An iridium complex, its preparation method, and its application in the treatment of neuromas.

Abstract

This invention discloses an iridium complex, its preparation method, and its application in the treatment of neuromas. The iridium complex has the following structure: The iridium complex of this invention is a near-infrared fluorescent iridium complex, which exhibits a strong photodynamic therapeutic effect on the mouse neuroma cell line (Neuro-2a cells). Under light irradiation, it strongly inhibits the growth and proliferation of mouse neuroma cells (IC50). 50 The concentration was 0.05 μM, while under dark conditions, its cytotoxicity was only 87.5 μM, and the phototherapy index (PI) was as high as 1750. This is of great significance for the research of metal drugs for the treatment of neuromas.

Description

Technical Field

[0001] This invention relates to the field of medicinal chemistry, and in particular to an iridium complex, its preparation method, and its application in the treatment of neuromas. Background Technology

[0002] Neuroblastoma is an embryonic malignant tumor of the sympathetic nervous system caused by neuroblasts (immature nerve cells). In the developing embryo, these cells invade, migrate along neural axes, and fill sympathetic ganglia, adrenal medulla, and other sites. The distribution pattern of these cells is related to the location of primary neuroblastoma. Neuroblastoma ranks third among childhood cancers and is a major life-threatening malignant tumor in children. Early diagnosis is difficult, it has a high degree of malignancy, and it metastasizes rapidly; therefore, the exploration of new therapies is urgently needed for the treatment of neuroblastoma.

[0003] Photodynamic therapy (PDT) for neuromas is currently a major research focus. Researchers previously discovered that when brain tumor cells absorb a hematoporphyrin molecule, exposure to high-intensity lasers kills the cells. Treatment methods based on this theory have been developed in some areas. Recent reports of clinical trial results in newly diagnosed high-grade glioma patients show even greater success, indicating the immense potential of PDT in treating neuromas. However, despite these advances, challenges and unresolved issues remain. For example, PDT requires a hematoporphyrin molecule that can be selectively absorbed by tumor cells. While some hematoporphyrin molecules have been researched and developed, further research is needed to find more effective molecules. Furthermore, the treatment process requires the use of high-intensity lasers to activate the hematoporphyrin molecules, demanding precise laser control to ensure the safety and effectiveness of the treatment.

[0004] Therefore, developing new drugs for photodynamic therapy of patients with neuromas is of great significance. Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an iridium complex, which shows promising application potential in the treatment of neuromas.

[0006] The present invention also proposes a method for preparing the above-mentioned iridium complex.

[0007] The present invention also proposes applications of the above-mentioned iridium complexes.

[0008] According to one aspect of the present invention, an iridium complex is provided, the structural formula of which is shown below:

[0009]

[0010] According to a preferred embodiment of the present invention, at least the following beneficial effects are achieved: Compared with small organic molecules, the transition metal iridium complex of the present invention has advantages such as a larger Stokes shift, stronger spin coupling, higher luminescence efficiency, longer phosphorescence lifetime, high triplet exciton generation efficiency, and simple and tunable color, and can be used as an effective photosensitizer (PS) in photodynamic therapy (PDT). The iridium complex of the present invention is a near-infrared fluorescent iridium complex, which has a strong photodynamic therapeutic effect on the mouse neuroma cell line (Neuro-2a cells). Under light irradiation, it has a strong ability to inhibit the growth and proliferation of mouse neuroma cells (IC50). 50 The concentration was 0.05 μM, while under dark conditions, its cytotoxicity was only 87.5 μM, and the phototherapy index (PI) was as high as 1750. This is of great significance for the research of metal drugs for the treatment of neuromas.

[0011] According to another aspect of the present invention, a method for preparing the above-mentioned iridium complex is provided, comprising the following steps:

[0012] S1, react 2-phenylpyridine (bpy) with IrCl3 to generate iridium(III)μ-Cl-bridged dimer;

[0013] S2. The iridium(III)μ-Cl-bridged dimer is reacted with 5-bromo-2,2'-bipyridine (bpy-Br) to generate an iridium complex precursor;

[0014] S3 is obtained by reacting an iridium complex precursor with 2,5-di(2-ethylhexyl)-3,6-di(5-(trimethyltin)thiophen-2-yl)pyrrolo[3,4-c]pyrrolo-1,4-(2H,5H)-dione.

[0015] The preparation method according to a preferred embodiment of the present invention has at least the following beneficial effects: the preparation process of the present invention is simple, easy to operate, and has good prospects for industrial application.

[0016] In some embodiments of the present invention, the reaction conditions of step S1 include at least one of the following conditions:

[0017] (1) The reaction is carried out in a mixed solvent system of 2-ethoxyethanol (also known as ethylene glycol ethyl ether) and water; preferably, the volume ratio of 2-ethoxyethanol to water is 3:1;

[0018] (2) The reaction temperature is 50-100℃;

[0019] (3) The reaction time is 8-10 hours;

[0020] (4) The molar ratio of 2-phenylpyridine (bpy) to IrCl3 is 2:1.

[0021] In some embodiments of the present invention, the reaction conditions of step S2 include at least one of the following conditions:

[0022] (1) The reaction is carried out in a mixed solvent system of chloroform and methanol; preferably, the volume ratio of chloroform to methanol is 2:1.

[0023] (2) The reaction temperature is 50-100℃; preferably 60℃;

[0024] (3) The reaction time is 8-14 hours; preferably 12 hours.

[0025] (4) The molar ratio of iridium(III)μ-Cl-bridged dimer to 5-bromo-2,2'-bipyridine (bpy-Br) is 1:2.

[0026] In some embodiments of the present invention, the reaction conditions of step S3 include at least one of the following conditions:

[0027] (1) The reaction is carried out under a protective atmosphere; preferably, the protective atmosphere is argon.

[0028] (2) The reaction was carried out in an N,N-dimethylformamide solvent system;

[0029] (3) The reaction temperature is 100-135℃; preferably 110-120℃; more preferably 115℃;

[0030] (4) The reaction time is 18-24 h; preferably 18-22 h; more preferably 20 h;

[0031] (5) The molar ratio of the iridium complex precursor to 1,3-bis(2-ethylhexyl)-5,7-bis(5-(trimethyltinyl)thiophen-2-yl)-4H,8H-benzo[1,2-c:4,5-c']dithiophene-4,8-dione is 2:1;

[0032] (6) The reaction is carried out under the catalysis of a catalyst, wherein the catalyst comprises tetra(triphenylphosphine)palladium; preferably, the molar ratio of the catalyst to the iridium complex precursor is 2:0.1.

[0033] According to another aspect of the present invention, the use of the above-mentioned iridium complex in the preparation of antineuroma drugs is proposed.

[0034] The application of a preferred embodiment of the present invention has at least the following beneficial effects: the present invention has good application prospects in the field of preparation of anti-neuroma drugs.

[0035] In some embodiments of the present invention, the antineuroma drug is a near-infrared photocatalytically activated antitumor drug.

[0036] According to another aspect of the present invention, an antineuroma drug is provided, wherein the active ingredient of the drug comprises the above-mentioned iridium complex.

[0037] In some embodiments of the present invention, the antineuroma drug is an antineuroma drug for mice.

[0038] In some embodiments of the present invention, the mouse neuroma cell line is Neuro-2a.

[0039] According to another aspect of the present invention, an antitumor metal photosensitizer is provided, wherein the active ingredient of the antitumor metal photosensitizer comprises the above-mentioned iridium complex.

[0040] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0041] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0042] Figure 1 The ultraviolet absorption spectrum of the iridium complex prepared in the embodiments of the present invention;

[0043] Figure 2 The fluorescence emission spectrum of the iridium complex prepared in the embodiments of the present invention is shown below.

[0044] Figure 3 The 3D fluorescence spectrum of the iridium complex prepared in an embodiment of the present invention;

[0045] Figure 4 The figure shows the experimental results of the ability of the iridium complex prepared in the embodiments of the present invention to generate singlet oxygen.

[0046] Figure 5 The figure shows the results of dark toxicity and phototoxicity tests of the iridium complex prepared in the embodiments of the present invention against mouse neuroma cells (Neuro-2a) under near-infrared excitation. Detailed Implementation

[0047] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention. Unless otherwise specified, the experimental methods used in the embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available. Unless otherwise specified, the same parameter value is the same in all embodiments. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] The term "room temperature" as used in this invention refers to any temperature between 25 and 5°C, and specifically 25°C in the embodiments.

[0049] Example

[0050] In this embodiment, an iridium complex was prepared, the structural formula of which is as follows:

[0051]

[0052] The specific process is as follows:

[0053] S1. 2-Phenyridine (bpy) (0.310 g, 2 mmol) and iridium(III) trichloride hydrate (0.299 g, 1 mmol) were added to a round-bottom flask and 2-ethoxyethanol / water (12 mL; 3:1 v / v) were added. The mixture was then refluxed for 12 hours. After cooling the reaction mixture to room temperature, a yellow precipitate was obtained by filtration, with a yield of 33.3%.

[0054] The chemical reaction equations for the above reactions are shown below:

[0055]

[0056] S2. Iridium(III)μ-chloro-bridged dimer (170 mg, 0.15 mmol) and 5-bromo-2,2'-bipyridine (71 mg, 0.3 mmol) were dissolved in chloroform / methanol (15 mL; 2:1 v / v), stirred overnight at 60 °C, cooled to room temperature, and dried under vacuum to obtain a ruthenium complex [Ir(bpy)2(bpy-Br)](Cl) red powder, with a yield of 70.8%.

[0057] The chemical reaction equations for the above reactions are shown below:

[0058]

[0059] S3.[Ir(bpy)2(bpy-Br)](Cl) (155 mg, 0.202 mmol), 2,5-di(2-ethylhexyl)-3,6-di(5-(trimethyltin)thiophen-2-yl)pyrrolo[3,4-c]pyrrolo-1,4-(2H,5H)-dione (85 mg, 0.1 mmol) and tetra(triphenylphosphine)palladium (11.5 mg, 0.01 mmol) were dissolved in 16 mL of N,N-dimethylformamide and stirred at 115 °C for 20 h under argon protection. After the reaction was completed, the mixture was cooled to room temperature, dried under vacuum, and purified to obtain a blue solid powder (yield 13%).

[0060] The chemical reaction equations for the above reactions are shown below:

[0061]

[0062] The mass spectrum of the product is: ESI-MS [CH3OH, m / z]: 916.9 [M-2Cl] - ] 2+ ;

[0063] The 1H NMR spectrum of the product is as follows: 1 H NMR (500MHz, DMSO-d6) δ9.11–8.84(m,2H),8.74(dd,J=10.4,3.6Hz,1H),8.27(dd,J=16.0,8.2Hz,2H),8.07–8.03(m ,1H),7.97–7.64(m,7H),7.21–6.89(m,6H),6.29–6.21(m,2H),3.87(s,2H),1.37–1.10(m,15H),0.86–0.65(m,5H).

[0064] Application examples

[0065] The iridium complexes prepared in the examples were subjected to performance tests, as detailed below:

[0066] 1. Absorption spectroscopy determination of near-infrared fluorescent iridium complexes

[0067] Using ethanol (CH3OH) as the solvent, 10 μM sample solutions of the near-infrared fluorescent iridium complexes from the examples were prepared. The UV absorption spectra of the binuclear ruthenium complexes were then recorded using a double-beam UV-Vis spectrophotometer. The results are as follows: Figure 1 As shown in the figure, the complex exhibits high absorbance in ethanol, indicating its good light absorption capacity in organic solvents.

[0068] 2. Fluorescence emission spectra of near-infrared fluorescent iridium complexes

[0069] Fluorescence emission spectroscopy was performed using a Techcomp FL970 fluorescence spectrophotometer. At λex = 635 nm, a near-infrared fluorescent iridium complex (5 μM) was dissolved in acetonitrile for excitation in a 1 cm quartz tube. The entrance and exit slits were set to 2.5 nm. The results are as follows: Figure 2 As shown. From Figure 2 As can be seen, the complex exhibits strong fluorescence emission intensity in acetonitrile, indicating that it has good near-infrared fluorescence in organic solvents.

[0070] 3. 3D fluorescence spectra of near-infrared fluorescent iridium complexes

[0071] 3D fluorescence spectroscopy was performed using a Techcomp FL970 fluorescence spectrophotometer. Near-infrared fluorescent iridium complex (5 μM) was dissolved in acetonitrile and excited in a 1 cm quartz tube at λex = 600 nm–800 nm. Its emission spectrum at λex = 450 nm–700 nm was then collected. The results are as follows: Figure 3 As shown. From Figure 3 As can be seen, the 3D fluorescence intensity is high in acetonitrile, indicating that it has a wide range of near-infrared fluorescence in organic solvents.

[0072] 4. Determination of the ability of near-infrared fluorescent iridium complexes to generate superoxide anions

[0073] To detect the photocatalytic ability of the near-infrared fluorescent iridium complex synthesized in the examples to generate superoxide anions, the superoxide anion probe dihydrorhodamine 123 (DHR123) was used to determine the ability of the novel near-infrared fluorescent iridium complex to generate superoxide anions. The change in fluorescence intensity of the test sample and the DHR123 mixed solution under different light exposure times was monitored by an enzyme-linked immunosorbent assay (ELISA) reader to reflect the superoxide anion generation ability.

[0074] Two aqueous solutions containing the same near-infrared fluorescent iridium complex (5 μM) and DHR123 reagent (5 μM) were placed in 96-well plates, and their superoxide anion generation capacity was measured under 635 nm illumination. The results are as follows: Figure 4 As shown in the figure, this near-infrared fluorescent iridium complex has the ability to generate superoxide anions after illumination, and this ability is much higher than that of Ce6.

[0075] 5. Photodynamic therapy effect of near-infrared fluorescent iridium complex on mouse neuroma cell lines

[0076] Resazurin solution is blue and is commonly used as an acid-base indicator (orange to deep purple at pH 3.8) and a redox indicator. In cell viability assays, resazurin can penetrate cells and be irreversibly reduced to pink by living cells, simultaneously producing the red fluorescence of resorufin. The absorbance or fluorescence intensity of resorufin is positively correlated with cell number and reducing capacity; therefore, cell proliferation can be analyzed using an enzyme-linked immunofluorescence assay (ELISA).

[0077] The experimental steps for the azure blade are as follows:

[0078] (1) First, revive one tube of Neuro-2a tumor cells (commercially available), and culture them in fresh complete culture medium (DMEM medium + 10 vol% fetal bovine serum + 1 vol% penicillin-streptomycin mixture, the fetal bovine serum and penicillin-streptomycin mixture were commercially available). After passage 2 times, start the experiment.

[0079] (2) When the cells reach the logarithmic growth phase, seed them into two 96-well plates at a density of 5000 cells / well (each well is cultured with 100 μL of culture medium, one plate is the light group and the other is the dark control group), and incubate them in a 37°C, 5 vol% CO2 incubator.

[0080] (3) After the culture medium adheres to the wall, remove the original culture medium and add 100 μL of iridium complex at seven concentrations of 100, 50, 10, 1, 0.1, 0.01 and 0.001 mM to each well. Shake gently and incubate in a carbon dioxide incubator (37℃, 5 vol% CO2) in the dark.

[0081] (4) After incubation for 6 hours, the cell culture plates of the light-illuminated group were placed under a 635nm light source for 45 minutes (light dose of 63.7 J / cm²). 2 Then, the cells were returned to the incubator and incubated in the dark for another 42 hours (the cells in the dark control group were kept in the incubator in the dark throughout the incubation).

[0082] (5) After incubation for 42 hours, the culture medium was discarded from each well, and 80 μL of resazurin (100 mg / mL) was added to each well. The cells were then incubated at 37°C for another 4 hours. The EX540 / EM590 ratio was detected using the fluorescence plate of an ELISA reader, and the cell proliferation inhibition rate was calculated. The IC50 value was then determined. 50 Value (drug concentration when inhibition rate equals 50%), results as follows Figure 5 As shown.

[0083] from Figure 5As can be seen from the resazurite assay, the killing effect of different concentrations of iridium complexes on mouse neuroma cell line (Neuro-2a cells) under dark and light treatment conditions is significantly reduced. Specifically, under dark conditions, the IC50 value for iridium complexes on mouse neuroma cell line (Neuro-2a cells) is significantly reduced. 50 The IC50 concentration was 87.5 μM, and under light conditions, it had an IC50 value of 87.5 μM for the mouse neuroma cell line (Neuro-2a cells). 50 The concentration is 0.08 μM, and the phototherapy index (PI) is as high as 1750, indicating that the iridium complex of the present invention has a strong photodynamic therapy effect.

[0084] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An iridium complex, characterized in that: It has the following structure: 。 2. The method for preparing the iridium complex according to claim 1, characterized in that: Includes the following steps: S1, react 2-phenylpyridine with IrCl3 to generate iridium(III)μ-Cl-bridged dimer; S2. The iridium(III)μ-Cl-bridged dimer is reacted with 5-bromo-2,2'-bipyridine to generate an iridium complex precursor; S3, from the iridium complex precursor and The reaction yields the desired result.

3. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions for step S1 include at least one of the following conditions: (1) The reaction is carried out in a mixed solvent system of 2-ethoxyethanol and water; (2) The reaction temperature is 50-100℃; (3) The reaction time is 8-10 hours; (4) The molar ratio of 2-phenylpyridine to IrCl3 is 2:

1.

4. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions for step S1 include: the reaction is carried out in a mixed solvent system of 2-ethoxyethanol and water; the volume ratio of 2-ethoxyethanol to water is 3:

1.

5. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions for step S2 include at least one of the following conditions: (1) The reaction is carried out in a mixed solvent system of chloroform and methanol; (2) The reaction temperature is 50-100℃; (3) The reaction time is 8-14 hours; (4) The molar ratio of iridium(III)μ-Cl-bridged dimer to 5-bromo-2,2'-bipyridine is 1:

2.

6. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions for step S2 include at least one of the following conditions: (1) the reaction is carried out in a chloroform and methanol mixed solvent system with a volume ratio of chloroform to methanol of 2:1; (2) the reaction temperature is 60℃; and (3) the reaction time is 12h.

7. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions for step S3 include at least one of the following conditions: (1) The reaction is carried out under a protective atmosphere; (2) The reaction is carried out in an N,N-dimethylformamide solvent system; (3) Reaction temperature: 100-135℃; (4) The reaction time is 18-24 hours; (5) The iridium complex precursor and The molar ratio is 2:1; (6) The reaction is carried out under the catalysis of a catalyst, which includes tetra(triphenylphosphine)palladium.

8. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions in step S3 include at least one of the following conditions: (1) the reaction is carried out under a protective atmosphere, wherein the protective atmosphere is argon; (2) the reaction temperature is 110-120℃; (3) the reaction time is 18-22h; (4) the reaction is carried out under the catalysis of a catalyst, wherein the molar ratio of the catalyst to the iridium complex precursor is 2:0.

1.

9. The method for preparing the iridium complex according to claim 2, characterized in that: The reaction conditions in step S3 include at least one of the following: (1) the reaction temperature is 115℃; (2) the reaction time is 20h; 10. The use of the iridium complex according to claim 1 in the preparation of antineuroma drugs.

11. The application according to claim 10, characterized in that: The anti-neuroma drug is a near-infrared photocatalytically activated anti-tumor drug.

12. An anti-neuroma drug, characterized in that: The active ingredient of the drug comprises the iridium complex as described in claim 1.

13. The antineuroma drug according to claim 12, characterized in that: The antineuroma drug is an antineuroma drug for mice.

14. The antineuroma drug according to claim 13, characterized in that: The mouse neuroma cell line was Neuro-2a.

15. An antitumor metal photosensitizer, characterized in that: The active ingredient of the antitumor metal photosensitizer includes the iridium complex as described in claim 1.

Images