Use of bicyclic depsispeptide in the preparation of antibacterial agents
By synthesizing and applying bicyclic phloroglucinol compounds, the treatment challenges of drug-resistant bacteria such as MRSA have been solved. This has achieved highly efficient inhibition of Gram-positive bacteria and synergistic effects with antibiotics, demonstrating significant antibacterial efficacy and commercial potential.
Patent Information
- Application Number
- CN202610543723.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-23
- Publication Date
- 2026-07-03
AI Technical Summary
Existing antimicrobial drugs have limited efficacy in treating drug-resistant bacterial infections such as MRSA, and commonly used drugs such as vancomycin have toxic side effects and drug resistance problems. There is an urgent need for new antimicrobial drugs to address Gram-positive bacterial infections, especially drug-resistant Gram-positive bacterial infections.
A series of bicyclic phloroglucinol compounds (BPs) were synthesized and found to have significant inhibitory activity against Gram-positive bacteria. Furthermore, they exhibited synergistic effects when used in combination with common antibiotics, reducing the effective concentration of antibiotics and enhancing antibacterial efficacy.
Bicyclic phloroglucinol compounds significantly inhibit a variety of Gram-positive bacteria, including MRSA, reduce the effective concentration of common antibiotics, broaden the antibacterial spectrum, and possess highly effective antibacterial activity and commercial potential value.
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Figure CN122320928A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of pharmaceutical technology, and more specifically, to the application of bicyclic phloroglucinol compounds in the preparation of antibacterial drugs. Background Technology
[0002] Bacterial infections, especially those caused by drug-resistant bacteria, are one of the challenges in clinical antimicrobial treatment. Among bacterial deaths, Staphylococcus aureus (Staphylococcus aureus) is a major culprit. Staphylococcus aureus,S. aureus Methicillin-resistant Staphylococcus aureus (MRSA) is the leading cause of death among Gram-positive bacteria. Staphylococcus aureus MRSA, also known as multidrug-resistant Staphylococcus aureus Staphylococcus aureus ( ) is a unique drug-resistant strain of Staphylococcus aureus.
[0003] Currently, treatment options for "superbug" infections such as MRSA are very limited, confined to a few drugs such as vancomycin. The nephrotoxicity and ototoxicity of vancomycin restrict its clinical use, and with the increasing use of vancomycin, its minimum inhibitory concentration (MIC) against many pathogens has been rising over the past 20 years, leading to the gradual development of bacterial resistance.
[0004] Therefore, the development of novel antimicrobial drugs is an urgent clinical need for the treatment of Gram-positive bacterial infections, especially drug-resistant Gram-positive bacterial infections (such as MRSA).
[0005] In view of this, the present invention is proposed. Summary of the Invention
[0006] The purpose of this invention is to provide an application of bicyclic phloroglucinol compounds in the preparation of antibacterial drugs, so as to solve or improve the above-mentioned technical problems.
[0007] This invention is implemented as follows: In a first aspect, the present invention provides the application of a bicyclic phloroglucinol compound in the preparation of antibacterial drugs.
[0008] Secondly, the present invention provides the application of a bicyclic phloroglucinol compound and an antibiotic in the preparation of a combined antibacterial drug.
[0009] Thirdly, the present invention provides an antibacterial drug selected from at least one of the bicyclic phloroglucinol compounds as described in the foregoing embodiments, or pharmaceutically acceptable salts or esters thereof, derivatives thereof, stereoisomers thereof, and pharmaceutically acceptable salts of their derivatives.
[0010] The present invention has the following beneficial effects: This invention relates to the screening of a series of synthesized bicyclic phloroglucinol compounds (BPs) to inhibit the proliferation of Gram-positive bacteria. The results showed that the synthesized BPs inhibited the proliferation of Gram-positive bacteria (including...) S. aureus MRSA, Listeria ( Listeria monocytogenes, L. monocytogenes It exhibits broad-spectrum inhibitory activity. Furthermore, the newly synthesized BPs can effectively reduce the activity of common antibiotics (vancomycin, norfloxacin, meropenem, erythromycin, and rifampin) at the levels of... S. aureus The effective concentration of the bacterial strain enhances the antibacterial effect of antibiotics and broadens their antibacterial spectrum. The BPs involved in this invention have novel structures, highly efficient antibacterial activity, and synergistic effects when used in combination with antibiotics, possessing great potential for preparation into antibacterial drugs and high commercial potential value. Attached Figure Description
[0011] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0012] Figure 1 For BP1-BP3 pairs S. aureus The results of the antibacterial activity test are as follows: (A) BP1, (B) BP2, (C) BP3; Figure 2 The results of the antibacterial activity test of BP1-BP3 against MRSA ATCC43300 are as follows: (A) BP1, (B) BP2, (C) BP3; Figure 3 For BP1-BP3 pairs L. monocytogenes The results of the antibacterial activity test are as follows: (A) BP1, (B) BP2, (C) BP3; Figure 4 The results of the antibacterial activity test of BP1-BP3 combined with norfloxacin against MRSA ATCC43300 are as follows: (A) BP1, (B) BP2, (C) BP3. Detailed Implementation
[0013] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0014] MRSA exhibits broad-spectrum drug resistance, exhibiting resistance not only to methicillin but also to all other β-lactam and cephalosporin antibiotics with the same structure as methicillin. Furthermore, MRSA can develop resistance to aminoglycosides, macrolides, tetracyclines, fluoroquinolones, sulfonamides, and rifampin through various mechanisms, such as altering the antibiotic target site to produce corresponding modifying enzymes that reduce membrane permeability. Therefore, these strains are referred to as "superbugs." MRSA is characterized by high infection rates, high mortality rates, long treatment cycles, and high treatment costs, placing a significant burden on healthcare systems and patients. Simultaneously, the rapid spread of community-acquired MRSA increases the risk of infection in healthy individuals. In particular, MRSA often co-infects with viruses, causing fulminant pneumonia, resulting in extremely high mortality rates among children and the elderly. MRSA infection, along with hepatitis B and HIV / AIDS, is considered one of the three most difficult infectious diseases to manage worldwide. Vancomycin is currently the first-line drug for treating MRSA and is the "last line of defense" antibiotic after MRSA infection, but its nephrotoxicity, ototoxicity and other toxic side effects limit its clinical use.
[0015] Phloroglucinols are mainly found in plants of the Myrtaceae, Clusiaceae, and Dryopteridaceae families. Some natural phloroglucinols exhibit antibacterial activity. To find lead compounds with better antibacterial activity, the research team of this invention synthesized a series of novel bicyclic phloroglucinols (BPs) based on phloroglucinol as the backbone, and systematically screened and evaluated their antibacterial activity, especially their activity against drug-resistant bacteria.
[0016] The BPs synthesized in this invention can significantly inhibit a variety of Gram-positive bacteria, including S. aureus MRSA L. monocytogenes Furthermore, the aforementioned BPs exhibit significant synergistic effects when used in combination with antibacterial drugs such as norfloxacin, vancomycin, erythromycin, meropenem, and rifampin. Therefore, these compounds hold great potential in the preparation and application of antibacterial drugs. The following analysis will elaborate on this: In a first aspect, the present invention provides the application of a bicyclic phloroglucinol compound in the preparation of antibacterial drugs.
[0017] In an optional embodiment, the antibacterial drug is an anti-Gram-positive bacteria drug.
[0018] In an optional embodiment, the Gram-positive bacteria are selected from at least one of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Listeria.
[0019] In an optional embodiment, the Gram-positive bacteria are selected from at least one of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.
[0020] In an optional embodiment, the structure of the bicyclic phloroglucinol compound is selected from at least one of the compounds shown in formula (I); .
[0021] In an optional embodiment, the structure of the bicyclic phloroglucinol compound is selected from at least one of the compounds shown in formula (II); .
[0022] The BP1-BP3 provided by this invention can significantly inhibit a variety of Gram-positive bacteria, including S. aureus MRSA L. monocytogenes Furthermore, the above-mentioned compounds exhibit significant synergistic effects when used in combination with antibacterial drugs such as norfloxacin, vancomycin, erythromycin, meropenem, and rifampin, demonstrating great potential in the preparation and application of antibacterial drugs.
[0023] It should be noted that the synthesis process of bicyclic phloroglucinol compounds in this invention is not particularly limited, and the method is conventional. The specific method can be reasonably adjusted according to the type and amount of raw materials.
[0024] Secondly, the present invention provides the application of a bicyclic phloroglucinol compound and an antibiotic in the preparation of a combined antibacterial drug.
[0025] In an optional embodiment, the antibiotic is selected from at least one of vancomycin, norfloxacin, meropenem, erythromycin, and rifampin.
[0026] It should be noted that bicyclic phloroglucinol compounds have a synergistic effect when used in combination with antibiotics, specifically by reducing the effective concentration of antibiotics.
[0027] Thirdly, the present invention provides an antibacterial drug selected from at least one of the bicyclic phloroglucinol compounds as described in the foregoing embodiments, or pharmaceutically acceptable salts or esters thereof, derivatives thereof, stereoisomers thereof, and pharmaceutically acceptable salts of their derivatives.
[0028] In an optional implementation, the antimicrobial agent may also include pharmaceutically acceptable excipients.
[0029] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0030] 1. Experimental materials All BPs used are synthetic compounds, and all chemical reagents used in the synthesis were purchased from commercial suppliers and can be selected according to actual needs.
[0031] 2. Experimental strains S. aureus The gift was presented to Professor Wang Ruibing of the Institute of Chinese Medical Sciences, University of Macau.
[0032] MRSA ATCC43300 was purchased from the ATCC Cell Bank in the United States.
[0033] L. monocytogenes The gift was presented to Professor Cao Junjie of the Institute of Chinese Medical Sciences, University of Macau.
[0034] 3. Strains culture S. aureus The strain was cultured using Luria-Bertani medium (purchased from Beyotime Biotechnology Co., Ltd.).
[0035] The MRSA ATCC43300 strain was cultured using Mueller-Hinton Broth (MHB) medium (purchased from Thermo Fisher Scientific).
[0036] L. monocytogenes Cultures were prepared using Brain Heart Infusion medium (purchased from Beina Innovation Biotechnology Co., Ltd.).
[0037] The culture conditions were 37 ℃ and 220 rpm.
[0038] 4. Preparation of drug stock solution Take BP powder, vancomycin (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.), norfloxacin (purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.), meropenem (Shanghai Yien Chemical Technology Co., Ltd.), erythromycin (Shanghai Yien Chemical Technology Co., Ltd.), and rifampin (Shanghai Yien Chemical Technology Co., Ltd.) powder, and prepare a 30 mM mother liquor with dimethyl sulfoxide (DMSO) solution.
[0039] 5. Experimental Investigation and Results Analysis It should be noted that vancomycin in S. aureus The MIC value of the strain was 2.8 μM, while the MIC of MRSA ATCC43300 strain was 2 μM. L. monocytogenes The MIC value of the strain is 2 μM.
[0040] 5.1, BPs S. aureus In vitro antibacterial activity assay BPs (including BP1-BP16) were determined using the broth dilution method. S. aureus The minimum inhibitory concentration (MIC) of the strain was determined. The initial concentration of the BP compound was 30 mM, the solvent was DMSO, and the culture medium was Luria-Bertani. The specific method is as follows: Add 1 μL of the prepared BP stock solution (30 mM) to the first well of a 96-well plate (99 μL of culture medium) for dilution; take 40 μL of the diluted solution from the first well and add it to the second well (80 μL of culture medium) for dilution; then dilute the diluted solutions from the first and second wells 10 times each and transfer them to the third and fourth wells of the 96-well plate.
[0041] Take 10 μL of the diluted drug solution from the first to the fourth well and add it to 90 μL of bacterial culture (OD). 600 =0.05). The OD of the solution was measured at 0h, 1h, 2h, 4h, 8h, and 24h after drug administration. 600 Compounds with MIC concentrations below 10 μM in the initial screening were further confirmed by serial dilution. BPs were compared with... S. aureus The results of the in vitro antibacterial activity assay are summarized in Table 1.
[0042] Table 1 BPs S. aureus Results of in vitro antibacterial activity assay
[0043] As can be seen from the data in Table 1, BPs have an impact on... S. aureus They exhibit significant inhibitory activity, with BP1-BP3, BP7, BP8, and BP12 having a MIC of 10 μM, while the MICs of the remaining BPs are higher than 10 μM.
[0044] Pair BP1-BP3 S. aureus The results of the antibacterial activity test are summarized in Figure 1 : (A) BP1, (B) BP2, (C) BP3.
[0045] 5.2. Determination of the in vitro antibacterial activity of BPs against MRSA ATCC43300 The MIC values of BPs in MRSA ATCC43300 strain were determined using the broth dilution method. The specific method is as follows: The broth dilution method is consistent with the procedure described in 5.1, except that the culture medium used for culturing MRSA ATCC43300 strain and drug treatment is Mueller-Hinton Broth medium.
[0046] The results of the in vitro antibacterial activity assays of BP1-BP3, BP7, BP8, and BP12 against MRSAATCC43300 are summarized in Table 2.
[0047] Table 2. Results of in vitro antibacterial activity of BPs against MRSA ATCC43300
[0048] As can be seen from the data in Table 2, BP1-BP3, BP7, BP8, and BP12 all exhibit inhibitory activity against MRSA ATCC43300. Among them, the MIC of BP1 is 5 μM, the MIC of BP2-BP3 is 10 μM, and the MIC of the remaining BPs is 15 μM.
[0049] The results of the inhibitory activity assays of BP1-BP3 against MRSA ATCC43300 were summarized as follows: Figure 2 : (A) BP1, (B) BP2, (C) BP3.
[0050] 5.3, BP1-BP3 pairs L. monocytogenes In vitro antibacterial activity assay BP1-BP3 were determined using the broth dilution method. L. monocytogenes The MIC value of the strain. The specific method is as follows: The broth dilution method is consistent with the procedure provided in 5.1, with the only difference being: L. monocytogenes The culture medium used for bacterial culture and drug treatment was Brain Heart Infusion medium.
[0051] Pair BP1-BP3 L. monocytogenes The results of the inhibitory activity assay were summarized to Figure 3 : (A) BP1, (B) BP2, (C) BP3.
[0052] according to Figure 3 It can be seen that BP1-BP3 are in L. monocytogenes The MIC values of the strains were all between 10 μM and 30 μM.
[0053] For ease of comparison, the MIC detection results of BP1-BP3 and vancomycin for different strains are summarized in Table 3.
[0054] Table 3. MIC detection results of BP1-BP3 and vancomycin against different strains.
[0055] 5.4. In vitro antibacterial activity assay of BP1-BP3 combined antibiotics The micro-checkerboard dilution method was used for drug combination studies. The specific method is as follows: Based on the antibiotics used S. aureus The highest concentrations were determined by diluting the solutions 4 times the MIC (corresponding to initial dilutions of vancomycin 11.2 μM, norfloxacin 6 μM, meropenem 1.6 μM, erythromycin 24 μM, and rifampin 80 nM). Six concentrations (corresponding to 4 × MIC, 2 × MIC, MIC, 1 / 2 × MIC, 1 / 4 × MIC, and 0) were halved using LB medium and arranged in each row of a 96-well plate. Based on the measured MIC values of BPs, 20 μM and 16 μM were determined as the highest concentrations. Ten concentrations (20 μM, 16 μM, 10 μM, 8 μM, 5 μM, 4 μM, 2.5 μM, 2 μM, 1 μM, and 0 μM) were halved using Luria-Bertani medium and arranged in each column of a 96-well plate. After dilution, each well of the 96-well plate contained 10 μL of the LB-diluted antibiotic solution and 10 μL of the compound solution. Add 180 μL of bacterial culture (OD) to all wells containing the drug solution. 600 =0.05), and the OD of the solution was measured after incubation at 37℃ for 24 h. 600 The partial inhibitory concentration index (FIC) was calculated to determine the interaction.
[0056] Wherein, FIC Index = (MIC of drug A when used in combination) / (MIC of drug A alone) + (MIC of drug B when used in combination) / (MIC of drug B alone). FIC Index ≤ 0.5 represents drug synergy, 0.5 < FIC Index ≤ 1 represents drug additive effect, 1 < FIC Index ≤ 2 represents no drug interaction, and FIC Index > 2 represents drug antagonism.
[0057] BP1-BP3 combined with antibiotics S. aureus The results of the antibacterial activity test are summarized in Table 4.
[0058] Table 4. Effects of BP1-BP3 combined antibiotics on S. aureus Antibacterial activity test results
[0059] As can be seen from the data in Table 4, the lowest FIC value of BP2 and BP3 combined with rifampicin is 0.45, and the FIC value of BP1 combined with norfloxacin is 0.5, indicating that BP2 and BP3 have a synergistic effect when used in combination with rifampicin, and BP1 has a synergistic effect when used in combination with norfloxacin. In addition, the FIC values of BP1-BP3 combined with antibiotics are all between 0.5 and 1, indicating that BP1-BP3 have an additive effect when used in combination with antibiotics.
[0060] The antibacterial activity of BP1-BP3 combined with norfloxacin against MRSA ATCC43300 was also determined using the micro-checkerboard dilution method. The specific procedure is the same as described above. S. aureus The procedures remained consistent throughout, with the difference being that the culture medium used was Mueller-Hinton Broth. The concentrations of norfloxacin after dilution were 48 μM, 24 μM, 12 μM, 6 μM, 3 μM, and 0 μM; the concentrations of BP1 after dilution were 10 μM, 8 μM, 5 μM, 4 μM, 2.5 μM, 2 μM, 1.25 μM, 1 μM, 0.5 μM, and 0 μM; and the concentrations of BP2 and BP3 after dilution were 20 μM, 16 μM, 10 μM, 8 μM, 5 μM, 4 μM, 2.5 μM, 2 μM, 1 μM, and 0 μM, respectively.
[0061] The heatmap summarizing the inhibitory effects of BP1-BP3 combined with norfloxacin on MRSA ATCC43300 strain is presented in [the original text]. Figure 4 (A) BP1, (B) BP2, (C) BP3. According to... Figure 4 The results showed that in MRSA ATCC43300 strain, the FIC index of BP1 combined with norfloxacin was 1, and the FIC index of BP2 and BP3 combined with norfloxacin was 0.925, indicating that the combination of BP1-BP3 with norfloxacin has an synergistic effect on the antibacterial effect of norfloxacin.
[0062] The BPs provided by this invention are effective against Gram-positive bacteria (including...) S. aureus MRSA L. monocytogenes BP1-BP3 exhibit broad inhibitory activity. Specifically, they can reduce the effectiveness of common antibiotics (vancomycin, norfloxacin, meropenem, erythromycin, and rifampin) at the levels of... S. aureus The effective concentration of the bacterial strain enhances the antibacterial effect of antibiotics, with the best results observed when used in combination with norfloxacin and rifampin. Specifically, when used in combination with the antibiotic norfloxacin, it can effectively reduce the effective concentration of norfloxacin in MRSAATCC43300, enhancing its antibacterial effect and broadening the antibacterial spectrum of norfloxacin. The BPs involved in this invention possess novel structures, highly efficient antibacterial activity, and synergistic effects when used in combination with antibiotics, demonstrating significant potential for development into antibacterial drugs and high commercial value.
[0063] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. The application of a bicyclic phloroglucinol compound in the preparation of antibacterial drugs.
2. The application according to claim 1, characterized in that, The antibacterial drug is an antimicrobial drug against Gram-positive bacteria.
3. The application according to claim 2, characterized in that, The Gram-positive bacteria are selected from at least one of Staphylococcus aureus, methicillin-resistant Staphylococcus aureus, and Listeria.
4. The application according to claim 3, characterized in that, The Gram-positive bacteria are selected from at least one of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus.
5. The application according to claim 1, characterized in that, The structure of the bicyclic phloroglucinol compound is selected from at least one of the compounds shown in formula (I); 。 6. The application according to claim 5, characterized in that, The structure of the bicyclic phloroglucinol compound is selected from at least one of the compounds shown in formula (II); 。 7. The application of a bicyclic phloroglucinol compound in the preparation of antibacterial combination drugs with antibiotics.
8. The application according to claim 7, characterized in that, The antibiotic is selected from at least one of vancomycin, norfloxacin, meropenem, erythromycin, and rifampin.
9. An antibacterial drug, characterized in that, The antibacterial agent is selected from at least one of the bicyclic phloroglucinol compounds as described in claim 1, or pharmaceutically acceptable salts or esters thereof, derivatives thereof, stereoisomers thereof, and pharmaceutically acceptable salts of their derivatives.
10. The antibacterial drug according to claim 9, characterized in that, The antimicrobial agent also includes pharmaceutically acceptable excipients.