Application of a diketone compound in the preparation of antifungal drugs
By developing antifungal drugs with diketone compounds as active ingredients, the problem of drug resistance in fungi such as Candida albicans has been solved, achieving effective antifungal effects against a variety of fungi, especially against fluconazole-resistant strains.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- THE NAVAL MEDICAL UNIV OF PLA
- Filing Date
- 2023-05-10
- Publication Date
- 2026-07-17
AI Technical Summary
Existing antifungal drugs, such as fluconazole, have led to increased resistance in Candida albicans due to long-term use. There is an urgent clinical need for new antifungal drugs, and no relevant literature reports have been found on the antifungal activity of diketone compounds.
Using diketone compounds as active ingredients, dosage forms such as injections, capsules, and tablets are developed to combat fungi such as Candida albicans and Candida glabrata via oral or injection routes, with particularly significant antibacterial effects against fluconazole-resistant strains.
Diketone compounds exhibit significant in vitro antifungal activity against a variety of fungi, including inhibitory effects on both standard and drug-resistant strains, with minimum inhibitory concentrations as low as 2 μg/mL, providing a new approach for the clinical treatment of antifungal resistance.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of pharmaceutical technology, specifically relating to the use of a diketone compound in the preparation of antifungal drugs. Background Technology
[0002] In recent years, with the rapid development of various surgeries and embedded devices, the rate of fungal infections has risen sharply, and the types of pathogenic fungi have increased. However, *Candida albicans* is the most common pathogenic fungus in immunocompromised patients, with a systemic *Candida albicans* infection mortality rate as high as 38%, making it a leading cause of death in cancer and AIDS patients. Fluconazole, due to its advantages, is the first-line drug for antifungal infections in clinical practice. However, the long-term widespread use of azole drugs has led to increasing resistance in *Candida albicans*. Currently, there is an urgent clinical need to develop new antifungal drugs or improve the mechanism of action of existing drugs (combination therapy, structural modifications, etc.). As eukaryotes, fungi share many similarities with mammalian cells, easily producing toxic side effects on the human body. This makes the development of new drugs more difficult and slows down the progress of antifungal drug research. Screening known or potential antifungal compounds to further narrow down the range of highly effective antifungal compounds can provide insights for subsequent antifungal researchers. Diketone compounds 1-3 are known compounds, but their antifungal activity has not been reported in the literature. Summary of the Invention
[0003] The purpose of this invention is to provide an application of a diketone compound in the preparation of an antifungal drug.
[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows:
[0005] A first aspect of the present invention provides the use of a diketone compound in the preparation of an antifungal medicament.
[0006] The structure of the diketone compound is selected from one of the following structures:
[0007]
[0008] The fungi are selected from Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida krusei, and Cryptococcus neoformans.
[0009] The fungi were selected from Candida albicans SC5314, fluconazole-resistant Candida albicans 936, 31, 103, 911, 529, 538, Cryptococcus neoformans H99, 30609, Candida glabrata 537, Candida tropicalis 293, Candida parapsilosis 22019, and Candida krusei 463.
[0010] The antifungal drug refers to a diketone compound as the sole active ingredient.
[0011] The dosage forms of the drug are injections, capsules, tablets, granules, pills, microcapsules, and microspheres.
[0012] The drug can be administered orally or by injection.
[0013] By adopting the above technical solution, the present invention has the following advantages and beneficial effects:
[0014] This invention has discovered that diketone compounds 1-3 possess significant in vitro antifungal activity and can be used as antifungal drugs. Compound 3, when tested using standard methods for antifungal drug experiments, is effective as the active ingredient. It is sensitive not only to the standard strain *Candida albicans* SC5314 and seven clinically isolated fluconazole-resistant *Candida albicans* strains (936, 31, and 103), but also to *Candida glabrata* 537, *Candida tropicalis* 293, *Candida parapsilosis* 22019, *Candida krusei* 463, and *Cryptococcus neoformans* H99 and 30609, with a minimum inhibitory concentration as low as 2 μg / mL. This invention demonstrates the in vitro antifungal activity of compound 3 and provides a new approach for the clinical treatment of antifungal resistance. Attached Figure Description
[0015] Figure 1 The purpose was to investigate the effect of compound 3 on the growth and proliferation of Candida albicans SC5314 and to draw a schematic diagram of the growth curve.
[0016] Figure 2 The purpose was to investigate the antibacterial effect of compound 3 on Candida albicans SC5314 and to plot a schematic diagram of the bactericidal curve.
[0017] Figure 3 This is a schematic diagram of Candida albicans hyphal formation during the Candida albicans hyphal formation induction experiment.
[0018] Figure 4 This is a schematic diagram illustrating the effect of compound 3 on the biofilm of Candida albicans SC5314. Detailed Implementation
[0019] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.
[0020] Example 1
[0021] 1. Synthesis of a novel platinum(II)complex with6,7-dichloro-5,8-quinolinedione and the study of its antitumor mechanism intesticular seminoma.Li Z,Zhou J,Gan Y,Yin Y,Zhang W,Yang J,Tang Y,Dai Y.JInorg Biochem.2019Aug;197:110701.doi:10.1016 / j.jinorgbio.2019.110701.Epub2019Apr 27.PMID:31055215. 2.Analysis of quinolinequinone reactivity,cytotoxicity,and anti-HIV-1properties.Alfadhli A,Mack A,Harper L,Berk S,Ritchie C,Barklis E.Bioorg Med Chem.2016Nov 1;24(21):5618-5625.doi:10.1016 / j.bmc.2016.09.028.Epub 2016Sep 12.PMID:27663546。3.Design,Synthesis and CancerCell Growth Inhibition Evaluation of New Aminoquinone Hybrid Molecules.Defant A,Mancini I.Molecules.2019Jun 14;24(12):2224.doi:10.3390 / molecules24122224。)The in vitro antifungal activity and antibacterial spectrum were determined by microdilution method.
[0022] Experimental methods:
[0023] The activated strain was inoculated into 1 mL of YPD liquid medium and cultured at 30°C with shaking for 16 h. The cells were counted using a hemocytometer, and the culture was diluted to 1 × 10⁻⁶ with RPMI 1640 liquid medium. 3 The drug concentration was serially diluted using sterile 96-well plates to prepare drug sensitivity plates, which were then incubated at 30°C for 24 hours. The OD of each well was measured at 630 nm using a microplate reader. 630 The MIC is the drug concentration corresponding to the well where the final OD value decreases by more than 80%.
[0024] Experimental Results: The sensitivity of the international standard strain SC5314 and six clinical fluconazole-resistant Candida albicans strains to compounds 1–3 was investigated. The sensitivity results of Candida albicans SC5314 to compounds 1–3 are shown in Tables 1 and 2. The results indicate that low concentrations of compound 3 also showed significant inhibitory effects on clinically isolated Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei. These results indicate that among common clinically pathogenic Candida species, compound 3 can inhibit the growth of the vast majority of Candida species. The results in Table 1 show that compound 3 has the strongest antifungal effect and a strong antibacterial effect. The results in Table 2 show that it is effective not only against the international standard strain SC5314 but also against clinically isolated strains.
[0025] Table 1. MICs of diketone compounds 1–3 against C. albicans SC5314 80 Determination of value
[0026]
[0027] Table 2 shows the minimum inhibitory concentrations of compound 3 against various common clinical pathogenic Candida species, determined by the microdilution method.
[0028] strain name <![CDATA[MIC of Compound 3 80 (μg / mL)]]> C. albicans SC5314 2 C. Albicans 936 8 C. albicans 31 1 C. albicans 103 8 C. albicans 911 4 C. albicans 529 2 C. albicans 538 8 Cryptococcus H99 8 Cryptococcus 30609 2 C. glabrata 537 4 C. tropicalist 293 8 C. parapsilosis 22019 4 C.krusei 463 8
[0029] II. Determination of Time-Growth Curve and Time-Bactericidal Curve
[0030] Experimental methods: Growth curve determination: Activated Candida albicans SC5314 was diluted with YPD medium to a concentration of 10. 6 cells / mL (OD) 630 =0.01), different concentrations of compound 3 were added to each tube, and the OD of the bacterial culture in each tube was measured at 0h, 3h, 6h, 9h, 12h, and 24h. 630 value.
[0031] Experimental results: such as Figure 1 As shown, Figure 1 The study investigated the effect of compound 3 on the growth and proliferation of Candida albicans SC5314 and plotted a growth curve. The results showed that compound 3 at a concentration of 8 μg / mL had a significant inhibitory effect on the growth and proliferation of Candida albicans (P<0.05).
[0032] Experimental methods: Bactericidal curve determination: Activated Candida albicans SC5314 was diluted with RPMI 1640 medium to a concentration of 2–3 × 10⁻⁶. 3Different concentrations of compound 3 were added to each tube, and the tubes were incubated at 30°C with shaking at 200 rpm for 24 h. At 0 h, 3 h, 6 h, 9 h, 12 h, and 24 h, 100 μl of bacterial culture was taken and serially diluted 10 times with sterile PBS. 100 μl of each culture was spread on the surface of SDA solid medium and incubated statically at 30°C for 36–48 h. The number of clones in the medium was counted and a curve was plotted against time using 1g CFU / mL.
[0033] Experimental Results: To determine whether compound 3 could kill Candida albicans in the culture medium, Candida albicans treated with compound 3 for different times were plated, and the results are as follows. Figure 2 As shown, Figure 2 The study investigated the antibacterial effect of compound 3 (shown as 3 in the figure) on Candida albicans SC5314 and plotted a bactericidal curve. The results showed that compound 3 at a concentration of 8 μg / mL significantly reduced the number of Candida albicans in the culture medium, demonstrating bactericidal activity (P<0.05). However, at concentrations below 4 μg / mL, compound 3 failed to kill Candida albicans in the culture medium for more than 12 hours.
[0034] III. Candida albicans hyphal formation induction experiment:
[0035] Experimental methods: Activate Candida albicans SC5314, collect the bacterial culture into 1.5 mL centrifuge tubes, centrifuge, remove the culture medium, wash three times with sterile PBS, and dilute to 5 × 10⁻⁶ with RPMI 1640 medium. 5 Cells / mL, add diluted bacterial solution to 24-well plate, add drug and serially dilute to form concentration gradient, place the treated well plate in constant temperature incubator at 37℃ for 3h, observe and photograph under microscope.
[0036] Experimental Results: The transition from yeast to hyphal stage is a crucial process in the invasion of *Candida albicans*. To investigate the inhibitory effect of compound 3 on *Candida albicans* hyphal formation, *Candida albicans* was treated with different concentrations of compound 3. The results are as follows: Figure 3 As shown, Figure 3 This is a schematic diagram of Candida albicans hyphal formation induction experiment. Compound 3 was added at concentrations of 2 μg / mL, 1 μg / mL, 0.5 μg / mL, and a control group, respectively. The results showed that in RPMI 1640 medium, when the drug concentration was higher than 2 μg / mL, compound 3 completely inhibited Candida albicans hyphal formation.
[0037] IV. Candida albicans Biofilm Formation Inhibition Experiment
[0038] Experimental method: Activate Candida albicans SC5314, wash the bacteria three times with sterile PBS, centrifuge to remove supernatant, and then dilute the bacterial culture with RPMI 1640 medium to 1×10⁻⁶.6 The reaction plate was prepared using a TC-treated 96-well plate with CFU / mL concentration. The plate was incubated at 37°C for 30 minutes to allow cells to settle and adhere to the bottom of the plate. The supernatant of RPMI 1640 medium was then aspirated, and the plate was washed three times with PBS buffer. A new sterile 96-well plate was used to obtain different drug concentrations by serial dilution of RPMI 1640 medium. Column 12 was used as a positive control, containing only the same volume of DMSO as the diluted bacterial culture. The prepared RPMI 1640 medium containing different drug concentrations was added to the reaction plate and incubated at 37°C for 24 hours. The supernatant was then aspirated, and the plate was washed three times with PBS. 200 μL of XTT / Menadione solution was added to each well, and the plate was incubated at 37°C in the dark for 3 hours. 100 μL of the upper orange liquid was then transferred to a regular 96-well plate, and the OD value at 490 nm was measured using a multi-mode microplate reader.
[0039] Experimental Results: A biofilm of *Candida albicans* is a mixture of mycelial and yeast states. Biofilm formation is an important pathway for *Candida albicans* to resist external stimuli and drug damage. To further investigate the antifungal activity of compound 3, the XTT method was used to determine the inhibitory effect of compound 3 on *Candida albicans* biofilm formation. Results are as follows... Figure 4 As shown, Figure 4 This is a schematic diagram investigating the effect of compound 3 on the biofilm formation of Candida albicans SC5314. The results showed that in RPMI 1640 medium, when the concentration of compound 3 was higher than 1 μg / mL, it had a significant inhibitory effect on Candida albicans biofilm formation (P < 0.05).
[0040] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.
Claims
1. The use of a diketone compound in the preparation of an antifungal drug, characterized in that, The structure of the diketone compound is shown below: ； The fungi are selected from Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, Candida krusei, and Cryptococcus neoformans.
2. The use of the diketone compound according to claim 1 in the preparation of antifungal drugs, characterized in that, The fungi were selected from Candida albicans SC5314, fluconazole-resistant Candida albicans 936, 31, 103, 911, 529, 538, Cryptococcus neoformans H99, 30609, Candida glabrata 537, Candida tropicalis 293, Candida parapsilosis 22019, and Candida krusei 463.
3. The use of the diketone compound according to claim 1 in the preparation of antifungal drugs, characterized in that, The antifungal drug refers to a diketone compound as the sole active ingredient.
4. The use of the diketone compound according to claim 1 in the preparation of antifungal drugs, characterized in that, The dosage forms of the drug are injections, capsules, tablets, granules, pills, microcapsules, and microspheres.
5. The use of the diketone compound according to claim 1 in the preparation of antifungal drugs, characterized in that, The drug can be administered orally or by injection.