A ruthenium complex with photodynamic activity and a preparation method and application thereof

Abstract

The present application belongs to the technical field of pharmaceutical chemistry, and particularly relates to a ruthenium complex with photodynamic activity and a preparation method and application thereof. The ruthenium complex has a general chemical formula of [Ru(L)2DFP]PF6, wherein DFP is a main ligand deferoxamine, and L is an auxiliary ligand bpy or phen. The complex can catalyze the generation of singlet oxygen under 560 nm visible light, has a photocatalytic antibacterial effect on Staphylococcus aureus, and has a proliferation inhibition capacity on Staphylococcus aureus under light irradiation, which has important significance for the research of antibacterial drugs of the ruthenium complex, and provides a new idea for the clinical development of antibacterial photocatalytic drugs or antibacterial metal photosensitizers of the ruthenium complex.

Description

Technical Field

[0001] This invention belongs to the field of pharmaceutical chemistry technology, specifically relating to a ruthenium complex with photodynamic activity, its preparation method, and its application. Background Technology

[0002] Bacterial infections pose a serious threat to human health. The overuse and misuse of antibiotics have led to a surge in multidrug-resistant bacteria, making the development of highly effective and safe antibacterial agents to combat bacterial infections an urgent necessity. Photodynamic therapy, a newly emerging cancer treatment method in recent years, has become an important direction for replacing traditional antibiotic treatment due to its advantages such as low drug resistance and fewer side effects. The core principle of this therapy is to use specific wavelengths of light to excite a photosensitizer, causing it to transition from the ground state to an excited state. This then generates reactive oxygen species (ROS), such as singlet oxygen and hydroxyl radicals, through energy transfer or electron transfer. These ROS can non-selectively destroy the bacterial biomolecules such as proteins, lipids, and nucleic acids, leading to bacterial death.

[0003] Photosensitizers are a core component of photodynamic antibacterial therapy. Currently reported photosensitizers mainly include organic photosensitizers (such as porphyrins and phthalocyanines) and metal complex photosensitizers. Organic photosensitizers suffer from poor water solubility, weak photostability, poor targeting, and cytotoxicity, limiting their clinical application. In contrast, transition metal complexes, due to their tunable structure and excellent photophysical and photochemical properties, have become a hot research area for photosensitizers, with ruthenium (Ru) complexes standing out due to their unique advantages.

[0004] Ruthenium complexes possess excellent photostability and biocompatibility, long excited-state lifetimes, and efficient ROS generation. Furthermore, their absorption wavelength, hydrophilicity / hydrophobicity, and biotargeting can be flexibly adjusted by regulating the ligand structure, overcoming many shortcomings of traditional photosensitizers. Previous studies have shown that polypyridine ruthenium complexes can effectively kill bacteria under light conditions, and some complexes can also simultaneously release active substances such as nitric oxide, further enhancing the antibacterial effect. However, existing ruthenium complex photosensitizers still have significant limitations: low efficiency in generating reactive oxygen species, poor water solubility, and low bioavailability, restricting their practical applications.

[0005] Literature indicates that iron intake is crucial for the survival of Staphylococcus aureus. Iron is not only a key nutrient source for microbial growth but also enhances microbial virulence and impairs the host's antimicrobial response. Therefore, the use of iron chelators has become a promising antimicrobial strategy. Existing literature data suggests that the combined use of the iron chelator deferiprone and vancomycin has a better inhibitory effect on methicillin-resistant Staphylococcus aureus compared to their use alone. Summary of the Invention

[0006] The primary objective of this invention is to provide a ruthenium complex with photodynamic activity.

[0007] A second objective of this invention is to provide a method for preparing the above-mentioned photodynamic ruthenium complex.

[0008] The third objective is to provide the application of the aforementioned photodynamic ruthenium complex, specifically, the photodynamic ruthenium complex exhibiting a strong photodynamic therapeutic effect against Staphylococcus aureus.

[0009] The first objective of this invention is achieved through the following technical solution: A photodynamic ruthenium complex with the general chemical formula [Ru(L)2DFP]PF6, wherein DFP is the main ligand deferoxone and L is the auxiliary ligand bpy or phen.

[0010] Preferably, the ruthenium complex is selected from any one of the following: [Ru(bpy)2DFP]PF6 or [Ru(phen)2DFP]PF6.

[0011] [Ru(bpy)2DFP]PF6, its structural formula is: ; [Ru(phen)2DFP]PF6, its structural formula is: .

[0012] The second objective of this invention is to provide a method for preparing the aforementioned photodynamic ruthenium complex, comprising the following steps: S1. Add bpy or phen, ruthenium trichloride hydrate, and lithium chloride as a catalyst to a polar aprotic solvent, stir and mix evenly, and heat under reflux under inert gas protection. After post-treatment, the precursor compound Ru(L)2Cl2 is obtained, where L is bpy or phen. S2. The precursor compound Ru(L)2Cl2 of S1, along with deferoxone (DFP) and a small amount of sodium hydroxide as a catalyst, are added to an organic solvent, stirred and mixed evenly, and then heated under reflux under inert gas protection to generate the ruthenium complex [Ru(L)2DFP]PF6 by ion exchange with potassium hexafluorophosphate.

[0013] Preferably, in the above preparation method, in step S1, the heating reflux reaction is a reflux reaction at 150°C for 12-14 hours.

[0014] Preferably, in the above preparation method, in step S1, the molar ratio of bpy or phen to ruthenium trichloride hydrate is 2:1.

[0015] Preferably, in the above preparation method, in step S1, the molar ratio of bpy or phen to the catalyst is 1:5.

[0016] Preferably, in the above preparation method, in step S1, the polar aprotic solvent is DMF.

[0017] Preferably, in the above preparation method, in step S1, the post-treatment is as follows: after the heating and reflux reaction is completed, a large amount of ice acetone is added dropwise to the reaction solution and stirred thoroughly. Then, the mixture is allowed to stand overnight at -4°C, filtered, and a purplish-black solid is obtained. The crystal is then washed with ice water and ice acetone, and vacuum dried to obtain a purplish-black crystal, which is the precursor compound Ru(L)2Cl2.

[0018] Preferably, in the above preparation method, the inert gas is nitrogen.

[0019] Preferably, in the above preparation method, in step S2, the molar ratio of Ru(L)2Cl2 to deferoxone (DFP) is 1:1.5.

[0020] Preferably, in the above preparation method, in step S2, the molar ratio of Ru(L)2Cl2 to the catalyst is 1:1.5.

[0021] Preferably, in the above preparation method, in step S2, the organic solvent is anhydrous ethanol.

[0022] Preferably, in the above preparation method, in step S2, the heating reflux reaction is a reflux reaction at 90~150℃ for 12h.

[0023] Preferably, in the above preparation method, in step S2, the ion replacement is as follows: after the heating and reflux reaction is completed, the mixture is cooled to room temperature, a saturated potassium hexafluorophosphate solution is added and stirred thoroughly, and then the mixture is left to stand overnight at -4°C. The resulting purplish-black solid is dried to obtain the ruthenium complex [Ru(L)2DFP]PF6.

[0024] The third objective of this invention is achieved through the following technical solution: This invention provides an application of the above-mentioned photodynamic ruthenium complex in the preparation of antibacterial photocatalytic drugs or antibacterial metal photosensitizers.

[0025] The aforementioned photodynamic ruthenium complex has the ability to generate singlet oxygen after irradiation with 560 nm visible light; and under this irradiation condition, it has a strong inhibitory effect on the growth of Staphylococcus aureus; as a novel photodynamic ruthenium complex, it is expected to be developed into a highly efficient and low-toxicity antibacterial photocatalytic drug or antibacterial photosensitizer.

[0026] Preferably, the antibacterial agent is against Staphylococcus aureus.

[0027] Compared with the prior art, the beneficial effects of the present invention are: This invention discloses a ruthenium complex with photodynamic activity, which exhibits photocatalytic therapeutic effects against Staphylococcus aureus (S. aureus) and demonstrates inhibitory ability (MIC) against the proliferation of S. aureus under 560 nm visible light catalysis. 90 The concentration is 160 μM, and singlet oxygen can be generated under this illumination condition. This is of great significance for the study of photodynamic ruthenium complex antibacterial drugs and provides new ideas for the clinical development of binuclear ruthenium complex antibacterial photocatalytic drugs or antibacterial metal photosensitizers. Attached Figure Description

[0028] Figure 1 The mass spectrum of [Ru(bpy)2DFP]PF6; Figure 2 The mass spectrum of [Ru(phen)2DFP]PF6; Figure 3 The UV absorption spectrum of [Ru(bpy)2DFP]PF6 (Ru(bpy)2DFP); Figure 4 The fluorescence emission spectrum of [Ru(bpy)2DFP]PF6 (Ru(bpy)2DFP); Figure 5 The ability of [Ru(bpy)2DFP]PF6 to photocatalyze the production of singlet oxygen; Figure 6 The ability of [Ru(phen)2DFP]PF6 to photocatalyze the production of singlet oxygen; Figure 7 The photocatalytic ability of [Ru(phen)2DFP]PF6, Ru(bpy)2Cl2, and Ru(bpy)2 to produce singlet oxygen under different light conditions; Figure 8 Images of Staphylococcus aureus colonies incubated with [Ru(bpy)2DFP]PF6 under conditions of presence and absence of visible light at 560 nm. Figure 9 A schematic diagram illustrating the quantitative data of Staphylococcus aureus incubated with [Ru(bpy)2DFP]PF6 under conditions of presence and absence of visible light at 560 nm. Figure 10 Images of Staphylococcus aureus colonies incubated with [Ru(phen)2DFP]PF6 under conditions of presence and absence of visible light at 560 nm. Figure 11 A schematic diagram illustrating the quantitative data of Staphylococcus aureus incubated with [Ru(phen)2DFP]PF6 under conditions of presence and absence of visible light at 560 nm. Figure 12The wound healing status of mice 1-7 days after bacterial infection under different treatment conditions. Detailed Implementation

[0029] According to the first aspect, the ruthenium complex has the general chemical formula: [Ru(L)2DFP]PF6, where DFP is deferoxone as the main ligand and L is the auxiliary ligand.

[0030] In one specific embodiment, the ruthenium complex is selected from any of the following: [Ru(bpy)2DFP]PF6, its structural formula is: ; [Ru(phen)2DFP]PF6, its structural formula is: .

[0031] The present invention will be further described below with reference to specific embodiments, but the present invention is not limited to the following embodiments.

[0032] Example 1: Synthesis of [Ru(bpy)2DFP]PF6

[0033] The synthesis of [Ru(bpy)2DFP]PF6 includes the following steps: (1) Ru(bpy)2Cl2 is generated by the reaction of 5,5-dimethyl-2,2-bipyridine (bpy) with ruthenium trichloride hydrate. In a 250 mL two-necked flask, bpy (0.184 g, 1 mmol), lithium chloride (0.212 g, 5 mmol), and ruthenium trichloride hydrate (0.131 g, 0.5 mmol) were dissolved in 15 mL of DMF. The mixture was heated to 150 °C and refluxed for 12 h under nitrogen protection. After the reaction was completed, the reaction solution was purplish-black. While the reaction solution was still hot, a large amount of ice-cold acetone was added dropwise and stirred thoroughly. The mixture was then allowed to stand overnight at -4 °C and filtered to obtain a purplish-black solid. The crystals were then washed with ice water and ice-cold acetone and dried under vacuum to obtain purplish-black crystals, which was Ru(bpy)2Cl2.

[0034] The chemical reaction equations for the above reactions are shown below:

[0035] (2) [Ru(bpy)2DFP]PF6 is generated by the reaction of Ru(bpy)2Cl2 with deferoxone.

[0036] In a 250 mL two-necked flask, Ru(bpy)₂Cl₂ (54 mg, 0.1 mmol), deferoxone (20 mg, 0.15 mmol), and NaOH (6 mg, 0.15 mmol) were dissolved in 10 mL of anhydrous ethanol. The mixture was heated to 90 °C and refluxed for 12 h under nitrogen protection. After the reaction, the solution turned purplish-black. The solution was cooled to room temperature, and saturated potassium hexafluorophosphate (0.5 mmol, 2.3 mL) was added and stirred thoroughly. The mixture was then allowed to stand overnight at -4 °C to obtain a purplish-black solid. Vacuum drying yielded purplish-black crystals, which is [Ru(bpy)₂DFP]PF₆. Mass spectrometry analysis of Ru(bpy)₂DFP samples showed... Figure 1 As shown, the theoretical value of m / z is 608.1594, and the experimental value is 608.1627.

[0037] The chemical reaction equations for the above reactions are shown below:

[0038] Example 2: Synthesis of [Ru(phen)2DFP]PF6

[0039] The synthesis of [Ru(phen)2DFP]PF6 includes the following steps: (1) Ru(phen)2Cl2 is generated by the reaction of o-phenanthroline (phen) with ruthenium trichloride hydrate. In a 250 mL two-necked flask, phen (0.184 g, 1 mmol), lithium chloride (0.212 g, 5 mmol), and ruthenium trichloride hydrate (0.131 g, 0.5 mmol) were dissolved in 15 mL of DMF. The mixture was heated to 150 °C and refluxed for 12 h under nitrogen protection. After the reaction was completed, the reaction solution was purplish-black. While the reaction solution was still hot, a large amount of ice-cold acetone was added dropwise and stirred thoroughly. The mixture was then allowed to stand overnight at -4 °C and filtered to obtain a purplish-black solid. The crystals were then washed with ice water and ice-cold acetone and dried under vacuum to obtain purplish-black crystals, which was Ru(phen)2Cl2.

[0040] The chemical reaction equations for the above reactions are shown below:

[0041] (2) [Ru(phen)2DFP]PF6 is generated by the reaction of Ru(phen)2Cl2 with deferoxone.

[0042] In a 250 mL two-necked flask, Ru(phen)₂Cl₂ (54 mg, 0.1 mmol), deferoxone (20 mg, 0.15 mmol), and NaOH (6 mg, 0.15 mmol) were dissolved in 10 mL of anhydrous ethanol. The mixture was heated to 150 °C and refluxed for 12 h under nitrogen protection. After the reaction, the solution turned purplish-black. After cooling to room temperature, saturated potassium hexafluorophosphate (0.5 mmol, 2.3 mL) was added and stirred thoroughly. The mixture was then allowed to stand overnight at -4 °C to obtain a purplish-black solid. Vacuum drying yielded purplish-black crystals, which is [Ru(phen)₂DFP]PF₆. Mass spectrometry analysis of Ru(phen)₂DFP samples showed... Figure 2 As shown, the theoretical value of m / z is 601.1047, and the experimental value is 601.1000.

[0043] The chemical reaction equations for the above reactions are shown below:

[0044] Example 3: Ultraviolet absorption characterization of [Ru(bpy)2DFP]PF6

[0045] Accurately weigh 0.0012 g of [Ru(bpy)2DFP]PF6 powder, dissolve it in 2 mL of acetonitrile, and prepare a 1 mM [Ru(bpy)2DFP]PF6 concentrate. Take 100 μL of the concentrate, add 1900 μL of acetonitrile, and dilute the concentrate to a 50 μM [Ru(bpy)2DFP]PF6 solution. Measure the ultraviolet absorption spectrum using a UV-Vis spectrophotometer.

[0046] like Figure 3 As shown, [Ru(bpy)2DFP]PF6 has a maximum absorption peak at 545 nm.

[0047] Example 4: Fluorescence spectral characterization of [Ru(bpy)2DFP]PF6 or [Ru(phen)2DFP]PF6

[0048] Taking the test of [Ru(bpy)2DFP]PF6 as an example, accurately weigh 0.0012 g of [Ru(bpy)2DFP]PF6 powder, dissolve it in 2 mL of acetonitrile, and prepare a 1 mM [Ru(bpy)2DFP]PF6 concentrate. Take 100 μL of the concentrate, add 1900 μL of acetonitrile, and dilute the concentrate to a 50 μM [Ru(bpy)2DFP]PF6 solution. Use a fluorescence spectrometer to test the fluorescence emission spectrum, and set the excitation wavelength to 271 nm.

[0049] like Figure 4 As shown, the maximum emission wavelength of [Ru(bpy)2DFP]PF6 is 409nm.

[0050] Example 5 investigated the photocatalytic ability of [Ru(bpy)2DFP]PF6 to produce singlet oxygen.

[0051] Accurately weigh 0.0012 g of [Ru(bpy)₂DFP]PF₆ powder and dissolve it in 2 mL of acetonitrile to prepare a 1 mM [Ru(bpy)₂DFP]PF₆ concentrate. Under light-protected conditions, accurately weigh 0.00266 g of 1,3-diphenylisobenzofuran (DPBF) powder and dissolve it in 2 mL of acetonitrile to prepare a 5 mM DPBF solution. Use a UV-Vis spectrophotometer for testing. Take 100 μL of the [Ru(bpy)₂DFP]PF₆ concentrate, add 1900 μL of acetonitrile to dilute the concentrate to a concentration of 50 μM, add 20 μL of the DPBF solution, and measure the UV absorption spectra at 0, 2, 4, 6, 8, and 10 minutes with and without 560 nm visible light irradiation. Record the absorbance change at a wavelength of 410 nm, where the power of the 560 nm visible light is 0.02 W. Following the same steps as above, the [Ru(bpy)₂DFP]PF₆ powder was replaced with Ru(bpy)₂Cl₂ or Ru(bpy)₃, and the singlet oxygen absorption capacity of the obtained Ru(bpy)₂Cl₂ or Ru(bpy)₃ was tested. A control group was also set up: 2000 μL of acetonitrile was used, to which 20 μL of DPBF solution was added. The UV absorption spectra at 0, 2, 4, 6, 8, and 10 minutes were measured under 560 nm visible light irradiation to verify whether 560 nm visible light alone could change the absorbance of DPBF at 410 nm.

[0052] like Figure 5 As shown, under visible light irradiation at 560 nm, [Ru(bpy)2DFP]PF6 can reduce the absorbance of DPBF at 410 nm at 2, 4, 6, 8, and 10 min, indicating that [Ru(bpy)2DFP]PF6 can catalyze the production of singlet oxygen under visible light irradiation at 560 nm, thus reducing the absorbance of DPBF at 410 nm.

[0053] like Figure 6 As shown, under visible light irradiation at 560 nm, [Ru(phen)2DFP]PF6 can reduce the absorbance of DPBF at 410 nm at 2, 4, 6, 8, and 10 min, indicating that [Ru(phen)2DFP]PF6 can catalyze the production of singlet oxygen under visible light irradiation at 560 nm, thus reducing the absorbance of DPBF at 410 nm.

[0054] Figure 7The ability of [Ru(phen)₂DFP]PF₆, Ru(bpy)₂Cl₂, and Ru(bpy)₃ to catalyze the production of singlet oxygen under different light conditions is shown. In the figure, L represents the irradiation under 560 nm visible light. Figure 7 As shown, under dark conditions, [Ru(bpy)2DFP]PF6 cannot produce singlet oxygen (curve [Ru(bpy)2DFP]PF6+DPBF). Under 560nm visible light irradiation, Ru(bpy)3 (curve Ru(bpy)3+DPBF+L), Ru(bpy)2Cl2 (curve Ru(bpy)2Cl2+DPBF+L), and [Ru(bpy)2DFP]PF6 (curve [Ru(bpy)2DFP]PF6+DPBF+L) can all produce singlet oxygen. Compared with the existing ruthenium complexes Ru(bpy)3 and Ru(bpy)2Cl2, the [Ru(bpy)2DFP]PF6 group has the strongest ability to produce singlet oxygen.

[0055] Example 6: Investigation of the antibacterial effects of [Ru(bpy)2DFP]PF6 or [Ru(phen)2DFP]PF6 against Staphylococcus aureus.

[0056] This study investigated the effects of [Ru(bpy)2DFP]PF6 or [Ru(phen)2DFP]PF6 on the survival rate of Staphylococcus aureus under conditions of no or no visible light irradiation at 560 nm.

[0057] Taking the testing of [Ru(bpy)2DFP]PF6 as an example, [Ru(bpy)2DFP]PF6 solutions with concentrations of 40μM, 80μM, 160μM, and 320μM were prepared using 1% DMSO. The blank control group was sterile water. For each concentration in the experimental group and the control group, there were light and dark groups. The logarithmic growth phase S. aureus second-generation bacterial culture was diluted 50 times with tryptic soy peptone liquid medium (TSB) and placed in a shaker (250rpm, 37℃) for 1.5h. The volumes of the bacterial culture and the [Ru(bpy)2DFP]PF6 solution were 100μL and 200μL, respectively. The light group was irradiated with 560nm, 0.02W visible light for 5min before incubation.

[0058] Dilute the co-incubated sample to 1.5 × 10⁻⁶. 4 Take 100 μL of the sample and spread it evenly on a solid agar plate. Place the plate in a 37°C incubator and count the bacteria after 24 hours. Compare the results with the blank control group to calculate the bacterial survival rate.

[0059] like Figure 8 , 9As shown, different concentrations of [Ru(bpy)2DFP]PF6 exhibited different bactericidal effects against Staphylococcus aureus under both dark and 560nm light conditions. Compared to the dark group, [Ru(bpy)2DFP]PF6 showed better bactericidal effects against Staphylococcus aureus under 560nm light conditions. When the concentration of [Ru(bpy)2DFP]PF6 was 320μM, the bacterial survival rate in the light group was approximately 2.15%.

[0060] like Figure 10 , 11 As shown, different concentrations of [Ru(phen)2DFP]PF6 exhibited different bactericidal effects against Staphylococcus aureus under both dark and 560nm light conditions. Compared to the dark group, [Ru(phen)2DFP]PF6 showed better bactericidal effects against Staphylococcus aureus under 560nm light conditions; when the concentration of [Ru(phen)2DFP]PF6 was 320μM, the bacterial survival rate in the light group was approximately 2%.

[0061] Example 7: Investigating whether [Ru(bpy)2DFP]PF6 can promote the healing of bacterial wounds in mice.

[0062] Before the experiment, hair was removed from the backs of mice using depilatory cream. A 1 cm² skin wound was prepared using sterile surgical scissors, and 100 μL of overnight cultured Staphylococcus aureus solution was locally instilled to establish an infection model. Infected mice were randomly divided into three groups: Control group, Ru(bpy)3 plus light irradiation group, and Ru(bpy)2DFP plus light irradiation group. 320 μM Ru(bpy)3 solution and [Ru(bpy)2DFP]PF6 solution were prepared using 1% DMSO, respectively. 100 μL of the drug (Ru(bpy)3 solution or [Ru(bpy)2DFP]PF6 solution) or sterile water (Control) was applied topically to the wound, and the wound was irradiated with 560 nm, 0.02 W visible light for 5 min. The treatment was repeated for three days, and the wound healing progress was observed daily.

[0063] like Figure 12 As shown, compared with the Control group and the Ru(bpy)3 plus light irradiation group, the Ru(bpy)2DFP plus light irradiation group showed better wound healing. L in the figure represents the light irradiation condition.

[0064] In summary, the photodynamic ruthenium complex [Ru(bpy)₂DFP]PF₆ of this invention exhibits good solubility in acetonitrile and a maximum UV absorption peak at 545 nm. Furthermore, the optimal excitation wavelength in acetonitrile is 271 nm, and the optimal emission wavelength is 409 nm. Simultaneously, this photodynamic ruthenium complex possesses the ability to generate singlet oxygen under 560 nm visible light irradiation, demonstrating a strong bactericidal effect against Staphylococcus aureus. Therefore, the photodynamic ruthenium complex of this invention belongs to the category of photocatalysts and has great potential for development into highly efficient and low-toxicity antibacterial photocatalytic drugs or antibacterial photosensitizers.

[0065] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A ruthenium complex with photodynamic activity, characterized in that, Its general chemical formula is [Ru(L)2DFP]PF6, where DFP is the main ligand deferoxone and L is the auxiliary ligand bpy or phen.

2. The photodynamic ruthenium complex according to claim 1, characterized in that, The ruthenium complex is selected from any one of the following: [Ru(bpy)2DFP]PF6 or [Ru(phen)2DFP]PF6; [Ru(bpy)2DFP]PF6, its structural formula is: ; [Ru(phen)2DFP]PF6, its structural formula is: 。 3. A method for preparing a photodynamic ruthenium complex according to claim 1 or 2, characterized in that, Includes the following steps: S1. Add bpy or phen, ruthenium trichloride hydrate, and catalyst A to a polar aprotic solvent, stir and mix thoroughly, and heat under reflux under inert gas protection. Post-treatment yields the precursor compound Ru(L)2Cl2. S2. Add the precursor compound Ru(L)2Cl2, deferoxone, and catalyst B to an organic solvent, stir and mix thoroughly, and then heat under reflux under inert gas protection to generate the ruthenium complex [Ru(L)2DFP]PF6 by ion exchange with potassium hexafluorophosphate.

4. The method for preparing the photodynamic ruthenium complex according to claim 3, characterized in that, Catalyst A in step S1 is lithium chloride; The polar aprotic solvent mentioned in step S1 is DMF; The molar ratio of bpy or phen to ruthenium trichloride hydrate in step S1 is 2:1; The molar ratio of bpy or phen to the catalyst in step S1 is 1:

5.

5. The method for preparing the photodynamic ruthenium complex according to claim 3, characterized in that, The heating reflux reaction in step S1 is carried out at a temperature of 150°C for 12-14 hours. The post-processing described in step S1 is as follows: After the heating and reflux reaction is completed, a large amount of ice acetone is added dropwise to the reaction solution and stirred thoroughly. Then, the mixture is allowed to stand overnight at -4°C, filtered, and a purplish-black solid is obtained. The crystal is then washed with ice water and ice acetone and dried under vacuum to obtain purplish-black crystals, which are the precursor compound Ru(L)2Cl2.

6. The method for preparing the photodynamic ruthenium complex according to claim 3, characterized in that, The catalyst B mentioned in step S2 is sodium hydroxide; The organic solvent mentioned in step S2 is anhydrous ethanol; The molar ratio of Ru(L)2Cl2 to deferoxone in step S2 is 1:1.5; The molar ratio of Ru(L)2Cl2 to catalyst B in step S2 is 1:1.

5.

7. The method for preparing the photodynamic ruthenium complex according to claim 3, characterized in that, The heating and reflux reaction described in step S2 is a reflux reaction at 90~150℃ for 12 hours; The ion replacement in step S2 is as follows: after the heating and reflux reaction is completed, the mixture is cooled to room temperature, a saturated potassium hexafluorophosphate solution is added and stirred thoroughly, and then allowed to stand overnight at -4°C. The resulting purplish-black solid is dried to obtain the ruthenium complex [Ru(L)2DFP]PF6.

8. The method for preparing the photodynamic ruthenium complex according to claim 3, characterized in that, The inert gas is nitrogen.

9. The use of a ruthenium complex with photodynamic activity according to claim 1 or 2 in the preparation of antibacterial photocatalytic drugs or antibacterial metal photosensitizers.

10. The use of the photodynamic ruthenium complex according to claim 1 or 2 in the preparation of antibacterial photocatalytic drugs or antibacterial metal photosensitizers for use against Staphylococcus aureus.

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