Organic compound with antibacterial activity as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of organic compounds, and particularly relates to an organic compound with antibacterial activity and a preparation method and application thereof. The organic compound provided by the invention has a structure as shown in a formula 1, a formula 2 or a formula 3. The organic compound provided by the invention has antibacterial activity, and the stenolnate C, the stenolnate H and the stenolnate I are various types of organic compounds, have activity on candida albicans, and show a relatively good antibacterial effect. The organic compound provided by the invention is a metabolite of Sterium sanguinol HF-41 and is prepared through microbial fermentation, the preparation method is short in period, mild in culture condition, few in by-products and low in cost, large-scale industrial production is easy to realize, and the requirements of modern environmental protection and low-carbon economy are met. .

Description

Technical Field

[0001] This invention belongs to the field of organic compound technology, specifically relating to an organic compound with antibacterial activity, its preparation method, and its application. Background Technology

[0002] Compounds are diverse, structurally complex, and possess varied properties, exhibiting a wealth of pharmacological effects and biological activities. Many derivatives have been developed into important drugs for treating cancer, bacterial infections, malaria, and various other human diseases. Simultaneously, many compounds demonstrate significant antibacterial, antiviral, and antifungal activities, enabling them to exert antimicrobial effects in food. Appropriate addition of compounds with antimicrobial activity can extend the shelf life of food and reduce microbial contamination, which is of great significance for addressing global food safety issues.

[0003] However, the types of antimicrobial compounds currently used as food antimicrobial agents are limited and their effectiveness is poor. Therefore, developing natural antimicrobial compounds as antimicrobial agents can not only improve food safety but also reduce the use of chemical preservatives, aligning with the concept of green environmental protection. Summary of the Invention

[0004] The purpose of this invention is to provide an organic compound with antibacterial activity, its preparation method, and its application. The organic compound provided by this invention has excellent antibacterial activity and can be used in antibiotics or food antibacterial agents. It is safe and environmentally friendly. Moreover, it is prepared by microbial fermentation, which is simple, easy to implement, low in cost, and suitable for industrial production.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides an organic compound having the structure shown in Formula 1, Formula 2 or Formula 3: .

[0006] This invention provides a method for preparing the organic compound described in the above technical solution, comprising the following steps: (1) Bloody stereum HF-41 was inoculated into a fermentation medium and fermented to obtain Bloody stereum HF-41 fermentation product; (2) The above Bloody stereum HF-41 fermentation product was mixed with ethyl acetate and subjected to ultrasonic extraction to obtain crude extract; (3) The crude extract is subjected to chromatographic separation and purification to obtain the organic compound.

[0007] Preferably, in step (1), the raw materials for preparing the fermentation culture medium include potatoes; the fermentation is solid-state fermentation; the fermentation temperature is 20~28℃; and the fermentation time is 25~35 days.

[0008] Preferably, in step (2), the Bloody stereum The mass ratio of HF-41 fermentation product to ethyl acetate volume is (40~60) g: (70~120) mL; the ultrasonic extraction power is 250~350W, the ultrasonic extraction is performed 2~4 times, and the ultrasonic extraction time is 20~40 min each time.

[0009] Preferably, in step (3), the chromatographic separation and purification includes the following steps: The crude extract was separated by silica gel column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 1, an eluent containing an organic compound with the structure shown in Formula 2, and an eluent containing an organic compound with the structure shown in Formula 3. The eluent used for the silica gel column chromatography was a dichloromethane-methanol system. The eluents containing the organic compound with the structure shown in Formula 1, the organic compound with the structure shown in Formula 2, and the organic compound with the structure shown in Formula 3 were respectively purified by gel chromatography to obtain the organic compounds.

[0010] Preferably, the silica gel column separation includes the following steps: The crude extract was mixed with silica gel, and the resulting mixture was packed into a column for first column chromatography separation. The first column chromatography separation was performed by gradient elution using a dichloromethane-methanol system with a volume ratio of 100:0 to 10:1, in descending order of volume ratio. Fractions of the same type were combined to obtain five fractions, which were named Fr.1 to Fr.5, respectively. The Fr.1 fraction was subjected to a second column chromatography separation to obtain an eluent containing an organic compound with the structure shown in Formula 2; the second column chromatography separation was carried out using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 98:1. The Fr.4 fraction was subjected to third column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 1; the third column chromatography was performed using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 85:1. The Fr.5 fraction was subjected to fourth column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 3; the fourth column chromatography was performed using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 90:1.

[0011] Preferably, the silica gel used in the silica gel chromatography column has a particle size of 300-400 mesh; the first column chromatography separation is performed by gradient elution using dichloromethane-methanol systems with volume ratios of 100:0, 100:1, 50:1, 25:1 and 10:1.

[0012] Preferably, the gel chromatography purification is performed using dextran gel, and the eluent used in the gel chromatography purification is methanol.

[0013] This invention provides the application of the organic compounds described in the above-described technical solutions and the organic compounds prepared by the above-described preparation methods in the preparation of antibacterial drugs or food antibacterial agents.

[0014] This invention provides a bloodstain-bearing fungus ( Bloody stereum The strain HF-41 was deposited at the China Center for Type Culture Collection on November 13, 2025, with accession number CCTCC NO: M20252546.

[0015] This invention provides an organic compound having the structure shown in Formula 1, Formula 2, or Formula 3. The organic compound with the structure shown in Formula 1 is named stenolnate C. The organic compound with the structure shown in Formula 2 is named stenolnate H. The organic compound with the structure shown in Formula 3 is named stenolnate I. The organic compound provided by this invention has antibacterial activity. Stenolnate C, stenolnate H, and stenolnate I are various types of organic compounds. In the embodiments of this invention, the antibacterial activity of compounds stenolnate C, stenolnate H, and stenolnate I was screened. The experiments showed that compounds stenolnate C, stenolnate H, and stenolnate I all have activity against Candida albicans, exhibiting good antibacterial effects.

[0016] This invention provides a method for preparing the organic compound described in the above technical solution, comprising the following steps: (1) taking Bloody stereum HF-41 was inoculated into a fermentation medium and fermented to obtain Stereo bloody HF-41 fermentation product; (2) the above Bloody stereum HF-41 fermentation product was mixed with ethyl acetate and subjected to ultrasonic extraction to obtain crude extract; (3) the crude extract was purified by chromatography to obtain the organic compound. The compounds stenolnate C, stenolnate H and stenolnate I with antibacterial activity provided by the present invention are metabolites of Stereum sanguinolentum HF-41, which are prepared by microbial fermentation. The preparation method has a short cycle, mild culture conditions, few by-products and low cost, and is easy to realize large-scale industrial production, which meets the needs of modern environmental protection and low-carbon economy. Attached Figure Description

[0017] Figure 1 The antibacterial active compound stenolnate C in this invention 1 H-NMR spectrum; Figure 2 The antibacterial active compound stenolnate C in this invention 13 C1-NMR and DEPT spectra; Figure 3 The antibacterial active compound stenolnate C in this invention 1 H- 1 H COSY spectrum; Figure 4 The HMBC spectrum of stenolnate C, the antibacterial active compound in this invention; Figure 5 The HSQC spectrum of stenolnate C, the antibacterial active compound in this invention; Figure 6 This is the NOESY spectrum of stenolnate C, the antibacterial active compound in this invention; Figure 7 The image shows the HR-ESI-MS spectrum of stenolnate C, the antibacterial active compound in this invention. Figure 8 The antibacterial active compound stenolnate H in this invention 1 H-NMR spectrum; Figure 9 The antibacterial active compound stenolnate H in this invention 13 C1-NMR and DEPT spectra; Figure 10 The antibacterial active compound stenolnate H in this invention 1 H- 1 H COSY spectrum; Figure 11 The HMBC spectrum of stenolnate H, the antibacterial active compound in this invention; Figure 12 The HSQC spectrum of stenolnate H, the antibacterial active compound in this invention; Figure 13 This is the NOESY spectrum of stenolnate H, the antibacterial active compound in this invention; Figure 14 The HR-ESI-MS spectrum of stenolnate H, the antibacterial active compound in this invention; Figure 15 The antibacterial active compound stenolnate I in this invention1 H-NMR spectrum; Figure 16 The antibacterial active compound stenolnate I in this invention 13 C1-NMR and DEPT spectra; Figure 17 The antibacterial active compound stenolnate I in this invention 1 H- 1 H COSY spectrum; Figure 18 This is the HMBC spectrum of stenolnate I, the antibacterial active compound in this invention; Figure 19 This is the HSQC spectrum of stenolnate I, the antibacterial active compound in this invention; Figure 20 This is the NOESY spectrum of stenolnate I, the antibacterial active compound in this invention; Figure 21 This is the HR-ESI-MS spectrum of stenolnate I, the antibacterial active compound in this invention. Detailed Implementation

[0018] This invention provides an organic compound having the structure shown in Formula 1, Formula 2 or Formula 3: .

[0019] This invention identifies the structures of organic compounds (stenolnate C, stenolnate H, and stenolnate I) by combining 1D / 2D NMR (one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy), HR-ESI-MS, and quantum chemical calculations. 1 H, 13 C 1 H- 1 H COSY, HMBC, HSQC, NOESY NMR data and HR-ESI-MS data are available in [link to data]. Figure 1~Figure 21 Its structure can be determined as shown in Equation 1, Equation 2 or Equation 3.

[0020] This invention provides a method for preparing the organic compound described in the above technical solution, comprising the following steps: (1) Bloody stereum HF-41 was inoculated into a fermentation medium and fermented to obtain Bloody stereum HF-41 fermentation product; (2) The above Bloody stereum HF-41 fermentation product was mixed with ethyl acetate and subjected to ultrasonic extraction to obtain crude extract; (3) The crude extract is subjected to chromatographic separation and purification to obtain the organic compound.

[0021] In this invention, unless otherwise specified, all raw materials / components used in the preparation are commercially available products well known to those skilled in the art.

[0022] This invention will Bloody stereum HF-41 was inoculated into a fermentation medium and fermented to obtain Bloody stereum HF-41 fermentation product.

[0023] In this invention, *Stereum sanguinolentum* HF-41 is an endophytic fungus of *Aconitum sanguinolentum*, preferably isolated from the roots of *Aconitum sanguinolentum*. This invention does not require a special method for the isolation; conventional techniques in the art can be used.

[0024] In this invention, the Bloody stereum HF-41 was deposited at the China Center for Type Culture Collection (CCTCC) on November 13, 2025, with accession number CCTCC NO: M 20252546. The address of CCTCC is Wuhan University, Wuhan, China.

[0025] Before the fermentation is carried out, the present invention preferably performs the fermentation on the fermented material. Bloody stereum HF-41 is activated; the activation is preferably performed by: activating the... Bloody stereum HF-41 was inoculated onto PDA slant culture medium and cultured at an incubator to obtain activated HF-41. Bloody stereum HF-41. In this invention, the temperature for the isothermal incubation is preferably 25~28℃, more preferably 28℃, and the time is preferably 3~7 days, more preferably 5 days. This invention preferably uses the obtained activated... Bloody stereum HF-41 should be stored at 4°C for future use.

[0026] In this invention, the raw materials for preparing the fermentation culture medium preferably include potatoes.

[0027] In this invention, the method for preparing the fermentation medium used in the fermentation preferably includes the following steps: The raw materials for preparing the culture medium are subjected to high-temperature sterilization and cooling in sequence to obtain the fermentation culture medium.

[0028] In this invention, the raw material for preparing the culture medium is preferably potato. Before the high-temperature sterilization, the potatoes are preferably washed, peeled, and crushed sequentially. The crushing process preferably involves cutting the potatoes into pieces, and the volume of the resulting pieces is preferably 1.0 cm³. 3In this invention, the preparation of the fermentation medium is preferably carried out in a tissue culture flask. In this invention, the temperature for high-temperature sterilization is preferably 120-130°C, more preferably 121°C; the time is preferably 30-40 min, more preferably 30 min. In this invention, the tissue culture flask is preferably sealed during the high-temperature sterilization process. This invention does not have any particular limitation on the cooling method, as long as it can be cooled to room temperature.

[0029] In this invention, the fermentation is preferably solid-state fermentation. Bloody stereum HF-41 has a long metabolic time in liquid fermentation; this invention uses solid-state fermentation, which can effectively shorten the fermentation time. In this invention, the fermentation is preferably performed by: [the process involves...] Bloody stereum HF-41 is inoculated into the fermentation medium. This invention does not impose special requirements on the inoculation conditions; any method well-known to those skilled in the art can be used. In this invention, the fermentation temperature is preferably 20-28°C, more preferably 26-28°C. The fermentation time is preferably 25-35 days, more preferably 28-30 days.

[0030] get Bloody stereum After the HF-41 fermentation product, the present invention will... Stereo bloody The HF-41 fermentation product was mixed with ethyl acetate and subjected to ultrasonic extraction to obtain a crude extract.

[0031] In this invention, the Bloody stereum The preferred mass ratio of HF-41 fermentation product to ethyl acetate volume is (40~60) g:(70~120) mL, more preferably 50 g:110 mL. In this invention, the ethyl acetate solvent exhibits excellent solubility for organic compounds stenolnate C, stenolnate H, and stenolnate I, effectively removing them from the solvent. Bloody stereum It was isolated from HF-41 fermentation product. This invention does not have special requirements for the mixing method, as long as it ensures uniform mixing.

[0032] In this invention, the power of the ultrasonic extraction is preferably 250-350W, more preferably 300W; the frequency of the ultrasonic extraction is preferably 35-45Hz, and in the embodiment it can be 40kHz. The number of ultrasonic extractions is preferably 2-4 times, and in the embodiment it can be 3 times; the time for each ultrasonic extraction is preferably 20-40 minutes, and in the embodiment it can be 30 minutes.

[0033] In this invention, after ultrasonic extraction, the system preferably includes filtration. The filtration method is not particularly limited and can be any conventional method. After filtration, the filtrate is preferably subjected to vacuum distillation to remove the solvent, yielding a crude extract. The vacuum degree of the vacuum distillation is preferably 10-15 kPa, more preferably 12 kPa; the temperature of the vacuum distillation is preferably 45-55°C, more preferably 45°C. The time of vacuum distillation is not particularly limited, as long as the solvent in the filtrate is removed.

[0034] After obtaining the crude extract, the present invention performs chromatographic separation and purification on the crude extract to obtain the organic compound.

[0035] In this invention, the chromatographic separation and purification preferably includes the following steps: separating the crude extract using a silica gel column to obtain an eluent containing an organic compound with the structure shown in Formula 1, an eluent containing an organic compound with the structure shown in Formula 2, and an eluent containing an organic compound with the structure shown in Formula 3, wherein the eluent used for the silica gel column separation is a dichloromethane-methanol system; and purifying the eluent containing the organic compound with the structure shown in Formula 1, the eluent containing the organic compound with the structure shown in Formula 2, and the eluent containing the organic compound with the structure shown in Formula 3 by gel chromatography to obtain the organic compound.

[0036] In this invention, the silica gel column separation preferably includes the following steps: mixing the crude extract with silica gel, packing the resulting mixture into a column, and performing a first column chromatography separation. The first column chromatography separation uses a dichloromethane-methanol system with a volume ratio of 100:0 to 10:1 (dichloromethane to methanol) for gradient elution, eluting from largest to smallest volume ratio. Fractions of the same type are combined to obtain five fractions, named Fr.1 to Fr.5 respectively. The Fr.1 fraction is then subjected to a second column chromatography separation to obtain an eluent containing an organic compound with the structure shown in Formula 2. The second column chromatography separation... The elution process employs a dichloromethane-methanol system with a volume ratio of 98:1 (dichloromethane to methanol). The Fr.4 fraction is then subjected to a third column chromatography separation to obtain an eluent containing an organic compound with the structure shown in Formula 1. This third column chromatography separation uses a dichloromethane-methanol system with a volume ratio of 85:1 (dichloromethane to methanol). The Fr.5 fraction is then subjected to a fourth column chromatography separation to obtain an eluent containing an organic compound with the structure shown in Formula 3. This fourth column chromatography separation uses a dichloromethane-methanol system with a volume ratio of 90:1 (dichloromethane to methanol). In this invention, the silica gel used for the silica gel column separation preferably has a particle size of 300-400 mesh. The preferred method for preparing the mixture includes: dissolving the crude extract in a dichloromethane-methanol system to obtain a crude extract solution; mixing the crude extract solution with silica gel, and then removing the solvent to obtain the mixture. The volume ratio of dichloromethane to methanol in the dichloromethane-methanol system used for dissolving the crude extract is preferably 1:1. This invention does not have specific requirements on the amount of dichloromethane-methanol used for dissolution, as long as it ensures complete dissolution of the crude extract. The mass ratio of the crude extract to the silica gel is preferably 1:(1~1.5). The solvent removal method is preferably vacuum distillation; the temperature of the vacuum distillation is 45~55℃, preferably 50℃. The first column chromatography separation is preferably performed by gradient elution with dichloromethane-methanol systems at volume ratios of 100:0, 100:1, 50:1, 25:1, and 10:1, respectively, yielding five fractions: Fr1, Fr2, Fr3, Fr4, and Fr5. In this invention, the eluent flow rate during the second column chromatography separation, the third column chromatography separation, and the fourth column chromatography separation is preferably 3~5 mL / min, more preferably 4 mL / min.

[0037] In this invention, the gel chromatography purification is preferably performed using dextran gel. The eluent used in the gel chromatography purification is preferably methanol. The methanol flow rate is preferably 0.6~0.8 mL / min, more preferably 0.7 mL / min.

[0038] This invention provides the application of the organic compounds described in the above-described technical solutions and the organic compounds prepared by the above-described preparation methods in the preparation of antibacterial drugs. In this invention, the antibacterial drug can be an antibiotic.

[0039] This invention provides the application of the organic compounds described in the above-described technical solutions and the organic compounds prepared by the above-described preparation methods in the preparation of food antibacterial agents.

[0040] The antibacterial drugs prepared by the present invention using compounds stenolnate C, stenolnate H, and stenolnate I as raw materials preferably also include pharmaceutical excipients. The present invention does not impose any particular limitation on the pharmaceutical excipients; conventional pharmaceutical excipients in the art can be selected. The present invention does not impose any particular requirements on the preparation method and dosage form of the antibacterial drugs; tablets, granules, or injections can be prepared using methods well-known in the art.

[0041] This invention provides a bloodstain-bearing fungus ( Bloody stereum The strain HF-41 was deposited at the China Center for Type Culture Collection on November 13, 2025, with accession number CCTCC NO: M20252546.

[0042] To further illustrate the present invention, the technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1: Preparation of antibacterial compounds stenolnate C, stenolnate H and stenolnate I 1. Strain activation: Bloody stereum HF-41 was inoculated onto PDA agar medium and incubated at 28°C for 5 days to obtain activated [product / product]. Bloody stereum HF-41, store at 4°C for later use; 2. Preparation of fermentation medium: Wash and peel 50.0 kg of potatoes and cut them into 1 cm³ pieces. 3 Potato chunks were divided into 100 tissue culture flasks with a volume of 1000 mL (500 g / flask), and then the tissue culture flasks were sealed and sterilized at 121℃ for 30 min. After cooling, solid fermentation medium was obtained. 3. The activated material obtained in step 1 Bloody stereum HF-41 was inoculated into PDB medium and cultured at 28°C for 3 days to prepare a seed culture. This seed culture was then inoculated into the solid fermentation medium obtained in step 2, sealed, and cultured at 28°C for 30 days to obtain the desired product. Bloody stereumHF-41 fermentation product; 4. Take the result obtained in step 3. Bloody stereum The HF-41 fermentation product was mixed with 400 mL of ethyl acetate at a mass-to-volume ratio of 50 g: 110 mL. After mixing, the mixture was sonicated three times at a power of 300 W and a frequency of 40 kHz for 30 min each time. The mixture was filtered, and the filtrate was distilled under reduced pressure (vacuum degree of 12 kPa, 50 °C) until there was no ethyl acetate odor, yielding 180.0 g of crude extract. 5. Dissolve 180.0 g of crude extract in 200 mL of dichloromethane and methanol at a volume ratio of 1:1, then mix with 180.0 g of silica gel (300-400 mesh) and concentrate under reduced pressure (vacuum degree 12 kPa, 50℃). Evaporate the solvent to dryness and pack into a column. Perform gradient elution using solutions with dichloromethane and methanol volume ratios of 100:0, 100:1, 50:1, 25:1, and 10:1 to obtain five fractions: Fr1, Fr2, Fr3, Fr4, and Fr5. Elute Fr1 with dichloromethane-methanol at a volume ratio of 98:1 using silica gel column chromatography to obtain the eluent for compound stenolnate H. Elute Fr4 with dichloromethane-methanol at a volume ratio of 85:1 using silica gel column chromatography to obtain the compound stenolnate. The eluent for C was obtained by silica gel column chromatography using Fr5 with a dichloromethane-methanol eluent at a volume ratio of 90:1, yielding the eluent for compound stenolnate I. The eluents for stenolnate H, stenolnate C, and stenolnate I were then purified by dextran gel electrophoresis with methanol as the solvent to obtain compounds stenolnate C, stenolnate H, and stenolnate I, respectively.

[0044] Example 2: Structural Identification The compounds stenolnate C, stenolnate H, and stenolnate I prepared in Example 1 were detected by nuclear magnetic resonance spectroscopy, yielding 1D / 2D NMR (one-dimensional and two-dimensional nuclear magnetic resonance spectra), HR-ESI-MS (high-resolution electrospray ionization mass spectra), and quantum chemical calculations. Figure 1~21 The compounds stenolnate C, stenolnate H and stenolnate I were identified and their structures were determined.

[0045] The chemical shifts of H atoms and C atoms in compounds stenolnate C, stenolnate H, and stenolnate I can be obtained by combining HSQC spectroscopy with carbon spectroscopy and DEPT spectroscopy. δThe attribution is shown in Table 1: Table 1. Compounds stenolnate C, stenolnate H, and stenolnate I 1 H and 13 C NMR data.

[0046] In Table 1: a Measured in deuterated chloroform (CDCl3), 1H NMR spectrum (… 1 H NMR) was 400 MHz, and carbon spectrum ( 13 The C NMR (C NMR) frequency is 100 MHz; b Measured in deuterated chloroform (CDCl3), 1H NMR spectrum (… 1 H NMR) was 600 MHz, and carbon spectrum ( 13 The C NMR (C6NMR) frequency is 150 MHz. c Measured in deuterated methanol (CD3OD), 1H NMR (1H NMR spectrum) 1 H NMR) was 400 MHz, and carbon spectrum ( 13 The C NMR (C6NMR) value is 100 MHz.

[0047] Compound 1: Pale brown solid. High-resolution mass spectrometry (HR-ESI-MS) of Compound 1. m / z 301.0683 [M + Na] + The calculated value is C 14 H 14 O6Na + (301.0683), its molecular formula is inferred to be: C 14 H 14 O6 has eight degrees of unsaturation. (Through...) 1 H, 13 Combined analysis of C, HSQC, and DEPT NMR spectra indicates that compound 1 contains 14 carbon atoms, including 2 methyl groups. δ H 3.96 (H3-9), 1.96 (H3-14); δ C 59.3 (C-9), 12.6 (C-14) ], 2 methylene groups [ δ H 5.54 (H2-8), 3.59 (H2-10); δ C 70.3 (C-8), 24.9 (C-10)], 2 methines [ δ H 6.95 (H-6), 6.75 (H-11); δC 105.2 (C-6), 141.1 (C-11)], and 8 quaternary carbons [ δ C 126.8 (C-1), 126.6 (C-2), 154.6 (C-3), 124.7 (C-4), 158.9 (C-5), 173.3 (C-7), 129.1 (C-12), 171.9 (C-13)]. Compound 1 1 H and 13 The C10 NMR data are similar to those of the known compound strobilol P. The main difference is that the -CH2OCOCH3 fragment at position 12 in strobilol P is replaced by a -COOH fragment to form compound 1. This is demonstrated by the HMBC correlation between H-11 and H3-14 and C-13 in compound 1, and the correlation between H2-13 and C-11 / C-12 / C-14 / carbonyl carbon in strobilol P. δ C 172.8), -CH3( δ H 2.04) and carbonyl carbon ( δ C The HMBC correlation of 172.8) was confirmed. This led to the determination of the structure of compound 1, which was named stenolnate C.

[0048] Compound 2: Yellow oily substance. High-resolution mass spectrometry (HR-ESI-MS) of compound 2. m / z 267.1567 [M + Na] + The calculated value is C 13 H 24 O4Na + (267.1567), its molecular formula is inferred to be: C 13 H 24 O4 has two degrees of unsaturation. (Through...) 1 H, 13 Combined analysis of C, HSQC, and DEPT NMR spectra indicates that compound 2 contains 13 carbon atoms, including 4 methyl groups. δ H 2.04(H3-1), 1.15 (H3-11), 1.19 (H3-12), 1.63 (H3-13); δ C 21.1 (C-1), 23.4 (C-11), 26.5 (C-12), 16.2 (C-13) ], 4 methylene groups [ δ H4.04 (H2-3), 2.33 (H2-4), 2.10 (H-7a), 2.24 (H-7b), 1.42 (H-8a), 1.58 (H-8b); δ C 64.2 (C-3), 27.7 (C-4), 36.9 (C-7), 29.7 (C-8) ], 2 methines [ δ H 5.19 (H-5), 3.33 (H-9); δ C 120.1 (C-5), 78.2 (C-9)], and 3 quaternary carbons [ δ C 171.4 (C-2), 138.2 (C-6), 73.1 (C-10)]. Compound 2 1 H and 13 The C10 NMR data are similar to those of the known compound asperginsin A. The main difference is that the -OH fragment at position 1 in asperginsin A is replaced by an -OCOCH3 fragment to form compound 2. This is confirmed by the HMBC correlation between H3-1 and H2-3 and C-2 in compound 2. This establishes the planar structure of compound 2. The absolute configuration of compound 2 is determined by calculated values ​​(9...). R -2, optical rotation value -54.673; 9 S The value was determined by comparing the optical rotation data of isomer 9 (-2, optical rotation value +54.673) and the experimental value (-24.780). The results show that isomer 9... R The calculated optical rotation value of -2 matches the experimental value better, thus determining the absolute configuration of compound 2 to be 9. R Compound 2 was named stenolnate H.

[0049] Compound 3: Yellow oily substance. High-resolution mass spectrometry (HR-ESI-MS) of compound 3. m / z 265.1410 [M + Na] + The calculated value is C 13 H 22 O4Na + (265.1411), its molecular formula is inferred to be: C 13 H 22 O4 has three degrees of unsaturation. (Through...) 1 H, 13 Combined analysis of C, HSQC, and DEPT NMR spectra indicates that compound 3 contains 13 carbon atoms, including 3 methyl groups. δ H3.67(H3-1), 1.67(H3-12), 1.59(H3-13); δ C 52.1 (C-1), 25.9 (C-12), 18.0 (C-13) ], 4 methylene groups [ δ H 2.43 (H2-6), 7.70 (H2-7), 4.06 (H2-8), 2.21 (H2-9); δ C 32.5 (C-6), 61.7 (C-7), 67.8 (C-8), 31.4 (C-9) ], 3 methines [ δ H 3.30 (H-3), 5.55 (H-4), 5.03 (H-10); δ C 44.9 (C-3), 127.6 (C-4), 120.4 (C-10)], and 3 quaternary carbons [ δ C 174.7 (C-2), 139.3 (C-5), 134.5 (C-11)]. Compound 3 1 H and 13 The C10 NMR data are similar to those of the known compound Sterepicacids A. The main difference is that the -OH fragment at position 1 in Sterepicacids A is replaced by an -OCH3 fragment to form compound 3. This is confirmed by the HMBC correlation between H3-1 and C2 in compound 3. This establishes the planar structure of compound 3. The absolute configuration of compound 3 is determined by calculation (3... S -3, optical rotation value +254.540; 3 R The value was determined by comparing the optical rotation data of isomer 3 (-3, optical rotation value -254.540) and the experimental value (-310.020). The results show that isomer 3... R The calculated optical rotation value of -3 matches the experimental value better, thus determining the absolute configuration of compound 3 to be 3. R Compound 3 was named stenolnate I.

[0050] In summary, the structural formulas of the compounds stenolnate C, stenolnate H, and stenolnate I prepared in Example 1 can be determined as follows: .

[0051] Example 3: Screening for antibacterial activity of compounds stenolnate C, stenolnate H and stenolnate I The minimum inhibitory concentrations (MICs) of compounds stenolnate C, stenolnate H, and stenolnate I were determined using the two-fold dilution method.

[0052] (1) Pathogen culture: Methicillin-resistant Staphylococcus aureus (MRSA ATCC 33591) and Staphylococcus aureus ( Staphylococcus aureus ATCC 25923), Escherichia coli ( Escherichia coli ATCC25922) and Salmonella typhimurium ( Salmonella typhimurium BNCC 103281) was inoculated onto LB broth medium, and Candida albicans ( Candida albicans ATCC 10231 was inoculated into PDB broth medium, and after incubation, the colony size was adjusted to 1×10⁻⁶. 5 CFU / mL.

[0053] (2) Sample preparation: Appropriate amounts of compounds stenolnate C, stenolnate H, and stenolnate I, as well as the positive control drugs chloramphenicol, vancomycin, and nystatin, were weighed and dissolved in LB broth or PDB broth (containing 0.2% DMSO) to prepare a final concentration of 512 μg / mL. The above solution was serially diluted to prepare 12 concentration gradients from 256 to 0.125 μg / mL, with each concentration set up in triplicate, and each well having a final volume of 200 μL. Wells containing 100 μL of bacterial suspension with 0.2% DMSO were set up as the negative control group, and wells containing only 100 μL of sterile LB broth or PDB broth were set up as the blank group.

[0054] (3) Results showed that after drug administration, the 96-well plate was transferred to a biochemical incubator, where bacteria and fungi were cultured for 24 h and 48 h, respectively. After the culture was completed, the turbidity of the bacterial solution in each well was observed and the OD was measured. 600 The MIC value of the test compound is determined by visually observing the lowest concentration pore in the experimental group where the solution becomes clearest and the OD value is closest to that of the blank control group.

[0055] Table 2. Antibacterial activity (MIC) of compounds stenolnate C, stenolnate H and stenolnate I.

[0056] As shown in the above embodiments, this invention specifically relates to three compounds with antibacterial activity: stenolnate C, stenolnate H, and stenolnate I, whose structures are shown in Formulas 1, 2, and 3. The organic compounds provided by this invention possess antibacterial activity. The antibacterial compounds stenolnate C, stenolnate H, and stenolnate I provided by this invention are various types of organic compounds. This invention prepares the antibacterial compounds stenolnate C, stenolnate H, and stenolnate I through microbial fermentation and also provides a method for preparing a class of antibacterial compounds stenolnate C, stenolnate H, and stenolnate I. The preparation method has a short cycle, mild culture conditions, few byproducts, and low cost, making it suitable for large-scale industrial production.

[0057] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. Other embodiments can be obtained based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. An organic compound, characterized in that, It has the structure shown in Equation 1, Equation 2 or Equation 3: 。 2. The method for preparing the organic compound according to claim 1, characterized in that, Includes the following steps: (1) Stereum sanguinolentum HF-41 was inoculated into a fermentation medium and fermented to obtain Stereum sanguinolentum HF-41 fermentation product; (2) The above Stereum sanguinolentum HF-41 fermentation product was mixed with ethyl acetate and subjected to ultrasonic extraction to obtain crude extract; (3) The crude extract is subjected to chromatographic separation and purification to obtain the organic compound.

3. The preparation method according to claim 2, characterized in that, In step (1), the raw materials for preparing the fermentation culture medium include potatoes; the fermentation is solid fermentation; the fermentation temperature is 20~28℃, and the fermentation time is 25~35 days.

4. The preparation method according to claim 2, characterized in that, In step (2), the Stereum sanguinolentum The mass ratio of HF-41 fermentation product to ethyl acetate volume is (40~60) g: (70~120) mL; the ultrasonic extraction power is 250~350W, the ultrasonic extraction is performed 2~4 times, and the ultrasonic extraction time is 20~40 min each time.

5. The preparation method according to claim 2, characterized in that, In step (3), the chromatographic separation and purification includes the following steps: The crude extract was separated by silica gel column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 1, an eluent containing an organic compound with the structure shown in Formula 2, and an eluent containing an organic compound with the structure shown in Formula 3. The eluent used for the silica gel column chromatography was a dichloromethane-methanol system. The eluents containing the organic compound with the structure shown in Formula 1, the organic compound with the structure shown in Formula 2, and the organic compound with the structure shown in Formula 3 were respectively purified by gel chromatography to obtain the organic compounds.

6. The preparation method according to claim 5, characterized in that, The silica gel column separation includes the following steps: The crude extract was mixed with silica gel, and the resulting mixture was packed into a column for first column chromatography separation. The first column chromatography separation was performed by gradient elution using a dichloromethane-methanol system with a volume ratio of 100:0 to 10:1, in descending order of volume ratio. Fractions of the same type were combined to obtain five fractions, which were named Fr.1 to Fr.5, respectively. The Fr.1 fraction was subjected to a second column chromatography separation to obtain an eluent containing an organic compound with the structure shown in Formula 2; the second column chromatography separation was carried out using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 98:

1. The Fr.4 fraction was subjected to third column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 1; the third column chromatography was performed using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 85:

1. The Fr.5 fraction was subjected to fourth column chromatography to obtain an eluent containing an organic compound with the structure shown in Formula 3; the fourth column chromatography was performed using a dichloromethane-methanol system with a volume ratio of dichloromethane to methanol of 90:

1.

7. The preparation method according to claim 6, characterized in that, The silica gel used in the silica gel chromatography column has a particle size of 300-400 mesh; the first column chromatography separation is performed by gradient elution using dichloromethane-methanol systems with volume ratios of 100:0, 100:1, 50:1, 25:1 and 10:

1.

8. The preparation method according to claim 5, characterized in that, The gel chromatography purification was performed using dextran gel, and the eluent used in the gel chromatography purification was methanol.

9. The use of the organic compound of claim 1 or the organic compound prepared by any one of claims 2 to 8 in the preparation of antibacterial drugs or food antibacterial agents.

10. A type of bloodstain fungus ( Stereum sanguinolentum strain HF-41, characterized in that, The strain HF-41 was deposited at the China Center for Type Culture Collection on November 13, 2025, with accession number CCTCC NO: M20252546.

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