Preparation method and application of a semi-sandwich type iridium, ruthenium and rhodium anticancer complex capable of targeting mitochondria

Abstract

The present application relates to metal iridium, ruthenium, rhodium complexes, belongs to the field of chemical pharmacy, specifically relates to a kind of organic metal iridium, ruthenium, rhodium complexes with the structure of triphenylphosphine semi sandwich configuration of mitochondria-targeting and preparation method, application.The structure formula provided by the present application is: the metal iridium complex, metal ruthenium complex and metal rhodium complex with the structure of triphenylphosphine semi sandwich configuration provided by the present application are compared with the metal iridium complex, metal ruthenium complex and metal rhodium complex of semi sandwich configuration without triphenylphosphine structure, it is found that Ir1, Ru1 and Rh1 can target mitochondria, induce its functional disorder to cause the apoptosis of cancer cell, and the anticancer activity is high, and the selectivity is good, and drug resistance is not easy to produce;The series of complexes have good anticancer activity, and the in-vitro anticancer activity is better than that of cisplatin, and the stability is good, which provides a new strategy and experimental basis for the development and research of anticancer metal complexes.The preparation method provided by the present application has high synthesis efficiency, and the target complex prepared can accumulate in mitochondria in cells to induce cell apoptosis.The cell imaging result shows that the complex can target mitochondria well.

Description

Technical Field

[0001] This invention relates to metal complexes, specifically to a method for preparing and applying a semi-sandwich type iridium, ruthenium, and rhodium anticancer complex that can target mitochondria, belonging to the field of chemical pharmaceuticals. Background Technology

[0002] Cancer is one of the most significant obstacles to improving life expectancy worldwide. While various treatments exist for cancer, chemotherapy remains one of the most advantageous and irreplaceable methods. Unfortunately, chemotherapy often comes with severe toxic side effects. Therefore, identifying new targets for anti-tumor drugs and synthesizing novel anti-tumor drugs has been a major research focus in cancer treatment. With advancements in medical science, excellent anti-tumor drugs not only require good therapeutic effects and fewer toxic side effects, but also ideally, lower dosages to achieve therapeutic efficacy. Organelle-targeted anti-tumor drugs can meet these requirements and have become one of the hottest research areas in anti-tumor drug research, such as mitochondrial-targeted anti-tumor drugs.

[0003] Mitochondrial targeting is an organelle-level targeting mechanism. Drug targeting of mitochondria is mainly achieved through two pathways: lipophilic cation-mediated delivery and mitochondrial protein delivery, as well as mitochondrial targeting via the binding of nitric oxide and cell membrane-penetrating peptides. The binding of mitochondrial-targeting drugs to drug molecules is an effective pathway for mitochondrial targeting. Triphenylphosphine is the most widely used mitochondrial-targeting lipophilic cation ligand, consisting of a positively charged phosphorus ion linked to three benzene rings, which makes it highly lipophilic. The phenyl group is spatially blocked to protect the phosphorus atom from dissolution. Furthermore, the positive charge on the phosphorus atom in this structure can be delocalized to the three benzene rings, forming a delocalized positive charge, promoting the penetration of triphenylphosphine through the lipid bilayer and targeting the mitochondrial interior (Cancers 2023, 15(3), 666). A mitochondrial membrane potential-driven triphenylphosphine targeting system can preferentially target antitumor drugs to the mitochondria of tumor cells. Hyperpolarized tumor cell membranes and mitochondrial membranes may allow for the selective accumulation of mitochondrial-targeting drugs. This enhances the direct killing effect of drug molecules on tumor cells while minimizing potential toxicity to normal cells.

[0004] In recent years, "semi-sandwich type" organometallic complexes [(η5-Cp) / (η 6 -arene)M(XY)Cl] 0 / + (Cp = cyclopentadienyl functional group; M = Ir, Rh, Ru; XY = bidentate ligand) (Formula A) has been shown to have significant anticancer activity compared to cyclic metals due to its easily tunable structure and specific mechanism of action (MoAs). This type of complex adopts a six-coordinate geometry, where the chlorine atom occupies one coordination site and the bidentate ligand XY occupies two coordination sites, (η5-Cp) / (η6 -arene occupies three coordination sites. The ligands of semi-sandwich platinum metal complexes such as Ir, Ru, and Rh are easy to modify, exhibiting rich molecular structural diversity, thus demonstrating different anticancer mechanisms and good biological activity.

[0005] Summary of the Invention

[0006] This invention synthesizes three "semi-sandwich type" organometallic complexes of iridium, ruthenium, and rhodium. The introduction of the triphenylphosphine group into the complex enables selective and preferential delivery of the drug to the mitochondria of cancer cells, thereby enhancing the anticancer activity of the complex and killing cancer cells while reducing damage to other normal cells.

[0007] To address the problems existing in the prior art, the present invention provides a metal iridium, ruthenium, and rhodium half-sandwich anticancer complex with a triphenylphosphine structure that targets mitochondria.

[0008] This invention also provides a method for preparing a triphenylphosphine-based iridium, ruthenium, and rhodium half-sandwich anticancer complex targeting mitochondria.

[0009] This invention also provides the application of a triphenylphosphine-based metal iridium, ruthenium, and rhodium half-sandwich anticancer complex with a mitochondrial-targeting structure in the preparation of anticancer drugs.

[0010] The technical solution adopted to achieve the above objectives is as follows:

[0011] This invention provides a triphenylphosphine-based iridium, ruthenium, and rhodium half-sandwich anticancer complex targeting mitochondria, with the following general structural formula:

[0012] .

[0013] This invention also provides a method for preparing a sandwich-configured organometallic iridium, ruthenium, and rhodium complex targeting mitochondria:

[0014] (1) Add 30 mL of anhydrous methanol to a microwave digestion vessel, sonicate for 5 min, then pour out and dry with a hair dryer. Take 0.5 g of iridium trichloride hydrate and 0.75 mL of 1,2,3,4,5-pentamethylcyclopentadiene and add them to the digestion vessel in sequence. Then add 20 mL of anhydrous methanol to the mixture and sonicate for 5 min. Puff nitrogen gas into the mixture and put it into a microwave digestion apparatus for digestion. After digestion, take it out and pour the supernatant into a prepared beaker. Wash the solid in the vessel with ice-cold methanol and pour the washing liquid into the beaker from the previous step. Add dichloromethane to the vessel to dissolve the remaining crystals. Filter out the unreacted iridium trichloride and then evaporate the solution to obtain the product. Evaporate the solution in the beaker containing the washing liquid, wash with ice-cold methanol, dissolve with dichloromethane, filter out the unreacted iridium trichloride, add 8 mL of n-hexane and 8 mL of anhydrous diethyl ether to the filtrate, and place it in a refrigerator to crystallize and prepare D1.

[0015] (2) Under a nitrogen atmosphere, 40.0 mg D1, 70.8 mg L1 and 15 mg ammonium hexafluorophosphonate and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sand core to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane. A precipitate was formed. The precipitate was filtered through a sand core and washed with n-hexane to obtain a crude product. The complex was purified by diffusion and dried under vacuum to obtain a yellow solid Ir1.

[0016] (3) Under a nitrogen atmosphere, 30.6 mg D2, 70.8 mg L1 and 15 mg ammonium hexafluorophosphonate and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sand core filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane. A precipitate was formed. The precipitate was filtered through a sand core filter and washed with n-hexane to obtain a crude product. The complex was purified by diffusion and dried under vacuum to obtain a yellow solid Ru1.

[0017] (4) Under a nitrogen atmosphere, 30.9 mg D3, 70.8 mg L1 and 15 mg ammonium hexafluorophosphonate and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sand core filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane. A precipitate was formed. The precipitate was filtered through a sand core filter and washed with n-hexane to obtain a crude product. The complex was purified by diffusion and dried under vacuum to obtain a yellow solid Rh1.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The semi-sandwich configuration metal iridium, ruthenium, and rhodium complex provided by the present invention can be localized to mitochondria, induce their functional impairment and thus lead to apoptosis of cancer cells. It has high anti-cancer activity, good selectivity and is not prone to drug resistance.

[0020] (2) This series of complexes have good anticancer activity, and their in vitro anticancer activity is better than that of cisplatin. They are also stable, providing a new strategy and experimental basis for the development and research of anticancer metal complexes.

[0021] (3) The preparation method provided by the present invention has high synthesis efficiency, and the prepared target complex can accumulate in the mitochondria of cells to induce apoptosis. Attached Figure Description

[0022] Figure 1 The above is the 1H NMR spectrum of the complex Ir1 of this invention.

[0023] Figure 2 The above is the 1H NMR spectrum of the complex Ru1 of this invention.

[0024] Figure 3 The above is the 1H NMR spectrum of the complex Rh1 of this invention.

[0025] Figure 4 The above is the 1H NMR spectrum of the comparative complex Ir2 of this invention.

[0026] Figure 5 The above is the 1H NMR spectrum of the comparative complex Ru2 of this invention.

[0027] Figure 6 The above is the 1H NMR spectrum of the comparative complex Rh2 of this invention.

[0028] Figure 7 This is the phosphorus spectrum of the complex Ir1 of this invention.

[0029] Figure 8 This is the phosphorus spectrum of the complex Ru1 of this invention.

[0030] Figure 9 This is the phosphorus spectrum of the complex Rh1 of this invention.

[0031] Figure 10 This is the mass spectrometry of the complex Ir1 of this invention.

[0032] Figure 11 This is the mass spectrometry of Ru1, the coordination compound of this invention.

[0033] Figure 12 This is the mass spectrometry of the complex Rh1 of this invention.

[0034] Figure 13The mass spectra of Ir2 in the comparative complex of this invention are shown.

[0035] Figure 14 This is the Ru2 mass spectrum of the comparative coordination compound of this invention.

[0036] Figure 15 The mass spectra of Rh2 for the comparative complex of this invention are shown.

[0037] Figure 16 The colocalization coefficients of Ir1 in mitochondria, nucleus, and lysosomes.

[0038] Figure 17 The colocalization coefficients of Ir2 in mitochondria, nucleus, and lysosomes.

[0039] Figure 18 is the colocalization coefficient of Ru1 in mitochondria, nucleus, and lysosome.

[0040] Figure 19 is the colocalization coefficient of Ru2 in mitochondria, nucleus, and lysosomes.

[0041] Figure 20 The colocalization coefficients of Rh1 in mitochondria, nucleus, and lysosomes.

[0042] Figure 21 The colocalization coefficients of Rh2 in mitochondria, nucleus, and lysosomes. Detailed Implementation

[0043] The present invention is further illustrated by the following examples of representative compounds, but these descriptions do not limit the invention.

[0044] The starting compounds used in the synthesis of these compounds are commercial products or can be prepared from known synthetic methods. Methods for preparing all organic compounds are readily available in the literature and are fundamental and obvious to synthetic chemists. Therefore, the following descriptions of synthetic methods can be considered detailed and specific.

[0045] Example 1

[0046] (1) Add 30 mL of anhydrous methanol to a microwave digestion vessel, sonicate for 5 min, then pour out and dry with a hair dryer. Add 0.5 g of iridium trichloride hydrate and 0.75 m of 1,2,3,4,5-pentamethylcyclopentadiene to the digestion vessel in sequence, then add 20 m of anhydrous methanol to the mixture and sonicate for 5 min. Purge nitrogen gas into the mixture and microwave digest. After digestion, remove the vessel and pour the supernatant into a prepared beaker. Wash the solid in the vessel with ice-cold methanol, and pour the washing liquid into the beaker from the previous step. Add dichloromethane to the vessel to dissolve the remaining crystals. Filter out the unreacted iridium trichloride, and then evaporate the solution to obtain the product. Evaporate the solution in the beaker containing the washing liquid, wash with ice-cold methanol, dissolve with dichloromethane, filter to remove the unreacted iridium trichloride, add 8 mL of n-hexane and 8 mL of anhydrous diethyl ether to the filtrate, and place in a refrigerator to crystallize, thus preparing D1.

[0047] (2) The complex Ir1 is prepared by the following method:

[0048] Under a nitrogen atmosphere, 40.0 mg D1, 70.8 mg L1, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Ir1.

[0049] The NMR characterization is as follows: 1 H NMR (500 MHz, DMSO- d 6) δ 14.24 (s, 1H, N) H ), 9.32 (s, 2H),9.24 (d, 2H), 8.27 (d, 3H), 7.92 (t, 3H), 7.88 (m, 13H), 7.18 (d, 2H), 4.18(t, 2H, OC H 2 ), 3.70 (m, 2H C H 2 CH2), 1.99 (m, 2H, CH2C H 2 ), 1.78 (d, 2H, PC H 2 ),1.73 (s, 15H, Cp -C H 3).

[0050] Mass spectrometry: C 51 H 48 Theoretical value of ClIrN4OP: 991.2878, Actual measured value: 991.28115, [MH-2PF6] + .

[0051] Elemental analysis. Theoretical value: C 51 H 49 ClIrN4OP3F 12 :C, 47.76; H, 3.85; N, 4.37. Actual measured:C, 48.01; H, 3.67; N, 4.21.

[0052] Comparative Example 1

[0053] Under a nitrogen atmosphere, 40.00 mg D1, 36.8 mg L2, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Ir2.

[0054] The NMR characterization is as follows: 1 H NMR (500 MHz, DMSO- d 6) δ 14.23 (s, 1H, N H ), 9.32 (s,2H), 9.25 (s, 2H), 8.35 (m, 4H), 7.23 (d, 2H), 4.12 (t, 2H, OC H 2 ), 1.78 (d,2H, C H 2 CH2), 1.78 (m, 15H, Cp -C H 3), 1.49 (m, 2H, CH2C H 2 ), 0.98 (t, 3H,CH2C H 3 ).

[0055] Mass spectrometry: C 33 H 35Theoretical value of ClIrN4O: 731.2129, Actual measured value: 731.2124 [M-PF6] + .

[0056] Elemental analysis. Theoretical value: C 33 H 35 ClIrN4OPF6: C, 45.23; H, 4.03; N, 6.39. Actual measured values: C, 45.52; H, 3.86; N, 6.12.

[0057] Example 2

[0058] Under a nitrogen atmosphere, 30.6 mg D2, 70.8 mg L1, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Ru1.

[0059] Nuclear magnetic resonance characterization was as follows: ¹H NMR (500 MHz, DMSO- d 6) δ 14.16 (s, 1H, N H ), 9.86 (d,2H), 9.20 (d, 2H), 8.24 (d, 3H), 8.19 (s, 1H), 7.92 (t, 3H), 7.87 (m, 13H),7.17 (d, 2H), 6.34 (d, 2H), 6.11 (d, 2H), 4.17 (t, 2H), 3.74 (m, 2H), 2.65(m, 1H, C H (CH3)2), 2.21 (s, 3H, CC H 3 ), 2.02 (m, 2H), 1.77 (m, 2H), 0.90 (d,6H,CH(C H 3 )2).

[0060] Mass spectrometry: C 51 H 48 Theoretical value of ClRuN4OP2F6: 1045.19, Actual measured value: 1045.1916, [M-PF6] + .

[0061] Elemental analysis. Theoretical value: C 51 H 48 ClRuN4OP3F 12 :C, 51.46; H, 4.06; N, 4.71. Actual measured:C, 51.59; H, 3.91; N, 4.44.

[0062] Comparative Example 2

[0063] Under a nitrogen atmosphere, 30.6 mg D2, 36.8 mg L2, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Ru2.

[0064] The NMR characterization is as follows: 1 H NMR (500 MHz, DMSO- d 6) δ 14.25 (s, 1H, N H ), 9.86 (d,2H), 9.24 (d, 2H), 8.26 (d, 2H), 8.25 (d, 2H), 7.21 (d, 2H), 6.34 (d, 2H), 6.12 (d, 2H), 4.11 (t, 2H), 2.62 (m, 1H, C H (CH3)2), 2.21 (s, 3H, CC H 3 ), 1.76(m, 2H), 1.49 (m, 2H), 0.98 (t, 3H, CH2C H 3 ), 0.91 (d, 6H, CH(C H 3 )2).

[0065] Mass spectrometry: C 33 H 34 ClRuN4O theoretical value: 639.639.1465, actual measured value: 639.1464, [M-PF6] + .

[0066] Elemental analysis. Theoretical value: C 33 H 34ClRuN4OPF6: C, 50.55; H, 4.37; N, 7.51. Actual measured values: C, 50.76; H, 4.21; N, 7.34.

[0067] Example 3

[0068] Under a nitrogen atmosphere, 30.9 mg D3, 70.8 mg L1, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Rh1.

[0069] The NMR characterization is as follows: 1 H NMR (500 MHz, DMSO) δ 9.33 (dd, 2H), 9.24 (d, 2H), 8.24(m, 3H), 7.92 (m, 3H), 7.86 (m, 13H), 7.18 (d, 2H), 4.18 (t, 2H, OC H 2 ), 3.71(m, 2H, C H 2 CH2), 1.99 (m, 2H, CH2C H 2 ), 1.83 (m, 2H, PC H 2 ), 1.76 (d, 15H, Cp -C H 3).

[0070] Mass spectrometry: C 51 H 48 Theoretical value of ClRhN4OP: 901.2304, Actual measured value: 901.2297, [MH-2PF6] + .

[0071] Elemental analysis. Theoretical value: C 51 H 49 ClRhN4OP3F 12 :C, 51.34; H, 4.14; N, 4.70. Actual measured:C, 51.59; H, 3.92; N, 4.46.

[0072] Comparative Example 3

[0073] Under a nitrogen atmosphere, 30.9 mg D3, 36.8 mg L2, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Rh2.

[0074] The NMR characterization is as follows: 1 H NMR (500 MHz, DMSO) δ 9.30 (d, 2H), 9.26 (d, 2H), 8.32(m, 4H), 7.20 (d, 2H), 4.10 (t, 2H, OC H 2 ), 1.82 (m, 2H, C H 2 CH2), 1.77 (s, 15H, Cp) -C H 3), 1.49 (m, 2H, CH2C H 2 ), 0.98 (t, 3H, CH2C H 3 ).

[0075] Mass spectrometry: C 33 H 35 Theoretical value of ClRhN4O: 605.1788, Actual measured value: 605.1780 [M-HCl-PF6] + .

[0076] Elemental analysis. Theoretical value: C 33 H 35 ClRhN4OPF6: C, 50.36; H, 4.48; N, 7.12. Actual measured values: C, 50.52; H, 4.26; N, 6.96.

[0077] Example 4

[0078] Experiment on the inhibitory activity of the complex with anticancer activity on the proliferation of tumor cell lines:

[0079] (1) Preparation of the test compound: Dissolve the solid complex in DMSO to prepare a stock solution of a certain concentration. Dilute the stock solution further with cell culture medium until the working concentration is reached, and incubate for 24 h.

[0080] (2) Cell growth inhibition assay (MTT method):

[0081] 1) Take 5000 cancer cells (A549) and prepare them into cell suspensions, then seed them into 96-well culture plates;

[0082] 2) Pre-culture cells in drug-free medium, incubate at 5% CO2 and 310 K for 24 hours, add the prepared test compound, and incubate for 24 hours;

[0083] 3) Add 15 μL of 5 mg / mL MTT solution to each well and continue culturing for 4 hours to form purple crystalline formazan;

[0084] 4) Terminate the culture, carefully aspirate the culture medium from the wells, add 100 μL of DMSO to each well to fully dissolve the formazan precipitate, mix with a shaker, and then measure the optical density of each well at a wavelength of 570 nm using a microplate reader.

[0085] 5) Each experiment was repeated three times, IC 50 = Mean ± SEM. The inhibition rates of complexes 1-4 and commercial cisplatin on the growth of cancer cells HeLa and A549 are shown in Table 1.

[0086] Table 1

[0087]

[0088] As demonstrated in Example 3, the complexes Ir1, Ru1, and Rh1 exhibited very good anticancer activity, approaching or exceeding that of commercially available cisplatin. The metal precursors D1, D2, and D3, and the ligand L1, did not show any anticancer activity (IC50). 50 >100µM), while Ir1, Ru1, and Rh1 showed better anticancer activity, indicating that the chelation of ligands with metals significantly improved the anticancer activity of the resulting complexes. Compared with Ir2, Ru2, and Rh2 without triphenylphosphine groups, Ir1, Ru1, and Rh1 containing triphenylphosphine groups showed significantly enhanced anticancer activity. This is because the introduction of triphenylphosphine groups into the complexes improved the mitochondrial targeting of the complexes, thereby enhancing the anticancer activity. These conclusions provide a theoretical basis for the preparation of novel antitumor drugs.

[0089] Example 5

[0090] Laser confocal microscopy can conveniently detect the targeting of the complex after it enters A549 cells. LysoTracker Red DND-99 (LTRD) and Mito Tracker Deep Red (MTDR) were used as fluorescent probes for lysosomes and mitochondria, respectively. A549 cells were incubated with the target complex (9.1 μM) at 37 °C for 1 h, followed by staining with LTRD (100 nM) and MTDR (50 nM) for 30 min. The cell plates were washed three times with phosphate-balanced saline (PBS) buffer, and observed under a laser confocal microscope. The excitation wavelength of the target complex was 405 nm, and the collection wavelength was 420–500 nm; the excitation wavelength of LTRD was 630 ± 30 nm, and the collection wavelength was 493–630 nm; the MTDR was excited at 644 nm, and the emission wavelength was 690 ± 30 nm. As shown in the figure below, the Pearson colocalization coefficient of the complex in mitochondria is greater than 0.9, while the colocalization coefficient in lysosomes is less than 0.3, confirming that the target complex mainly targets mitochondria.

[0091] The mitochondrial colocalization coefficients of complexes Ir1, Ru1, and Rh1 were 0.95, 0.94, and 0.94, respectively, indicating their targeting of mitochondria. The mitochondrial colocalization coefficients of complexes Ir2 and Ru2 were 0.30, 0.23, and 0.24, respectively, indicating almost no targeting to mitochondria. The comparison of colocalization coefficients shows that the addition of triphenylphosphine significantly enhances the mitochondrial targeting ability of the complexes.

[0092] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A semi-sandwich configuration organometallic iridium, ruthenium, and rhodium complex targeting mitochondria, characterized in that, Its structural formula is: 。 2. A method for preparing a semi-sandwich configuration mitochondrial-targeting heteronuclear organometallic iridium complex, characterized in that, The target complex was obtained by reacting a metallic iridium dimer with L1, and the specific reaction route is as follows: 。 3. The preparation method according to claim 2, characterized in that, It is prepared by the following method: (1) Add 30 mL of anhydrous methanol to a microwave digestion vessel, sonicate for 5 min, then pour out and dry with a hair dryer. Take 0.5 g of iridium trichloride hydrate and 0.75 mL of 1,2,3,4,5-pentamethylcyclopentadiene and add them to the digestion vessel in sequence. Then add 20 mL of anhydrous methanol to the mixture and sonicate for 5 min. Puff nitrogen gas into the mixture and put it into a microwave digestion apparatus for digestion. After digestion, take it out and pour the supernatant into a prepared beaker. Wash the solid in the vessel with ice-cold methanol and pour the washing liquid into the beaker from the previous step. Add dichloromethane to the vessel to dissolve the remaining crystals. Filter out the unreacted iridium trichloride and then evaporate the solution to obtain the product. Evaporate the solution in the beaker containing the washing liquid, wash with ice-cold methanol, dissolve with dichloromethane, filter out the unreacted iridium trichloride, add 8 mL of n-hexane and 8 mL of anhydrous diethyl ether to the filtrate, and place it in a refrigerator to crystallize and obtain D1. (2) Under a nitrogen atmosphere, 40.0 mg D1, 70.8 mg L1 and 15 mg ammonium hexafluorophosphonate and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sand core to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane. A precipitate was formed. The precipitate was filtered through a sand core and washed with n-hexane to obtain a crude product. The complex was purified by diffusion and dried under vacuum to obtain a yellow solid Ir1.

4. A method for preparing a semi-sandwich configuration mitochondrial-targeting heteronuclear organometallic ruthenium complex, characterized in that, The complex was obtained by reacting the dichlorobis(4-methylisopropylphenyl)ruthenium(II) dimer with L1, and the specific reaction route is as follows: 。 5. The preparation method according to claim 4, characterized in that, It is prepared by the following method: Under a nitrogen atmosphere, 30.6 mg D2, 70.8 mg L1, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Ru1.

6. A method for preparing a mitochondrial-targeting heteronuclear organometallic rhodium complex with a semi-sandwich configuration, characterized in that, The target complex was obtained by reacting rhodium dimer with L1, and the specific reaction route is as follows: 。 7. The preparation method according to claim 6, characterized in that, It is prepared by the following method: Under a nitrogen atmosphere, 30.9 mg D3, 70.8 mg L1, 15 mg ammonium hexafluorophosphonate, and 30 mL anhydrous methanol were added to a 50 mL Schlenk flask. The reaction was carried out at room temperature for 24 h. After the reaction was completed, the solution was dried by rotary evaporation. The solid was dissolved in dichloromethane and filtered through a sintered glass filter to remove ammonium chloride and excess ammonium hexafluorophosphate. The filtrate was recrystallized by diffusion with dichloromethane and n-hexane, resulting in a precipitate. The precipitate was filtered through a sintered glass filter and washed with n-hexane to obtain a crude product. The crude product was purified by diffusion to obtain a complex and dried under vacuum to obtain a yellow solid, Rh1.

8. The use of a mitochondrial-targeting organometallic iridium, ruthenium, and rhodium complex with a semi-sandwich configuration as described in claim 1 in the preparation of anticancer drugs.

9. The application according to claim 8, characterized in that, The cancers are lung cancer and cervical cancer.

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