Homoserine lactone compound for effectively inhibiting formation of multi-drug-resistant pseudomonas aeruginosa biofilm

Abstract

The invention discloses a homoserine lactone compound N-(3-cyclobutyrolactone)-4-nitrobenzene butyramide which can effectively inhibit the formation of a multi-drug-resistant pseudomonas aeruginosa biofilm, and an application of the N-(3-cyclobutyrolactone)-4-nitrobenzene butyramide in the treatment of chronic infection of drug-resistant bacteria. The N-(3-cyclobutyrolactone)-4-nitrobenzene butyramide not only can inhibit QS systems of pseudomonas aeruginosa standard strains and clinical strains and enhance the inhibitory activity of antibiotics to pseudomonas aeruginosa, but also is good in safety and can be used for treating chronic infection caused by pseudomonas aeruginosa.

Description

Technical Field

[0001] The invention belongs to the technical field of microorganisms and discloses a homoserine lactone compound N-(3-cyclobutyrolactone)-4-nitrophenylbutyramide which effectively inhibits the formation of multi-drug resistant Pseudomonas aeruginosa biofilm. Background Art

[0002] Pseudomonas aeruginosa is a common pathogen that is widely distributed and highly pathogenic. As an important nosocomial pathogen, Pseudomonas aeruginosa may threaten patients with long-term intubation and immunodeficiency, as well as patients with cystic fibrosis, corneal trauma, burns, and Gustilo open fractures, and cause fatal infections. The pathogenicity of Pseudomonas aeruginosa is closely related to its formation of biofilms on surfaces and the virulence factors it secretes. Recent studies have found that the quorum sensing system of Pseudomonas aeruginosa plays an important role in its biofilm formation and the secretion of virulence factors. The formation of biofilms is associated with 80% of bacterial infections in humans. Biofilms are some microbial communities associated with surfaces. These fixed microbial communities are constructed by the attachment of planktonic bacteria to the surface. Subsequently, cells interact with the extracellular matrix and develop into growing colonies with complex three-dimensional structures, thereby promoting chronic infections. Antibiotic resistance is partly mediated by biofilms attached to the surface, and biofilms become physical barriers to antibiotic penetration. Therefore, inhibiting the development of quorum sensing is one of the effective methods to control Pseudomonas aeruginosa infection and antibiotic resistance. In the present invention, a series of compounds were designed by structurally modifying the existing QSI (Quorum sensing inhibitor). Among the modified compounds, compound L2 not only showed excellent inhibitory activity against multiple virulence factors, but also significantly enhanced the inhibitory activity of antibiotics against Pseudomonas aeruginosa in vitro. Therefore, compound L2 can be used as an effective QSI for further developing antibacterial infections. Summary of the invention

[0003] The purpose of the present invention is to provide a homoserine lactone compound that effectively inhibits the formation of multidrug-resistant Pseudomonas aeruginosa biofilm, which specifically includes the following contents:

[0004] In one aspect, the present invention provides a homoserine lactone compound, wherein the general formula of the homoserine lactone compound (Formula I) is:

[0005]

[0006] Preferably, the homoserine lactone compound is N-(3-cyclobutyrolactone)-4-nitrophenylbutyramide, and the structural formula of N-(3-cyclobutyrolactone)-4-nitrophenylbutyramide (Formula II) is:

[0007]

[0008] In another aspect, the present invention provides use of the homoserine lactone compound described in the first aspect in the preparation of a drug for inhibiting biofilm formation of Pseudomonas aeruginosa.

[0009] Furthermore, the homoserine lactone compound is used in the preparation of a drug for treating chronic infectious diseases caused by Pseudomonas aeruginosa.

[0010] Preferably, the dosage form of the chronic infectious disease drug is selected from oral liquid, tablet, capsule, granule, ear drop, nasal drop, suppository, pill, liniment, ointment, cream, patch, paste, spray, aerosol or powder spray.

[0011] Preferably, the chronic infectious diseases caused by Pseudomonas aeruginosa include chronic wound infection, chronic sinusitis, and chronic otitis media.

[0012] Beneficial effects of the present invention:

[0013] N-(3-cyclobutyrolactone)-4-nitrophenylbutyramide can not only significantly inhibit the QS system of standard strains and clinical strains of Pseudomonas aeruginosa, significantly enhance the inhibitory activity of antibiotics against Pseudomonas aeruginosa, but also has good safety and can be used to treat chronic infections caused by Pseudomonas aeruginosa. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The inhibitory effect of compound L2 at different concentrations on the growth of Pseudomonas aeruginosa;

[0015] Figure 2 To evaluate the inhibitory effect of compound L2 at different concentrations on biofilm formation of Pseudomonas aeruginosa;

[0016] Figure 3 CLSM was used to observe the inhibitory effect of 25 μM compound L2 on the biofilm formation of Pseudomonas aeruginosa;

[0017] Figure 4 SEM observation of the inhibitory effect of 25 μM compound L2 on Pseudomonas aeruginosa biofilm formation. A, B, and C were observed at 20000x, and D, E, and F were observed at 2000x.

[0018] Figure 5 The inhibitory effect of L2 on the motility of Pseudomonas aeruginosa. (A)(E) represents the swimming motility of Pseudomonas aeruginosa PAO1, (B)(F) represents the swarming motility of Pseudomonas aeruginosa PAO1, and (C)(G) represents the twitching motility of Pseudomonas aeruginosa PAO1;

[0019] Figure 6The effect of 25 μM compound L2 on the secretion of pyocyanin by Pseudomonas aeruginosa PAO1;

[0020] Figure 7 The effect of 25 μM compound L2 on the elastase activity of Pseudomonas aeruginosa PAO1;

[0021] Figure 8 The effect of 25 μM compound L2 on the expression level of QS regulatory genes of Pseudomonas aeruginosa PAO1 was evaluated;

[0022] Fig. 9 The effect of 25 μM compound L2 on Pseudomonas aeruginosa PAO1 to different quorum sensing system fluorescent reporter strains;

[0023] Fig.10 To evaluate the toxicity of 25 μM compound L2 on nematodes;

[0024] Fig.11 The hemolytic effect of compound L2 at different concentrations on mouse erythrocytes. DETAILED DESCRIPTION

[0025] The following specific embodiments are provided to implement the technical solutions described in the present invention, but are not limited to these embodiments.

[0026] Example 1 Synthesis and characterization of homoserine lactone analogs

[0027]

[0028] The raw materials (Formula III and Formula IV) were mixed in a mass ratio of 1:1 and dissolved in dichloromethane (DCM). 2.5eq N, N-diisopropylethylamine (DIEPA) and 1.0eq 2-(7-azabenzotriazole)-N, N, N', N'-tetramethyluronium hexafluorophosphate (HATU) were added to the system as condensation agents. The reaction was stirred at room temperature for 18-24h. After the reaction was completed, the reaction solution was washed 3 times with an equal volume of 10% (v / v) HCl solution and saturated NaCl solution in a separatory funnel. The organic phase solution was then collected, anhydrous MgSO4 was added to remove the residual moisture in the organic phase, and the crude product was obtained after drying at 50°C on a rotary evaporator. The crude product was chromatographed on a SiO2 column and monitored by TLC, eluted with dichloromethane:ethyl acetate = 10:1, and the eluate was evaporated by a rotary evaporator at 50°C and filtered under reduced pressure with an oil pump to obtain the target products L1, L2, L6, L9, and L10. The structural spectra of the products are shown above.

[0029] Example 2 Evaluation of the activity of compounds in inhibiting biofilm formation of Pseudomonas aeruginosa

[0030] Single colonies of Pseudomonas aeruginosa PAO1, clinical strains C1, C2, and C3 were selected and inoculated into LB medium and cultured at 180 rpm and 37°C until the logarithmic growth phase. Next, the bacterial solution was diluted to 5 × 10 7 CFU / mL, and then add compounds L1, L2, L6, L9, and L10 dissolved in DMSO to the diluted PAO1 bacterial solution to make the final concentration gradient of each compound 6.25, 12.5, 25, 50, and 100 μM as the experimental group. The negative control group added an equal volume of DMSO. The positive control group was N-(3-cyclobutyrolactone)-4-bromobenzenebutanamide (NO.10) with a final concentration of 6.25, 12.5, 25, 50, and 100 μM, with 6 replicates in each group and 150 μL of bacterial solution in each well. The 96-well plate was placed in a 37°C incubator and cultured at a constant temperature for 24 hours. After the culture was completed, the bacterial solution in the 96-well plate was aspirated, 280 μL of sterile water was added to each well and gently washed twice. After it was dried, 150 μL of 0.5% crystal violet solution was added to each well and stained at room temperature for 15 minutes. After staining, the crystal violet staining solution in the well was aspirated, and then 280 μL of sterile water was added to gently wash 3 times. After drying, 150 μL of 33% acetic acid solution was added to each well to dissolve the biofilm for 30 minutes. Then, the OD was detected with an enzyme reader. 570 The evaluation test operation of clinical strains C1, C2, and C3 is the same as above, and the experimental results are shown in the table:

[0031] Table 1 Inhibitory activity of compounds against biofilm formation of standard and clinical strains of Pseudomonas aeruginosa

[0032]

[0033] As shown in Table 1, all compounds L1, L2, L6, L9, and L10 showed inhibitory activity against biofilm formation of standard and clinical strains of Pseudomonas aeruginosa. Among all analogs, compared with L1, L6, L9, L10, and NO.10, compound L2 showed more significant inhibitory activity against the standard strain of Pseudomonas aeruginosa and three clinical strains, and was identified as a candidate compound for subsequent experimental evaluation.

[0034] Example 3 Evaluation of the inhibitory effect of compound L2 on the growth of Pseudomonas aeruginosa

[0035] Pseudomonas aeruginosa PAO1 was cultured overnight and diluted in LB medium. The L2 concentration in the diluted LB solution ranged from 10 to 400 μM and incubated at 37°C. Then, 1 mL samples were taken every 2 h and the OD was measured using a spectrophotometer. 600 , and then generate a growth curve. At the same time, NO.10 was used as a control

[0036] like Figure 1 As shown, similar to NO.10, compound L2 had no inhibitory effect on the growth of Pseudomonas aeruginosa PAO1 in the concentration range of 10 to 400 μM.

[0037] Example 4 Evaluation of the inhibitory effect of compound L2 on Pseudomonas aeruginosa biofilm formation

[0038] The inhibitory effects of compound L2 and N-(3-cyclobutyrolactone)-4-bromobenzenebutanamide (NO.10) on biofilm formation were further identified at a concentration gradient of 6.25 to 400 μM. Single colonies of Pseudomonas aeruginosa PAO1, clinical strains C1, C2, and C3 were selected and inoculated into LB medium and cultured at 180 rpm and 37°C until the logarithmic growth phase. Next, the bacterial solution was diluted to 5×10 7 CFU / mL, and then add compounds L1, L2, L6, L9, and L10 dissolved in DMSO to the diluted PAO1 bacterial solution to make the final concentration gradient of each compound 6.25, 12.5, 25, 50, and 100 μM as the experimental group. An equal volume of DMSO was added to the control group. There were 6 replicate wells in each group, with 150 μL of bacterial solution in each well. The 96-well plate was placed in a 37°C incubator and cultured at a constant temperature for 24 hours. After the culture was completed, the bacterial solution in the 96-well plate was aspirated, 280 μL of sterile water was added to each well and gently washed twice. After it was dried, 150 μL of 0.5% crystal violet solution was added to each well and stained at room temperature for 15 minutes. After staining, the crystal violet staining solution in the well was aspirated, and then 280 μL of sterile water was added to gently wash 3 times. After drying, 150 μL of 33% acetic acid solution was added to each well to dissolve the bacterial biofilm for 30 minutes. Then, the OD was detected with an enzyme marker. 570 value.

[0039] like Figure 2 As shown, compound L2 has a more obvious inhibitory effect on biofilm formation in the concentration range of 6.25 to 25 μM, and it is dose-dependent. In contrast, NO.10 has a more obvious inhibitory effect on biofilm formation in the concentration range of 25 to 200 μM, among which the inhibition rate is the highest at 200 μM, reaching 45%. It is worth noting that the inhibition rate of compound L2 on PA biofilm formation reached 56% at 25 μM, and the inhibitory effect is more significant.

[0040] Example 5 CLSM observation of the inhibitory effect of compound L2 on Pseudomonas aeruginosa biofilm formation

[0041] Compound L2 and NO.10 were added to the diluted PAO1 bacterial solution to make the final concentration of 25μM, of which NO.10 was used as a positive control, and the same volume of DMSO treatment group was added as a negative control. Take 1mL of the above-treated bacterial solution and add it to a 6-well culture plate, place a glass slide in each experimental well, and 3 replicates per group. Place the 6-well culture plate in a constant temperature incubator, incubate at 37℃ for 24h, and gently rinse it three times with PBS to remove free bacteria. Fix the slide with 2.5% glutaraldehyde solution at 4℃ for 4h, then gently rinse it three times with PBS buffer for 10min each time, and use absorbent paper to absorb the remaining liquid on the slide. Evenly add 20μL of 1mg / mL FITC-ConA solution on the slide and stain it at room temperature for 20min. After staining, discard the excess dye, gently rinse it 3 times with PBS buffer to remove the excess dye, and use absorbent paper to absorb the remaining liquid on the slide. Then, 20 μL of 50 μg / mL PI solution was evenly added to the slide again, and the slide was placed at room temperature for staining for 15 minutes. After staining, the excess dye was discarded, and the slide was gently rinsed with PBS buffer for 3 times to remove the excess dye, and the residual liquid on the slide was blotted dry with absorbent paper. Finally, the slide was placed under a laser confocal microscope to observe the changes in the biofilm structure.

[0042] The results of fluorescence microscopy observations were as follows Figure 3 As shown, the amount of bacteria in the L2 treatment group was significantly reduced compared with the control group, and the reduction in the L2 treatment group was more obvious than that in the NO.10 treatment group. The green fluorescence thickness of the control group was about 16 μm. After treatment with NO.10 and L2, the thickness of the green fluorescence in the biofilm became thinner, decreasing to 6 μm and 4 μm, respectively. This result further proves that the candidate compound L2 has more significant biofilm inhibition activity.

[0043] Example 6 SEM observation of the inhibitory effect of compound L2 on Pseudomonas aeruginosa biofilm formation

[0044] After the bacterial solution was treated and fixed according to the above-mentioned CLSM experimental method for observing changes in biofilm structure, it was dehydrated in a gradient manner using 30%, 50%, 70%, 85%, 95% and 100% ethanol solutions, each for 10 minutes, with 100% ethanol dehydration treatment twice. After the biofilm sample was air-dried in a desiccator for 24 hours, it was sprayed with gold and images were taken using a scanning electron microscope to observe the formation of bacterial biofilm.

[0045] Depend on Figure 4It can be seen that the bacteria in the control group formed a multi-layer overlapping structure of bacteria, the biofilm was relatively thick, and the bacteria were densely distributed. Compared with the control group, the biofilm formed by the treatment group was thin and uneven, with a loose structure and loose bacterial distribution. Moreover, the biofilm structure of the compound L2 treatment group was looser than that of the NO.10 treatment group. The results show that compound L2 can reduce the formation of bacterial biofilms and change the structure of bacterial biofilms.

[0046] Example 7 Evaluation of the inhibitory effect of L2 on the motility of Pseudomonas aeruginosa

[0047] 1.Swimming

[0048] The swimming agar plates (10 g / L peptone, 5 g / L NaCl and 0.3% agarose) containing 25 μM compound L2 and the blank control plates were pierced with the center of Pseudomonas aeruginosa PAO1 using a sterile toothpick. In addition, compound NO.10 was used as a positive control. After incubation at 30°C for 12-14h, the swimming motion zone was determined by measuring the blue diameter zone in the center of the plate.

[0049] 2. Swarming

[0050] The swarming plate was composed of nutrient agar (8 g / L) and glucose (5.0 g / L). 25 μM of compound L2 and NO.10 were added to the swarming plate, and the swarming plate without compound addition was used as a blank control, and NO.10 was used as a positive control, and then 5 μL of overnight cultured Pseudomonas aeruginosa was added to the plate. Then, the swarming plate was placed in a 30°C incubator and incubated for 18-24 hours, and the swarming movement diameter area in the center of the plate was measured.

[0051] 3. Twitching

[0052] The medium used in this experiment was LB medium. Compound L2 and NO.10 were added at 25 μM in LB medium. LB plates without compound were used as blank controls and NO.10 was used as positive controls. The plates were punctured and overnight cultured Pseudomonas aeruginosa PAO1 was added to the bottom of the culture dish. After culturing at 37°C for 48 h, the agar was removed and the plates were air dried and stained with crystal violet. The dye was washed off with sterile water and the twitching movement area was measured.

[0053] like Figure 5As shown, the swimming, swarming and twitching ranges of Pseudomonas aeruginosa PAO1 in the blank control group were 2.70±0.06cm, 3.50±0.15cm and 8.00±0.12cm, respectively. In the presence of NO.10, the swimming, swarming and twitching ranges of Pseudomonas aeruginosa PAO1 were 1.40±0.04cm, 2.80±0.12cm and 6.40±0.18cm, respectively. In the presence of compound L2, it caused a significant reduction in the movement area by 51.85±0.05%, 60.00±0.11% and 31.25±0.06%. In summary, NO.10 and compound L2 had a significant inhibitory effect on the motility of PAO1, and compound L2 showed stronger inhibitory activity.

[0054] Example 8 Evaluation of the inhibitory effect of L2 on the production of virulence factors of Pseudomonas aeruginosa

[0055] 1. Pyocyanin analysis

[0056] After picking a single colony of PAO1 and growing it aerobically at 37°C for 24 hours, the overnight cultured Pseudomonas aeruginosa PAO1 was subcultured into LB medium with an L2 concentration of 25 μM and cultured for 24 hours. The culture color was observed. In addition, compound No. 10 was used as a positive control. Finally, by measuring OD 520 To determine the content of pyocyanin.

[0057] The experimental results are as follows Figure 6 As shown, at the same concentration, NO.10 and compound L2 can inhibit the production of PAO1 pyocyanin. Compound NO.10 reduced the production of pyocyanin by 36.98±0.23%, and L2 reduced the production of PA pyocyanin by 46.69±0.21%. Compared with compound NO.10, L2 had a more obvious inhibitory effect on the production of Pseudomonas aeruginosa pyocyanin.

[0058] 2. Analysis of Elastase

[0059] After overnight culture of Pseudomonas aeruginosa, the overnight cultured PAO1 was subcultured into fresh LB medium containing 25 μM L2, with the group without compound as blank control and the group containing compound NO.10 as positive control, and incubated at 37°C at 180 rpm for 24 h. After 24 h, the culture was centrifuged at 10,000 rpm for 15 min, the supernatant was collected, and 100 μL of the supernatant was added to the wells of the skim milk agar plate, and the plate was incubated at 37°C for 24 h. The elastase activity was determined by measuring the diameter of the transparent zone of the plate.

[0060] The experimental results are as follows Figure 7 As shown, compared with the control group, both compound 10 and compound L2 can inhibit the activity of elastase. After treatment with compound 10, the diameter of the transparent area on the skim milk plate decreased by 26±1.02%, and after treatment with L2, the transparent diameter decreased by 41±0.87%. In summary, compound NO.10 and compound L2 can both inhibit the activity of elastase, and the inhibitory effect of compound L2 is more significant.

[0061] Example 9 Evaluation of the effect of L2 on the expression level of QS regulatory genes in Pseudomonas aeruginosa

[0062] The relative expression levels of key QS regulatory genes (lasI, lasR, rhlI, rhlR, mvfR) and antibiotic resistance gene ampC of Pseudomonas aeruginosa PAO1 were detected in the presence of compound L2, and compound No. 10 was used as a positive control and 16SrRNA housekeeping gene as an internal reference gene. The primers of the detected genes are shown in Table 2.

[0063] Table 2 Primers for the genes detected

[0064]

[0065] Total RNA was isolated using an Ultrapure RNA kit (CWBIO, Beijing, China) and analyzed according to the manufacturer’s instructions. III. First Strand cDNA Synthesis SuperMix (Yeasen, Beijing, China) for qPCR was used to synthesize the first strand cDNA. The reaction was performed using Hieff Universal Blue qPCR SYBRGreen premix (Yeasen, Beijing, China) was used. -ΔΔCt Methods Relative gene expression was calculated.

[0066] Compared with the untreated group, NO.10 inhibited the expression of lasI, lasR, rhlI, mvfR, and ampC, but upregulated the expression of rhlR. After NO.10 treatment, the relative expression of lasI, lasR, rhlI, mvfR, and ampC decreased by 16±0.76%, 47±2.01%, 25±0.39%, 38±0.83%, and 38±1.21%, respectively. Compared with NO.10, L2 downregulated the expression of 6 genes, and the relative expression of lasI, lasR, rhlI, rhlR, mvfR, and ampC decreased by 48±0.34%, 68±0.62%, 16±0.28%, 17±1.01%, 79±0.36%, and 50±0.48%, respectively.

[0067] Example 10 Effect of L2 on fluorescent reporter strains of different quorum sensing systems

[0068] PAO1-lasB-gfp, PAO1-rhlA-gfp, and PAO1-pqsA-gfp were selected and cultured for 12-14 hours, and then subcultured to new LB medium at a ratio of 1:100 and cultured to the logarithmic growth phase. Then, the bacteria in the logarithmic growth phase were added to a 96-well plate, and the concentrations of compounds L2 and NO.10 in the 96-well plate reached 25 μM. The group without compound addition was used as the blank control and NO.10 as the positive control. The inoculated bacterial plate was placed in an ELISA instrument, the temperature was set at 37°C, the excitation light was set at 485nm, the emission light was set at 528nm, the fluorescence was measured every 15 minutes, and the growth optical density of the reporter strain was monitored at 600nm (OD 600 ) to ensure that the compounds had no effect on bacterial growth, and the assay was continued for 16 h to detect the effects of the compounds on the three pathways.

[0069] Compound L2 slightly inhibited the fluorescent protein expression of PAO1-rhlA-gfp and PAO1-pqsA-gfp green fluorescent protein reporter strains of rhl and pqs systems, and significantly inhibited the expression of fluorescent protein in PAO1-lasB-gfp green fluorescent protein reporter strain of las system. However, compound NO.10 had no obvious inhibitory effect on the three pathways. This result indicates that the inhibitory effect of compound L2 on LasR is significantly stronger than that of compound NO.10.

[0070] Implementation Case 11 Nematode Quick Killing Experiment

[0071] The quick killing experiment of Caenorhabditis elegans was used to evaluate the inhibitory effect of 25 μM compound L2 on the production of virulence factors of PA. In addition, compound NO.10 was used as a positive control. After Caenorhabditis elegans grew to the L4 stage at 20°C, the nematodes were synchronized and inoculated into new NGM medium and cultured at 20°C for 48h to reach the L4 stage. In addition, during the growth of nematodes, compound L2 was added to Pseudomonas aeruginosa PAO1 to a final concentration of 25 μM, cultured at 37°C for 24h, DMSO as a blank control, and NO.10 as a positive control. Then, the treated overnight cultured PAO1 was inoculated on a solid medium containing PGS agar (1% peptone, 1% NaCl, 1% glucose, 150mM sorbitol and 1.7% agar) and cultured at 37°C for 24h. After that, the synchronized nematodes at the L4 stage were inoculated on the plate inoculated with PAO1, and 25-30 were inoculated on each plate. Then, the surviving nematodes were counted every 3 h at 25 °C.

[0072] Compared with compound NO.10, compound L2 can significantly improve the survival rate of Pseudomonas aeruginosa Caenorhabditis elegans within 18 hours. Compared with the untreated group, the survival rate of Caenorhabditis elegans in the compound L2 group was close to 80% within 6 hours of incubation, and it can still reach 60% within 18 hours. The experimental results show that compound L2 has a more significant inhibitory effect on the QS system of PA than NO.10.

[0073] Implementation Case 12 Hemolysis Test

[0074] Freshly isolated mouse erythrocytes were washed three times with PBS buffer to prepare a 5% erythrocyte solution. Compound L2 was serially diluted with PBS buffer so that the concentrations of the compound in the 200 μL system were 12.5 μM, 25 μM, 50 μM, and 100 μM, respectively, and then the compound L2 and 5% erythrocyte mixture were incubated at 37 ° C for 1 hour. The incubation solution was centrifuged at 1500 rpm for 10 minutes. The supernatant (30 μL) was transferred to a 96-well plate, each well containing PBS buffer (70 μL), and the absorbance of all wells at 540 nm was recorded by an ELISA instrument. PBS buffer was used as a negative control, and 2% Triton X-100 was used as a positive control.

[0075] The hemolysis rates of compound L2 at concentrations of 12.5, 25, 50, and 100 μM were 0.05%, 1.5%, 2.1%, and 2.3%, respectively. Even at a high concentration of 100 μM, the hemolysis rate of compound L2 was lower than 2.5%, indicating that compound L2 had little hemolytic effect on mouse erythrocytes.

Claims

1. A homoserine lactone compound, characterized in that: The general formula of the homoserine lactone compound (Formula I) is:

2. The homoserine lactone compound according to claim 1, characterized in that The homoserine lactone compound is N-(3-cyclobutyrolactone)-4-nitrophenylbutyramide (Formula II), and the structural formula is:

3. Use of the homoserine lactone compound according to claim 1 in the preparation of a drug for inhibiting biofilm formation of Pseudomonas aeruginosa.

4. Use of the homoserine lactone compounds according to claims 1-3 in the preparation of drugs for treating chronic infectious diseases caused by Pseudomonas aeruginosa.

5. The use according to claim 4, characterized in that: The dosage form of the chronic infectious disease drug is selected from oral liquid, tablet, capsule, granule, ear drop, nasal drop, suppository, pill, liniment, ointment, cream, patch, paste, spray, aerosol or powder spray.

6. The use according to claim 4, characterized in that: The chronic infectious diseases caused by Pseudomonas aeruginosa include chronic wound infection, chronic sinusitis, and chronic otitis media.

Images