A mitochondria-targeting and apoptosis-inducing photosensitive iridium complex and a preparation method thereof

Abstract

The application discloses a photosensitive iridium complex with mitochondrial targeting and apoptosis induction and a preparation method thereof, and more particularly discloses a 2,2'-bipyridine compound, a cyclometalated iridium complex comprising the compound as a ligand, a preparation method and application as an antitumor drug. The cyclometalated iridium complex provided by the application takes the 2,2'-bipyridine compound as a ligand, can selectively induce tumor cell apoptosis under light conditions, can be used for preparing an antitumor drug and has great potential value in the field of photodynamic treatment of tumors.

Description

Technical Field

[0001] This invention relates to a mitochondrial-targeting and apoptosis-inducing photosensitive iridium complex and its preparation method, and more specifically to a 2,2'-bipyridine compound, a cyclic metal iridium complex including the compound as a ligand, a preparation method, and its application as an antitumor drug, belonging to the field of chemistry. Background Technology

[0002] Currently, malignant tumors remain one of the major diseases threatening human health worldwide. Although various treatment methods, including chemotherapy, radiotherapy, and targeted therapy, exist, problems such as treatment resistance, poor targeting, and strong systemic toxicity still exist, severely limiting their clinical efficacy. In recent years, photodynamic therapy has attracted widespread attention in the field of tumor treatment due to its non-invasiveness, spatial selectivity, and controllability.

[0003] Mitochondria, as the core regulatory center of cellular metabolism and apoptosis, exhibit highly reprogrammable functional characteristics in tumor cells, including redox imbalance, membrane potential alteration, and metabolic pathway remodeling, providing a unique therapeutic window. In recent years, increasing research has shown that targeting mitochondria can effectively induce tumor cell death through mechanisms such as inducing reactive oxygen species (ROS) accumulation, disrupting mitochondrial membrane potential, and activating apoptosis pathways. Based on this, developing anti-tumor molecules with mitochondrial targeting capabilities, especially drugs that can be activated and enhance therapeutic effects under specific conditions (such as light exposure), has become an important research direction for novel precision oncology treatment strategies.

[0004] Cyclic iridium(III) complexes exhibit excellent photoactivity. Under illumination, they absorb light energy and transition to an excited state, then transfer energy to oxygen to generate highly cytotoxic singlet oxygen, inducing local oxidative damage and selectively killing tumor cells. Therefore, developing a cyclic iridium(III) complex with good mitochondrial targeting and the ability to selectively induce tumor cell apoptosis under illumination is of great significance for improving the efficiency of photodynamic therapy and the precision of tumor treatment. Summary of the Invention

[0005] To address the aforementioned problems in the prior art, the present invention aims to provide a 2,2'-bipyridine compound, a cyclic iridium complex including the compound as a ligand, a preparation method, and its application as an antitumor drug.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] This invention provides a 2,2'-bipyridine compound with the general structural formula shown in Formula I:

[0008] ;

[0009] Where: n is any natural number from 0 to 6;

[0010] m is any natural number from 0 to 3;

[0011] X1 and X2 are each independently selected from any one of S, O, NH, and CH2;

[0012] R1, R2, R3, R4, R5, R6, and R7 are each independently selected from hydrogen, halogens (e.g., fluorine, chlorine, bromine, iodine), nitro, cyano, C1-C6 alkyl (including straight-chain alkyl, linear alkyl, and cycloalkyl, e.g., methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, etc.), C2-C6 alkenyl (e.g., vinyl, propenyl, butenyl, etc.), C1-C6 alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), C6-C20 aryl (e.g., phenyl, 1-naphthyl, 2-naphthyl, 9-anthrayl, etc.), C5-C20 heterocyclic (e.g., azircyclopropane, oxetane, furanyl, thiophene, pyrrole, imidazolyl, thiazolyl, pyranyl, indole, etc.), OCOR a COR b COOR c NR d R e Any one of them;

[0013] R a R b R c R d R e Each is independently selected from any one of C1-C6 alkyl and C6-C20 aryl groups.

[0014] One implementation scheme, where n is any natural number from 1 to 6;

[0015] m is any natural number from 2 to 3;

[0016] X1 and X2 are each independently selected from any one of S, O, NH, and CH2;

[0017] R1, R2, R3, R4, R5, R6, and R7 are each independently selected from hydrogen, halogen, nitro, cyano, C1-C6 alkyl, C2-C6 alkenyl, C1-C6 alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), phenyl, OCOR, etc. a COR b COOR c NR d R e Any one of them;

[0018] Ra R b R c R d R e Each is independently selected from any one of C1-C6 alkyl or phenyl groups.

[0019] In a preferred embodiment, the 2,2'-bipyridine compound represented by Formula I has any one of the following structural formulas:

[0020] , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0021] This invention also provides a method for preparing a 2,2'-bipyridine compound, which involves reacting compound I-1, compound I-2, a condensing agent, and a catalyst in a first solvent to obtain the 2,2'-bipyridine compound shown in Formula I. The specific reaction formula is shown below:

[0022] .

[0023] In one embodiment, the first solvent is dichloromethane or trichloromethane.

[0024] In one embodiment, the condensing agent is any one of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC), dicyclohexylcarbodiimide (DCC), 2-(7-benzotriazole oxide)-N,N,N',N'-tetramethylurea hexafluorophosphate (HATU), and O-benzotriazole-tetramethylurea hexafluorophosphate (HBTU), preferably 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC).

[0025] In one embodiment, the catalyst is 4-dimethylaminopyridine (DMAP) or triethylamine (Et3N), preferably 4-dimethylaminopyridine (DMAP).

[0026] In one embodiment, the molar ratio of compound I-1: compound I-2: condensing agent: catalyst is (4.5-5.5):6:(0.5-1.5), preferably 5:6:6:1.

[0027] In one embodiment, after the reaction, the mixture is washed with a second solvent, the organic phase is extracted, dried and concentrated, and then subjected to column chromatography to obtain the 2,2'-bipyridine compound shown in Formula I.

[0028] In a preferred embodiment, the second solvent is water.

[0029] In a preferred embodiment, compounds I-1, I-2, EDC, and DMAP in a molar ratio of 5:6:6:1 are reacted in dichloromethane for 15-30 hours (preferably 24 hours). After the reaction, the reaction solution is washed with water, the organic phase is concentrated, and column chromatography is performed to obtain the 2,2'-bipyridine compound shown in Formula I.

[0030] The present invention also provides a cyclic metallic iridium complex [Ir(NC)₂L]. + PF6 - The ligand is a 2,2'-bipyridine compound as shown in Formula I, whose general structural formula (the anionic part is omitted) is shown in Formula II:

[0031] In Formula II The general structural formula is shown in Formula III:

[0032] ;in:

[0033] R8, R9, R 10 R 11 R 12 R 13 R 14Each group is independently selected from hydrogen, halogens (e.g., fluorine, chlorine, bromine, iodine), nitro, cyano, hydroxyl, aldehyde, C1-C6 alkyl (including straight-chain alkyl, linear alkyl, cycloalkyl, e.g., methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, etc.), C2-C6 alkenyl (e.g., vinyl, propenyl, butenyl, etc.), C1-C6 alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), C6-C20 aryl (e.g., phenyl, 1-naphthyl, 2-naphthyl, 9-anthrayl, etc.), C5-C20 heterocyclic (e.g., azircyclopropane, oxetane, furanyl, thiophene, pyrrole, imidazolyl, thiazolyl, pyranyl, indole, etc.), OCOR f COR g COOR h NR i R j Any one of them; or, adjacent R8, R9, R 10 R 11 R 12 R 13 R 14 They form saturated or unsaturated carbon rings through covalent bonds; R f R g R h R i R j Each is independently selected from any one of C1-C6 alkyl and C6-C20 aryl groups.

[0034] One implementation scheme, R8, R9, R 10 R 11 R 12 R 13 R 14 Each group is independently selected from hydrogen, halogens (e.g., fluorine, chlorine, bromine, iodine), nitro, cyano, hydroxyl, aldehyde, C1-C6 alkyl (including straight-chain alkyl, linear alkyl, cycloalkyl, e.g., methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, tert-butyl, cyclobutyl, n-pentyl, cyclopentyl, n-hexyl, cyclohexyl, etc.), C2-C6 alkenyl (e.g., vinyl, propenyl, butenyl, etc.), C1-C6 alkoxy (e.g., methoxy, ethoxy, propoxy, etc.), phenyl, OCOR f COR g COOR h NR i R j Any one of them; or, adjacent R8, R9, R 10 R 11 R 12 R 13 R 14A benzene ring is formed between them through covalent bonds; R f R g R h Each alkyl group is independently selected from C1-C6 alkyl groups; R i R j Each is independently selected from any one of C1-C6 alkyl or phenyl groups.

[0035] In a preferred embodiment, equation III has any of the following structural formulas:

[0036] , , , , , , , , , , , , , , , , , , , , , , , , , , , , .

[0037] This invention also provides a method for preparing cyclic iridium complexes, which involves refluxing the iridium precursor [Ir(NC)2]Cl2 and a compound of formula I in a mixed solvent to obtain the cyclic iridium complex. The specific reaction formula is shown below:

[0038] .

[0039] In one embodiment, the mixed solution is a dichloromethane-methanol solution, wherein the volume ratio of dichloromethane to methanol is 1:1.

[0040] In one embodiment, the molar ratio of iridium precursor to compound of formula I is 1:(2.2-2.4).

[0041] In one embodiment, the reaction is concentrated under reduced pressure, dissolved in methanol, ammonium hexafluorosulfate is added, and column chromatography is performed to obtain a cyclic metal iridium complex.

[0042] In a preferred embodiment, ammonium hexafluorophosphate is added and reacted overnight at room temperature. The mixture is then concentrated, dissolved again in dichloromethane, and the organic phase is washed with water. After the organic phase is concentrated, it is added dropwise into diethyl ether, and the precipitate is formed. The precipitate is then filtered and dried to obtain a cyclic metal iridium complex.

[0043] In a preferred embodiment, an iridium precursor and a compound of formula I in a molar ratio of 1:2.2-2.4 are refluxed in a 1:1 dichloromethane-methanol mixed solvent. After the reaction, the mixture is concentrated under reduced pressure, dissolved in a small amount of methanol, and then ammonium hexafluorophosphate is added and stirred. After the reaction, the mixture is concentrated and recrystallized to obtain a cyclic metallic iridium complex.

[0044] This invention also provides the application of cyclic iridium complexes in the preparation of antitumor drugs.

[0045] Compared with the prior art, the present invention has the following significant advantages:

[0046] The cyclic iridium complex provided by this invention, using the 2,2'-bipyridine compound shown in Formula I as a ligand, has good mitochondrial targeting and can selectively induce tumor cell apoptosis under light conditions. It is expected to be used to prepare anti-tumor drugs and has great potential value in the field of photodynamic therapy for tumors. Attached Figure Description

[0047] Figure 1 This is a diagram showing the mitochondrial targeting results of the cyclic iridium complex Ir1 prepared in this invention;

[0048] Figure 2 This is a diagram showing the apoptosis induced by the cyclic iridium complex Ir1 prepared in this invention. Detailed Implementation

[0049] The technical solution of the present invention will be further described in detail and completely below with reference to the embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. Experimental methods in the following embodiments that do not specify specific conditions are generally performed under conventional conditions or as recommended by the manufacturer.

[0050] Example 1: 2,2'-Bipyridine Compound Preparation of (ligand L1)

[0051]

[0052] Will (0.21 g, 0.10 mmol) 0.2 g (0.10 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (0.23 g, 0.12 mmol), and 4-dimethylaminopyridine (0.012 g, 0.01 mmol) were stirred in dichloromethane for 24 hours. The reaction solution was washed with water, the organic phase was concentrated, and the solution was subjected to column chromatography to obtain a white solid, which was the target compound, abbreviated as ligand L1, with a yield of 82.5%.

[0053] Tested: 1 HNMR (400 MHz, Chloroform-d)δ8.67 (d, J = 5.0 Hz, 1H), 8.55(d, J = 5.0 Hz, 1H), 8.38 (s, 1H), 8.25 (s, 1H), 7.29–7.26 (m, 1H), 7.16 (m,J = 5.1, 1.7 Hz, 1H), 5.21 (s, 2H), 3.60–3.51 (m, 1H), 3.21–3.05 (m, 2H), 2.48 (s, 1H), 2.47–2.42 (m, 5H), 1.89 (m, J = 13.7, 6.9 Hz, 1H), 1.78–1.63(m, 4H), 1.49 (m, J = 18.3, 13.3, 9.2, 6.9 Hz, 2H);

[0054] 13 CNMR (101 MHz, Chloroform-d)δ173.06, 156.53, 155.43, 149.42, 148.93,148.41, 146.09, 124.99, 122.14, 121.95, 119.53, 64.47, 56.30, 40.22, 38.52,34.61, 33.96, 28.76, 24.68, 21.27;

[0055] ESI-MS: m / z: 389.20 [M+H] + .

[0056] Example 2: Preparation of ligands L2-L10

[0057] Referring to the reaction conditions and post-treatment of Example 1, the reaction conditions and post-treatment of Example 1 were used... Replace with in sequence , , , , , , , , The ligands L2-L10 were obtained sequentially, specifically as follows:

[0058] Ligand L2: Yield 79.8%, ESI-MS: m / z: 405.20 [M+H] + ;

[0059] Ligand L3: Yield 80.2%, ESI-MS: m / z: 419.18 [M+H] + ;

[0060] Ligand L4: Yield 80.8%, ESI-MS: m / z: 433.20 [M+H] + ;

[0061] Ligand L5: Yield 78.5%, ESI-MS: m / z: 147.20 [M+H] + ;

[0062] Ligand L6: Yield 79.5%, ESI-MS: m / z: 451.21 [M+H] + ;

[0063] Ligand L7: Yield 77.6%, ESI-MS: m / z: 418.22 [M+H] + ;

[0064] Ligand L8: Yield 80.6%, ESI-MS: m / z: 409.14 [M+H] + ;

[0065] Ligand L9: Yield 76.5%, ESI-MS: m / z: 400.18 [M+H] + ;

[0066] Ligand L10: Yield 81.0%, ESI-MS: m / z: 401.20 [M+H] + .

[0067] Example 3: Cyclic Metal Iridium Complex Ir1 Preparation

[0068]

[0069] Under nitrogen protection, [Ir(NC)2]Cl2 (specifically: [Ir(ppy)2Cl]2, 0.100 g, 0.093 mmol) and ligand L1 (0.073 g, 0.186 mmol) in a mixed solvent (V DCM :V MeOH The reaction mixture was refluxed in a 1:1 solution for 7 hours, the solution was evaporated to dryness, dissolved in a small amount of methanol, and then ammonium hexafluorophosphate (0.07 g, 0.38 mmol) was added and stirred for 5-7 hours. The reaction solution was concentrated and subjected to column chromatography to obtain a yellow solid, which is the cyclic iridium complex Ir1, with a yield of 76.4%.

[0070] Tested: 1 HNMR (400 MHz, DMSO-d6)δ8.82 (s, 1H), 8.75 (s, 1H), 8.26 (d,J = 8.2 Hz, 2H), 7.95 (s, 1H), 7.93 (d, J = 2.9 Hz, 2H), 7.91 (s, 2H), 7.83(d, J = 5.7 Hz, 1H), 7.70 (d, J = 5.6 Hz, 1H), 7.65 (s, 1H), 7.63 (d, J = 7.1Hz, 3H), 7.54 (d, J = 5.6 Hz, 1H), 7.16 (t, J = 6.6 Hz, 2H), 7.02 (t, J = 7.4Hz, 2H), 6.90 (t, J = 7.4 Hz, 2H), 6.19 (t, J = 7.4 Hz, 2H), 5.32 (s, 2H), 3.63–3.53 (m, 1H), 3.34 (d, J = 1.7 Hz, 5H), 3.22–3.01 (m, 2H), 2.54 (s, 3H), 2.48 (s, 1H), 2.46 (s, 1H), 2.37 (m, J = 12.5, 6.3 Hz, 1H), 1.84 (m, J =13.4, 6.8 Hz, 1H), 1.58 (m, J = 28.9, 13.6, 7.4 Hz, 5H), 1.37 (m, J = 8.6, 8.2 Hz, 2H);

[0071] 13CNMR (101 MHz, DMSO-d6)δ173.00, 167.33, 167.27, 155.93, 155.17,152.05, 151.00, 150.94, 150.28, 149.91, 149.57, 149.27, 144.29, 144.24,139.22, 131.57, 131.51, 130.70, 129.89, 126.63, 126.20, 125.53, 124.37,123.13, 122.70, 120.50, 63.62, 56.51, 38.55, 34.45, 33.50, 28.54, 24.48, 21.43;

[0072] ESI-MS: m / z: 888.30 [MH] + ].

[0073] Example 4: Preparation of cyclic iridium complexes Ir2-Ir14

[0074] Referring to the reaction conditions and post-treatment of Example 3, while keeping ligand L1 unchanged, the reaction conditions and post-treatment of Example 3 were used... Replace with in sequence , , , , , , , , , , , , The iridium complexes Ir2-Ir14 were obtained sequentially, specifically as follows:

[0075] Ir2, a metallic iridium complex: Yield 73.2%, ESI-MS: m / z: 916.30 [MH] + ];

[0076] Ir3, a metallic iridium complex: Yield 73.5%, ESI-MS: m / z: 940.30 [MH] + ];

[0077] Ir4, a metallic iridium complex: Yield 72.5%, ESI-MS: m / z: 956.20 [MH] + ];

[0078] Ir5, a metallic iridium complex: Yield 70.2%, ESI-MS: m / z: 938.30 [MH] + ];

[0079] Ir6, a metallic iridium complex: Yield 70.1%, ESI-MS: m / z: 978.28 [MH] + ];

[0080] Ir7, a metallic iridium complex: Yield 73.5%, ESI-MS: m / z: 920.30 [MH] + ];

[0081] Ir8, a metallic iridium complex: Yield 70.5%, ESI-MS: m / z: 1040.35 [MH] + ];

[0082] Ir9, a metallic iridium complex: Yield 77.5%, ESI-MS: m / z: 948.30 [MH] + ];

[0083] Ir10, a metallic iridium complex: Yield 70.8%, ESI-MS: m / z: 944.28 [MH] + ];

[0084] Ir11, a metallic iridium complex: Yield 72.5%, ESI-MS: m / z: 972.30 [MH] + ];

[0085] Ir12, a metallic iridium complex: Yield 72.1%, ESI-MS: m / z: 1004.30 [MH] + ];

[0086] Ir13, a metallic iridium complex: Yield 73.6%, ESI-MS: m / z: 974.37 [MH] + ];

[0087] Ir14, a metallic iridium complex: Yield 71.8%, ESI-MS: m / z: 988.30 [MH] + ].

[0088] Example 5: Preparation of cyclic iridium complexes Ir15-Ir23

[0089] Following the reaction conditions and post-treatment of Example 3, [Ir(NC)2]Cl2 was maintained. Without changing the original composition, ligand L1 in Example 3 was replaced sequentially with ligands L2-L10 to obtain iridium complexes Ir15-Ir23, specifically as follows:

[0090] Ir15, a metallic iridium complex: Yield 78.5%, ESI-MS: m / z: 904.30 [MH] + ];

[0091] Ir16, a metallic iridium complex: Yield 70.3%, ESI-MS: m / z: 919.27 [MH] + ];

[0092] Ir17, a metallic iridium complex: Yield 70.3%, ESI-MS: m / z: 932.29 [MH] + ];

[0093] Ir18, a metallic iridium complex: Yield 71.5%, ESI-MS: m / z: 916.30 [MH] + ];

[0094] Ir19, a metallic iridium complex: Yield 68.5%, ESI-MS: m / z: 950.30 [MH] + ];

[0095] Ir20, a metallic iridium complex: Yield 69.8%, ESI-MS: m / z: 917.30 [MH] + ];

[0096] Ir21, a metallic iridium complex: Yield 72.6%, ESI-MS: m / z: 908.25 [MH] + ];

[0097] Ir22, a metallic iridium complex: Yield 73.1%, ESI-MS: m / z: 899.28 [MH] + ];

[0098] Ir23, a metallic iridium complex: Yield 73.6%, ESI-MS: m / z: 900.30 [MH] + ].

[0099] Example 6: Cytotoxicity test of cyclic iridium complex

[0100] Cytotoxicity experiments were conducted on the cyclic iridium complexes Ir1-Ir23 prepared in the examples to investigate their cytotoxicity in human ovarian cancer cells A2780, human cervical cancer cells HeLa, human cervical squamous cell carcinoma cells Siha, human hepatocellular carcinoma cells HepG2, and human embryonic kidney cells 293T, thereby evaluating their antitumor activity. The specific CCK8 experimental procedures are as follows:

[0101] (1) The five cell types required for resuscitation (A2780, Hela, Siha, HepG2 and 293T) were cultured in fresh complete medium (DMEM medium + 10 vol% fetal bovine serum + 1 vol% penicillin-streptomycin) and passaged 3-4 times before starting the experiment.

[0102] (2) When the cells reach the logarithmic growth phase, seed 5000 cells / well into a 96-well plate and incubate at 37°C in a 5% CO2 incubator;

[0103] (3) After the cells adhered, fresh culture medium containing different concentrations of iridium complex or cisplatin (CDDP) was added to replace the original culture medium, and the mixture was gently mixed. The dark group was incubated in the dark for 48 hours; the light group was incubated for 12 hours and then treated with a 405 nm laser at 15 mw / cm². 2 Irradiate with high power for 3 minutes, then continue incubation for 36 hours;

[0104] (4) After incubation for 48 hours, aspirate the original culture medium, add fresh complete culture medium containing 10 vol% CCK8 solution, mix gently, and continue incubation at 37°C for 1-4 hours. Detect A450 nm using an enzyme-linked immunosorbent assay (ELISA) reader, calculate the cell proliferation inhibition rate, and determine the IC50 value. 50 Value (IC) 50 The value is the drug concentration at which the inhibition rate equals 50%, IC50. 50 (The higher the value, the lower the cytotoxicity); the experimental results are shown in Tables 1-5.

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] As can be seen from Tables 1-5, the cyclic iridium complexes Ir1-Ir23 provided by this invention exhibit different cell-inhibiting effects under dark and light conditions. Under dark conditions, the complexes exhibit moderate cell-inhibiting effects, similar to cisplatin (CDDP). Under light conditions, the cyclic iridium complexes Ir1-Ir23 exhibit stronger inhibitory effects, superior to cisplatin. This indicates that the cyclic iridium complexes Ir1-Ir23 of this invention have excellent photoactivity and superior antitumor activity under light conditions.

[0111] In Tables 1-5, 293T represents normal kidney cells, and IC50 is... 50 The higher the value, the lower the cytotoxicity. As can be seen from the table, the cyclic iridium complexes Ir1-Ir23 have an IC50 value for tumor cells. 50 The value was significantly lower than the IC50 value for 293T normal kidney cells. 50 The values ​​indicate that the iridium complexes Ir1-Ir23 exhibited weaker cytotoxicity against normal renal 293T cells than the four tumor cell types. Correspondingly, their inhibitory effect on normal renal 293T cells was weaker than that against the four tumor cell types. This may be related to the lower uptake efficiency of normal cells. Compared to tumor cells, normal cells have lower metabolic and uptake efficiency, meaning they may take up less of the iridium complexes into the cells, thus reducing the IC50 concentration. 50 The value is too high.

[0112] Example 7: Mitochondrial targeting experiments with cyclic iridium complexes

[0113] The mitochondrial targeting experiments on the cyclic iridium complex Ir1 were performed using the following steps:

[0114] (1) A2780 cells in the logarithmic growth phase were subjected to 3×10 4 Cells were evenly seeded in 3 cm confocal culture dishes and cultured for 24 hours until they adhered. Then, 10 μM of the Ir1 complex was added and incubated for 1 hour. The culture medium was removed, and the cells were washed once with PBS. Complete culture medium containing 150 nM of commercial mitochondrial green fluorescent dye MitoTracker Deep Green (MTG, 150 nM) and commercial lysosomal green fluorescent dye LysoTracker Deep Green (LTG, 150 nM) was added and incubated for 30 minutes. The culture medium was removed, and fresh culture medium was added. The cells were then photographed under a confocal microscope. The excitation wavelengths were 405 nm for the Ir1 complex, 490 nm for the MTG, and 500 nm for the LTG. The emission and reception wavelengths were 610 ± 30 nm (Ir1 complex), 515 ± 15 nm (MTG), and 515 ± 10 nm (LTG).

[0115] (2) Organelle colocalization experiments further confirmed this. The experimental results are as follows: Figure 1 visible.

[0116] like Figure 1 As shown, the Ir1 complex has a very high degree of overlap with commercial mitochondrial dyes, with a colocalization coefficient of 0.98. In contrast, the Ir1 complex has a relatively low degree of overlap with commercial lysosomal dyes, with a colocalization coefficient of only 0.36. This indicates that the Ir1 complex has good mitochondrial targeting and can selectively locate in the mitochondria of tumor cells after entering the cell.

[0117] Example 8: Experiment on apoptosis induced by cyclic iridium complexes

[0118] The specific steps for inducing apoptosis in the cyclic iridium complex Ir1 are as follows:

[0119] (1) A2780 cells were loaded with 5 × 10 4 Cells were evenly seeded per well in a 6-well plate and cultured for 24 hours until adherence. The original culture medium was then removed, and fresh culture medium containing different concentrations of Ir1 (0.5 μM, 1 μM) was added. The dark group was incubated in the dark for 24 hours, while the light group was incubated for 12 hours. Cells were then treated with a 405 nm laser at 15 mw / cm². 2 Irradiate with high power for 3 minutes, then continue incubation for 12 hours;

[0120] (2) After incubation for 24 hours, aspirate the original culture medium, wash once with PBS, digest with trypsin and collect the cells in EP tubes, wash once with PBS to remove residual trypsin, centrifuge, remove the supernatant and add dye (first add 195 μL 1×Annexin V-FITC binding solution, then add 5 μL Annexin V-FITC dye, and finally add 10 μLPI dye), and perform detection as soon as possible;

[0121] (3) To determine the apoptosis-inducing effect of the complex Ir1 on A2780 cells, flow cytometry was used to analyze A2780 cells by Annexin V-FITC / PI double staining. The experimental results are as follows: Figure 2 As shown.

[0122] from Figure 2As can be seen, under dark conditions, the number of apoptotic cells in the control group was 6.16% (the sum of early and late apoptotic cells). After induction with the complex Ir1, the number of apoptotic cells in A2780 cells was 6.51% (0.5 μM) and 16.54% (1 μM), respectively, representing increases of 0.35% and 10.38% compared to the control group. Under light conditions, the number of apoptotic cells in the control group was 6.20%. After induction with the complex Ir1, the number of apoptotic cells in A2780 cells was 15.10% (0.5 μM) and 35.49% (1 μM), respectively, representing increases of 8.90% and 29.29% compared to the control group. This indicates that the complex Ir1 has the ability to induce apoptosis in A2780 cells, and exhibits better results under light conditions.

[0123] Finally, it should be noted that the above are only some preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A cyclic metallic iridium complex, characterized in that, The structural general formula is shown as formula II: ; the structural formula of formula II is as shown in formula III: ; the structural formula of formula II is as shown in formula III: ; wherein: n is any natural number from 1 to 6; m is 2; X1, X2 are both S; R1, R2, R3, R4, R5, R6, R7 are independently selected from hydrogen, halogen, nitro, cyano, C1-C6 alkyl, C2-C6 alkenyl, C1-C6 alkoxy, C6-C20 aryl, C5-C20 heterocyclyl, OCOR a , COR b , COOR c , NR d R e , any one of them; R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 are independently selected from hydrogen, halogen, nitro, cyano, hydroxyl, aldehyde, C1-C6 alkyl, C2-C6 alkenyl, C1-C6 alkoxy, C6-C20 aryl, C5-C20 heterocyclyl, OCOR f , COR g , COOR h , NR i R j , any one of them; R 15 is hydrogen; or, adjacent R8, R9, R 10 form a benzene ring through covalent bond; R a , R b , R c , R d , R e are independently selected from C1-C6 alkyl, C6-C20 aryl, any one of them; R f , R g , R h , R i , R j are independently selected from C1-C6 alkyl, C6-C20 aryl, any one of them.

2. The cyclometalated iridium complex of claim 1, wherein: R8, R9, R 10 , R 11 , R 12 , R 13 , R 14 are each independently selected from the group consisting of hydrogen, halogen, nitro, cyano, hydroxy, aldehyde, C1-C6alkyl, C2-C6alkenyl, C1-C6alkoxy, phenyl, OCOR f , COR g , COOR h , NR i R j ; or, adjacent R8, R9, R 10 are joined by a covalent bond to form a benzene ring; R f , R g , R h are each independently selected from the group consisting of C1-C6alkyl; R i , R j are each independently selected from the group consisting of C1-C6alkyl, phenyl.

3. The cyclometalated iridium complex of claim 2, wherein The cyclometallated iridium complex of formula II has any of the following structures: , , , , , , , , , , , , , , , , , , , , , , .

4. A process for the preparation of a cyclometalated iridium complex as claimed in claim 1, characterized in that, The iridium precursor [Ir(N-C)2]Cl2 and the compound of formula I are refluxed in a mixed solvent to obtain a cyclometalated iridium complex, and the specific reaction formula is shown as follows: 。 5. Use of the cyclometalated iridium complex of claim 1 in the preparation of an antitumor drug for human ovarian cancer, human cervical cancer, and human liver cancer.

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