but are not limited to, sulfates, pyrosulfates, bisulfates, sulfites, bisulfites, nitrates, phosphates, monohydrogen phosphates, dihydrogen phosphates, metaphosphates, pyrophosphates, hydrochlorides, hydrobromates, iodates, acetates, propionates, octanoates, isobutyrates, oxalates, malonates, succinates, octanoates, sebacic acid salts, fumarates, maleates, amygdalinates, benzoates, chlorobenzoates, methylbenzoates, dinitrobenzoates, phthalates, benzenesulfonates, toluenesulfonates, phenylacetates, citrates, lactates, maleates, tartrates, and methanesulfonates, as well as salts of amino acids such as arginine salts, gluconates, and galacturonic acids. Acid addition salts can be prepared by contacting a sufficient amount of the desired acid in a conventional manner to form a salt. The free base can be regenerated by contacting the salt with a base, and the free base can be separated in a conventional manner.

[0150] The aforementioned base addition salt refers to a salt formed with a metal or amine, such as hydroxides of alkali metals and alkaline earth metals, or with an organic amine. Examples of metals used as cations include, but are not limited to, sodium, potassium, magnesium, and calcium. Suitable amines include, but are not limited to, N,N′-dibenzylethylenediamine, chloroprocaine, choline, diethanolamine, ethylenediamine (ethane-1,2-diamine), N-methylglucosamine, and procaine. Base addition salts can be prepared by contacting the free acid form with a sufficient amount of the desired base in a conventional manner to form a salt. The free acid form can be regenerated by contacting the salt form with an acid, and the free acid can be separated in a conventional manner.

[0151] The stereoisomers described in this invention include enantiomers, diastereomers, and geometric isomers. Some compounds of this invention have cyclic hydrocarbon groups that can be substituted at more than one carbon atom; in this case, all their geometric forms, including cis and trans, and mixtures thereof, are within the scope of this invention. The cyclic hydrocarbon groups include alicyclic hydrocarbon groups and aryl groups, wherein the alicyclic hydrocarbon groups can be non-aromatic monocyclic, fused, bridged, or spirocyclic saturated or unsaturated cyclic hydrocarbon groups, such as phenyl, naphthyl, phenanthrene, biphenyl, etc.

[0152] The solvates described in this invention refer to the physical bonding of the compounds of this invention with one or more solvent molecules. This physical bonding includes various degrees of ionic and covalent bonding, including hydrogen bonding. In some cases, the solvates can be isolated, for example when one or more solvent molecules are incorporated into the crystal lattice of a crystalline solid. Solvates include solution phases and separable solvates. Representative solvates include ethanolides, methanolides, etc.

[0153] The prodrugs described in this invention refer to Formula I compounds that are suitable for administration to patients without excessive toxicity, irritation, or allergic reactions, and are effective for their intended use, including acetals, esters, and zwitterionic forms. The prodrugs are converted in vivo, such as through hydrolysis in the blood, to obtain the parent compound.

[0154] The terms “patient” or “subject”, etc., may be used interchangeably herein to refer to any animal or its cells, whether in vitro or in situ, treated according to the methods described herein. Specifically, the aforementioned animals include mammals, such as rats, mice, guinea pigs, rabbits, dogs, cats, pigs, cattle, horses, sheep, monkeys, or humans, especially humans.

[0155] In this invention, "treatment" refers to the prevention, cure, reversal, weakening, mitigation, minimization, inhibition, cessation, and / or cessation of one or more clinical symptoms of a disease after its onset.

[0156] In this invention, "prevention" refers to the treatment taken before the onset of a disease to avoid, minimize, or prevent the disease from developing or progressing.

[0157] All publications, patents, and published patent specifications cited in this article are incorporated herein in their entirety through citation.

[0158] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0159] Example 1: Isolation and identification of Subplenodomus fungus CPCC 401465 1. Isolation of strains Subplenodomus fungus CPCC 401465 was isolated from the root sample of *Subplenodomus*, a medicinal plant from Mila Mountain, Gongbo'gyamda County, Nyingchi City, Tibet Autonomous Region. The specific methods are as follows: The entire *Subplenodomus* plant was collected, placed in a resealable bag, and brought back to the laboratory for processing. The entire plant was then rinsed sequentially with 75% alcohol for 1 min, 2% sodium hypochlorite for 3 min, 75% alcohol for 30 s, and sterile water three times. The surface water was then absorbed with sterile absorbent paper, and the plant was cut into approximately 0.5 cm long tissue blocks using sterile scissors. These blocks were then placed in a solution containing streptomycin sulfate (50 mg / L). -1 ) and tetracycline (50 mg L) -1 Prepare PDA solid medium plates. Incubate at 28°C. After 5-7 days, select single colonies based on their color, size, and shape, and place them on test tube slants containing PDA medium to obtain pure cultures. Once fully grown, store in a refrigerator. Perform the following identifications on strain CPCC401465.

[0160] Preservation method for strain CPCC 401465: Store in 20% glycerol cryovials at -80℃.

[0161] 2. Identification of strains (1) Morphological characteristics The colonies of strain CPCC 401465 grow on PDA medium with smooth edges and a raised center. The aerial hyphae are white and well-developed. The mycelium is light yellow to gray, with a dull and dry surface. The reverse side has white edges and a brown to tan center.

[0162] (2) Molecular biological identification Pick cells of strain CPCC 401465 from solid culture medium into a sterile 1.5 mL centrifuge tube, add liquid nitrogen, and after cooling, quickly grind the sample into powder using a special glass grinding rod; add 300 μL of 2×CTAB extraction buffer, mix gently, and incubate at 95°C for 2 min; add an equal volume (300 μL) of phenol-chloroform mixture (phenol:chloroform:isoamyl alcohol (25:24:1, V / V / V)), vortex to mix, and centrifuge at 12000 rpm for 5 min; transfer the supernatant to a new 1.5 mL sterile centrifuge tube, add an equal volume of isopropanol, vortex to mix, transfer to a silica membrane adsorption centrifuge column, let stand for 2 min, and centrifuge at 12000 rpm for 30 s; discard the liquid, add 500 μL of EB washing buffer to the silica membrane adsorption centrifuge column, and centrifuge at 12000 rpm for 30 s; centrifuge the silica column at 12000 rpm to dry for 2 minutes. min; transfer the silica membrane adsorption centrifuge column to a new 1.5 mL sterile centrifuge tube, add 50 μL of TE elution buffer at 65℃, centrifuge at 12000 rpm for 30 s; discard the silica column, collect 50 μL of liquid in the centrifuge tube to obtain the crude extract of total DNA. The above crude DNA extract was sent to Shanghai Sangon Biotech Co., Ltd. for sequencing. The sequencing results were submitted to NCBI and compared with the corresponding gene sequences of effectively described strains in related genera and species to preliminarily determine the taxonomic group of the strain.

[0163] The ITS gene sequence of strain CPCC 401465 is shown in SEQ ID NO: 1. It shows 100% ITS sequence similarity to strain Subplenodomus drobnjacensis PRG11-03; 89% tublin sequence similarity to Comoclathris incompta isolate CH-12; and 100% LSU sequence similarity to Subplenodomus drobnjacensis PRG11-03. Based on the morphological characteristics and ITS gene sequence, the strain is identified as Subplenodomus sp. This strain was deposited at the China General Microbiological Culture Collection Center on April 25, 2022, with accession number CGMCC No. 40181. It will be referred to below as Subplenodomus fungus CPCC 401465.

[0164] Example 2: Fermentation Culture

[0165] (1) The spores of the fungus CPCC 401465 of the genus Subplenodomus were inoculated into the slant culture medium and cultured at 28℃ for 5 days to obtain the slant culture.

[0166] The slant culture medium consists of potato extract powder, glucose, agar, and water. The concentrations of these components in the slant culture medium are as follows: potato extract powder 4 g / L, glucose 20 g / L, and agar 15 g / L; the pH value of the slant culture medium is 5.6 ± 0.2.

[0167] (2) 100 mL of seed culture medium was added to several 500 mL glass bottles and sterilized at 121 °C for 20 minutes. Mycelia were picked from the slant and inoculated. The culture was shaken at 28 °C (200 rpm) for 2 days to obtain the seed liquid.

[0168] The seed culture medium consists of potato extract powder, glucose, and water. The concentrations of these components in the seed culture medium are as follows: potato extract powder 4 g / L; glucose 20 g / L; and the pH value of the liquid culture medium is 5.6 ± 0.2.

[0169] (3) 80 g of rice was placed in a 500 mL Erlenmeyer flask and soaked in 80 mL of water. The flask was sterilized at 121°C for 20 minutes to obtain the fermentation medium. The seed liquid obtained in step (2) above was inoculated into the fermentation medium (5 mL of seed liquid was inoculated into each bottle of fermentation medium). The fermentation product was obtained by static culture at 28~30°C for 30 days.

[0170] Example 3: Isolation, purification and identification of antibacterial compounds 1. Isolation and purification of antibacterial compounds Adsorption chromatography: The solid-state fermentation culture product of CPCC 401465 rice (4.0 kg) was poured into a 30 L round drum, soaked in methanol for 3 days, ultrasonically extracted 3 times, filtered through a filter screen, centrifuged the filtrate, collected the supernatant, and concentrated under reduced pressure to obtain 350.0 g of crude methanol extract; the crude methanol extract was dispersed in 3 L of deionized water and extracted 3 times with ethyl acetate in equal volume to obtain 180.0 g of ethyl acetate extract; the antibacterial activity was detected by the paper disc method, and the active component was found to be the ethyl acetate extract. TLC analysis was performed, and the fractions were purified by silica gel column chromatography using a dichloromethane-methanol system with gradient elution (v / v, 100:0, 95:5, 90:10, 85:15, 80:10, 75:15, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, 35:65, 0:100). The fractions were then combined by TLC analysis to obtain 15 fractions, numbered 1 to 15.

[0171] 2,500 mg of the fraction was purified by ODS under pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min flow rate) to obtain fractions B1-B3. Fraction B2 was prepared by HPLC (68% acetonitrile-0.01% TFA water, 3.5 mL / min flow rate) to obtain compounds A13 (10.8 mg, tR 14.2 min) and A6 (10.2 mg, tR 18.2 min). Components 3 (14.63 g) and 4 (33.24 g) have the same main components, so the two components were combined and then purified. 500 mg of component 3 was purified under ODS pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min flow rate) to obtain components C1-C3. Component C1 was prepared by HPLC (60% acetonitrile-0.01% TFA water, 3.5 mL / min flow rate) to obtain A10 (14.2 mg, tR 13.2 min) and A11 (10.3 mg, tR 14.5 min). Component C3 was prepared by HPLC (70% acetonitrile-0.01% TFA water, 3.5 mL / min flow rate) to obtain A4 (17.1 mg, tR 16.2 min), A5 (5.0 mg, tR 17.5 min), and A1 (6.7 mg, tR 18.7 min). Fragment 5 was purified by ODS under pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min) to obtain fractions D1-D5. Fragment D4 (60 mg) was directly prepared by HPLC (50% acetonitrile-0.01% TFA water, 3.5 mL / min) to obtain compounds A3 (19.0 mg, tR 14.4 min) and A12 (19.8 mg, tR 12.1 min). Fragment 6 (3.50 g) was purified by ODS under pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min) to obtain fractions E1-E4. Fragment E4 was prepared by HPLC (65% acetonitrile-0.01% TFA water, 3.5 mL / min) to obtain compound A9 (10.8 mg, tR 14.2 min). Fraction 7 (2.82 g) was purified by ODS pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min flow rate) to obtain fractions F1-F4. Fraction F3 was prepared by HPLC (65% acetonitrile-0.01% TFA water, 3.5 mL / min flow rate) to obtain compound A7 (6.6 mg, tR 16.2 min).Fraction 8 (5.53 g) was purified by ODS pressure (10%-100% acetonitrile-0.01% TFA water, 25.0 mL / min flow rate) to obtain fractions G1-G7. Fraction G5 was prepared by HPLC (55% acetonitrile-0.01% TFA water, 3.5 mL / min flow rate) to obtain compound A8 (13.1 mg, tR 16.6 min).

[0172] 2. Identification of antibacterial compounds The compounds A1~A13 obtained above were identified as follows: (1) Appearance: Compounds A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12 and A13 are light yellow solid powders.

[0173] (2) Solubility: Compounds A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12 and A13 are all soluble in dichloromethane, ethyl acetate, methanol and acetonitrile.

[0174] (3) Mass spectrometry: Figure 1 This is the HRESIMS mass spectrum of compound A1, showing its [MH] content. - The peak at m / z 543.12964 indicates that its molecular formula is C. 30 H 24 O 10 . Figure 2 This is the HRESIMS mass spectrum of compound A2, showing its [MH] content. - The peak value is m / z 543.12946, indicating that its molecular formula is C. 30 H 24 O 10 . Figure 3 This is the HRESIMS mass spectrum of compound A3, showing its [MH] content. - The peak value is m / z 545.14465, indicating that its molecular formula is C. 30 H 26 O 10 . Figure 4 This is the HRESIMS mass spectrum of compound A4, showing its [MH] content. - The peak value is m / z 543.13007, indicating that its molecular formula is C. 30 H 24 O 10 . Figure 5 This is the HRESIMS mass spectrum of compound A5, showing its [MH] content.- The peak at m / z 543.12958 indicates that its molecular formula is C. 30 H 24 O 10 . Figure 6 This is the HRESIMS mass spectrum of compound A6, showing its [MH] content. - The peak at m / z 541.11407 indicates that its molecular formula is C. 30 H 22 O 10 . Figure 7 This is the HRESIMS mass spectrum of compound A7, showing its [MH] content. - The peak value is m / z 561.14093, indicating that its molecular formula is C. 30 H 26 O 11 . Figure 8 This is the HRESIMS mass spectrum of compound A8, showing its [MH] content. - The peak at m / z 547.16174 indicates that its molecular formula is C. 30 H 28 O 11 . Figure 9 This is the HRESIMS mass spectrum of compound A9, showing its [MH] content. - The peak at m / z 565.17218 indicates that its molecular formula is C. 30 H 30 O 11 . Figure 10 This is the HRESIMS mass spectrum of compound A10, showing its [MH] content. - The peak at m / z 545.11490 indicates that its molecular formula is C. 30 H 26 O 10 . Figure 11 This is the HRESIMS mass spectrum of compound A11, showing its [MH] content. - The peak at m / z 543.12958 indicates that its molecular formula is C. 30 H 24 O 10 . Figure 12 This is the HRESIMS mass spectrum of compound A12, showing its [MH] content. - The peak value is m / z 545.14490, indicating that its molecular formula is C. 30 H 26 O 10 . Figure 13 This is the HRESIMS mass spectrum of compound A13, showing its [MH] content. - The peak value is m / z 541.11475, indicating that its molecular formula is C. 30H 22 O 10 HRESIMS assays were performed using a Thermo Scientific LTQOrbitrap XL mass spectrometer system with methanol as the solvent.

[0175] (4) Nuclear magnetic resonance spectrum: Figures 14-15 These are compounds A1. 1 H-NMR, 13 C-NMR spectrum, Figures 16-17 These are compounds A2. 1 H-NMR, 13 C-NMR spectrum, Figures 18-19 These are compounds A3. 1 H-NMR, 13 C-NMR spectrum, Figures 20-21 These are compounds A4. 1 H-NMR, 13 C-NMR spectrum, Figures 22-23 It is compound A5. 1 H-NMR, 13 C-NMR spectrum. Figures 24-25 It is compound A6. 1 H-NMR, 13 C-NMR spectrum. Figures 26-27 It is compound A7. 1 H-NMR, 13 C-NMR spectrum. Figures 28-29 It is compound A8. 1 H-NMR, 13 C-NMR spectrum. Figures 30-31 It is compound A9. 1 H-NMR, 13 C-NMR spectrum. Figures 32-33 It is compound A10. 1 H-NMR, 13 C-NMR spectrum. Figures 34-35 It is compound A11 1 H-NMR, 13 C-NMR spectrum. Figures 36-37 It is compound A12 1 H-NMR, 13 C-NMR spectrum. Figures 38-39 It is compound A13 1 H-NMR, 13 C-NMR spectra. The NMR signals of the compounds were assigned, as shown in the table below.

[0176] Table 1.1 NMR data of compounds A1-A6 (1 H NMR 600 MHz; 13 C NMR 151 MHz; CDCl3)

[0177] Table 1.2 NMR data of compounds A7-A11 ( 1 H NMR 600 MHz; 13 C NMR 151 MHz; CDCl3)

[0178] Table 1.3 NMR data of compounds A12-A13 ( 1 H NMR 600 MHz; 13 C NMR 151 MHz; CDCl3)

[0179] The chemical structures of compounds A1-A13 are based on their 1 H-NMR, 13 C-NMR, HSQC, HMBC, DEPT 1 H- 1 The structures of compounds A1-A13 were determined by HCl COSY and NOE spectra as follows:

[0180]

[0181]

[0182]

[0183]

[0184] Example 4: Detection of the antibacterial activity of the compound The specific steps for determining the MIC of compounds A1-A13 using the microplate method are as follows: According to the Clinical and Laboratory Standards Institute (CLSI) standards, the microdilution method was used to determine the in vitro activity of the isolated compounds against clinically resistant bacteria: the test bacteria were streaked from cryopreserved tubes onto nutrient agar plates for activation, incubated overnight at 35±2℃, and 3-5 single colonies were picked and transferred to nutrient broth medium and incubated at 35±2℃ for 6-8 hours. The test compound was diluted to 256 μg / mL using CAMHB medium. 100 μL of the diluted compound was added to each well in the second column of a 96-well plate. 100 μL of CAMHB medium was added to each well in the remaining columns. Another 100 μL of CAMHB medium was added to each well in the second column using a pipette, and the mixture was repeatedly pipetted to ensure homogeneity. 100 μL of this mixture was then added to each well in the third column, and the mixture was again pipetted to ensure homogeneity. 100 μL of this mixture was added to each well in the fourth column, and so on, until a two-fold dilution was achieved up to the second-to-last column. 100 μL of this second-to-last column was discarded. The final concentrations of the drug in the second to last columns were: 128, 64, 32, 16, 8, 4, 2, 1, 0.5, and 0.25 μg / mL, respectively, with a final system volume of 100 μL. The first and last columns of the 96-well plate served as a blank control and a growth control for the bacterial strain (only medium or bacterial culture was added). The cultured bacterial suspension was adjusted to 0.5 McF (approximately 1 × 10⁻⁶) with 0.85% physiological saline. 8 (CFU / mL), then diluted 20-fold with CAMHB medium to prepare a concentration of approximately 5 × 10⁻⁶ CFU / mL. 6 A bacterial suspension of CFU / mL was prepared. 10 μL of the diluted bacterial suspension was added to each well in rows 1-7, columns 2-12. Row 8 served as a blank control for the drug. The final bacterial concentration in each well was approximately 5 × 10⁻⁶. 5 CFU / mL. After incubating the 96-well plate at 35±2℃ for 16-18 hours, the results were observed. The lowest concentration of the compound in the well where no bacterial growth was observed (no turbidity was visible to the naked eye) was the minimum inhibitory concentration (MIC). The antibacterial activity test strains used in the experiment were deposited at the Medicinal Microorganisms Related to Microorganisms (Viruses) Preservation Branch Center, Pathogenic Microorganisms (Viruses) Preservation Center, Chinese Academy of Medical Sciences, Beijing, 100054. The information includes: *Staphylococcus epidermidis* (ATCC 12228, MSSE), *Staphylococcus aureus* (ATCC29213, MSSA), *Staphylococcus aureus* (ATCC 43300, MRSA), *Staphylococcus aureus* (ATCC 700698, MRSA, VISA), *Enterococcus faecalis* (ATCC 29212, VSE), *Enterococcus faecalis* (ATCC 51299, VRE), and *Enterococcus faecium* (ATCC 700221, VRE). The experimental results are shown in the table below.

[0185] Table 2.1 Antibacterial activity of compounds A1-A7

[0186] Table 2.2 Antibacterial activity of compounds A8-A13

[0187] The above data indicate that compounds A1-A13 have inhibitory effects on Staphylococcus epidermidis (ATCC 12228, MSSE), Staphylococcus aureus (ATCC 29213, MSSA), Staphylococcus aureus (ATCC 43300, MRSA), Staphylococcus aureus (ATCC700698, MRSA, VISA), Enterococcus faecalis (ATCC 29212, VSE), Enterococcus faecium (ATCC 700221, VRE), and Enterococcus faecalis (ATCC 51299, VRE), especially showing good antibacterial activity against Enterococcus faecalis and Staphylococcus epidermidis, even superior to the positive control drug levofloxacin.

[0188] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0189] The foregoing embodiments and methods described in this invention may vary based on the capabilities, experience, and preferences of those skilled in the art.

[0190] Listing the steps of the method in a certain order in this invention does not constitute any restriction on the order of the method steps.

Claims

1. A compound or a pharmaceutically acceptable salt thereof, said compound being selected from the following structures: 。 2. The method for preparing the compound according to claim 1, characterized in that, The preparation method includes taking a... Subplenodomus The compound is obtained by fermentation with fungi and extraction and separation of the fermentation products; Subplenodomus The ITS gene sequence of fungi is shown in SEQ ID NO: 1; The fungus has the accession number CGMCC No. 40181; The extraction and separation includes: (1) The fermentation product is extracted with organic solvent I to obtain a crude extract; wherein organic solvent I is methanol or ethanol; (2) Disperse the crude extract obtained in step (1) and extract it with organic solvent II to obtain an extract; the organic solvent II is selected from one or more of ethyl acetate, isopropyl acetate, methyl acetate, and methyl isobutyl ketone. (3) The extract obtained in step (2) is subjected to adsorption chromatography and the eluent is collected; the adsorbent of the adsorption chromatography is silica gel, and the mobile phase is a mixture of dichloromethane and methanol with a volume ratio of 100-0:0-100. (4) Extract and separate the eluent obtained in step (3), wherein the extraction and separation includes the steps of ODS column chromatography separation and preparative HPLC separation.

3. The preparation method according to claim 2, characterized in that, The organic solvent I mentioned in step (1) is methanol; and / or the organic solvent II mentioned in step (2) is ethyl acetate.

4. The preparation method according to claim 2, characterized in that, Step (1) also includes the step of filtering the extract.

5. The preparation method according to claim 4, characterized in that, Step (1) also includes the step of concentrating the filtrate.

6. The preparation method according to claim 2, characterized in that, The solvent used for dispersion in step (2) is water.

7. A pharmaceutical composition, characterized in that, The pharmaceutical composition comprises the compound of claim 1 or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable excipients.

8. The use of the compound of claim 1 or a pharmaceutically acceptable salt thereof in the preparation of an antimicrobial agent for treating diseases caused by bacterial infections.

9. The application as described in claim 8, characterized in that, The bacteria are selected from one or more of Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis, and Enterococcus faecium.

10. The application as described in claim 8, characterized in that, The bacteria are selected from one or more of the following: methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA), methicillin-resistant Staphylococcus epidermidis (MRSE), and vancomycin-resistant Enterococcus (VRE).

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