Thiazolidinone compound and application of thiazolidinone compound in preparation of anti-staphylococcus aureus infection medicine

Abstract

The invention provides a thiazolidinone compound and application thereof in preparation of drugs for resisting staphylococcus aureus infection. The molecular structural formula of the thiazolidinone compound is shown as a formula (1), a formula (2), a formula (3) or a formula (4). The technical scheme of the invention discloses several thiazolidinone compounds, which not only have an excellent bactericidal effect on staphylococcus aureus and can significantly inhibit the formation of a biofilm of staphylococcus aureus, but also have low cytotoxicity and hemolytic activity. According to the technical scheme, a certain foundation is laid for research and development of novel staphylococcus aureus biofilm infection resisting drugs, and the potential of thiazolidone derivatives for developing novel antibacterial agents for staphylococcus aureus related infection can be deeply known possibly.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular to a thiazolidinone compound and an application thereof in preparing a drug for resisting Staphylococcus aureus infection. Background Art

[0002] Because bacterial resistance has increased dramatically over the past two decades, antibiotic-resistant bacteria have become a major concern for public health professionals. Indeed, bacteria that grow as adherent biofilms on catheters, orthopedic implants, and bone are inherently resistant to antibiotics and are poorly recognized by the host immune defense system. Biofilm-associated bacteria exhibit enhanced resistance to many conventional antibiotics. Staphylococcus aureus has become an important pathogen causing infections due to the formation of biofilms on the surfaces of indwelling medical devices. Therefore, there is an urgent need to design new antibiotics against S. aureus infections, especially those that can kill cells embedded in biofilms. Summary of the Invention

[0003] In response to the above technical problems, the present invention discloses a thiazolidinone compound and its use in preparing an anti-Staphylococcus aureus infection drug, which has bactericidal activity and anti-biofilm activity against Staphylococcus aureus, low cytotoxicity to mammalian cells, and low hemolytic activity against human red blood cells.

[0004] To this end, the technical solution adopted in the present invention is:

[0005] A thiazolidinone compound, whose molecular structure is shown in formula (1), formula (2), formula (3) or formula (4):

[0006]

[0007]

[0008] This proposal discloses several new thiazolidinone compounds, which have better bactericidal activity against Staphylococcus aureus and effective anti-biofilm activity against Staphylococcus.

[0009] More preferably, the molecular structural formula of the thiazolidinone compound is formula (1) or formula (3).

[0010] The present invention discloses the use of the thiazolidinone compounds mentioned above in preparing drugs for resisting Staphylococcus aureus infection.

[0011] As a further improvement of the present invention, the concentration of the thiazolidinone compound in the treatment system is not less than 0.78 μM.

[0012] As a further improvement of the present invention, the medicine is an injection, tablet, pill, capsule, suspension, granule, spray or emulsion.

[0013] The present invention discloses a drug for resisting Staphylococcus aureus infection, which comprises the thiazolidinone compound described above.

[0014] The present invention discloses the use of the thiazolidinone compound mentioned above in preparing a coating for inhibiting Staphylococcus aureus. The coating is used on the surface of medical devices.

[0015] As a further improvement of the present invention, in the coating, the concentration of the thiazolidinone compound is not less than 0.78 μM.

[0016] The present invention discloses the use of the thiazolidinone compound mentioned above in preparing a disinfectant for inhibiting Staphylococcus aureus.

[0017] As a further improvement of the present invention, in the disinfectant, the concentration of the thiazolidinone compound is not less than 0.78 μM.

[0018] The invention discloses a coating for inhibiting Staphylococcus aureus, which comprises the thiazolidinone compound described above.

[0019] The invention discloses a disinfectant for inhibiting Staphylococcus aureus, which comprises the thiazolidinone compound described above.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The technical solution of this invention discloses several thiazolidinone compounds that not only exhibit excellent bactericidal activity against Staphylococcus aureus and significantly inhibit biofilm formation, but also exhibit low cytotoxicity and hemolytic activity. This technical solution lays a foundation for the development of novel antimicrobial agents against S. aureus biofilm infections and may provide further insights into the potential of thiazolidinone derivatives to develop novel antimicrobial agents for S. aureus-associated infections. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The killing effect of the thiazolidinone compounds of the embodiments of the present invention on MRSAUSA300 planktonic bacteria; wherein (a) is H2-3, (b) is H2-15, (c) is H5-7, and (d) is H5-11.

[0023] Figure 2 These are the results of the thiazolidinone compounds of the examples of the present invention inhibiting the biofilm formation of Staphylococcus aureus; wherein (a) is H2-3, (b) is H2-15, (c) is H5-7, and (d) is H5-11.

[0024] Figure 3 Results of the thiazolidinone compounds of the present invention in clearing mature Staphylococcus aureus biofilms. (a) and (b) show the mature biofilms formed by cultures of MSSA SA113 and MRSAYUSA145, respectively. (c) shows the relative quantitative fluorescence results, with a scale of 20 μM. (d) and (e) show the absorbance of H2-3 and H5-7, respectively, measured by crystal violet staining at OD570. **P < 0.01, ***P < 0.001 indicates significant differences. ns indicates P > 0.05, indicating no significant differences.

[0025] Figure 4 The safety evaluation results of the thiazolidinone compound H5-7 according to an embodiment of the present invention in the greater wax moth model are shown; (a) shows the statistical results of the three-day survival rate of the insects after administration of different doses of H5-7, (b) shows the blank sample, and (c) to (e) show the results of administration of 100 mg / kg LZD, 20 mg / kg H5-7, and 50 mg / kg H5-7, respectively.

[0026] Figure 5 The safety evaluation results of the thiazolidinone compound H5-7 according to the present invention in a mouse drug toxicity model are shown. (a) to (f) show the test results of different toxicity-related indicators. Data are expressed as mean ± standard deviation. n = 3, ns indicates no significant difference.

[0027] Figure 6 This figure shows the pathological analysis of the thiazolidinone compound H5-7 in the examples of the present invention on mouse liver and kidney tissues. Normal saline was used as a control. Scale bar: 50 μm, magnification: 40x. DETAILED DESCRIPTION

[0028] The preferred embodiments of the present invention are described in further detail below.

[0029] Example 1

[0030] A thiazolidinone compound, whose molecular structure is shown in formula (1), formula (2), formula (3) or formula (4):

[0031]

[0032] Preferably, the molecular structural formula of the thiazolidinone compound is formula (1) or formula (3).

[0033] The above-mentioned novel thiazolidinone compounds have better bactericidal activity against Staphylococcus aureus and effective anti-biofilm activity against Staphylococcus aureus.

[0034] Comparative Example 1

[0035] The structures of the thiazolidinone compounds H2-10, H2-12, and H5-5 in this comparative example are different from those in Example 1, and are:

[0036]

[0037] The preparation methods of the above Examples H2-3, H2-15 and Comparative Examples H2-10, H2-12 are as follows:

[0038] (1) Synthesis of intermediate 1,3-diphenylthiourea (1a-1d):

[0039]

[0040] The specific steps include dissolving an amine (20 mmol) and phenyl isothiocyanate (20 mmol) in 25 mL of dichloromethane, stirring at room temperature for 30 minutes, then heating to 40°C and continuing the reaction for 50 minutes. TLC confirms completion of the reaction, followed by extraction with ethyl acetate, drying over anhydrous MgSO₄, and vacuum concentration. Recrystallization from dichloromethane / petroleum ether affords the 1,3-diphenylthiourea intermediates (1a-1d) in 90-95% yields.

[0041] (2) Synthesis of intermediate 2-phenylimino-3-phenyl-thiazolidin-4-one derivatives (2a-2d), the synthetic route is:

[0042]

[0043] The specific steps include dissolving 1,3-diphenylthiourea intermediates 1a-1d (10 mmol), ethyl bromoacetate (12 mmol), and anhydrous sodium acetate (12 mmol) in 30 mL of anhydrous ethanol and heating under reflux for 6 hours. The reaction is monitored by TLC until complete, cooled to room temperature, concentrated under vacuum, extracted with ethyl acetate, dried over anhydrous MgSO4, filtered, and concentrated under vacuum. Purification by column chromatography (ethyl acetate:petroleum ether = 1:10) affords the crude product, which is then recrystallized from dichloromethane / petroleum ether to afford 2-phenylimino-3-phenyl-thiazolidin-4-one derivatives (2a-2d). Yields range from 36-60%.

[0044] (3) Synthesis of 4-(5-(Z)-((Z)-2-((4-chlorophenyl)imino)-4-oxo-3-phenylthiazolidin-5-ylidene)methyl)thiophen-2-yl)benzoic acid (H2-3). The synthetic route is:

[0045]

[0046] The specific steps include dissolving the intermediate 2-phenylimino-3-phenyl-thiazolidin-4-one derivative 2a (1 mmol), 4-(5-formyl-2-thienyl)benzoic acid (1.2 mmol), and β-alanine (2 mmol) in 5 mL of acetic acid, heating under reflux for 6 hours, and monitoring the reaction by TLC until complete. The reaction is then cooled to room temperature and added to ice water. Solids precipitate, which are filtered and recrystallized from methanol / dichloromethane to obtain the target compound H2-3 in a 34% yield. The product's spectral data are as follows: 1 H NMR (400MHz, DMSO) δ13.01(s,1H),8.13(s,1H),7.98(s,2H),7.85(s,3H),7.75(s,1H),7.53(d,J=28.4Hz,7H),7.06(s,2H). 13 C NMR(101MHz,DMSO)δ167.3,165.7,150.8148.4,147.2,138.2,136.9,136.4,135.5, 131.0,130.8,130.0,129.5,129.4,129.3,129.0,127.4,126.2,124.4,123.2,119.6

[0047] (4) Synthesis of 4-(5-((Z)-((Z)-3-(3,5-dichlorophenyl)-4-oxo-2-(phenyl)thiazolidin-5-ylidene)methyl)thiophen-2-yl)benzoic acid (H2-10). The synthetic route is based on the synthetic route of (3). The specific steps include:

[0048] The intermediate 2-phenylimino-3-phenyl-thiazolidin-4-one derivative 2b (1 mmol), 4-(5-formyl-2-thienyl)benzoic acid (1.2 mmol), and β-alanine (2 mmol) were dissolved in 5 mL of acetic acid and heated under reflux for 6 h. The reaction was monitored by TLC until complete. The mixture was cooled to room temperature and added to ice water. A solid precipitated, which was filtered and recrystallized from methanol / dichloromethane to obtain the target compound H2-10 in a 37% yield. The product's spectral data are as follows: 1 HNMR (400MHz, DMSO) δ13.06(s,1H),8.14–8.08(m,1H),8.02(d,J=8.4Hz,2H),7.95(dd,J=11.6,8.4Hz,3H),7.85(dd, J=11.3,6.4Hz,3H),7.76(q,J=4.1Hz,1H),7.55(dd,J=6.6,3.9Hz,2H),7.45(t,J=7.8Hz,2H),7.03(d,J=7.4Hz,1H). 13C NMR(101MHz,DMSO)δ169.3,166.8,159.5,150.9,149.2,148.0,146.9,143.0,139.1, 137.6,134.0,130.3,129.6,129.1,127.9,126.7,126.3,125.7,124.0,122.8,120.8

[0049] (5) Synthesis of 4-(5-((Z)-((Z)-3-(4-acetylphenyl)-2-((4-chlorophenyl)imino)-4-oxothiazolidin-5-ylidene)methyl)thiophen-2-yl)benzoic acid (H2-12). The synthetic route is referenced to the synthetic route of (3). The specific steps include:

[0050] The intermediate 2-phenylimino-3-phenyl-thiazolidin-4-one derivative 2c (1 mmol), 4-(5-formyl-2-thienyl)benzoic acid (1.2 mmol), and β-alanine (2 mmol) were dissolved in 5 mL of acetic acid and heated under reflux for 6 h. The reaction was monitored by TLC until complete. The mixture was cooled to room temperature and added to ice water. A solid precipitated, which was filtered and recrystallized from methanol / dichloromethane to obtain the target compound H2-12 in a 64% yield. The product's spectral data are as follows: 1 HNMR (400MHz, DMSO) δ13.09 (s, 1H), 8.12 (d, J = 8.5Hz, 2H), 7.97 (d, J = 8.1Hz, 2H), 7.84 (d, J = 7.4Hz, 3H),7.73(d,J=8.2Hz,2H),7.63(s,2H),7.47(d,J=8.5Hz,2H),7.04(d,J=8.4Hz,2H),2.50(s,3H). 13 C NMR (101MHz, DMSO) δ197.4,166.8,165.0,158.9,150.1,148.1,146.5,143.0,138.9,137.6 ,136.8,136.4,136.0,130.3,129.9,129.6,128.9,126.9,125.7,124.2,122.7,118.9,26.9

[0051] (6) Synthesis of 4-(5-((Z)-((Z)-2-((4-chlorophenyl)imino)-3-(4-fluorophenyl)-4-oxothiazolidin-5-ylidene)methyl)thiophen-2-yl)benzoic acid (H2-15). The synthetic route is based on the synthetic route of (3). The specific steps include:

[0052] The intermediate 2-phenylimino-3-phenyl-thiazolidin-4-one derivative 2d (1 mmol), 4-(5-formyl-2-thienyl)benzoic acid (1.2 mmol), and β-alanine (2 mmol) were dissolved in 5 mL of acetic acid and heated under reflux for 6 h. The reaction was monitored by TLC until complete. The mixture was cooled to room temperature and added to ice water. A solid precipitated, which was filtered and recrystallized from methanol / dichloromethane to obtain the target compound H2-15 in a 44% yield. The product's spectral data are as follows: 1 HNMR (400MHz, DMSO) δ13.07(s,1H),8.13(d,J=2.1Hz,1H),7.98(d,J=8.2Hz,2H),7.88–7.83(m,3H),7.76(d,J=2.4H z,1H),7.68–7.59(m,3H),7.49(d,J=8.6Hz,1H),7.41(t,J=8.8Hz,1H),7.28(t,J=8.8Hz,1H),7.05(t,J=7.0Hz,2H). 13 C NMR (101 MHz, DMSO) δ

[0053] 166.8,165.3,165.1,158.3,147.9(d,J=3.8Hz),146.6,144.1(d,J=2.5Hz),137.7(d,J=3.7Hz),136 .5,135.9(d,J=5.1Hz),133.9,133.4,130.3,129.6,129.1,126.9,125.7,122.8,119.1,116.5,115.9

[0054] The preparation methods of the above-mentioned Examples H5-7 (also known as TZDH-7), H5-11 (also known as TZDH-11) and Comparative Example H5-5 are as follows:

[0055] (1) Synthesis of intermediate substituted chalcone (3a-3c):

[0056]

[0057] The specific steps include: dissolving a substituted acetophenone (1 mmol) and a substituted benzaldehyde (1 mmol) in 6 mL of ethanol, slowly adding 10 mL of a 20% aqueous NaOH solution dropwise, until the solution turns from clear to turbid and a solid precipitates. The reaction is continued at room temperature for 3 h. TLC is performed until the reaction is complete, the reaction solution is filtered, and the filter cake is washed with water and methanol to obtain the substituted chalcone intermediates (3a-3c) (yield 85-95%).

[0058] (2) Synthesis of intermediate pyrimidinethione derivatives (4a-4c):

[0059]

[0060] Dissolve the intermediate substituted chalcone 3a-3c (1 mmol), thiourea (1.5 mmol), and KOH (3 mmol) in 6 mL of ethanol and reflux at 80°C for 4 h. TLC confirms the completion of the reaction. The reaction solution is poured into ice water and the pH is adjusted to neutral with acetic acid, resulting in the precipitation of solids. Filter the crude product and wash it several times with water to obtain pyrimidinethione derivatives (4a-4c).

[0061] (Yield: 85% to 98%)

[0062] (3) Synthesis of intermediate pyrimidothiazolone derivatives (5a-5c):

[0063]

[0064] The specific steps include dissolving the intermediate pyrimidinethione derivatives 4a-4c (1 mmol), ethyl bromoacetate (1 mmol), and NaOAc (2 mmol) in 8 mL of a mixed solvent (glacial acetic acid: acetic anhydride = 3:1) and reacting at 75°C for 6 h. TLC analysis indicates that the reaction is complete, and the reaction solution is poured into ice water to precipitate solids. Filtration and multiple washings of the crude product with water yield pyrimidothiazolone derivatives (5a-5c). (Yield: 56% to 90%)

[0065] (4) Synthesis of (Z)-4-((4-((5-(2,4-dichlorophenyl)-3-oxo-7-phenyl-5-hydrogen-thiazolo[3,2-a]pyrimidin-2-ylidene)methyl)phenoxy)methyl)benzoic acid (H5-5) by the following synthetic route:

[0066]

[0067] The specific steps include dissolving the intermediate pyrimidothiazolone derivative 5a (1 mmol), an aldehyde compound (1 mmol), and β-alanine (1 mmol) in 6 mL of glacial acetic acid and refluxing at 100°C for 4 hours. TLC is performed until the reaction is complete. The reaction solution is poured into water, and solid precipitates. The solid is filtered and washed with water. The filter cake is slurried twice with methanol, filtered, and dried to obtain the target compound H5-5 in a 71% yield. The product chromatographic data are as follows: 1HNMR(400MHz,DMSO)δ8.01–7.96(m,2H),7.79(d,J=6.9Hz,2H),7.69–7.68(m,2H),7.62–7.56(m,4H),7.48–7.43(m ,2H),7.41–7.34(m,3H),7.22(d,J=8.7Hz,2H),6.29(d,J=4.3Hz,1H),6.03(d,J=4.3Hz,1H),5.31(d,J=6.2Hz,2H); 13 C NMR(101MHz,DMSO)δ167.1,164.7,159.8,153.0,144.1,141.6,139.1,136.8,135.9,133.4,132.0,13 1.1,131.0,130.6,129.5,129.4,128.6,128.4,128.3,127.5,126.0,125.3,116.8,115.8,68.9,52.2

[0068] (5) Synthesis of (Z)-4-((5,7-di(4-chlorophenyl)-3-oxo-5-hydrogen-thiazolyl[3,2-a]pyrimidin-2-ylidene)methyl)benzoic acid (H5-7). The synthetic route is detailed in (4) above.

[0069] The specific steps include dissolving the intermediate pyrimidothiazolone derivative 5b (1 mmol), an aldehyde compound (1 mmol), and β-alanine (1 mmol) in 6 mL of glacial acetic acid and reflux at 100°C for 4 hours. TLC is performed until the reaction is complete. The reaction solution is poured into water, and solid precipitates. The solid is filtered and washed with water. The filter cake is slurried twice with methanol, filtered, and dried to obtain the target compound H5-7 in a 60% yield. The product chromatographic data are as follows: 1 HNMR(400MHz,DMSO)δ13.19(brs,1H),8.07(d,J=8.4Hz,2H),7.83(d,J=8.6Hz,2H), 7.79–7.73(m,3H),7.49–7.40(m,6H),6.24(d,J=4.6Hz,1H),6.03(d,J=4.5Hz,1H); 13C NMR (101MHz, DMSO) δ173.9,166.8,166.6,163.5,152.4,149.8,139.3,138.2,136.9,136.6,133.1,132.6,13 2.3,130.1,129.9,129.8,128.9,128.8,128.5,128.3,127.9,127.6,127.3,127.2,127.0,122.4,121.5,55.7

[0070] (6) Synthesis of (Z)-4-((7-(4-chloro)-5-(4-fluoro-3-oxo-5-hydrogen-thiazolyl[3,2-a]pyrimidin-2-ylidene)methyl)benzoic acid (H5-11). The synthetic route is detailed in (4) above.

[0071] The specific steps include dissolving the intermediate pyrimidothiazolone derivative 5b (1 mmol), an aldehyde compound (1 mmol), and β-alanine (1 mmol) in 6 mL of glacial acetic acid and reflux at 100°C for 4 hours. TLC is performed until the reaction is complete. The reaction solution is poured into water, and solid precipitates. The solid is filtered and washed with water. The filter cake is slurried twice with methanol, filtered, and dried to obtain the target compound H5-11 in a 63% yield. The product chromatographic data are as follows: 1 HNMR (400MHz, DMSO) δ13.11(brs,1H),8.07(d,J=8.4Hz,2H),7.97(d,J=8.4Hz,1H),7.84(d,J= 8.6Hz,1H),7.77–7.68(m,3H),7.58–7.43(m,6H),6.24(d,J=4.6Hz,1H),6.03(d,J=4.6Hz,1H); 13 CNMR(101MHz,DMSO)δ174.1,166.6,163.5,162.0,149.9,138.3,133.0,132.6,131.8,130.1,129.9,12 9.8,129.3,129.0,128.8,128.4,127.9,127.5,127.3,127.0,122.4,121.6,115.9,115.6,115.5,55.6

[0072] In the following examples, biofilm-positive Staphylococcus aureus isolated from a hospital clinic was selected as the experimental strain. After the strain was revived, the strain was preliminarily identified and analyzed using the Phoenix 100 automatic analysis and identification instrument of BD Company, USA. Planting and cultivation After two generations, the samples were identified using a flight mass spectrometer (German IVD MALDI Biotyper) to identify again. The control strain was Staphylococcus aureus ATCC 29213.

[0073] Example 2

[0074] The antibacterial effects of the compounds of Example 1 and the comparative example on Gram-positive bacteria are as follows:

[0075] Prepare suspensions of Staphylococcus epimers SE1457, Staphylococcus aureus SA113 and Enterococcus faecalis OG1RF (1×10 7 CFU / mL) and treated with the test thiazolidinone compounds of Example 1 and the comparative example at a concentration of 50 μM, respectively, and incubated at 37°C, 220 rpm. Aliquots (1 mL) were then removed from the culture medium at various time points (0, 1, 3, and 24 hours), serially diluted, and 100 μL of each dilution was plated on tryptic soy agar. After incubation at 37°C for 24 hours, bacterial colonies were counted and plotted to determine rapid bactericidal activity against growing cells.

[0076] The above method was used to detect the minimum inhibitory concentration (MIC) of the four thiazolidinone compounds H2-3, H2-15, H5-7 and H5-11 of Example 1, as well as the thiazolidinone compounds H2-10, H2-12, H5-5 and H5-17 of the comparative example against three Gram-positive bacteria: Staphylococcus epimers SE1457, Staphylococcus aureus SA113 and Enterococcus faecalis OG1RF. The results are shown in Table 1. Using the same method, the MIC of compound 2 was 50 μM and the MIC of compound 5 was 6.25 μM. It can be seen that the MIC values ​​of H2-3 and H2-15 were significantly increased by 32-64 times compared to compound 2, and the MIC values ​​of H5-7 and H5-11 were also increased by 2-8 times compared to compound 5. However, the antibacterial activity of H2-10 and H2-12 was not improved compared to compound 2, and that of H5-5 was not improved compared to compound 5. Among them, the structural formulas of compound 2 and compound 5 are as follows:

[0077]

[0078] Subsequently, the minimum bactericidal concentrations (MBCs) of thiazolidinone derivatives H2-3, H2-15, and H5-7 against the experimental strains were tested. The results showed that the MBC values ​​of thiazolidinone derivatives against the above three Gram-positive strains were all ≤25μM.

[0079] Table 1 Antibacterial activity of thiazolidinone derivatives

[0080]

[0081] Example 3

[0082] In order to explore the killing effect of thiazolidinone derivatives on methicillin-resistant Staphylococcus aureus (MRSA), a dynamic bactericidal experiment was conducted in this example. USA300 cultured overnight was prepared into about 10 7 CFU / mL suspension was added with 50μM of the thiazolidinone compound to be tested. The suspension was smeared on TSA plates at 0h, 1h, 3h and 24h of action and colony counts were performed. The growth of MRSAUSA300 under the action of thiazolidinone compounds was observed. The results are shown in Figure 2. Figure 1 As shown, compared with vancomycin (VAN), thiazolidinone compounds H2-3, H2-15, H5-7, and H5-11 have a significant killing effect on USA300 planktonic bacteria.

[0083] Example 4

[0084] Biofilm formation inhibition test, including:

[0085] Overnight cultures of Staphylococcus aureus were diluted 1:200 and plated into 96-well plates. The corresponding concentration of the thiazolidinone compound to be tested was added and incubated at 37°C. After 24 hours, the absorbance of the cells was measured using crystal violet staining at OD570.

[0086] The results are as follows Figure 2 As shown, it can be seen that the thiazolidinone compounds H2-3, H2-15, H5-7, and H5-11 at a concentration of 0.4-3.13 μM can significantly inhibit the biofilm formation of SA113 and YUSA145 strains.

[0087] Example 5

[0088] The experiment of removing mature biofilm of Staphylococcus aureus includes:

[0089] Overnight cultures of Staphylococcus aureus MSSA SA113 and MRSAYUSA145 were diluted 1:200 in TSBG medium and plated onto Fluoro dishes. After overnight culture, mature biofilms formed and were treated with 50 μM H2-3 and H5-7 for 48 hours. The biofilms were washed with PBS and then stained with 5 mM SYTO 9 green fluorescent nucleic acid stain and 10 mM PI. After 15 minutes, the biofilms were observed and photographed using a confocal fluorescence microscope. Images were analyzed using Image J software, and live and dead bacteria were quantified as a percentage of the total bacteria. A control group without drug was used.

[0090] Overnight cultures of Staphylococcus aureus were diluted 1:200 and plated into 96-well plates. After 24 hours of incubation, various concentrations of H2-3 and H5-7 were added, and fresh TSBG was replaced. The plates were incubated at 37°C for 48 hours. The plates were then stained with crystal violet, and the OD570 absorbance was measured. A group without drug was used as a negative control.

[0091] The results are as follows Figure 3 As shown, H2-3 at a concentration of 3.13-50 μM and H5-7 at a concentration of 6.25-50 μM were able to significantly eliminate the mature biofilm of S. aureus.

[0092] Example 6

[0093] Cytotoxicity assay.

[0094] The cytotoxicity of the derivatives against HEK293T cells was measured using CCK8 (Transgene, China) according to the manufacturer's protocol. HEK293T cells were plated in 96-well plates and incubated at 37°C, 5% CO2 for 24 hours. H5-7 and H5-11 were then added at concentrations ranging from 1.56 to 100 μM. After an additional 24 hours of incubation, 10 μl of CCK8 was added, and the OD490 absorbance was measured on a microplate reader after 1 hour. DMSO was used as a control. CC50 (the concentration that produces toxicity to half of the cells) was calculated using GraphPad software.

[0095] Hemolytic activity test. The specific steps include:

[0096] Red blood cells from healthy individuals were washed three times in sterile saline and diluted to a 5% concentration. The cell suspension was then added to a 96-well plate containing 50 or 200 μM of the test thiazolidine compound. After incubation at 37°C for 1 hour and centrifugation at 1200 rpm for 5 minutes, the supernatant was transferred to another plate and the OD570 value was measured. 1% Triton-X 100 or 0.1% DMSO was used as a positive or negative control, respectively.

[0097] The results of the above cytotoxicity and hemolytic activity experiments are shown in Table 2. It can be seen that the CC50 of H2-3, H2-15, H5-7 and H5-11 is greater than 100 μM, and the hemolytic activity is less than 10% at a concentration of 200 μM. These results indicate that these thiazolidinone compounds have low cytotoxicity and hemolytic activity.

[0098] Table 2 Cytotoxicity and hemolytic activity of thiazolidinone derivatives

[0099]

[0100] Example 7

[0101] In order to explore the safety of thiazolidinone compounds, two acute drug animal models, wax moth and mouse, were constructed in this example.

[0102] (1) Acute drug toxicity model of G. mellonella: G. mellonella were randomly divided into four groups, with 10 in each group. Saline, H5-7 (20 mg / kg), H5-7 (50 mg / kg) and LZD (100 mg / kg) were injected into the abdomen in a volume of 20 μl, respectively. The survival rate of the insects was then observed within 3 days and photographed.

[0103] (2) Detection of biochemical indicators of liver and kidney toxicity: Female BABL / c mice (6-8 weeks old, n=6) were used to evaluate the toxicity of drugs on the liver and kidneys. Mice were intraperitoneally injected with 100 μL of a certain dose of drug. Blood samples were collected from the mice on the 1st and 3rd day after administration. The levels of biomarkers such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatinine (CREA), blood urea nitrogen (BUN), sodium ion (Na+), and potassium ion (K+) in the blood were measured using a kit.

[0104] (3) HE staining: Mice were intraperitoneally injected with 100 μL of a certain dose of drug. Liver and kidney tissues were obtained for pathological examination on days 1 and 3 after administration. The drug was dissolved in corn oil, and the maximum DMSO concentration did not exceed 10%.

[0105] The results of acute drug experiments on wax moth are as follows Figure 4 As shown, compared with the control group, the survival rate of the worms in the 20 mg / kg H5-7 injection group was not significantly different, while the survival rate of the worms in the 50 mg / kg H5-7 injection group was significantly decreased. This result indicates that there is no obvious drug toxicity when the dosage is less than 20 mg / kg.

[0106] In the acute toxicity experiment in mice, 20 mg / kg of H5-7 was also administered by intraperitoneal injection, and blood samples and liver and kidney tissues were collected on the first and third days after administration for toxicity-related biochemical index detection and HE staining, respectively. Figure 5 As shown, there were no significant differences in the liver toxicity markers ALT and AST, the nephrotoxicity markers BUN and CREA, and the levels of electrolytes Na+ and K+ compared with the control group.

[0107] In addition, the results of HE pathological sections were as follows Figure 6 As shown in Figure 2, 1 and 3 days after administration of 20 mg / kg H5-7, the liver and kidney tissues of mice were intact with no obvious pathological damage. The above safety assessment results all indicate that H5-7 has good drug safety.

[0108] Statistical analysis was performed using GraphPad Prism software (version 8.0). Results are presented as mean ± standard deviation. Multiple comparisons were performed using one-way analysis of variance (ANOVA) followed by a post hoc Dunnett test. P < 0.05 was considered statistically significant.

[0109] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A thiazolidinone compound, characterized in that: Its molecular structure is shown in formula (1), formula (2), formula (3) or formula (4):

2. Use of the thiazolidinone compound according to claim 1 for preparing a drug for treating Staphylococcus aureus infection.

3. The use of the thiazolidinone compound according to claim 2 for preparing a drug for anti-Staphylococcus aureus infection, characterized in that: The concentration of the thiazolidinone compound in the treatment system is not less than 0.78 μM; the drug is in the form of an injection, tablet, pill, capsule, suspension, granule, spray or emulsion.

4. A drug for resisting Staphylococcus aureus infection, characterized in that: The invention comprises the thiazolidinone compound as claimed in claim 1.

5. Use of the thiazolidinone compound according to claim 1 in preparing a coating for inhibiting Staphylococcus aureus, characterized in that: The coating is used for the surface of medical devices.

6. Use of the thiazolidinone compound according to claim 5 for preparing a coating for inhibiting Staphylococcus aureus, characterized in that: In the coating, the concentration of the thiazolidinone compound is not less than 0.78 μM.

7. Use of the thiazolidinone compound according to claim 1 in preparing a disinfectant for inhibiting Staphylococcus aureus.

8. Use of the thiazolidinone compound according to claim 7 for preparing a disinfectant for inhibiting Staphylococcus aureus, characterized in that: In the disinfectant, the concentration of the thiazolidinone compound is not less than 0.78 μM.

9. A coating for inhibiting Staphylococcus aureus, characterized in that: The invention comprises the thiazolidinone compound as claimed in claim 1.

10. A disinfectant for inhibiting Staphylococcus aureus, characterized in that: The invention comprises the thiazolidinone compound as claimed in claim 1.

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