Mitochondrial DNA (deoxyribonucleic acid) targeted 4-aminobenzopyran photosensitive dye as well as preparation method and application thereof

Abstract

The invention discloses a mitochondrial DNA (Deoxyribose Nucleic Acid) targeted 4-aminobenzopyran photosensitive dye as well as a preparation method and application thereof. The structural general formula of the 4-aminobenzopyran photosensitive dye is # imgabs0. The invention also specifically discloses a preparation method of the 4-aminobenzopyran photosensitive dye and an application of the 4-aminobenzopyran photosensitive dye in preparation of a mitochondrial DNA photosensitive imaging agent and a mitochondrial DNA targeted photosensitizer for tumor photodynamic therapy. The photosensitive dye disclosed by the invention has excellent photosensitive activity and spectral feedback performance at the same time, and the in-vivo tumor treatment effect of the photosensitive dye is improved. The 4-aminobenzopyran photosensitive dye prepared by the invention has relatively low biotoxicity and relatively high phototoxicity in living tumor treatment, and the 4-aminobenzopyran photosensitive dye has the advantages of easily available raw materials, simple structure, easy preparation and easy industrialization.

Description

Technical Field

[0001] The invention belongs to the technical field of photosensitizing dyes and photodynamic tumor therapy, and specifically relates to a class of mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dyes and a preparation method and application thereof. Background Art

[0002] Photodynamic therapy (PDT) is a new treatment method based on photochemical reactions. With its excellent characteristics such as high spatiotemporal selectivity, non-invasiveness and negligible drug resistance, it has become an emerging and promising cancer treatment method. PDT mainly involves the generation of a large amount of reactive oxygen species (ROS) by photosensitizers under the irradiation of a light source of a specific wavelength through energy (type II) or / and electron transfer (type I), which then induces apoptosis and necrosis of tumor cells based on high oxidative activity. In the above treatment process, photosensitizers are the most critical core factor in regulating their therapeutic efficacy. Their structural design and performance optimization are also the focus of current research, and a large number of related photosensitizers have been developed and reported. However, most of the existing photosensitizers still have the following limitations and challenges in clinical treatment: (1) low photosensitivity, which makes them insufficient in killing tumor cells, seriously limiting their PDT therapeutic efficacy; (2) lack of spectral monitoring performance, which makes it impossible to monitor the treatment process in real time, resulting in over-treatment / under-treatment and affecting the treatment efficacy. Therefore, it is urgent to construct new photosensitizers that have both high tumor cell killing ability and spectral detection performance of treatment process to maximize their tumor treatment efficacy.

[0003] In the study of photosensitizers, strategies such as introducing heavy atoms, regulating intramolecular electron transfer, and steric hindrance have been widely reported to regulate the intersystem crossing efficiency (ISC) of photosensitizers, thereby effectively improving their photosensitivity. On this basis, researchers have also paid attention to the spectral detection performance of photosensitizers, and developed target photosensitizers using viscosity, pH, etc. as biomarkers. While initiating the photodynamic therapy process, it monitors the corresponding markers in real time, so that it can provide real-time feedback and regulate the PDT treatment process through spectral signal changes, thereby maximizing its therapeutic efficacy. However, target photosensitizers are still extremely scarce, and it is urgent to develop new target photosensitizers with excellent performance. Here, mitochondrial DNA (mtDNA), as the unique genetic material in the mitochondria of cells, is easily damaged based on its unique structure and existence environment, which can cause mitochondrial dysfunction and induce cell apoptosis. In addition, studies have shown that reactive oxygen can damage mtDNA and accelerate cell apoptosis, and the degree of mtDNA damage can also provide real-time feedback on the process of cell apoptosis. Therefore, taking mtDNA as the target, the corresponding photosensitizer is constructed, which can not only improve its tumor killing ability by damaging mtDNA, but also optimize its PDT process based on real-time spectral monitoring of the degree of mtDNA damage to achieve efficient treatment of clinical cancer. At present, the design of mtDNA target photosensitizer is still relatively scarce, and its design rules are not clear, which greatly increases the difficulty of designing target photosensitizer. And based on the principle of dye fluorescence emission and photochemical reaction, the two are in a competitive relationship, which makes the coordinated regulation of photosensitizer spectral monitoring performance and photosensitivity is also a major difficulty in current research. Therefore, taking mtDNA as the target, designing and synthesizing photosensitizers with both high photosensitivity and spectral detection performance to improve its clinical cancer treatment efficacy is still a huge challenge, and there are currently no relevant reports in this regard. Summary of the invention

[0004] The technical problem solved by the present invention is to provide a class of mitochondrial DNA-targeted 4-aminobenzopyran-type photosensitizers and a preparation method thereof. The photosensitizer prepared by the method takes mtDNA as a target, can highly and specifically bind to mitochondrial DNA in living cells, and emit a strong fluorescence signal, so as to trace the content of mtDNA in cells through the fluorescence signal, and can be used to prepare mtDNA photosensitizers and mtDNA-targeted tumor photodynamic therapy photosensitizers.

[0005] The present invention adopts the following technical solutions to solve the above technical problems:

[0006] A type of mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer, the general structural formula of which is shown in Formula I:

[0007]

[0008] In formula I, R1 and R2 are respectively -H or one of the following groups:

[0009]

[0010] Where m is -H, -Cl, -Br or -I, and x is -CH3, -OH, -NH2, -COOH, -SO3 - , -Cl, -Br or -I, y is O, S or Se, and n is an integer between 0 and 4;

[0011] In formula I, K and L are -CO-, -Cp=CH-(CH=CH) respectively. n -or-Cp=CH-(CH=CH) n -CH=Cp-;

[0012] Where p is -CH3, -CN, -Br, -Cl, -H, -OH, -NH2, -(CH2)nNH2 or -SO3 - , n is an integer between 0 and 8.

[0013] A class of mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dyes includes compounds with the following structures:

[0014]

[0015] The preparation method of the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye of the present invention comprises the following specific preparation steps:

[0016] Step S1: under acidic conditions, salicylamide, acetone and acetic anhydride are first added to a reaction solvent, and then an oxidant is added and an oxidation reaction is carried out at 0-100° C. to obtain compound A, the structural formula of which is:

[0017]

[0018] The oxidant is one or more of potassium permanganate, hydrogen peroxide, sodium hypochlorite, Vilsmeier reagent, potassium dichromate, sodium dichromate, nitric acid, peracetic acid or chromic acid;

[0019] Step S2: heating the compound A obtained in step S1 and 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide or 1,2,3,3-tetramethyl-3H-indolium iodide under reflux to obtain the compounds represented by formula 1-1 to formula 1-4, i.e., mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer dyes.

[0020] Furthermore, in step S1, the molar ratio of salicylamide, acetone and acetic anhydride is 1:1:1-1:2:2.

[0021] Furthermore, the reaction solvent in step S1 is one or more of dichloromethane, ethanol, methanol, acetone, 1,4-dioxane, propylene glycol, ethyl acetate, acetic acid, sulfuric acid, acetic anhydride, sodium hydroxide aqueous solution or N,N-dimethylformamide.

[0022] Furthermore, in step S2, the molar ratio of compound A to 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide or 1,2,3,3-tetramethyl-3H-indolium iodide is 1:0.5-1:4.

[0023] Furthermore, the reaction solvent in step S2 is one or more of dichloromethane, ethanol, methanol, acetone, 1,4-dioxane, propylene glycol, ethyl acetate, acetic acid, sulfuric acid, piperidine or N,N-dimethylformamide.

[0024] The invention discloses an application of the mitochondrial DNA targeted 4-aminobenzopyran photosensitizing dye in the preparation of a mitochondrial DNA photosensitizing imaging agent.

[0025] The invention discloses an application of the mitochondrial DNA targeted 4-aminobenzopyran photosensitizer in the preparation of a mitochondrial DNA targeted tumor photodynamic therapy photosensitizer.

[0026] The 4-aminobenzopyran photosensitizer of the present invention can be highly specifically bound to mtDNA through the minor groove effect, and can be used for specific quantitative and real-time monitoring of mtDNA. In addition, this type of photosensitizer has a high photosensitivity, and can generate a large amount of ROS under the corresponding wavelength laser irradiation to efficiently damage mtDNA, induce cell apoptosis and necrosis. And this type of photosensitizer has good biocompatibility, and can react to mtDNA damage in real time through spectral signals while inducing photodynamic therapy, thereby evaluating the degree of cell apoptosis, feedback regulating the treatment process, and improving the efficacy of cancer treatment.

[0027] The 4-aminobenzopyran photosensitizer of the present invention can trigger a photochemical reaction to produce a large amount of reactive oxygen under light activation, and start the photodynamic therapy process. In addition, this type of photosensitizer takes mtDNA as a target, can be highly and specifically combined with mitochondrial DNA in living cells, and emits a strong fluorescent signal to trace the content of mtDNA in cells through fluorescent signals. The strong mitochondrial targeting ability of this type of photosensitizer enables it to improve its cell killing power by quickly damaging mtDNA, and can also react to mitochondrial damage through changes in fluorescent signals to feedback the living tumor treatment process in real time, thereby adjusting the treatment plan in time to maximize the therapeutic effect of living tumors. The 4-aminobenzopyran photosensitizer of the present invention also has low biological toxicity, suitable water solubility and good anti-interference ability.

[0028] The present invention has the following advantages and beneficial effects: the photosensitizer of the present invention has a semi-cyanine conjugated structure, has a strong binding ability to mtDNA, and improves its spectral feedback performance on the degree of mtDNA damage. The photosensitizer of the present invention has a classic D-Π-A structure, can induce excellent photochemical reactions under the action of intramolecular charge transfer, and optimizes its photosensitivity. The photosensitizer of the present invention has excellent photosensitivity and spectral feedback performance at the same time, and improves its therapeutic effect on living tumors. The photosensitizer of the present invention has lower biological toxicity and higher phototoxicity during living tumor treatment, and its raw materials are easily available, the structure is simple, it is easy to prepare, and it is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 These are the results of an experiment to test the responsiveness of the photosensitizing dye 1-1 to mtDNA.

[0030] Figure 2 This is the result of the photosensitivity test of photosensitizing dye 1-1.

[0031] Figure 3 This is the experimental result of the photosensitive dye 1-1 recognizing and imaging mtDNA in living cells.

[0032] Figure 4 These are the test results for evaluating the performance of photosensitizing dye 1-1 in generating ROS in living cells.

[0033] Figure 5 These are the results of an experiment evaluating the killing ability of the photosensitive dye 1-1 on tumor cells.

[0034] Figure 6 These are the results of an experiment to test the responsiveness of photosensitizing dye 1-2 to mtDNA.

[0035] Figure 7 These are the results of the experiment to test the responsiveness of photosensitizing dyes 1-3 to mtDNA.

[0036] Figure 8 These are the results of the experiment to test the responsiveness of photosensitizing dyes 1-4 to mtDNA. DETAILED DESCRIPTION

[0037] The specific technical contents of the present invention are further described in detail below through examples, but this should not be understood as the scope of the above subject matter of the present invention being limited to the following examples, and all technologies implemented based on the above contents of the present invention belong to the scope of the present invention.

[0038] Example 1

[0039] The photosensitizing dye 1-1 was prepared using the following synthetic route:

[0040]

[0041] Synthesis of photosensitizing dye 1-1:

[0042] 5.0 mmol of compound A and 3.0 mmol of 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide were added to a round-bottom flask containing 30.0 mL of N,N-dimethylformamide, and the mixture was stirred and mixed evenly. Then, 1.5 mL of trimethylsilyl chloride was added, and the mixture was stirred and refluxed for 5.0 h before the reaction was stopped. The mixture was poured into ice water to precipitate. A purple solid crude product was obtained by suction filtration. The purple solid powder compound, i.e., photosensitizer 1-1, was separated by column chromatography in a yield of 82%. 1 H NMR (600MHz, CDCl3) δ10.05(s,2H),9.64(s,1H),8.47(s,1H),8.01(s,2H),7.87(s,1H),7.74(d,J= 6.7Hz,1H),7.67(s,1H),7.28(d,J=6.6Hz,1H),6.94(s,1H),4.11(s,1H),3.64(s,3H),1.72(s,6H).

[0043] Photosensitive dye 1-1 response to mtDNA detection test:

[0044] The above-synthesized photosensitizing dye 1-1 was added to a PBS buffer solution (pH=7.2) at a final concentration of 5.0 μM, and then mtDNA (0-10.16 μg / mL) was continuously added to the solution, and its ultraviolet absorption and fluorescence emission spectra were tested in turn. The test results are as follows: Figure 1As shown in the figure, the results show that as the mtDNA content increases, its absorbance at 520nm decreases significantly and a slight red shift occurs. At the same time, its fluorescence signal at 601nm increases significantly. This result shows that the photosensitizer 1-1 can bind to mtDNA and can feedback its content changes through fluorescence signals. Figure 1 The UV absorption and fluorescence spectrum signal changes after the photosensitive dye 1-1 binds to different amounts of mtDNA. The instruments used are Cintra 2020 (GBC Scientific Equipment Pty Ltd) and Fluoromax-4C-L (HORIBA).

[0045] Photosensitivity test of photosensitizing dye 1-1:

[0046] The above-synthesized photosensitizer 1-1 was used, and diphenylisobenzofuran (DPBF) was used as a ROS indicator. The photosensitizer 1-1 was added to a DPBF solution with a concentration of 40.0 μM at a final concentration of 5.0 μM, and its absorbance change at 415 nm under different illumination times was tested. The test results are shown in FIG. Figure 2 As shown in the figure, the absorbance at 415nm decreased significantly with the increase of illumination time, and the decreasing trend was much greater than that of DPBF alone under illumination. This result shows that the photosensitizer 1-1 has photosensitivity, which can produce a large amount of reactive oxygen species by photochemical reaction under illumination, thus initiating the photodynamic therapy process. Figure 2 The light source used is a 525nm xenon lamp with a light power density of 23.0mW / cm 2 .

[0047] Experiment on the recognition and imaging of mtDNA by photosensitive dye 1-1 in living cells:

[0048] Using the above-mentioned synthesized photosensitizer 1-1, human breast cancer cells (MCF-7) were used as the research object. MCF-7 cells were pretreated with DNA digestion enzyme (100U / mL), and then incubated with photosensitizer 1-1 at a final concentration of 5.0μM, and incubated at 37°C, 5wt% / vol CO2 for 30min. Then, PBS was shaken and rinsed for 5min×3, and cell culture medium was added, and laser confocal imaging was performed. Representative areas were selected and observed with a dry lens (40×), and repeated three times. The fluorescence collection band was 550-650nm, and the excitation wavelength was 515nm. The experimental results are as follows Figure 3 As shown in the figure, it can be seen that the fluorescence signal of the photosensitive dye 1-1 is mainly concentrated in the mitochondria, and after pretreatment with DNA digestion enzyme, its fluorescence signal is significantly reduced. This result shows that the photosensitive dye 1-1 targets mtDNA and can identify changes in the mtDNA content in living cells.

[0049] Evaluation test of the performance of photosensitizing dye 1-1 in generating ROS in living cells:

[0050] Using the above-mentioned synthesized photosensitizer 1-1, human breast cancer cells (MCF-7) were used as the research object, and 2',7'-difluorescein diacetate (DCFH-DA) was used as the ROS indicator in living cells. Experimental group: MCF-7 cells were co-incubated with photosensitizer 1-1 (3.0μM) at 37°C and 5wt% / vol CO2 for 30 minutes, and then DCFH-DA (10μM) was added and incubated for another 20 minutes; control group: MCF-7 cells were co-incubated with DCFH-DA (10μM) only for 20 minutes. The above cells were placed under a 525nm xenon lamp for 60 seconds, and then laser confocal imaging was performed. Representative areas were selected and observed with a dry lens (40×), and repeated three times. The fluorescence collection band was 510-540nm, and the excitation wavelength was 488nm. The experimental results are as follows Figure 4 As shown in the figure, under light conditions, obvious green fluorescence signals appeared in the cells of the experimental group, while the fluorescence signals in the cells of the control group were negligible. This result shows that in living cells, the photosensitizer 1-1 can produce a large amount of reactive oxygen species under light conditions and initiate the photodynamic therapy process.

[0051] Evaluation test of the killing ability of photosensitizing dye 1-1 on tumor cells:

[0052] The photosensitizer 1-1 synthesized above was used to study human breast cancer cells (MCF-7) and the MTT method was used to evaluate its tumor cell killing ability. 4 100 μL of the solution was inoculated into a 96-well plate at a density of 100 μL per well and placed in a 5wt% / vol CO2, 37°C incubator for 24 hours. The photosensitizer was added to the 96-well plate according to a certain concentration gradient, and the wells without photosensitizer were used as blank control wells. The 96-well plate was incubated in a 5wt% / vol CO2, 37°C incubator for 1 hour, and then the 96-well plate was placed under a xenon lamp (525 nm xenon lamp, light power density was 23 mW / cm 2 ) for 10 min, and the irradiated 96-well plate was placed in the incubator for 3 h. Subsequently, 20 μL (5 mg / mL) of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) was added to each well, and the incubation was continued for 4 h to convert the succinate dehydrogenase in the mitochondria of the living cells into formazan. All the solutions in the 96-well plate were removed, and DMSO was added to each well at a volume of 150 μL to dissolve the formazan in the cells. The absorbance at 490 nm was measured by an enzyme reader, and the formula (cell viability (%) = (OD 实验孔 / OD空白孔 )×100) to calculate the cell survival rate (100%) of the photosensitizing dye 1-1, and use this to evaluate its killing ability on tumor cells. Figure 5 As shown in the figure, it can be seen that the cell survival rate of photosensitizer 1-1 is above 95% in the absence of light, and in the presence of light, the cell survival rate at a concentration of 0.8 μM is only about 20%. This result shows that photosensitizer 1-1 can trigger targeted photodynamic therapy of mitochondrial DNA under light conditions and has a high cell killing ability on tumor cells.

[0053] Example 2

[0054] The photosensitizing dye 1-2 was prepared using the following synthetic route:

[0055]

[0056] Synthesis of photosensitizing dye 1-2:

[0057] 5.0 mmol of compound A and 3.0 mmol of 1,2,3,3-tetramethyl-3H-indolium iodide were added to a round-bottom flask containing 30.0 mL of N,N-dimethylformamide, and the mixture was stirred and mixed evenly, and then 1.5 mL of trimethylsilyl chloride was added. The mixture was stirred and heated to reflux for 3.0 h and then stopped. The mixture was poured into ice water to precipitate. A purple solid crude product was obtained by suction filtration. The purple solid powder compound, i.e., photosensitizer 1-2, was separated by column chromatography in a yield of 82%. 1 H NMR (600MHz, DMSO-d6) δ10.24(s,2H),9.66(s,1H),8.63(s,1H),7.99(s,1H),7.88(s,2H),7.66(s,1H),7.63(d,J=7.4Hz,1 H),7.47(d,J=7.9Hz,1H),7.43(t,J=7.5Hz,1H),7.28(d,J=6.4Hz,1H),4.16(s,1H),4.15(s,1H),3.70(s,3H),1.73(s,6H).

[0058] Photosensitive dye 1-2 response to mtDNA detection test:

[0059] The above-synthesized photosensitizing dye 1-2 was added to a PBS buffer solution (pH=7.2) at a final concentration of 3.0 μM, and then mtDNA (0-10.16 μg / mL) was continuously added to the solution, and its ultraviolet absorption and fluorescence emission spectra were tested in turn. The test results are as follows: Figure 6As shown in the figure, the results show that as the mtDNA content increases, its absorbance at 509nm decreases significantly and a slight red shift occurs. At the same time, its fluorescence signal at 567nm increases significantly. This result shows that the photosensitizing dye 1-2 can also bind to mtDNA and can feedback its content changes through fluorescence signals.

[0060] Example 3

[0061] The following synthetic route was used to prepare photosensitizing dyes 1-3:

[0062]

[0063] Synthesis of photosensitizing dyes 1-3:

[0064] 3.0 mmol of compound A and 10.0 mmol of 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide were added to a round-bottom flask containing 30.0 mL of N,N-dimethylformamide, and the mixture was stirred and evenly mixed, and then 1.5 mL of trimethylsilyl chloride was added. The mixture was stirred and heated to reflux and the reaction was continued for 3.0 h and then stopped. The mixture was poured into ice water to precipitate. A blue solid crude product was obtained by suction filtration. The blue solid powder compound, i.e., photosensitizer 1-3, was separated by column chromatography in a yield of 62%. 1 H NMR (600MHz, DMSO-d6) δ11.56(s,2H),8.97(s,1H),8.45(s,2H),8.08(d,J=40.9Hz,3H),7.83(d,J=75.3H z, 5H), 7.58 (d, J = 44.6Hz, 1H), 7.39 (d, J = 71.1Hz, 2H), 6.41 (d, J = 57.5Hz, 2H), 1.75 (s, 12H), 1.21 (s, 6H).

[0065] Detection test of the responsiveness of photosensitizing dyes 1-3 to mtDNA:

[0066] The above-synthesized photosensitizing dyes 1-3 were added to a PBS buffer solution (pH=7.2) at a final concentration of 5.0 μM, and then DNA (0-10.16 μg / mL) was continuously added to the solution, and its ultraviolet absorption and fluorescence emission spectra were tested in turn. The test results are as follows: Figure 7 As shown in the figure, the results show that with the increase of mtDNA content, the absorbance at 618nm and the fluorescence signal at 637nm are significantly reduced. At the same time, a new fluorescence signal appears at 676nm, and its signal intensity increases significantly with the increase of mtDNA content. This result shows that photosensitizers 1-3 can bind to mtDNA and can feedback its content changes through obvious changes in proportional fluorescence signals.

[0067] Example 4

[0068] The following synthetic route was used to prepare photosensitizing dyes 1-4:

[0069]

[0070] Synthesis of photosensitizing dyes 1-4:

[0071] 3.0 mmol of compound A and 10.0 mmol of 1,2,3,3-tetramethyl-3H-indolium iodide were added to a round-bottom flask containing 30.0 mL of N,N-dimethylformamide, and the mixture was stirred and evenly mixed. Then, 1.5 mL of trimethylsilyl chloride was added, and the mixture was stirred and heated to reflux for 3.0 h before the reaction was stopped. The mixture was poured into ice water to precipitate. A blue solid crude product was obtained by suction filtration. The blue solid powder compound, i.e., photosensitizer 1-4, was separated by column chromatography in a yield of 52%. 1 H NMR(600MHz,DMSO-d6)δ8.55(d,J=8.2Hz,1H),8.42(s,1H),8.39(s,1H),8.11( t,J=7.8Hz,1H),7.96(d,J=9.1Hz,1H),7.82(t,J=7.7Hz,1H),7.73(d,J=7.3Hz ,3H),7.69–7.67(m,1H),7.54(d,J=8.0Hz,2H),7.48(t,J=7.6Hz,2H),7.37(t, J=7.4Hz,2H),7.16(s,1H),6.49(d,J=14.6Hz,2H),3.67(s,6H),1.79(s,12H).

[0072] Detection test of the response ability of photosensitizing dyes 1-4 to mtDNA:

[0073] The above-synthesized photosensitizing dyes 1-4 were added to a PBS buffer solution (pH=7.2) at a final concentration of 5.0 μM, and then DNA (0-10.16 μg / mL) was continuously added to the solution, and its ultraviolet absorption and fluorescence emission spectra were tested in turn. The test results are as follows: Figure 8 As shown in the figure, the absorbance at 632nm decreased significantly with the increase of mtDNA content. At the same time, a new fluorescence signal appeared at 700nm, which increased successively with the increase of mtDNA content. This result shows that photosensitizing dyes 1-4 can also bind to mtDNA and can feedback its content changes through obvious changes in fluorescence signals.

[0074] The above embodiments describe the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for illustrating the principles of the present invention. Without departing from the scope of the principles of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of protection of the present invention.

Claims

1. A type of mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer, characterized in that Its general structural formula is shown in Formula I: In formula I, R1 and R2 are respectively -H or one of the following groups: Where m is -H, -Cl, -Br or -I, and x is -CH3, -OH, -NH2, -COOH, -SO3 - , -Cl, -Br or -I, y is O, S or Se, and n is an integer between 0 and 4; In formula I, K and L are -CO-, -Cp=CH-(CH=CH) respectively. n -or-Cp=CH-(CH=CH) n -CH=Cp-; Where p is -CH3, -CN, -Br, -Cl, -H, -OH, -NH2, -(CH2)nNH2 or -SO3 - , n is an integer between 0 and 8.

2. The mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer according to claim 1, characterized in that It includes compounds of the following structure:

3. A method for preparing the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer according to claim 2, characterized in that The specific preparation steps are: Step S1: under acidic conditions, salicylamide, acetone and acetic anhydride are first added to a reaction solvent, and then an oxidant is added and an oxidation reaction is carried out at 0-100° C. to obtain compound A, the structural formula of which is: The oxidant is one or more of potassium permanganate, hydrogen peroxide, sodium hypochlorite, Vilsmeier reagent, potassium dichromate, sodium dichromate, nitric acid, peracetic acid or chromic acid; Step S2: heating the compound A obtained in step S1 and 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide or 1,2,3,3-tetramethyl-3H-indolium iodide under reflux to obtain the compounds represented by formula 1-1 to formula 1-4, i.e., mitochondrial DNA-targeted 4-aminobenzopyran photosensitizer dyes.

4. The method for preparing the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye according to claim 3, characterized in that: The molar ratio of salicylamide, acetone and acetic anhydride in step S1 is 1:1:1-1:2:

2.

5. The method for preparing the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye according to claim 3, characterized in that: The reaction solvent in step S1 is one or more of dichloromethane, ethanol, methanol, acetone, 1,4-dioxane, propylene glycol, ethyl acetate, acetic acid, sulfuric acid, acetic anhydride, sodium hydroxide aqueous solution or N,N-dimethylformamide.

6. The method for preparing the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye according to claim 3, characterized in that: In step S2, the molar ratio of compound A to 5-iodo-1,2,3,3-tetramethyl-3H-indolium iodide or 1,2,3,3-tetramethyl-3H-indolium iodide is 1:0.5-1:

4.

7. The method for preparing the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye according to claim 3, characterized in that: The reaction solvent in step S2 is one or more of dichloromethane, ethanol, methanol, acetone, 1,4-dioxane, propylene glycol, ethyl acetate, acetic acid, sulfuric acid, piperidine or N,N-dimethylformamide.

8. Use of the mitochondrial DNA-targeted 4-aminobenzopyran photosensitizing dye according to claim 1 or 2 in the preparation of a mitochondrial DNA photosensitizing imaging agent.

9. Use of the mitochondrial DNA targeted 4-aminobenzopyran photosensitizer according to claim 1 or 2 in the preparation of a mitochondrial DNA targeted tumor photodynamic therapy photosensitizer.

Images