Use of geldanamycin and analogs thereof

Abstract

The application discloses a new use of geldanamycin and analogues thereof, and application of the geldanamycin and the analogues thereof in preparation of a medicine with a broad-spectrum antibacterial effect on various plant pathogens or plant diseases. One or more of compounds 1, compound 2 and compound 3 in the geldanamycin and the analogues thereof have antibacterial activity on crop pathogenic fungi, and can be used as a biological pesticide for plant diseases caused by pathogenic bacteria such as xanthomonas bacteria, and the biological pesticide includes but is not limited to crop diseases caused by rice bacterial leaf blight and mango bacterial angular spot pathogens.

Description

[0001] Case Separation Statement

[0002] This application is a divisional application of Chinese patent application No. 202210373144.6, filed on April 11, 2022, entitled "New Uses of Gerdmycin and Its Analogs". Technical Field

[0003] This invention belongs to the field of biomedical technology, specifically relating to new uses of gerdemycin and its analogues, especially the application of gerdemycin and its analogues in the preparation of drugs with broad-spectrum antibacterial effects against a variety of plant pathogens or plant diseases. Background Technology

[0004] Chemical pesticides can achieve good results in controlling plant diseases in a short period of time, but their adverse effects become increasingly apparent over time. Coupled with the growing promotion of the "green ecology" concept, the research and development and production of pollution-free biological pesticides have become an urgent priority. As a branch of biological pesticides, pesticide antibiotics are characterized by being residue-free, easily decomposable, and environmentally friendly. However, currently, there are relatively few commercially available agricultural antibiotics, which cannot meet the needs of agricultural production. Furthermore, some antibiotics target only a single disease, limiting their application. Especially in tropical regions, chemical pesticides are still the primary means of controlling many tropical crop diseases, with agricultural antibiotics being used less frequently or having little effect. Therefore, discovering agricultural antibiotics that are effective in controlling crop diseases, especially those of tropical crops, is of significant production importance. Summary of the Invention

[0005] The purpose of this invention is to provide new uses for gerdromycin and its analogues.

[0006] The above-mentioned objective of this invention is achieved through the following technical solution: a novel use of gerdemycin and its analogues, wherein gerdemycin and its analogues are used in the preparation of drugs with broad-spectrum antibacterial effects against a variety of plant pathogens or plant diseases, and wherein gerdemycin and its analogues are one or more of compounds 1, 2 and 3 having the following structures:

[0007]

[0008] Preferably, the plant is a variety of economic crops.

[0009] Preferably, the plant is cucumber, chili pepper, papaya, cowpea, mango, banana, rice, wheat, or rubber tree.

[0010] Preferably, the plant pathogen is one or more of the following fungi: Anthracnose, Corynebacterium, Fusarium, Phytophthora, Trichoderma, Pyrethrum, Pyrethrum, Pseudomonas, and Xanthomonas.

[0011] Preferably, the plant diseases include one or more of the following: banana wilt fungus, banana anthracnose fungus, pepper anthracnose fungus, pepper leaf spot fungus, pepper blight fungus, papaya anthracnose fungus, papaya brown stem rot fungus, papaya canker fungus, cowpea gray spot fungus, mango anthracnose fungus, rubber anthracnose fungus, wheat scab fungus, rice blast fungus, cucumber root rot fungus, rice bacterial leaf blight fungus, and mango bacterial angular leaf spot fungus.

[0012] Preferably, the germamycin and its analogues are prepared by the following method:

[0013] (1) Selection of fermentation strain: The fermentation strain was Streptomyces sp. HNBCa1, which was deposited at Guangdong Provincial Microbial Culture Collection Center on September 3, 2021, with the collection registration number GDMCC NO.61901;

[0014] (2) Seed culture preparation: The Streptomyces from step (1) is cultured in seed culture medium to obtain seed culture;

[0015] (3) Fermentation: The seed liquid from step (2) is inoculated into the fermentation medium for fermentation treatment to obtain fermentation liquid;

[0016] (4) Extraction of fermentation products: Filter the fermentation broth in step (3), extract the bacterial broth with ethyl acetate to obtain the extract, extract the bacterial cells with a methanol-dichloromethane mixture to obtain the extract, combine the extract and the extract and concentrate under reduced pressure to obtain a crude extract containing gerdromycin and its analogues.

[0017] (5) Separation of geldmycin and its analogues: The crude extract was separated by normal phase silica gel column, reverse phase silica gel column, dextran gel column and semi-preparative high performance liquid chromatography to obtain geldmycin and its analogues.

[0018] Preferably, the seed culture medium in step (2) contains: 15-20g tryptone, 2-4g soybean papain hydrolysate, 4-6g sodium chloride, 2-3g dipotassium hydrogen phosphate, 2-3g glucose, and 1L distilled water, and the pH of the seed culture medium is 7.3±0.2.

[0019] Preferably, when seed culture medium is used in step (2), the culture is shaken at 28-30℃ and 150-170rpm for 3-5 days.

[0020] Preferably, the fermentation medium in step (3) contains: 15-25g soluble starch, 4-6g peptone, 2-4g malt extract, 2-4g yeast extract, 8-12g glucose, 0.5-1.5g calcium carbonate, and 1L distilled water, and the pH of the fermentation medium is 7.0.

[0021] Preferably, in step (4), the ethyl acetate and the bacterial solution are of equal volume, and the volume ratio of methanol to dichloromethane in the methanol-dichloromethane mixture is 1:1.

[0022] Preferably, in step (5), when the crude extract is passed through a normal-phase silica gel column, it is eluted with a chloroform-methanol gradient at volume ratios of 100:0, 100:1, 100:2, 100:4, 100:8, 100:16, 100:32, 100:64, and 0:100 to obtain nine polar fractions Fr.A to Fr.I; wherein Fr.D and Fr.F are purified by reverse-phase silica gel column, dextran gel column, and semi-preparative high-performance liquid chromatography to obtain compound 1 and compound 2, respectively, and Fr.G is purified by normal-phase silica gel column, reverse-phase silica gel column, dextran gel column, and semi-preparative high-performance liquid chromatography to obtain compound 3.

[0023] Preferably, the reversed-phase silica gel column in step (5) is an ODS C18 reversed-phase silica gel column, and the dextran gel column is a Sephadex LH-20 dextran gel column.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] (1) Compounds 1, 2 and 3 of the geldmycin and its analogues provided by the present invention are natural products of microbial origin, which are easily degradable and environmentally friendly;

[0026] (2) The raw materials for producing compounds 1, 2 and 3 of geldmycin and its analogues provided by the present invention are readily available, the process is relatively simple and the cost is low, making them suitable for use as pesticides.

[0027] (3) The present invention demonstrates through bioactivity testing that one or more of compounds 1, 2 and 3 in Gerdemycin and its analogues have antibacterial activity against a variety of crop pathogenic fungi and bacteria, and can be used as a biological pesticide for the prevention and control of plant diseases caused by pathogens such as Anthracnose, Corynebacterium, Fusarium, Phytophthora, Trichoderma, Pyrethrum, Pseudomonas, and Xanthomonas, including but not limited to the prevention and control of crop diseases caused by pathogens such as Fusarium wilt of banana, Anthracnose of banana, Anthracnose of pepper, Corynebacterium leaf spot of pepper, Phytophthora of pepper, Anthracnose of papaya, Brown stem rot of papaya, Canker of papaya, Gray spot of cowpea, Anthracnose of mango, Anthracnose of rubber, Fusarium graminearum of wheat, Blast of rice, Root rot of cucumber, Bacterium blast of rice, and Bacterial angular leaf spot of mango. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0029] Figure 1 The chemical structures of compounds 1-3 isolated and identified in Example 1 are shown;

[0030] Figure 2 The diagram shows the antibacterial effects of compounds 1-3 in Example 2 against certain pathogenic fungi. Compound solutions were added to the culture medium plates after holes were punched in the center, and pathogenic fungi were inoculated at both ends. Specifically: 1A-1D are the control group (pathogenic fungi inoculated only at both ends of the culture medium plates); 2A-2D are the compound 1 (geldanamycin) treatment group; 3A-3D are the compound 1 + compound 2 (geldanamycin + 17-O-demethyl-geldanamycin) treatment group; 4A-4D are the compound 3 (reblastatin) treatment group; 5A-5D are the chlorothalonil treatment group; 6A-6D are the carbendazim treatment group; 7A-7D are the tebuconazole treatment group. Row A represents *Corynebacterium tumefaciens* leaf spot pathogen; row B represents *Phytophthora capsici*; row C represents *Papaver somniferum* brown stem rot pathogen; and row D represents *Pheretima aspergillum* root rot pathogen. Detailed Implementation

[0031] Example 1: Fermentation of strain HNBCa1 and extraction of fermentation products

[0032] (1) The fermentation strain is Streptomyces sp. HNBCa1, which was deposited at the Guangdong Provincial Microbial Culture Collection Center on September 3, 2021, with the collection registration number GDMCC NO.61901 (strain patent application number: 202111339491.9, application date: November 12, 2021);

[0033] (2) Seed culture preparation: The seed culture medium formula is 17.0g tryptone, 3.0g soybean papain hydrolysate, 5.0g sodium chloride, 2.5g dipotassium hydrogen phosphate, 2.5g glucose, 1L distilled water, pH 7.3±0.2. The Streptomyces sp. HNBCa1 strain from step (1) was activated on a commercially available ISP2 solid plate, and 10 circular mycelial blocks with a diameter of 7mm were inoculated into the seed culture medium. The culture was carried out at 28℃ and 160rpm for 5 days with shaking to obtain the seed culture.

[0034] (3) Fermentation: The fermentation medium formula is 20.0g soluble starch, 5.0g peptone, 3.0g malt extract, 3.0g yeast extract, 10.0g glucose, 1.0g calcium carbonate, 1L distilled water, pH 7.0. The seed liquid in step (2) is inoculated into the fermentation medium at an inoculation amount of 10% (volume percentage content). The fermentation is carried out at 28℃ and 160rpm for 10 days with shaking.

[0035] (4) Extraction of fermentation products: After filtering the obtained 10L fermentation broth through gauze, the bacterial broth was extracted with an equal volume of ethyl acetate to obtain an extract. The bacterial cells were extracted with methanol:dichloromethane at a volume ratio of 1:1 to obtain an extract. The extract and the extract were combined and concentrated under reduced pressure using a rotary evaporator to obtain a crude extract containing gerdemycin and its analogues.

[0036] Example 2: Isolation of Gerdmycin-like Compounds

[0037] The crude extract obtained in Example 1 was subjected to silica gel column chromatography (particle diameter 45-75 μm) with a chloroform-methanol gradient elution at volume ratios of 100:0, 100:1, 100:2, 100:4, 100:8, 100:16, 100:32, 100:64, and 0:100 to obtain nine polar fractions (Fr.A to Fr.I). Fr.D and Fr.F were subjected to reversed-phase silica gel column chromatography, Sephadex LH-20 gel column chromatography, and semi-preparative high-performance liquid chromatography (Waters 1525, hereinafter the same) to obtain compound 1 (230.5 mg) and compound 2 (10.1 mg), respectively. Fr.G was subjected to normal-phase silica gel column chromatography, reversed-phase silica gel column chromatography, and Sephadex LH-20 gel column chromatography. Compound 3 (33.8 mg) was obtained by LH-20 gel column chromatography and semi-preparative high-performance liquid chromatography. The structural formulas of compounds 1, 2 and 3 are as follows: Figure 1 As shown.

[0038] Example 3: Structural Identification of Gerdmycin-like Compounds

[0039] The chemical structures of the monomeric compounds isolated in Example 2 were determined by nuclear magnetic resonance (NMR) spectroscopy and high-resolution mass spectrometry (HRESIMS). The obtained data were consistent with those reported in the literature, as detailed below. The NMR spectrometer was a Bruker AVIII-500MHz NMR spectrometer, and the HRESIMS spectrometer was an Agilent 6210TOF LC-MS mass spectrometer.

[0040] Compound 1: Orange-yellow powder, its quasi-molecular ion peak mass-to-charge ratio was measured to be m / z 559.2773 [MH]- by negative source HRESIMS, and its molecular formula is C 29 H 40 N2O9. Its 1 H-NMR data (CDCl3, 500MHz) δ HRespectively: 8.72(1H,br s,NH-1),7.29(1H,s,H-19),6.94(1H,d,J=12.1Hz,H-3),6.58(1H,t,J=11.7,10.8Hz,H-4),5.90(1H,q, J=11.1,9.9Hz,H-5),5.82(1H,d,J=9.7Hz,H-9),5.19(1H,d,J=4.9Hz,H-7),4.32(1H,d,J=9.3Hz,H-6), 4.13(1H,s,OCH3-17),3.54(1H,d,J=8.5Hz,H-10),3.37(3H,s,OCH3-12),3.31(3H,s,OCH3-12),3.30(3 H,s,OCH3-6),2.79(1H,q,H-12),2.46(2H,m,H-15),2.03(3H,s,CH3-2),1.80(3H,s,CH3-8),1.65(H,br s,H-14),1.01(3H,d,J=6.5Hz,CH3-10),0.97(3H,d,J=7.0Hz,CH3-14); 13 C-NMR data (CDCl3-d6, 125MHz) δ C The values ​​are as follows: 185.0 (C-21), 184.1 (C-18), 168.3 (C-1), 157.0 (C-17), 156.0 (OCONH2-7), 138.1 (C-20), 136.4 (C-5), 134.8 (C-2), 133.2 (C-8), 133.1 (C-9), 127.6 (C-3), 127.2 (C-16), 126.3 (C-4), 111.7 (C-19), and 81.7. (C-7), 81.3(C-6), 81.0(C-12), 72.7(C-11), 61.7(OCH3-17), 57.3(OCH3-6), 56.7(OCH3-12), 34.7(C-13), 32.8(C-15), 32.2(C-10), 27.9(C-14), 23.0(CH3-14), 12.9(CH3-10), 12.5(CH3-8), 12.3(CH3-2). Based on the above proton and carbon spectral data, consistent with literature reports, it was identified as geldanamycin.

[0041] Compound 2: Yellow powder; its quasi-molecular ion peak mass-to-charge ratio was measured to be m / z 545.2516 [MH] using HRESIMS negative source. - The molecular formula is C 28 H 38 N2O9. Its 1H-NMR data (CDCl3, 500MHz) δ H The values ​​are: 8.96 (1H,s,NH-1), 7.42 (1H,s,H-19), 6.97 (1H,d,J=11.8Hz,H-3), 6.58 (1H,t,J=11.8Hz,H-4), 5.90 (1H,t,J=11.8Hz,H-5), 5.81 (1H,d,J=9.5Hz,H-9), 5.18 (1H,s,H-7), and 4.32 (1H,d,J). =9.3Hz,H-6),3.53(1H,m,H-11),3.51(1H,m,H-5),3.36(3H,s,OCH3-6),3.31(3H,s,OCH3-12) ,2.79(1H,m,H-10),2.45(1H,m,H-15),2.03(3H,s,OCH3-8),1.80(3H,s,OCH3-2),1.76(1H,br s, H-13, H-14), 1.00 (3H, d, J = 6.3 Hz, CH3-10), 0.97 (3H, d, J = 7.0 Hz, CH3-14). 13 C-NMR data (CDCl3-d6, 125MHz) δ C The values ​​are: 184.3 (C-21), 183.1 (C-18), 168.2 (C-1), 156 (OCONH2-7), 153.1 (C-17), 140.5 (C-20), 134.6 (C-2), 133.3 (C-8), 133.1 (C-9), 127.6 (C-3), 126.2 (C-4), 117.4 (C-16), 108.2 (C-19), and 81. 8(C-7), 81.4(C-6), 81.0(C-12), 72.7(C-11), 57.4(OCH3-8), 56.7(OCH3-6), 34.3(C-13), 32.6(C-15), 32.2(C-10), 28.0(C-14), 23.2(CH3-10), 12.8(CH3-14), 12.5(CH3-8), 12.3(CH3-2). Based on the above proton and carbon spectral data, consistent with literature reports, it was identified as 17-O-demethyl-geldanamycin.

[0042] Compound 3: White powder; its quasi-molecular ion peak mass-to-charge ratio was measured to be m / z 547.3031 [MH] using HRESIMS with a negative source. - The molecular formula is C 29 H 44 N2O8. Its 1 H-NMR data (CDCl3, 500MHz) δH The values ​​are: 9.21 (1H, s, NH-1), 6.87 (1H, br s, 19-H), 6.45 (2H, br s, NH2-24), 6.30 (1H, s, H-21), 5.86 (1H, br t,H-3),5.30(1H,d,J=9.8Hz,H-9),4.86(1H,d,J=7.4Hz,H-7),4.29(1H,d,J=5.2Hz,OH-11),3.63(1H,s,OCH3-17),3.32(1H,s, OCH3-6),3.21(1H,s,OCH3-12),3.02(1H,m,J=8.3,3.7Hz,H-12),2.56(1H,dd,J=13.4,6.3Hz,H-15),2.36(1H,m,H-15),2.20(1 H,m,J=13.4,6.6Hz,H-4),2.10(1H,m,H-4),1.74(1H,m,J=13.3,6.8Hz,H-14),1.68(3H,s,CH3-2),1.54(1H,m,H-13),1.44(3H, s,CH3-8),1.35(1H,m,H-5),1.26(1H,m,H-5),1.16(1H,m,H-13),0.90(3H,d,J=6.6Hz,CH3-10),0.80(3H,d,J=6.6Hz,CH3-14). 13 C-NMR data (CD3Cl3-d6, 125MHz) δ C The values ​​are as follows: 156.66 (OCONH2-7), 150.36 (C-18), 143.00 (C-17), 135.06 (C-3), 134.03 (C-20), 133.89 (C-16), 132.73 (C-2), 130.23 (C-8), 107.68 (C-19), 81.62 (C-12), 81.18 (C-7), 80 0.04 (C-6), 60.30 (OCH3-17), 58.76 (OCH3-6), 56.96 (OCH3-12), 36.32 (C-15), 34.20 (C-13), 31.65 (C-14), 30.27 (C-5), 24.07 (C-4), 20.27 (C-28), 13.55 (C-22), 12.20 (C-25). Based on the above proton and carbon spectral data, which are consistent with literature reports, it was identified as reblastatin.

[0043] Example 4: Determination of the antifungal activity of geldmycin and its analogues against crop pathogenic fungi.

[0044] 4.1 Tested pathogenic fungi: *Colletotrichum sp.* (anthracnose causal agent for pepper), *Corynesporacassiicola* (leaf spot causal agent for pepper), *Phytophthora capsici* (pesticide for pepper), *Corynesporasp.* (grey spot causal agent for cowpea), *Colletotrichum gloeosporioides* (anthracnose causal agent for mango), *Lasiodiplodiatheobromae* (canker causal agent for papaya), *Phomopsis caricae-papayae Fetrak & Cif.* (brown stem rot causal agent for papaya), *Colletotrichum gloeosporioides Penz.* (anthracnose causal agent for papaya), *Colletotrichum musae* (anthracnose causal agent for banana), *Fusarium oxysporum f.sp. cubense, Foc4* (wilt causal agent for banana), *Pyricularia oryzae* (rice blast causal agent), *Fusarium graminearum schw.* (wheat scab causal agent), *Colletotrichum* (anthracnose causal agent for rubber). acutatum and Fusarium solani, the pathogen causing cucumber root rot, were used as indicator bacteria for antibacterial spectrum determination.

[0045] 4.2 Test Method: The compounds isolated in Example 2 and commercially available positive control agents (chlorothalonil, cyazofamid, and carbendazim) were dissolved in dimethyl sulfoxide to prepare solutions with a concentration of 10 mg / mL. 10 mL of potato dextrose agar (dry powder medium sold by Qingdao High-Tech Industrial Park Haibo Biotechnology Co., Ltd.) was poured into a 6 cm diameter sterile petri dish. After solidification, a 5 mm diameter hole was punched in the center of the plate, and 10 μL of the solution was added to the hole. Pathogenic fungal blocks with a diameter of 5 mm were placed on both sides of the plate. The control group was inoculated only with pathogenic fungi. Chlorothalonil (75% effective content, powder sold by Limin Chemical Co., Ltd.), cyazofamid (40% effective content, powder sold by Shanghai Yuelian Biotechnology Co., Ltd.), and carbendazim (98% effective content, powder sold by Shanghai Maclean Biochemical Technology Co., Ltd.) served as positive controls. Each treatment was repeated three times. After the control group reached full colony size, the inhibition diameter was measured, and the inhibition rate was calculated.

[0046]

[0047] 4.3 Results of antifungal activity are shown in Table 1. The monomeric compounds 1 and 3 of the geldmycin class, as well as the combination of compounds 1 and 2, exhibit a broad antifungal spectrum. They show antifungal activity against *Fusarium wiltii*, *Anthracnose spp.*, *Anthracnose spp.*, *Cyclocarya paliurus*, *Phytophthora indicum*, *Anthracnose spp.*, *Phytophthora indicum*, *Phytophthora indicum*, *Phytophthora indicum*, *Grey spot spp.*, *Anthracnose spp.*, *Phytophthora indicum*, *Grey spot spp.*, *Phytophthora indicum ... Figure 2 As shown. Although the antifungal activity of the germymycin monomer compounds 1 and 3 and the combination of compounds 1 and 2 found in this embodiment is weaker than that of some positive control drugs, the most important significance of this discovery is that it is the first time that germymycin and its analogues have antifungal activity against plant pathogenic fungi. In the future, their chemical structures can be modified to obtain compounds with stronger activity.

[0048] Table 1. Effects of Gerdmycin and its derivatives against plant pathogenic fungi

[0049]

[0050]

[0051] Note: Different lowercase letters after the data in the same row indicate that the difference is significant at the P<0.05 level.

[0052] Early tests revealed that compound 2 alone had relatively weak general activity. However, further tests showed that mixing compound 2 and compound 1 at the same concentration in a 1:1 volume ratio and then performing activity tests showed that compound 2 had better activity against a variety of pathogens than compound 1 alone.

[0053] Example 5: Determination of antibacterial activity of gerdromycin and its analogues

[0054] 5.1 Test pathogenic bacteria: Xanthomonas oryzaepv.oryzae, the pathogen causing bacterial blight of rice, and Xanthomanas campestris pv.mangiferaeindicae, the pathogen causing angular leaf spot of mango.

[0055] 5.2 Test Method: The minimum inhibitory concentration (MIC) method was used. The compound isolated in Example 2 and commercially available kanamycin were dissolved in dimethyl sulfoxide to prepare solutions with a concentration of 1.3 mg / mL. A 96-well plate was used, with 160 μL of culture medium and 40 μL of samples of different concentrations added to the first well of each row. The solutions were then diluted sequentially using a two-fold dilution method. Finally, 100 μL of pathogenic bacterial solution was added. The absorbance of the bacterial solution (OD600) was 0.6–0.8. The solutions were incubated at 28°C for 24–48 hours and then observed.

[0056] 5.3 Results on antibacterial activity are shown in Table 2. The monomeric compounds 1 and 3 of the geldmycin class, as well as the combination of compounds 1 and 2, all exhibited significant antibacterial activity against *A. mangoisylum angularis* strain L3 and *Bacillus oryzae*, the causal agent of rice bacterial blight, and their activity was stronger than that of the positive control agents. When compound 1 and compound 2 were mixed at a 1:1 volume ratio, the resulting activity was stronger than the individual antibacterial activity of compound 1, indicating a synergistic effect of their antibacterial activities.

[0057] Table 2. Antibacterial efficacy of geldamicin compounds

[0058]

[0059] The above description represents a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, any optimization, improvement, combination, or substitution of the present invention based on the principles of the present invention should be considered within the scope of protection of the present invention.

Claims

1. The application of geldmycin and its analogues in the control of plant diseases caused by Xanthomonas bacteria, characterized in that, The geldamycin and its analogues are one or both of compounds 1 and 3 having the structure shown below; or, the geldamycin and its analogues are compounds 1 and 2 having the structure shown below, wherein compounds 1 and 2 are mixed in a mass ratio of 1:

1. ； The Xanthomonas bacteria mentioned are *Bacillus oryzae*, the pathogen causing bacterial leaf blight in rice, and *Bacillus angularis*, the pathogen causing bacterial angular leaf spot in mango.

2. The application according to claim 1, characterized in that, The geldromycin and its analogues are prepared by the following method: (1) Selection of fermentation strain: The fermentation strain is Streptomyces ( Streptomyces sp.) HNBCa1 was deposited at the Guangdong Provincial Center for Microbial Culture Collection on September 3, 2021, with accession number GDMCC No. 61901; (2) Seed culture preparation: The Streptomyces from step (1) is cultured in seed culture medium to obtain seed culture; (3) Fermentation: The seed liquid from step (2) is inoculated into the fermentation medium for fermentation treatment to obtain fermentation liquid; (4) Extraction of fermentation products: Filter the fermentation broth in step (3), extract the bacterial broth with ethyl acetate to obtain the extract, extract the bacterial cells with a methanol-dichloromethane mixture to obtain the extract, combine the extract and the extract and concentrate under reduced pressure to obtain a crude extract containing gerdromycin and its analogues. (5) Separation of gerdemycin and its analogues: The crude extract was separated by normal phase silica gel column, reverse phase silica gel column, dextran gel column and semi-preparative high performance liquid chromatography to obtain gerdemycin and its analogues.

3. The application according to claim 2, characterized in that, The seed culture medium in step (2) contains: 15-20 g tryptone, 2-4 g soybean papain hydrolysate, 4-6 g sodium chloride, 2-3 g dipotassium hydrogen phosphate, 2-3 g glucose, and 1 L distilled water. The pH of the seed culture medium is 7.3±0.

2. When culturing with the seed culture medium, the culture is shaken at 28-30 ℃ and 150-170 rpm for 3-5 days.

4. The application according to claim 2, characterized in that, The fermentation medium in step (3) contains: 15-25 g of soluble starch, 4-6 g of peptone, 2-4 g of malt extract, 2-4 g of yeast extract, 8-12 g of glucose, 0.5-1.5 g of calcium carbonate, and 1 L of distilled water. The pH of the fermentation medium is 7.

0. Seed liquid is inoculated into the fermentation medium at a volume percentage of 5-15%, and fermented by shaking at 28-30 ℃ and 150-170 rpm for 9-13 days.

5. The application according to claim 2, characterized in that, In step (4), the ethyl acetate and the bacterial solution are of equal volume, and the volume ratio of methanol to dichloromethane in the methanol-dichloromethane mixture is 1:

1.

6. The application according to claim 2, characterized in that, In step (5), when the crude extract is passed through a normal-phase silica gel column, it is eluted with a chloroform-methanol gradient at volume ratios of 100:0, 100:1, 100:2, 100:4, 100:8, 100:16, 100:32, 100:64, and 0:100 to obtain nine polar fractions Fr.A to Fr.I. Among them, Fr.D and Fr.F are passed through a reverse-phase silica gel column, a dextran gel column, and a semi-preparative high-performance liquid chromatograph to obtain compound 1 and compound 2, respectively. Fr.G is passed through a normal-phase silica gel column, a reverse-phase silica gel column, a dextran gel column, and a semi-preparative high-performance liquid chromatograph to obtain compound 3.

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