Near-infrared iridium complex, preparation method thereof and application of near-infrared iridium complex in preparation of photodynamic therapy preparation

Abstract

The invention belongs to the technical field of photosensitizers, and provides a near-infrared iridium complex, a preparation method thereof and application of the near-infrared iridium complex in preparation of a photodynamic therapy preparation. According to the near-infrared iridium complex, 1-(benzo [b] thiophene-2-yl) isoquinoline-4-formonitrile is introduced, and the introduction of cyano groups can significantly reduce an energy gap, so that the iridium complex emits red shift, and the tissue penetrating power is improved; meanwhile, a 2-(3, 5-dimethoxyphenyl)-1-phenyl-1H-imidazo [4, 5-f] [1, 10] phenanthroline ring structure is combined, and a 2-dimethoxyphenyl electron donating group is introduced, so that charge transfer of the near-infrared iridium complex is effectively promoted, the triplet-state service life of the complex is prolonged, and the capability of generating reactive oxygen species (ROS) of the near-infrared iridium complex can be effectively improved. The maximum absorption wavelength of the near-infrared iridium complex is 544 nm, the maximum emission wavelength of the near-infrared iridium complex is 720 nm, and the limitation of tissue penetration can be effectively overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of photosensitizers, and in particular to a near-infrared iridium complex, a preparation method thereof, and an application thereof in preparing a photodynamic therapy preparation. Background Art

[0002] Since the iridium (III) complex has a triplet excited state, the electron transfer between the triplet excited state and the biological substrate molecules, or the energy transfer with the surrounding molecular oxygen, induces the generation of type I reactive oxygen species (ROS) such as superoxide anion radical (O2 ·- ) and hydroxyl radicals ( · OH) or type II reactive oxygen species singlet oxygen ( 1 O2), effectively damaging cells. Therefore, iridium complexes can be used as photosensitizers for photodynamic therapy, killing cancer cells directly or indirectly under light irradiation.

[0003] However, traditional iridium complexes exhibit problems such as insufficient tissue penetration depth, which limits their application in PDT. Summary of the Invention

[0004] In view of this, the object of the present invention is to provide a near-infrared iridium complex and its preparation method and application in the preparation of photodynamic therapy preparations. The near-infrared iridium complex of the present invention has strong tissue penetrating power.

[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 near-infrared iridium complex having a structure shown in Formula I:

[0007]

[0008] The present invention also provides a method for preparing the near-infrared iridium complex described in the above technical solution, comprising the following steps:

[0009] Mixing benzothiophene-2-boronic acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, a catalyst, and a first solvent to perform a carbon-nitrogen coupling reaction to obtain a ligand having a structure shown in Formula II;

[0010] The ligand of the structure shown in formula II, an iridium salt and a second solvent are mixed to perform a first coordination reaction to obtain an iridium complex intermediate of the structure shown in formula III; the iridium salt includes iridium trichloride;

[0011] Mixing 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and a third solvent to carry out a condensation reaction to obtain a ligand having a structure shown in Formula IV;

[0012] The iridium complex intermediate of the structure represented by formula III, the ligand of the structure represented by formula IV and the fourth solvent are mixed to carry out a second coordination reaction to obtain a near-infrared iridium complex of the structure represented by formula I;

[0013]

[0014] Preferably, the catalyst comprises tetrakis(triphenylphosphine)palladium, and the usage ratio of the benzothiophene-2-boric acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, tetrakis(triphenylphosphine)palladium and the first solvent is 712.0 mg:754.4-792.2 mg:1105.67 mg:231.1 mg:80-120 mL.

[0015] Preferably, the temperature of the carbon-nitrogen coupling reaction is 75-110° C., and the time is 18-24 hours; the carbon-nitrogen coupling reaction is carried out under a nitrogen protective atmosphere.

[0016] Preferably, the usage ratio of the ligand having the structure represented by formula II, the iridium salt and the second solvent is 572.1-600.7 mg:597.2 mg:100 mL.

[0017] Preferably, the temperature of the first coordination reaction is 100-110° C., the time is 18-24 hours, and the first coordination reaction is carried out under a nitrogen protective atmosphere.

[0018] Preferably, the usage ratio of the 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and the third solvent is 332.1 mg:420.4 mg:186.1 μL:770.5 mg:20-30 mL.

[0019] Preferably, the condensation reaction temperature is 75-85° C., and the time is 5-8 hours; the condensation reaction is carried out under a nitrogen protective atmosphere.

[0020] Preferably, the usage ratio of the iridium complex intermediate represented by formula III, the ligand represented by formula IV, and the fourth solvent is 79.8 mg:43.2 mg:50-70 mL;

[0021] The temperature of the second coordination reaction is 70-75° C., and the time is 18-24 hours; the second coordination reaction is carried out under a nitrogen protective atmosphere.

[0022] The present invention also provides the use of the near-infrared iridium complex described in the above technical solution or the near-infrared iridium complex prepared by the preparation method described in the above technical solution in the preparation of photodynamic therapy preparations.

[0023] The present invention provides a near-infrared iridium complex having a structure shown in Formula I:

[0024]

[0025] The near-infrared iridium complex of the present invention introduces 1-(Benzo[b]thiophen-2-yl)isoquinoline-4-carbonitrile (PTCN), which can significantly reduce the energy gap, causing the iridium complex to red-shift its luminescence and lengthen its absorption wavelength, thereby improving tissue penetration. At the same time, the combination of 2-(3,5-dimethoxyphenyl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline ring structure (DMIP) can promote charge transfer in the complex and extend the triplet lifetime of the complex, thereby effectively increasing the ability of the near-infrared iridium complex to generate reactive oxygen species (ROS). In the present invention, the chemical formula of the near-infrared iridium complex is: [(PTCN)2-Ir-DMIP] + .

[0026] The present invention introduces a cyano group into the main ligand, which can reduce the lowest unoccupied molecular orbital (LUMO) of the molecule, causing the molecular spectrum to red-shift and the absorption wavelength to lengthen, thereby improving tissue penetration. At the same time, the introduction of a 2-bismethoxyphenyl electron-donating group into the imidazole ring ligand effectively promotes charge transfer in the complex and prolongs the triplet state lifetime of the complex, thereby effectively improving the ability of the near-infrared iridium complex to generate reactive oxygen species (ROS). The emission spectrum of the near-infrared iridium complex of the present invention is located in the near-infrared region; under the conditions of 400-800nm light, it can generate type I reactive oxygen singlet oxygen ( 1 O2) and type II reactive oxygen species superoxide anion radicals (O2 ·- ) and hydroxyl radicals (·OH), and can generate singlet oxygen and superoxide anion radicals in cells, causing cancer cells to undergo apoptosis. It has the ability to kill cancer cells with photodynamic force, providing an option for photodynamic therapy. The near-infrared iridium complex of the present invention has a maximum absorption wavelength of 544nm and a maximum emission wavelength of 720nm, which can effectively overcome the limitation of tissue penetration. The data in the examples show that the near-infrared iridium complex of the present invention [(PTCN)2-Ir-DMIP] + It has the ability to generate both type I and type II reactive oxygen species of PDT and can effectively generate 1 O2 and O2 ·- , inducing apoptosis of cancer cells, which promotes the improvement of PDT effect in the tumor hypoxic environment.

[0027] The present invention also provides a method for preparing the near-infrared iridium complex described in the above technical solution. The preparation method provided by the present invention is simple to operate and is easy to industrialize and produce. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 The absorption spectrum and phosphorescence emission spectrum of the near-infrared iridium complex prepared in Example 1;

[0029] Figure 2 Absorption spectra of the near-infrared iridium complex prepared in Example 1 plus 9,10-anthryl-bis(methylene)dimalonic acid (ABDA) under different illumination times;

[0030] Figure 3 The fluorescence emission spectra of the near-infrared iridium complex prepared in Example 1 and dihydrorhodamine (DHR 123) under different illumination times;

[0031] Figure 4 The fluorescence emission spectra of the near-infrared iridium complex prepared in Example 1 plus hydroxyphenylfluorescein (HPF) under different illumination times;

[0032] Figure 5 The near-infrared iridium complex prepared in Example 1 plus the singlet oxygen fluorescence probe SOSG in MCF-7 cells under different illumination times 1 Fluorescence imaging of O2 content;

[0033] Figure 6 The near-infrared iridium complex prepared in Example 1 plus DHR 123 under different illumination times is O2 in MCF-7 cells ·- Fluorescence imaging of the content;

[0034] Figure 7 Fluorescence imaging of MCF-7 cell activity under different illumination times of the near-infrared iridium complex prepared in Example 1 plus calcein AM;

[0035] Figure 8 Fluorescence imaging of early apoptosis of MCF-7 cells induced by the near-infrared iridium complex prepared in Example 1 and the apoptosis detection reagent Annexin V-FITC under different illumination times;

[0036] Figure 9 These are fluorescence imaging images of the near-infrared iridium complex prepared in Example 1 combined with the mitochondrial membrane potential detection reagent JC-1 inducing a decrease in mitochondrial membrane potential in MCF-7 cells under different illumination times. DETAILED DESCRIPTION

[0037] The present invention provides a near-infrared iridium complex having a structure shown in Formula I:

[0038]

[0039] The present invention introduces 1-(Benzo[b]thiophen-2-yl)isoquinoline-4-carbonitrile (PTCN) to significantly reduce the energy gap, red-shifting the luminescence of the near-infrared iridium complex, lengthening the absorption wavelength, and improving tissue penetration. Simultaneously, the combination of the 2-(3,5-dimethoxyphenyl)-1-phenyl-1H-imidazo[4,5-f][1,10]phenanthroline ring structure (DMIP) and the introduction of a 2-dimethoxyphenyl electron-donating group promotes charge transfer in the complex and prolongs the triplet lifetime of the complex, thereby effectively increasing the near-infrared iridium complex's ability to generate reactive oxygen species (ROS).

[0040] In the present invention, the chemical formula of the near-infrared iridium complex is: [(PTCN)2-Ir-DMIP] + .

[0041] The near-infrared iridium complex provided by the present invention can generate type I reactive oxygen species in both solution and tumor cells under the condition of 400-800nm light. 1 O2 and type II reactive oxygen species O2 ·- It has a more red-shifted excitation wavelength (544nm), a larger Stokes shift (176nm), and near-infrared luminescence. Therefore, it has the advantages of minimal photodamage, strong tissue penetration, and low background autofluorescence in biological imaging. Furthermore, its ability to photodynamically kill cancer cells opens up the possibility of photodynamic therapy.

[0042] The present invention also provides a method for preparing the near-infrared iridium complex described in the above technical solution, comprising the following steps:

[0043] Mixing benzothiophene-2-boronic acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, a catalyst, and a first solvent to perform a carbon-nitrogen coupling reaction to obtain a ligand having a structure shown in Formula II;

[0044] The ligand of the structure shown in formula II, an iridium salt and a second solvent are mixed to perform a first coordination reaction to obtain an iridium complex intermediate of the structure shown in formula III; the iridium salt includes iridium trichloride;

[0045] Mixing 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and a third solvent to carry out a condensation reaction to obtain a ligand having a structure shown in Formula IV;

[0046] The iridium complex intermediate of the structure represented by formula III, the ligand of the structure represented by formula IV and the fourth solvent are mixed to carry out a second coordination reaction to obtain a near-infrared iridium complex of the structure represented by formula I;

[0047]

[0048] Unless otherwise specified, the raw materials used in the present invention are preferably commercially available products.

[0049] The present invention mixes benzothiophene-2-boric acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, a catalyst and a first solvent, and performs a carbon-nitrogen coupling reaction to obtain a ligand with a structure shown in formula II.

[0050] In the present invention, the catalyst preferably includes tetrakis(triphenylphosphine)palladium (Pd(PPh3)4).

[0051] In the present invention, the first solvent preferably includes one or more of ethanol, toluene and water, and is further preferably a mixed solvent of ethanol, toluene and water. The volume ratio of ethanol, toluene and water in the mixed solvent is preferably 1-2:6-8:2, and specifically preferably 1:7:2.

[0052] In the present invention, the usage ratio of the benzothiophene-2-boric acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, tetrakis(triphenylphosphine)palladium and the first solvent is preferably 712.0 mg:754.4-792.2 mg:1105.7 mg:231.1 mg:80-120 mL.

[0053] In the present invention, the temperature of the carbon-nitrogen coupling reaction is preferably 75-110°C, specifically preferably 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C or 110°C; the time is preferably 18-24h, specifically preferably 18h, 20h, 22h or 24h; the carbon-nitrogen coupling reaction is preferably carried out under a nitrogen protective atmosphere.

[0054] After the carbon-nitrogen coupling reaction, the present invention preferably further comprises: extracting the obtained carbon-nitrogen coupling reaction system to obtain an extract phase; after the extract phase is spin-dried, column chromatography purification (referred to as the first column chromatography purification) is performed to obtain the ligand of the structure shown in Formula II. In the present invention, the extractant of the extraction is preferably ethyl acetate, and the present invention does not specifically limit the conditions for the spin-drying, as long as the extractant can be completely removed. In the present invention, the developing agent of the column chromatography purification is preferably a mixed solvent of petroleum ether and ethyl acetate, and the volume ratio of petroleum ether and ethyl acetate in the mixed solvent of petroleum ether and ethyl acetate is preferably 20:1 to 10:1, specifically preferably 20:1, 15:1 or 10:1.

[0055] After obtaining the ligand of formula II, the present invention mixes the ligand of formula II, an iridium salt and a second solvent to perform a first coordination reaction to obtain an iridium complex intermediate of formula III; the iridium salt includes iridium trichloride.

[0056] In the present invention, the iridium trichloride is preferably iridium trichloride trihydrate.

[0057] In the present invention, the second solvent is preferably a mixed solvent of 2-ethoxyethanol and water, and the volume ratio of 2-ethoxyethanol to water in the mixed solvent of 2-ethoxyethanol and water is preferably 2.5 to 3:1.

[0058] In the present invention, the usage ratio of the ligand having the structure represented by formula II, the iridium salt and the second solvent is preferably 572.1-600.7 mg:597.2 mg:100 mL.

[0059] In the present invention, the temperature of the first coordination reaction is preferably 100-110°C, specifically preferably 100°C, 105°C or 110°C; the time is preferably 18-24h, specifically preferably 18h, 20h, 22h or 24h, and the first coordination reaction is preferably carried out under a nitrogen protective atmosphere.

[0060] After the first coordination reaction, the present invention preferably further comprises: performing solid-liquid separation on the obtained first coordination reaction system to obtain a solid; and sequentially washing and drying the solid to obtain the iridium complex intermediate having the structure represented by Formula III. In the present invention, the solid-liquid separation is preferably performed by suction filtration. In the present invention, the washing preferably comprises sequentially washing with water and washing with anhydrous ethanol. The present invention does not impose any specific restrictions on the amount of reagents used and the number of times the water and anhydrous ethanol washes are performed, as long as the impurities can be completely removed.

[0061] The present invention mixes 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and a third solvent, and performs a condensation reaction to obtain a ligand with a structure shown in formula IV.

[0062] In the present invention, the third solvent preferably includes glacial acetic acid.

[0063] In the present invention, the usage ratio of the 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and the third solvent is preferably 332.1 mg:420.4 mg:186.1 μL:770.5 mg:20-30 mL.

[0064] In the present invention, the condensation reaction temperature is preferably 75-85°C, specifically preferably 75°C, 80°C, or 85°C; the reaction time is preferably 5-8 hours, specifically preferably 5 hours, 6 hours, 7 hours, or 8 hours; the condensation reaction is preferably carried out under a nitrogen atmosphere. In the present invention, the condensation reaction is preferably carried out under reflux conditions.

[0065] After the condensation reaction, the present invention preferably further comprises: neutralizing the resulting condensation reaction system, performing solid-liquid separation, and drying the resulting solid to obtain the ligand having the structure represented by Formula IV. In the present invention, the neutralizing agent used in the neutralization is preferably sodium bicarbonate. The amount of sodium bicarbonate used is not specifically limited, as long as it can neutralize the condensation reaction system; the neutralization is preferably performed in an ice-water bath. In the present invention, the solid-liquid separation method is preferably suction filtration. The temperature and time of the drying are not specifically limited, as long as the solid can be dried.

[0066] After obtaining the iridium complex intermediate of the structure shown in formula III and the ligand of the structure shown in formula IV, the present invention mixes the iridium complex intermediate of the structure shown in formula III, the ligand of the structure shown in formula IV and a fourth solvent to perform a second coordination reaction to obtain a near-infrared iridium complex of the structure shown in formula I.

[0067] In the present invention, the fourth solvent is preferably a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol in the mixed solvent of dichloromethane and methanol is preferably 1:1.

[0068] In the present invention, the usage ratio of the iridium complex intermediate represented by formula III, the ligand represented by formula IV and the fourth solvent is preferably 79.8 mg:43.2 mg:50-70 mL.

[0069] In the present invention, the temperature of the second coordination reaction is preferably 70-75° C., and the time is preferably 18-24 h, specifically preferably 18 h, 20 h, 22 h or 24 h; the second coordination reaction is preferably carried out under a nitrogen protective atmosphere.

[0070] After the second coordination reaction, the present invention preferably further comprises: subjecting the obtained second coordination reaction system to column chromatography purification (referred to as second column chromatography purification), wherein the developing solvent for the second column chromatography purification is preferably a mixed solvent of dichloromethane and methanol, and the volume ratio of dichloromethane to methanol in the mixed solvent of dichloromethane and methanol is preferably 30:1 to 10:1, specifically preferably 30:1, 25:1, 20:1, 15:1 or 10:1.

[0071] In the present invention, the preparation formula of the near-infrared iridium complex is as follows:

[0072]

[0073] The present invention also provides the use of the near-infrared iridium complex described in the above technical solution or the near-infrared iridium complex prepared by the preparation method described in the above technical solution in the preparation of photodynamic therapy preparations.

[0074] The present invention does not specifically limit the application mode of the near-infrared iridium complex, and those skilled in the art can configure it according to actual needs.

[0075] The near-infrared iridium complex provided by the present invention, its preparation method and its application in the preparation of photodynamic therapy preparations are described in detail below with reference to the examples, but they should not be construed as limiting the scope of protection of the present invention.

[0076] Example 1

[0077] Benzothiophene-2-boric acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, tetrakis(triphenylphosphine)palladium and a first solvent were mixed in a ratio of 712.0 mg:792.2 mg:1105.6 mg:231.1 mg:80 mL, where the first solvent was a mixed solvent of ethanol, toluene and water (the volume ratio of ethanol, toluene and water was 1:7:2). The temperature was 75° C., and a carbon-nitrogen coupling reaction was carried out under a nitrogen atmosphere for 24 hours. The obtained carbon-nitrogen coupling reaction system was extracted with ethyl acetate to obtain an ethyl acetate phase. The ethyl acetate in the ethyl acetate phase was dried, and then column chromatography was performed using a mixed solvent of petroleum ether and ethyl acetate in a volume ratio of 15:1 as a developing solvent to obtain a ligand with a structure shown in Formula II.

[0078] The ligand of the structure shown in formula II, iridium trichloride trihydrate and a second solvent (the volume ratio of 2-ethoxyethanol and water is 3:1) are mixed according to 600.7 mg:597.2 mg:100 mL, and a first coordination reaction is carried out at 110° C. for 24 hours. After the reaction, the obtained first coordination reaction system is filtered, rinsed with water and anhydrous ethanol to obtain a solid, and dried to obtain an iridium complex intermediate of the structure shown in formula III.

[0079] 3,4-Dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, and ammonium acetate were mixed in the ratio of 332.1 mg:420.4 mg:186.1 μL:770.5 mg, 20 mL of glacial acetic acid was added, and the mixture was refluxed under nitrogen for 5 h at 85° C. The resulting reaction solution was neutralized with sodium bicarbonate in ice water, and the solid was filtered and dried to obtain a ligand with the structure represented by Formula IV.

[0080] The iridium complex intermediate of the structure represented by formula III, the structure represented by formula IV and the fourth solvent (the volume ratio of dichloromethane and methanol is 1:1) are mixed at a ratio of 79.8 mg:43.2 mg:50 mL, and a second coordination reaction is carried out at 75°C under nitrogen protection for 24 hours; column chromatography is performed using a mixed solvent of dichloromethane and methanol with a volume ratio of 10:1 as a developing solvent to obtain a near-infrared iridium complex of the structure represented by formula I.

[0081] Characterization

[0082] 1) The ligand of the structure shown in Formula II prepared in Example 1 was characterized by nuclear magnetic resonance and mass spectrometry, and the obtained nuclear magnetic resonance data were: 1 HNMR (400 MHz, CDCl3) δ8.94 (s, 1H), 8.74 (d, J = 8.5 Hz, 1H), 8.28 (d, J = 8.3 Hz, 1H), 8.01-7.87 (m, 4H), 7.86-7.78 (m, 1H), 7.50-7.40 (m, 2H); Mass spectral characterization data: HRMS (ESI) C 18 H 10 N2S[M+H] + calcd:287.0638found:287.0648.

[0083] 2) The ligand of formula IV prepared in Example 1 was characterized by nuclear magnetic resonance and mass spectrometry. The obtained nuclear magnetic resonance data were: 1 HNMR (400 MHz, DMSO) δ9.16-8.79 (m, 3H), 7.88 (dd, J = 7.9, 4.3 Hz, 1H), 7.76 (dd, J = 16.5, 7.0 Hz, 5H), 7.48 (dd, J = 8.3, 4.0 Hz, 1H), 7.36 (d, J = 8.1 Hz, 1H), 6.74 (d, J = 1.9 Hz, 2H), 6.52 (s, 1H), 3.65 (s, 6H); Mass spectral characterization data: HRMS (ESI) C 27 H 20 N4O2[M+H] + calcd:433.1659found:433.1661.

[0084] 3) The near-infrared iridium complex of the structure shown in Formula I prepared in Example 1 was characterized by nuclear magnetic resonance and mass spectrometry, and the obtained nuclear magnetic resonance data were 1HNMR (400 MHz, MeOD) δ9.41 (d, J = 7.4 Hz, 2H), 9.21 (d, J = 15.4 Hz, 2H), 8.31 (s, 2H), 8.17 (s, 2H), 8.07 (s, 4H), 7.98-7.91 (m, 2H), 7.85 (s, 1H), 7.74 (s, 4H), 7.67 (s, 2H), 7.58 (s, 2H), 7.48-7.27 (m, 4H), 6.83 (s, 2H), 6.78 (s, 2H), 6.53 (s, 1H), 3.66 (s, 6H); Mass spectral characterization data: HRMS (ESI) C 63 H 38 N8O2S2Ir + calcd:1195.2183found:1195.2184.

[0085] Test Example 1

[0086] The steps for testing the absorption spectrum and phosphorescence emission spectrum of the near-infrared iridium complex prepared in Example 1 in PBS solution (pH=7.4) are as follows:

[0087] The near-infrared iridium complex prepared in Example 1 was dissolved in dimethyl sulfoxide (DMSO) to obtain a near-infrared iridium complex mother solution with a concentration of 10 mmol / L; 2 μL of the 10 mmol / L mother solution was dissolved in a PBS solution (pH = 7.4) to obtain a solution with a concentration of 10 μmol / L. The absorption spectrum was tested, and the maximum absorption peak was used as the excitation wavelength, and the emission spectrum at 600 nm to 900 nm was collected. The results are shown as follows: Figure 1 shown by Figure 1 It can be seen that the emission light (720 nm) of the near-infrared iridium complex prepared in Example 1 is in the near-infrared region (700 nm); the absorption spectrum shows that the absorption peak of the complex can be red-shifted to the visible light region, with a maximum absorption peak of about 544 nm.

[0088] Test Example 2

[0089] Test of the singlet oxygen generation ability of the near-infrared iridium complex prepared in Example 1 in aqueous solution:

[0090] Different volumes of 10 mmol / L near-infrared iridium complex mother solution were transferred into 2 mL of PBS solution (pH = 7.4), and the concentration of the near-infrared iridium complex was adjusted to obtain an absorbance of 0.2 at the maximum absorption wavelength. Then, 20 μL of 5 mmol / L 9,10-anthryl-bis(methylene)dimalonic acid (ABDA) solution was added, and the solution was illuminated with a xenon lamp at a wavelength of 400-800 nm. The changes in the absorption spectrum of ABDA at 350-410 nm were measured every 10 seconds using a UV-visible spectrometer.

[0091] The results obtained in the range of 0 to 100 seconds are as follows Figure 2 shown by Figure 2 It can be seen that with the increase of illumination time, the absorption value of ABDA in the ultraviolet absorption spectrum at 350-410nm decreases, which indicates that singlet oxygen reacts with ABDA, that is, the near-infrared iridium complex [(PTCN)2-Ir-DMIP] + Singlet oxygen is produced under light.

[0092] Test Example 3

[0093] The near-infrared iridium complex prepared in Example 1 is O2 in aqueous solution ·- Tests of production capacity:

[0094] To 2 mL of PBS solution (pH = 7.4), add 2 μL of a 10 mmol / L near-infrared iridium complex stock solution and 8 μL of a 5 mmol / L dihydrorhodamine (DHR 123) solution. Illuminate with a xenon lamp at a wavelength of 400-800 nm, and measure changes in the fluorescence spectrum of DHR 123 at 526 nm every 5 seconds using a fluorescence spectrometer.

[0095] The results obtained in the range of 0 to 100 seconds are as follows Figure 3 shown by Figure 3 It can be seen that with the increase of illumination time, the fluorescence intensity of DHR 123 at 526nm increases, which indicates that there is O2 ·- reacted with DHR 123, that is, the near-infrared iridium complex [(PTCN)2-Ir-DMIP] + O2 is produced under light ·- .

[0096] Test Example 4

[0097] Test of the ability of the near-infrared iridium complex prepared in Example 1 to generate ·OH in aqueous solution:

[0098] To 2 mL of PBS solution (pH = 7.4), add 2 μL of 10 mmol / L near-infrared iridium complex stock solution and 8 μL of 5 mmol / L hydroxyphenylfluorescein (HPF) solution. Irradiate with a xenon lamp of 400-800 nm wavelength, and measure the changes in the fluorescence spectrum of HPF at 515 nm every 30 s using a fluorescence spectrometer.

[0099] The results obtained in the range of 0 to 300 seconds are as follows Figure 4 shown by Figure 4It can be seen that with the increase of illumination time, the fluorescence intensity of HPF at 515nm increases, which indicates that ·OH reacts with HPF, that is, the near-infrared iridium complex [(PTCN)2-Ir-DMIP] + ·OH is produced under light.

[0100] Test Example 5

[0101] The near-infrared iridium complex prepared in Example 1 is active in tumor cells 1 Test of O2 production capacity:

[0102] a) Inoculate MCF-7 cells and allow them to adhere overnight;

[0103] b) MCF-7 cells were treated with 10 μmol / L [(PTCN)2-Ir-DMIP] + (DMSO / H2O=1 / 199, volume ratio) and incubated for 1 hour, then washed three times with PBS, and the MCF-7 cells composited with the near-infrared iridium complex were incubated with 10 μmol / L SOSG singlet oxygen fluorescence probe (PBS, pH=7.4) for 30 minutes; the incubated cells were irradiated with a solar simulator xenon lamp (400-800 nm) for 0 minutes, 5 minutes and 10 minutes respectively, and confocal fluorescence imaging was performed using a confocal laser scanning microscope with an excitation channel of 488 nm and a collection channel of 510-540 nm. The obtained fluorescence channel imaging results are shown in FIG. Figure 5 ;Depend on Figure 5 It can be seen that under dark conditions, no singlet oxygen fluorescence signal is generated in the cells. As the illumination time increases, the fluorescence in the MCF-7 cells gradually increases, indicating that the near-infrared iridium complex produces singlet oxygen under light conditions. 1 O2, and the longer the illumination time, 1 The more O2 is produced, the more it is. Furthermore, the bright field and superimposed field were used to confirm that the fluorescence signal came from the cells.

[0104] Test Example 6

[0105] The near-infrared iridium complex prepared in Example 1 is used to measure the O2 ·- Tests of production capacity:

[0106] a) Inoculate MCF-7 cells and allow them to adhere overnight;

[0107] b) MCF-7 cells were treated with 10 μmol / L [(PTCN)2-Ir-DMIP] +The cells were incubated with DMSO / H2O (DMSO / H2O=1 / 199, volume ratio) for 1 hour, then washed three times with PBS, and the MCF-7 cells complexed with the near-infrared iridium complex were incubated with 10 μmol / L DHR123 superoxide anion free radical fluorescent probe (PBS, pH=7.4) for 30 minutes; the incubated cells were irradiated with a solar simulator xenon lamp (400-800 nm) for 0 minutes, 1 minute, and 5 minutes in sequence, and confocal fluorescence imaging was performed using a confocal laser scanning microscope, with an excitation channel of 488 nm and a collection channel of 510-550 nm.

[0108] The fluorescence channel imaging results are shown in Figure 6 ;Depend on Figure 6 It can be seen that under dark conditions, no O2 is produced in the cells. ·- The fluorescence signal of MCF-7 cells gradually increased with the extension of illumination time, indicating that the near-infrared iridium complex produced O2 under illumination conditions. ·- , and the longer the illumination time, the higher the O2 ·- The more cells are generated, the more fluorescent signals are generated. And the bright field and superimposed field are used to confirm that the fluorescent signals come from cells.

[0109] Test Example 7

[0110] Photodynamic therapy detection of tumor cell apoptosis induced by the near-infrared iridium complex prepared in Example 1:

[0111] a) Inoculate MCF-7 cells and allow them to adhere overnight;

[0112] b) MCF-7 cells were divided into three groups and treated with 10 μmol / L [(PTCN)2-Ir-DMIP] + The cells were incubated with a solution (DMSO / H2O = 1 / 199, volume ratio) for 1 h, and then washed three times with PBS. After incubation, the cells were irradiated with a solar simulator xenon lamp (400-800 nm) for 0 min, 10 min, and 15 min, respectively. 2 μmol / L of the live cell detection kit CalceinAM was then added and incubated for 30 min. Confocal fluorescence imaging was performed using a confocal laser scanning microscope to monitor the fluorescence signal of CalceinAM. The excitation channel was 488 nm and the collection channel was 505-525 nm. The fluorescence channel imaging results are shown in the figure. Figure 7 ;Depend on Figure 7As can be seen, cells exhibit a strong fluorescence signal in the dark, but as the illumination time increases, the CalceinAM fluorescence intensity gradually decreases. This phenomenon indicates that the near-infrared iridium complex generates ROS under illumination, inducing cell death. As the illumination time increases, the fluorescence in the cells becomes weaker, indicating that the number of viable cells is decreasing and the photodynamic killing effect of the near-infrared iridium complex is leading to an increasing number of cell deaths. Further, bright field and superimposed field analysis confirmed that the fluorescence signal originated from the cells.

[0113] Test Example 8

[0114] Photodynamic therapy detection of tumor cell apoptosis induced by the near-infrared iridium complex prepared in Example 1:

[0115] a) Inoculate MCF-7 cells and allow them to adhere overnight;

[0116] b) MCF-7 cells were divided into three groups and treated with 10 μmol / L [(PTCN)2-Ir-DMIP] + The cells were incubated with a solution (DMSO / H2O = 1 / 199, volume ratio) for 1 hour, then washed three times with PBS. After incubation, the cells were irradiated with a solar simulator xenon lamp (400-800 nm) for 0 min, 5 min, and 10 min, and then a buffer solution containing 5 μL Annexin V-FITC was added and incubated for 30 min in each group of cells. Confocal fluorescence imaging was performed using a confocal laser scanning microscope to monitor the fluorescence signal of Annexin V-FITC. The excitation channel was 488 nm and the collection channel was 505-525 nm. The fluorescence channel (FL) imaging results are shown in Figure 2. Figure 8 ;Depend on Figure 8 As can be seen, the cells exhibit no fluorescence signal in the dark, but the fluorescence intensity gradually increases with increasing illumination time. This phenomenon suggests that the near-infrared iridium complex generates ROS under illumination, inducing early cell apoptosis. Furthermore, as illumination time increases, the photodynamic killing effect of the near-infrared iridium complex leads to an increasing number of early apoptosis. Furthermore, bright field and superimposed field images confirm that the fluorescence signal originates from the cells.

[0117] Test Example 9

[0118] Photodynamic therapy detection of tumor cell mitochondrial membrane potential reduction induced by the near-infrared iridium complex prepared in Example 1:

[0119] a) Inoculate MCF-7 cells and allow them to adhere overnight;

[0120] b) MCF-7 cells were divided into two groups and treated with 10 μmol / L [(PTCN)2-Ir-DMIP] +The cells were incubated with a solution (DMSO / H2O = 1 / 199, volume ratio) for 1 hour, then washed three times with PBS. After incubation, the cells were irradiated with a solar simulator xenon lamp (400-800 nm) for 0 min and 10 min, and then a buffer solution containing 5 μL JC-1 was added and incubated for 30 min in each group of cells. Confocal fluorescence imaging was performed using a confocal laser scanning microscope to monitor the fluorescence signal of JC-1. The excitation channel was 515 nm, the collection channel 1 was 530-660 nm, and the collection channel 2 was 580-640 nm. The fluorescence channel imaging results are shown in Figure 9 ;Depend on Figure 9 It can be seen that in the dark, the red fluorescence is more prominent in the red-green fluorescence ratio of cells. However, as the illumination time increases, the red fluorescence becomes weaker and the green fluorescence becomes more prominent, indicating that the mitochondrial membrane potential of the cells is decreasing. This phenomenon indicates that the near-infrared iridium complex generates ROS under illumination, inducing a decrease in the mitochondrial membrane potential of the cells. The fluorescence signal is confirmed to come from the cells through bright field and superimposed field.

[0121] 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 near-infrared iridium complex, characterized in that Having the structure shown in formula I:

2. The method for preparing the near-infrared iridium complex according to claim 1, wherein The following steps are involved: Mixing benzothiophene-2-boronic acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, a catalyst, and a first solvent to perform a carbon-nitrogen coupling reaction to obtain a ligand having a structure shown in Formula II; The ligand of the structure shown in formula II, an iridium salt and a second solvent are mixed to perform a first coordination reaction to obtain an iridium complex intermediate of the structure shown in formula III; the iridium salt includes iridium trichloride; Mixing 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and a third solvent to carry out a condensation reaction to obtain a ligand having a structure shown in Formula IV; The iridium complex intermediate of the structure represented by formula III, the ligand of the structure represented by formula IV and the fourth solvent are mixed to carry out a second coordination reaction to obtain a near-infrared iridium complex of the structure represented by formula I; 3. The preparation method according to claim 2, characterized in that The catalyst includes tetrakis(triphenylphosphine)palladium, and the usage ratio of the benzothiophene-2-boric acid, 1-chloro-4-cyanoisoquinoline, potassium carbonate, tetrakis(triphenylphosphine)palladium and the first solvent is 712.0 mg:754.4-792.2 mg:1105.7 mg:231.1 mg:80-120 mL.

4. The preparation method according to claim 2 or 3, characterized in that The temperature of the carbon-nitrogen coupling reaction is 75-110° C., and the time is 18-24 hours; the carbon-nitrogen coupling reaction is carried out under a nitrogen protective atmosphere.

5. The preparation method according to claim 2, characterized in that The usage ratio of the ligand of the structure represented by formula II, the iridium salt and the second solvent is 572.1-600.7 mg:597.2 mg:100 mL.

6. The preparation method according to claim 2 or 5, characterized in that The temperature of the first coordination reaction is 100-110° C., the time is 18-24 hours, and the first coordination reaction is carried out under a nitrogen protective atmosphere.

7. The preparation method according to claim 2, characterized in that The usage ratio of the 3,4-dimethoxybenzaldehyde, 1,10-phenanthroline-5,6-dione, aniline, ammonium acetate and the third solvent is 332.1 mg:420.4 mg:186.1 μL:770.5 mg:20-30 mL.

8. The preparation method according to claim 2 or 7, characterized in that The condensation reaction is carried out at a temperature of 75 to 85° C. and for a time of 5 to 8 hours. The condensation reaction is carried out under a nitrogen protective atmosphere.

9. The preparation method according to claim 2, characterized in that The amount ratio of the iridium complex intermediate represented by formula III, the ligand represented by formula IV and the fourth solvent is 79.8 mg:43.2 mg:50-70 mL; The temperature of the second coordination reaction is 70-75° C., and the time is 18-24 hours; the second coordination reaction is carried out under a nitrogen protective atmosphere.

10. Use of the near-infrared iridium complex according to claim 1 or the near-infrared iridium complex prepared by the preparation method according to any one of claims 2 to 9 in the preparation of photodynamic therapy preparations.

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