A type of gold complex with aggregation-induced emission properties and its preparation method and application

Abstract

The present invention provides a gold complex exhibiting aggregation-induced emission properties, as well as its preparation method and application, belonging to the field of organometallic compounds. The structural formula of the gold complex described herein is as follows: #imgabs0#. The gold complex prepared by the present invention effectively inhibits fungal growth at low concentrations, exhibiting strong antifungal activity with minimal toxicity to normal cells. It exhibits excellent biocompatibility and enables fluorescent visualization of fungal infections, providing strong diagnostic support.

Description

Technical Field

[0001] The present invention relates to the field of metal organic compounds, in particular to a gold complex with aggregation-induced emission properties and a preparation method and application thereof. Background Art

[0002] In recent years, fungal pathogen infections have posed a serious threat to human health. Fungal infections cause up to 1.5 million fatal complications each year, particularly in immunocompromised individuals. Currently, clinically available antifungal drugs are limited and have significant side effects.

[0003] Furthermore, current drugs for treating fungal pathogen infections cannot be visualized, which limits the research of antifungal drugs. Therefore, there is a need for low-toxicity, high-efficiency drugs that have both significant antifungal effects and visualization. Summary of the Invention

[0004] The purpose of the present invention is to provide a class of gold complexes with aggregation-induced emission properties, as well as their preparation methods and applications. The gold complexes prepared by the present invention can completely inhibit fungal growth at low concentrations, exhibit extremely strong antifungal activity, have little toxicity to normal cells, and have good biocompatibility.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] The present invention provides a gold complex having aggregation-induced emission properties, the structural formula of the gold complex is shown below:

[0007] .

[0008] The present invention provides a method for preparing the above-mentioned gold complexes. The synthetic routes of the gold complexes 1 to 5 are as follows:

[0009] ,

[0010] ,

[0011] ,

[0012] ,

[0013]

[0014] Preferably, the preparation method of the gold complexes 1 and 2 is:

[0015] KPF6, 4, and the ligand raw materials were mixed under a nitrogen atmosphere to obtain a mixture, and then after vacuuming and nitrogen replacement, dry DCM and dry methanol were added and stirred at room temperature for 24 hours. After the reaction was completed, the mixture was extracted, dried over anhydrous sodium sulfate, filtered, and evaporated to obtain a crude product; the crude product was recrystallized to obtain the target product;

[0016] When the ligand raw material is PPh3, gold complex 1 is obtained;

[0017] When the ligand raw material is PCy3, gold complex 2 is obtained.

[0018] Preferably, the molar ratio of KPF6, 4 and ligand raw materials is (2.8-3.2): (1.8-2.2): (1.8-2.2);

[0019] The mass volume ratio of the mixture, dry DCM, and dry methanol is (130-150) mg: (15-25) mL: (8-12) mL.

[0020] Preferably, the preparation method of the gold complex 3 is:

[0021] Potassium carbonate, 1d, and 3a were mixed under a nitrogen atmosphere to obtain a mixture, which was then stirred at room temperature for 24 hours. After the reaction was completed, the mixture was extracted, dried over anhydrous sodium sulfate, filtered, and evaporated to obtain a crude product. The crude product was recrystallized to obtain the target product.

[0022] Preferably, the molar ratio of potassium carbonate, 1d, and 3a is (0.8-1.2): (0.4-0.6): (0.4-0.6).

[0023] Preferably, the extractions are performed independently with ethyl acetate and water.

[0024] Preferably, the evaporation is independently performed under reduced pressure.

[0025] Preferably, the recrystallization is performed independently using CH2Cl2 / n-hexane.

[0026] Preferably, the preparation method of the gold complex 4 is:

[0027] 1d and silver oxide were mixed under a nitrogen atmosphere to obtain a mixture. After vacuuming and nitrogen replacement, degassed dichloromethane was added and stirred at room temperature in the dark under nitrogen for 48 h. Then, tetrahydrothiophene gold chloride was added and stirring was continued at room temperature for 12 h. After the reaction was completed, the mixture was filtered, concentrated under reduced pressure, separated and purified, and then precipitated with dichloromethane / n-hexane to obtain the target product.

[0028] Preferably, the molar ratio of 1d, silver oxide, and tetrahydrothiophene gold chloride is (13-18): (6-10): (13-18);

[0029] The mass volume ratio of the mixture and the degassed dichloromethane is (95-105) mg: (18-22) mL.

[0030] Preferably, the preparation method of the gold complex 5 is:

[0031] 5b and silver oxide were mixed under a nitrogen atmosphere to obtain a mixture, which was then vacuumed and replaced with nitrogen. Degassed methanol was added and stirred at room temperature in the dark under nitrogen for 48 h. Sodium chloride and tetrahydrothiophene gold chloride were then added and stirring was continued at room temperature for 12 h. After the reaction was completed, the mixture was filtered, concentrated under reduced pressure, separated and purified, and then precipitated with dichloromethane / n-hexane to obtain the target product.

[0032] Preferably, the molar ratio of 5b, silver oxide, sodium chloride, and tetrahydrothiophene gold chloride is (13-16): (6-10): (13-16): (13-16);

[0033] The mass volume ratio of the mixture and the degassed methanol is (95-105) mg: (25-35) mL.

[0034] Preferably, the separation and purification are each independently performed by neutral alumina column separation and purification.

[0035] The present invention also provides the use of the gold complex in fungal infection visualization and / or in medicines for treating fungal infections.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. The gold complex with aggregation-induced emission properties prepared by the present invention can completely inhibit fungal growth at low concentrations, exhibiting extremely strong antifungal activity, and has little toxicity to normal cells and good biocompatibility.

[0038] 2. The gold complex prepared by the present invention has excellent AIE properties and can perform fluorescent visualization imaging of fungal infections, providing strong support for diagnosis.

[0039] 3. Experiments have shown that the gold complex prepared by the present invention significantly accelerates the healing speed of fungal infection wounds. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Photoluminescence spectra of gold complex 1 in mixed solvents of CH3CN / H2O at different ratios.

[0041] Figure 2Photoluminescence spectra of gold complex 2 in mixed solvents of CH3CN / H2O at different ratios.

[0042] Figure 3 Photoluminescence spectra of gold complex 3 in mixed solvents of CH3CN / H2O at different ratios.

[0043] Figure 4 Photoluminescence spectra of gold complex 4 in THF / H2O mixed solvents with different ratios.

[0044] Figure 5 Photoluminescence spectra of gold complex 5 in THF / H2O mixed solvents with different ratios.

[0045] Figure 6 The in vitro antibacterial effects of five gold complexes; standard Candida albicans (ATCC 14053).

[0046] Figure 7 The in vitro antibacterial effects of five gold complexes; standard Candida parapsilosis (ATCC 22019).

[0047] Figure 8 The in vitro antibacterial effects of five gold complexes; standard Candida glabrata (ATCC MYA 2950).

[0048] Figure 9 The in vitro antibacterial effects of five gold complexes; standard Candida krusei (ATCC 14243).

[0049] Figure 10 The in vitro antibacterial effects of five gold complexes; standard Candida tropicalis (ATCC 1369).

[0050] Figure 11 The CCK8 cytotoxicity assay was performed on five gold complexes co-incubated with normal human liver (LO2) cells and human umbilical vein endothelial (HUVEC) cells.

[0051] Figure 12 This is a diagram showing the therapeutic effect of fungal infection on mouse wounds.

[0052] Figure 13 Visualization imaging of standard Candida albicans and Candida tropicalis by five AIE gold complexes.

[0053] Figure 14 Visualization imaging of standard Candida krusei and Candida parapsilosis by five AIE gold complexes.

[0054] Figure 15 Visualization imaging of standard Candida glabrata by five AIE gold complexes. DETAILED DESCRIPTION

[0055] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as limiting the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0056] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0057] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of any conflict with any incorporated document, the contents of this specification shall prevail.

[0058] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention without departing from the scope or spirit of the invention. Other embodiments will be apparent to those skilled in the art from the present invention. The present description and examples are intended to be illustrative only.

[0059] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0060] Unless otherwise specified, the "room temperature" and "normal temperature" mentioned in the present invention are all calculated as 25±2°C.

[0061] Unless otherwise specified, the raw materials used in the following examples of the present invention are commercially available.

[0062] The synthetic routes of gold complexes 1 to 5 are as follows:

[0063] ,

[0064] ,

[0065] ,

[0066] ,

[0067]

[0068] The following examples were prepared with reference to the above synthetic route, and the synthetic raw materials used were the raw materials described in the synthetic route, for example, 4 in Example 1 represents .

[0069] Example 1

[0070] This embodiment provides a gold complex having aggregation-induced emission properties, and the preparation method is as follows:

[0071] The 50 mL two-necked flask required for the reaction was dried in a T-type drying oven for 30 min, and then the reaction apparatus was evacuated for 10 min and introduced with nitrogen gas.

[0072] Under nitrogen atmosphere, KPF6 (0.24 mmol, 44.2 mg), 4 (0.16 mmol, 51.5 mg) and PPh3 (0.16 mmol, 42.0 mg) were put into a reaction flask, vacuumed for 15 min, and replaced with nitrogen three times; then 0.3% ultra-dry DCM (20 mL) and 0.25% ultra-dry methanol (10 mL) were added with a syringe, respectively, and stirred at room temperature for 24 hours; after the reaction was stopped, it was extracted with ethyl acetate and water, the organic phases were combined, and dried over anhydrous sodium sulfate; filtered; the filtrate was removed by reduced pressure evaporation to obtain the crude product.

[0073] The crude product was separated and purified by column chromatography and then recrystallized from CH2Cl2 / n-hexane to obtain the target product as a white solid.

[0074] The product is:

[0075]

[0076] Yield: 65 mg (80 %)

[0077] 1 H NMR (400 MHz, CD3CN): δ 7.62-7.53 (m, 15H, CH aromatic PPh3), 7.40(s, 1H, CH imidazole), 7.33 (s, 1H, CH imidazole), 7.25 (d, J = 8.0 Hz, 2H, CHaromatic TPE), 7.16-6.91 (m, 17H, CH aromatic TPE), 3.71 (s, 3H, CH3); 13 C NMR (100 MHz, CD3CN): δ 182.8 (NCN carbene), 144.8, 143.4, 143.4, 143.2, 142.4,139.9, 137.6, 134.4, 134.4, 132.6, 131.9, 131.0, 130.6, 129.6, 129.4, 128.4,127.9, 127.5, 126.8, 126.9, 126.4, 124.6, 123.7, 122.4, 37.6; 31 P NMR (160 MHz, CD3CN): 44.0, -144.7; HRMS: m / z: [M-PF6] + calcd for [C 48 H 39 AuN2P] + : 871.2511;found: 871.2510.

[0078] Example 2

[0079] This embodiment provides a gold complex having aggregation-induced emission properties, and the preparation method is as follows:

[0080] The 50 mL two-necked flask required for the reaction was dried in a T-type drying oven for 30 min, and then the reaction apparatus was evacuated for 10 min and introduced with nitrogen gas.

[0081] Under a nitrogen atmosphere, KPF6 (0.24 mmol, 44.2 mg), 4 (0.16 mmol, 51.5 mg), and PCy3 (0.16 mmol, 44.8 mg) were placed in a reaction flask. The flask was evacuated for 15 min and the atmosphere was replaced with nitrogen three times. Ultra-dry DCM (20 mL) and ultra-dry methanol (10 mL) were then added via syringe, respectively, and stirred at room temperature for 24 h. After the reaction ceased, the mixture was extracted with ethyl acetate and water. The organic phases were combined, dried over anhydrous sodium sulfate, and filtered. The filtrate was evaporated under reduced pressure to obtain the crude product.

[0082] The crude product was separated and purified by column chromatography and then recrystallized from CH2Cl2 / n-hexane to obtain the product as a white solid.

[0083] The product is:

[0084]

[0085] Yield: 110.9 mg (78 %)

[0086] Example 3

[0087] This embodiment provides a gold complex having aggregation-induced emission properties, and the preparation method is as follows:

[0088] The 50 mL two-necked flask required for the reaction was dried in a T-type drying oven for 30 min, and then the reaction apparatus was evacuated for 10 min and introduced with nitrogen gas.

[0089] Potassium carbonate (1 mmol, 138 mg), 1d (0.5 mmol, 270 mg), and 3a (0.5 mmol, 311 mg) were added to a reaction flask under a nitrogen atmosphere. The mixture was stirred at room temperature for 24 h. After the reaction ceased, the mixture was extracted with ethyl acetate and water. The organic phases were combined and dried over anhydrous sodium sulfate. The mixture was filtered, and the filtrate was evaporated under reduced pressure to obtain the crude product.

[0090] The crude product was separated and purified by column chromatography, and then recrystallized from dichloromethane / n-hexane to obtain a white solid product.

[0091] The product is:

[0092]

[0093] Yield: 217 mg (65 %)

[0094] 1 H NMR (400 MHz, CD2Cl2): δ 7.46 (t, J = 8.0 Hz, 2H), 7.34 (s, 2H, CHimidazole), 7.27-7.22 (m, 8H, CH imidazole and aromatic), 7.16-7.02 (m, 13H,CHaromatic), 6.98 (d, J = 12.0 Hz, 2H, CH aromatic), 6.73 (d, J = 8.0 Hz, 2H, CHaromatic), 3.11 (s, 3H, N-CH3), 2.50 (m, 4H, CH(CH3)2isopropyl), 1.23-1.16(dd, , J = 4.0 Hz, 24 H, CH(CH3)2isopropyl); 13C NMR (100 MHz, CD2Cl2): δ 187.0((NCN-TPE carbene)), 181.5 (NCN carbene), 146.6, 143.6, 143.5, 143.4, 143.2,139.4, 136.2, 134.0, 132.5, 131.4, 131.3, 131.2, 128.4, 128.2, 128.1, 127.5,127.4, 127.1, 124.6, 124.5, 121.6, 37.9 (N-CH3), 29.5 (CH(CH3)2isopropyl),24.6 (CH(CH3)2isopropyl), 24.4 (CH(CH3)2isopropyl); HRMS: m / z: [MI] + calcd for C 57 H 60 AuN4 + : 997.4478; found: 997.4468.

[0095] Example 4

[0096] This embodiment provides a gold complex having aggregation-induced emission properties, and the preparation method is as follows:

[0097] The 50 mL two-necked flask required for the reaction was dried in a T-type drying oven for 30 min, and then the reaction apparatus was evacuated for 10 min and introduced with nitrogen gas.

[0098] Under a nitrogen atmosphere, 1d (0.15 mmol, 81.0 mg) and silver (I) oxide (0.08 mmol, 18.0 mg) were placed in a reaction flask. The reaction was evacuated for 15 min and replaced with nitrogen three times. Degassed dichloromethane (20 mL) was then added using a syringe. The mixture was stirred at room temperature under nitrogen in the dark for 48 h. Tetrahydrothiophene gold chloride (0.15 mmol, 48.0 mg) was then added, and stirring at room temperature continued for 12 h. After the reaction ceased, the product was filtered through celite, and the filtrate was concentrated under reduced pressure to remove the residue. The product was then separated and purified by neutral alumina column chromatography and then precipitated with dichloromethane / n-hexane to obtain a white solid product.

[0099] The product is:

[0100]

[0101] Yield: 79.2 mg (82 %)

[0102] 1H NMR (400 MHz, CDCl3): δ 7.34 (s, 1H, CH imidazole), 7.32 (s, 1H, CH imidazole), 7.17-7.03 (m, 19H, CH aromatic TPE), 3.93 (s, 3H); 13 C NMR (100MHz, CDCl3): δ 170.6, 144.8, 143.5, 143.4, 143.3, 142.7, 139.6, 137.0, 132.8,131.7, 131.3, 128.5, 128.0, 127.6, 127.4, 126.6, 126.4, 123.9, 122.6, 121.4,46.0 (CH3); HRMS: m / z: [M] + calcd for C 30 H 24 AuClN2 + : 644.1294; found: 644.1242.

[0103] Example 5

[0104] This embodiment provides a gold complex having aggregation-induced emission properties, and the preparation method is as follows:

[0105] The 50 mL two-necked flask required for the reaction was dried in a T-type drying oven for 30 min, and then the reaction apparatus was evacuated for 10 min and introduced with nitrogen gas.

[0106] Under a nitrogen atmosphere, 5b (0.15 mmol, 78.1 mg) and silver oxide (0.08 mmol, 18.0 mg) were placed in a reaction flask. The reaction was evacuated for 15 min and replaced with nitrogen three times. Degassed methanol (30 mL) was then added via syringe. The mixture was stirred at room temperature under nitrogen in the dark for 48 h. Sodium chloride (0.15 mmol, 8.7 mg) and tetrahydrothiophene gold chloride (0.15 mmol, 48.0 mg) were then added, and stirring continued at room temperature for 12 h. After the reaction ceased, the product was filtered through celite, and the filtrate was concentrated under reduced pressure. The product was then purified by neutral alumina column chromatography and precipitated with methanol / diethyl ether to obtain a white solid product.

[0107] The product is:

[0108]

[0109] Yield: 77.9 mg (67%)

[0110] Experimental Example 1

[0111] The AIE gold complexes obtained in Examples 1-5 were physically characterized, including UV-visible absorption spectra, compound excitation spectra, and compound emission spectra.

[0112] Five AIE gold complexes were dissolved in DMF and purified water, respectively, to prepare stock solutions at concentrations of 5 mmol / L and 500 μmol / L. Their UV-visible absorption spectra were measured using a UV-visible spectrophotometer, and their excitation and emission spectra were measured using a fluorescence spectrometer.

[0113] In order to explore the AIE properties of five AIE gold complexes, their fluorescence emission properties were measured in different solvent systems. THF was the effective solvent for the target gold complex, and H2O was the poor solvent for the target gold complex. The fluorescence emission properties of the five AIE gold complexes in different H2O volume fractions ( f w ) in the DMF / H2O solvent system. Use the previously prepared stock solution to prepare it into a H2O volume fraction ( f w ) were 99%, 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, and 0% solvent systems, and the final concentration of the five AIE gold complexes was 50 μmol / L THF / H2O mixed solutions. After thorough mixing, the photoluminescence spectra of these 11 groups of solutions were measured at an excitation wavelength of 560 nm. Figure 1-3 The photoluminescence spectra of AIE gold complexes 1-3 in mixed solvents of CH3CN / H2O at different ratios are shown respectively; Figure 4-5 The photoluminescence spectra of AIE gold complexes 4-5 in tetrahydrofuran (THF) / H2O mixed solvents with different ratios are shown.

[0114] Experimental Example 2

[0115] The AIE gold complexes obtained in Examples 1-5 were tested for biological activity:

[0116] The invasive fungi used included standard strains (Candida albicans, Candida glabrata, Candida tropicalis, Candida parapsilosis, and Candida krusei) and strains resistant to azole drugs.

[0117] Experimental preparation:

[0118] YPD agar medium plates (prepared in advance), sterile centrifuge tubes, micropipettes, sterile pipette tips, disposable sterile inoculation loops, sterile plastic EP tubes, disposable sterile coating sticks and other experimental consumables were placed in a biosafety cabinet after being disinfected with alcohol and subjected to conventional ultraviolet sterilization for 30 minutes. Experimental operations can only be carried out after disinfection under ultraviolet light for 30 minutes.

[0119] Experimental operators need to take appropriate biosafety protection measures, such as wearing protective work clothes, masks, hats and laboratory-specific nitrile sterile gloves, and wipe the biosafety cabinet operating table again with a cotton ball soaked in 75% alcohol.

[0120] Experimental steps:

[0121] First, prepare a fungal suspension. Remove the revived fungal suspension and place it in a biosafety cabinet. From the cabinet, take 20 mL of the suspension and place it in a centrifuge tube. Centrifuge the tube for 15 minutes (3500 rpm) and remove the supernatant to obtain a bacterial pellet. Wash the pellet with PBS and centrifuge again for 15 minutes (3500 rpm). Repeat this process three times with PBS. After washing, resuspend the pellet in PBS. Measure the turbidity of the resuspended suspension using a turbidimeter and adjust the turbidity to 0.5 for later use. This corresponds to a bacterial suspension concentration of 0.5 × 10 7 CFU / mL.

[0122] Disposable plastic EP tubes were used to test the bactericidal effect of the new gold complex on invasive fungi. The cells were divided into six groups according to the different concentrations of the gold complex, namely PBS control group, 2.5 μmol / L, 5 μmol / L, 10 μmol / L, 12.5 μmol / L, and 15 μmol / L. The reaction system in the EP tubes was configured according to the different concentration groups. The fungal culture liquid and the gold complex molecules were mixed together for co-culture. The reaction concentration of the culture liquid was 1×10 4CFU / mL. After configuring the reaction system, use an oscillator to mix it and place it in a 35℃, 5% CO2 incubator for incubation for 0.5 h. Then take out the EP tube and mix it again with an oscillator. Use a micropipette in the biosafety cabinet to draw 100 μL of the mixture from each group of EP tubes and add it to the YPD agar culture medium plate. Use a disposable coating stick to evenly spread it. Spread the mixture in the other groups of EP tubes evenly on the plate and mark each group of plates. After the mixture of each group is spread, all the culture medium plates of each group are turned upside down and placed in a 35℃, 5% CO2 incubator for culture for 16-24 h. Take it out the next day, observe the growth status of the colonies in the control group to ensure that it is not contaminated by bacteria, and observe the number of colonies growing on each group of plates. Use a high-definition mobile phone to take pictures of the colony growth status of each group and each plate, and record the number of colonies on each plate. The number of colonies in the control group is the average of the three groups. The fungal survival rate is calculated according to the following formula. See the antibacterial effect. Figure 6-10 , Figure 6-10 The in vitro antibacterial effects of five gold complexes against standard Candida albicans (ATCC 14053), standard Candida parapsilosis (ATCC 22019), standard Candida glabrata (ATCC MYA 2950), standard Candida krusei (ATCC 14243), and standard Candida tropicalis (ATCC 1369) are shown (AIE gold complexes 1-5 represent AIE gold complexes 1-5, respectively). The five AIE gold complexes exhibited significant inhibitory effects against the five Candida species at concentrations up to 15 μM, exhibiting a clear concentration-dependent pattern. Higher AIE gold complex concentrations resulted in stronger antibacterial effects.

[0123] Experimental Example 3

[0124] CCK-8 cytotoxicity assay:

[0125] Subculture cells (HACAT cells, C166 cells, LO2 cells, and L929 cells): DMEM + 10% newborn calf serum + double-antibody (antibody) at a ratio of 9:1:0.1 was used as growth medium. After cell recovery, the cell suspension was added to 10 ml of growth medium to a disposable sterile cell culture dish and incubated for 24 hours to allow the cells to adhere and grow. When the cell distribution reached approximately 90%, the cells were digested and resuspended to prepare a cell suspension. After pipetting and mixing, the suspension was added to a disposable cell culture dish and the cells were counted under a microscope, with approximately 5,000 cells per 100 μL. After pipetting and mixing, 100 μL of the cell suspension was added to a 96-well plate and incubated for 24 hours to allow the cells to adhere. The target AIE gold complex material was then added. Different concentrations of each material were set, and triplicate wells were prepared for each concentration. After incubation at 37°C for 30 minutes, the liquid in the wells was aspirated, 100 μl of PBS buffer was added to each well, and the mixture was mixed by pipetting for 1 minute, and the liquid was aspirated. The PBS washing step was repeated 3 times. 10 μl of CCK-8 solution was added to each well, shaken to avoid bubbles, and placed in the incubator for 2 hours. 100 μl of PBS buffer was added to each well, and the shaker was shaken for 1 minute until the color was uniform. The absorbance at 450 nm was measured with a microplate reader, and the absorbance ratio was calculated using Origin 2022 software to evaluate the biocompatibility of the five AIE gold complexes. Figure 11 In the concentration range of 0 to 25 μM (μmol / L), materials 1, 2, 4, and 5 achieved cell viability exceeding 80% in both cell lines. In the figure, 1-5 represent AIE gold complexes 1-5, respectively.

[0126] Experimental Example 4

[0127] Animal experiments:

[0128] Establishment of a fungal infection mouse model: a circular skin trauma wound was created on the back of the mouse, and then the wound was covered with a Candida albicans suspension. The model was completed after 48 hours of growth. The mice with successfully fungal skin wounds were then divided into three groups, including a PBS control group, a gold complex treatment group, and an antifungal drug treatment group, with 5 mice in each group. Different treatment regimens were applied to each group of mice for three consecutive days, namely: AIE gold complex 1 prepared in Example 1, miconazole, and PBS, for a total of 3 treatments (days 1, 2, and 3). Afterwards, the skin infection wounds of the mice were photographed and recorded to obtain the healing status, and the wound healing status of the mice was calculated using ImageJ software to evaluate the effects of different treatment regimens, see Figure 14 Compared with the control group, the wound healing rate of mice treated with AIE gold complex 1 was significantly accelerated.

[0129] Experimental Example 5

[0130] Fluorescence imaging experiments:

[0131] 5 μmol / L of the five AIE gold complexes were added to the prepared fungal suspension, shaken to mix, and incubated in a constant temperature water bath for 30 min without washing. The suspension was then taken out and centrifuged for 5 min (3500 rpm). After centrifugation, about 10 μL of the stained fungal solution at the bottom was transferred to a glass slide and covered with a coverslip. Under a confocal laser scanning microscope, the gold complex was excited by a 488 nm laser to directly image the fungus. Figure 13-15 AIE gold complexes 1-5 can effectively illuminate the cell bodies and nuclei of five fungal species, demonstrating high imaging depth and clarity in fungal imaging. Figures 1-5 represent AIE gold complexes 1-5, respectively.

[0132] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A gold complex having aggregation-induced emission properties, characterized in that: The structural formula of the gold complex is shown below:

2. The method for preparing the gold complex according to claim 1, wherein The synthetic routes of the gold complexes 1 to 4 are as follows:

3. The preparation method according to claim 2, characterized in that The preparation method of the gold complexes 1 and 2 is: KPF6, 4, and the ligand raw materials were mixed under a nitrogen atmosphere to obtain a mixture, and then after vacuuming and nitrogen replacement, dry DCM and dry methanol were added and stirred at room temperature for 24 hours. After the reaction was completed, the mixture was extracted, dried over anhydrous sodium sulfate, filtered, and evaporated to obtain a crude product; the crude product was recrystallized to obtain the target product; When the ligand raw material is PPh3, gold complex 1 is obtained; When the ligand raw material is PCy3, gold complex 2 is obtained.

4. The preparation method according to claim 3, characterized in that The molar ratio of KPF6, 4 and ligand raw materials is (2.8-3.2): (1.8-2.2): (1.8-2.2); The mass volume ratio of the mixture, dry DCM, and dry methanol is (130-150) mg: (15-25) mL: (8-12) mL.

5. The preparation method according to claim 2, characterized in that The preparation method of the gold complex 4 is: 1d and silver oxide were mixed under a nitrogen atmosphere to obtain a mixture, which was then vacuumed and replaced with nitrogen, followed by the addition of degassed dichloromethane and stirring at room temperature in the dark under nitrogen for 48 h. Then, tetrahydrothiophene gold chloride was added and stirring was continued at room temperature for 12 h. After the reaction was completed, the mixture was filtered, concentrated under reduced pressure, separated and purified, and then precipitated with dichloromethane / n-hexane to obtain the target product, gold complex 4.

6. The preparation method according to claim 5, characterized in that The molar ratio of 1d, silver oxide, and tetrahydrothiophene gold chloride is (13-18): (6-10): (13-18); The mass volume ratio of the mixture and the degassed dichloromethane is (95-105) mg: (18-22) mL.

7. The method for preparing the gold complex according to claim 1, wherein The preparation method of the gold complex 5 is: 5b and silver oxide were mixed under a nitrogen atmosphere to obtain a mixture, which was then evacuated and replaced with nitrogen. Degassed methanol was added and stirred at room temperature in the dark under nitrogen for 48 h. Sodium chloride and tetrahydrothiophene gold chloride were then added and stirred at room temperature for 12 h. After the reaction was completed, the mixture was filtered, concentrated under reduced pressure, separated and purified, and then precipitated with dichloromethane / n-hexane to obtain the target product. The molar ratio of 5b, silver oxide, sodium chloride, and tetrahydrothiophene gold chloride is (13-16): (6-10): (13-16): (13-16); The mass volume ratio of the mixture and degassed methanol is (95-105) mg: (25-35) mL; The structural formula of 5b is:

8. Use of the gold complex according to claim 1 in preparing a medicament for visualizing fungal infection and / or treating fungal infection.

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