A coptis alkaloid iridium photosensitizer and its preparation method and application

Abstract

The application discloses a Coptis alkaloid iridium photosensitizer, a preparation method and application thereof, and belongs to the technical field of antitumor drugs, and provides a Coptis alkaloid iridium photosensitizer with high phototoxicity, a preparation method thereof, and application of the Coptis alkaloid iridium photosensitizer in photodynamic therapy of tumors. The iridium photosensitizer prepared by the application has super-high singlet oxygen generation capacity, is higher than a reference substance Rose Bengal B (RB), and shows high phototoxicity (half inhibitory concentration IC 50 = 1.65 micromoles, and an in-vivo phototumor inhibition rate is 58.21%), can achieve excellent photodynamic therapy effect at an extremely low concentration, and has low toxicity to normal liver cancer cells.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-tumor drugs, and particularly relates to a coptis alkaloid iridium photosensitizer and a preparation method and application thereof. Background Art

[0002] Photodynamic therapy (PDT) is a tumor treatment method based on the production of reactive oxygen species (ROS) that can kill diseased tissue cells after photosensitizers absorb photon energy, thereby achieving therapeutic effects. Photosensitizers can absorb photon energy and convert to an excited state under light conditions, and then interact with the surrounding oxygen to produce reactive oxygen species (ROS), such as singlet oxygen ( 1 O2). These ROS can damage surrounding cellular structures, leading to the death of diseased cells. Because this process can be performed at a specific location without affecting surrounding healthy tissue, PDT is considered a relatively safe treatment with minimal side effects. In recent years, photodynamic therapy has been shown to be effective in treating skin cancer, oral cancer, early-stage obstructive lung cancer, and head and neck cancer.

[0003] On the other hand, iridium (III) complexes have become a promising candidate for photosensitizers due to their outstanding photophysical properties, including long-lived triplet excited states and the ability to efficiently transfer energy to oxygen or undergo electron transfer with various acceptor molecules to generate phototoxic reactive oxygen species. Furthermore, iridium (III) complexes exhibit good water solubility and stability, which are crucial for improving the biocompatibility and therapeutic efficacy of photosensitizers in vivo.

[0004] Although iridium (III) complexes have shown great potential for PDT, many challenges remain to be addressed, such as further improving the selectivity of photosensitizers, reducing toxicity, and improving drug delivery systems. Furthermore, more preclinical studies and clinical trials are needed to verify the safety and efficacy of iridium-based photosensitizers. With advances in nanotechnology and drug design, iridium (III) complexes are expected to play a more important role in photodynamic therapy in the future.

[0005] Coptis chinensis, a plant from the Ranunculaceae family, holds a prominent place in traditional medicine for its dried roots and rhizomes. Known for its remarkable effects in clearing heat and dampness, purging heat and detoxifying, it has been used as a traditional Chinese medicine for over two thousand years. The main active ingredients in Coptis chinensis are its various alkaloids, such as berberine, coptisine, and jatrorrhizine, which contribute to its wide range of pharmacological effects, including anti-inflammatory, antibacterial, antifungal, and anti-tumor properties.

[0006] In recent years, with the in-depth study of the modernization of traditional Chinese medicine, efforts have been made to explore how to combine traditional active ingredients of Chinese medicine with modern pharmaceutical chemistry to develop more effective drugs. However, as of now, there has been no relevant report on the use of alkaloids in Coptis as ligands to synthesize iridium complexes. Iridium complexes have potential application value in the field of anti-tumor drugs due to their unique electronic structure and biological activity. Therefore, the combination of alkaloids in Coptis with iridium elements to form new complexes may become a new direction for the research and development of new drugs and promote the expansion of the application of Coptis in modern medicine. SUMMARY

[0007] To achieve the above-mentioned purpose, the iridium photosensitizer synthesized by taking the alkaloid jatrorrhizine in Coptis as an active skeleton has high singlet oxygen generation capacity and shows high phototoxicity to liver cancer cells HepG-2 in vivo and in vitro. Therefore, the present application provides a Coptis alkaloid iridium photosensitizer, a preparation method and application thereof, and the chemical structural formula of the Coptis alkaloid iridium photosensitizer is as follows:

[0008]

[0009] Further, the preparation method of the Coptis alkaloid photosensitizer comprises the following steps:

[0010] Step S1, hydrochloric acid jatrorrhizine and 4-bromomethyl-4'-methyl-2,2'-bipyridine are placed in a reaction bottle at a molar ratio of 1:0.9-1.2 to undergo a substitution reaction to obtain 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L);

[0011] Step S2, the ligand L and dichlorotetra[2-(2-pyridyl)phenyl]diiridium(III) are dissolved in anhydrous methanol solvent at a molar ratio of 1:0.9-1.3 to undergo a coordination reaction to obtain the target Coptis alkaloid iridium photosensitizer (1-Ir).

[0012] Further, the reaction system in step S1 is in an oxygen-free state.

[0013] Further, the reaction temperature of the reaction system in step S1 is 65-90℃, and the reaction time is 4-6h.

[0014] Further, the reaction system in step S2 is in an oxygen-free and anhydrous state.

[0015] Further, the reaction temperature of the reaction system in step S2 is 65-90℃, and the reaction time is 8-24h.

[0016] Further, the Coptis alkaloid iridium photosensitizer is prepared according to the above method.

[0017] Further, the application relates to application of the berberine alkaloid iridium photosensitizer in preparation of a tumor photodynamic therapy drug.

[0018] Further, the tumor is a subcutaneous tumor.

[0019] Compared with the prior art, the application has the following advantages and effects.

[0020] 1. The berberine alkaloid iridium photosensitizer has the characteristics of simple structure, which makes the synthesis path more direct and reduces the complexity in the production process. Meanwhile, as the berberine alkaloid is used as a raw material, it naturally exists in the coptis plant, and compared with some artificially synthesized compounds, the natural product is easier to obtain and has a relatively low cost. In addition, the berberine alkaloid is widely used in traditional Chinese medicine, and its safety has been verified by long-term clinical use, which also provides a favorable basis for the research and development of new drugs.

[0021] 2. The berberine alkaloid iridium photosensitizer has super-high singlet oxygen generation capacity, which is higher than that of the reference material rose Bengal B, and the core performance is excellent. The new photosensitizer has great potential in the treatment of tumors and is expected to become an important breakthrough in the field of anti-tumor drugs, and has a broad application prospect.

[0022] 3. The berberine alkaloid iridium photosensitizer has super-high phototoxicity to cancer cells under laser (535nm, 100mW / cm -2 ) irradiation, and the half-inhibitory concentration IC 50 is as low as 1.65μM, and the in-vivo photoinhibition tumor rate reaches 58.21%. Excellent treatment effect can be achieved at very low concentration, which can effectively reduce the drug dosage and drug cost.

[0023] The above description is only a summary of the technical scheme of the application. In order to more clearly understand the technical means of the application, the contents of the specification can be implemented, and in order to make the above and other purposes, characteristics and advantages of the application more obvious and easy to understand, the following will be described in detail with the preferred embodiments of the application and the accompanying drawings.

[0024] According to the detailed description of the specific embodiments of the application in the following text combined with the drawings, those skilled in the art will more clearly understand the above and other purposes, advantages and characteristics of the application. DETAILED DESCRIPTION

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the accompanying drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual proportions.

[0026] wherein:

[0027] Figure 1 is the chemical structural formula of the iridium photosensitizer of the alkaloid of Coptis;

[0028] Figure 2 is the synthetic route diagram of the iridium photosensitizer of the alkaloid of Coptis;

[0029] Figure 3 is the hydrogen spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L);

[0030] Figure 4 is the carbon spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L);

[0031] Figure 5 is the mass spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L);

[0032] Figure 6 is the hydrogen spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine pyridine iridium photosensitizer (1-Ir);

[0033] Figure 7 is the carbon spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine pyridine iridium photosensitizer (1-Ir);

[0034] Figure 8 is the mass spectrum diagram of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine pyridine iridium photosensitizer (1-Ir);

[0035] Figure 9 Fig. A in the middle is a degradation effect diagram of 1-Ir on ABDA under laser action,

[0036] Fig. B is a degradation effect diagram of Rose Bengal B on ABDA under laser action,

[0037] Fig. C is a rate comparison diagram,

[0038] Fig. D is an EPR spectrum of 1-Ir under light irradiation;

[0039] Figure 10 Figure 11 is a comparison chart of the effect of 1-Ir on cell survival rate under the condition of laser action and non-action;

[0040] Figure 11 Figure 15 is a comparison chart of H&E staining of heart, liver, spleen, lung and kidney organs after treatment;

[0041] Figure 12 Figure 18 is a tumor growth inhibition effect chart in vivo. DETAILED DESCRIPTION

[0042] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. In the following description, specific details such as specific configurations and components are provided only to help a comprehensive understanding of the embodiments of the present application. Therefore, those skilled in the art should understand that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. In addition, in order to be clear and concise, the description of known functions and structures is omitted in the embodiments.

[0043] It should be understood that the "one embodiment" or "the embodiment" mentioned throughout the specification means that the specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present application. Therefore, "one embodiment" or "the embodiment" appearing throughout the specification does not necessarily mean the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner.

[0044] In addition, reference numerals and / or letters can be repeated in different examples in the present application. Such repetition is for the purpose of simplification and clarity, and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0045] The term "and / or" herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that there are three cases of A alone, B alone and A and B together. The term "and" herein is a description of another association relationship of the associated objects, which means that there can be two relationships, for example, A and B can mean that there are two cases of A alone and A and B together. In addition, the character " / " herein generally indicates that the associated objects before and after the " / " are in an "or" relationship.

[0046] The term "at least one", as used herein, merely describes an associated relationship of objects, and indicates that there can be three relationships, for example, at least one of A and B, which can represent three cases: A exists alone, A and B exist together, and B exists alone.

[0047] It should also be noted that in this paper, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion.

[0048] Embodiment 1

[0049] This embodiment introduces a preparation method of a Coptis alkaloid ir photosensitizer, please refer to Figure 1 As shown in the figure, the chemical structural formula of the Coptis alkaloid ir photosensitizer is:

[0050]

[0051] Further, please refer to Figure 2 As shown in the figure, the synthesis route of the Coptis alkaloid photosensitizer is:

[0052]

[0053] Further, the preparation method of the Coptis alkaloid photosensitizer comprises the following steps:

[0054] Step S1, preparing 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L):

[0055] Step S101, place jatrorrhizine (1 mmol) in a round-bottom flask, add 30 mL of anhydrous acetonitrile, and maintain an argon atmosphere;

[0056] Step S102, under continuous stirring, add dropwise to the reaction bottle a solution of 4'-methyl-[2,2'-bipyridine]-4-bromomethyl dissolved in acetonitrile (1.1 mmol, 5 mL), and react the reaction system at 85°C for 6h.

[0057] Step S103, after the temperature of the reaction solution drops to room temperature, slowly add the reaction solution to a beaker containing distilled water (200 mL) and continuously stir, and yellow solid is precipitated, without additional purification, and the yellow solid obtained by suction filtration is 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L).

[0058] Step S2, preparing 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine pyridine ir photosensitizer (1-Ir):

[0059] Step S201, the above ligand L (0.1 mmol), dichloro tetrakis [2-(2-pyridyl) phenyl] iridium (0.12 mmol), dichloromethane (0.5 mL), methanol (4.5 mL) were added to a 30 mL thick-walled glass tube, argon atmosphere, reaction at 85°C for 12h.

[0060] Step S202, after the reaction was completed, the temperature was lowered, and the solvent was removed by natural evaporation to obtain a brown solid, which was purified by column chromatography, eluent V (methanol): V (chloroform) = 1:50, to obtain a light brown solid as a photosensitizer (1-Ir).

[0061] Example 2

[0062] This example introduces a preparation method of a Coptis alkaloid iridium photosensitizer, please refer to the attached Figures 3-4 As shown in the figure, the nuclear magnetic resonance data of 9-(4'-methyl-2,2'-bipyridine) methyl jatrorrhizine ligand (L) obtained based on example 1 is: 1 H NMR (600 MHz, DMSO-d6) δ 9.85 (s, 1H), 9.07 (s, 1H), 8.68 (d, J = 4.9 Hz, 1H), 8.55 (d, J = 4.9 Hz, 1H), 8.43 (d, J = 1.5 Hz, 1H), 8.22 (d, J = 1.6 Hz, 1H), 8.13 (d, J = 9.0 Hz, 1H), 8.02 (d, J = 9.0 Hz, 1H), 7.75 (s, 1H), 7.49 (dd, J = 5.0, 1.7 Hz, 1H), 7.30 (dd, J = 5.0, 1.7 Hz, 1H), 7.15 (s, 1H), 5.34 (s, 2H), 4.96 (t, J = 6.5 Hz, 2H), 4.10 (s, 3H), 4.03 (d, J = 10.1 Hz, 6H), 3.21 (t, J = 6.2 Hz, 2H), 2.42 (s, 3H). 13 C NMR (151 MHz, DMSO-d6) δ 155.91, 155.20, 150.70, 150.36, 149.89, 149.51, 149.40, 148.48, 147.26, 145.79, 144.01, 137.83, 133.43, 128.75, 127.02, 125.59, 123.90, 122.23, 121.77, 121.75, 120.55, 120.07, 118.75, 113.20, 109.51, 68.93, 62.33, 57.43, 56.87, 55.76, 40.50, 26.41, 21.19.

[0063] Please refer to the attachedFigure 5 The obtained 9-(4'-methyl-2,2'-bipyridine)methyl-phenanthroline ligand (L) mass spectrum data is shown as follows: ESI-MS m / z: 520.2538.

[0064] The obtained 9-(4'-methyl-2,2'-bipyridine)methyl-phenanthroline ligand (L) elemental analysis data is as follows:

[0065] The theoretical calculation value is: C 73.83, H 5.81, N 8.07; the experimental test value is: C 73.80, H 5.82, N 8.05.

[0066] The obtained 9-(4'-methyl-2,2'-bipyridine)methyl-phenanthroline ligand (L) molecular formula is: C 32 H 30 N3O4 + .

[0067] Reference is made to the accompanying drawings Figures 6-7 The obtained 9-(4'-methyl-2,2'-bipyridine)methyl-phenanthroline ligand (L) mass spectrum data is shown as follows: ESI-MS m / z: 520.2538.

[0068] 1 H NMR (600 MHz, DMSO-d6) δ 9.86 (s, 1H), 9.07 (s, 1H), 8.71-8.65 (m, 2H), 8.60-8.51 (m, 3H), 8.45 (s, 2H), 8.29-8.22 (m, 2H), 8.15 (d, J = 9.1 Hz, 2H), 8.10-8.01 (m, 3H), 7.96 (d, J = 7.8 Hz, 1H), 7.88 (td, J = 7.7, 1.9 Hz, 1H), 7.76 (s, 1H), 7.73 (dd, J = 7.6, 1.7 Hz, 1H), 7.53-7.46 (m, 4H), 7.30 (dt, J = 5.9, 2.9 Hz, 2H), 7.17 (s, 1H), 5.36 (s, 2H), 4.96 (d, J = 6.2 Hz, 2H), 4.10 (s, 3H), 4.05 (s, 3H), 4.02 (s, 3H), 3.21 (d, J = 6.3 Hz, 2H), 2.42 (s, 3H). 13CNMR(151MHz,DMSO-d6)δ155.95,155.30,155.22,150.73,150.41,149.92,149.53,149.44,148. 96,148.50,148.11,147.30,145.84,144.04,137.87,134.60,133.45,129.62,129.22,128.80,12 8.62,127.36,127.09,126.96,125.60,124.36,123.92,123.07,122.29,121.81,121.77,120.57,120.11,118.81,113.24,109.56,68.97,62.34,57.45,56.87,55.78,40.51,36.27,26.41,21.19.

[0069] Please refer to the attached Figure 8 As shown, the mass spectrum data of the obtained 9-(4'-methyl-2,2'-bipyridyl)methyl jatrorrhizine pyridine iridium photosensitizer (1-Ir) is: ESI-MS m / z: 1019.449.

[0070] The elemental analysis data of the obtained 9-(4'-methyl-2,2'-bipyridyl)methyl pyridine iridium photosensitizer (1-Ir) are as follows:

[0071] The theoretical calculated values ​​are: C 55.66, H 3.89, N 6.01; the experimental tested values ​​are: C 55.64, H 3.90, N6.02.

[0072] Based on the above analysis, the molecular formula of the obtained 9-(4'-methyl-2,2'-bipyridine)methyl pyridine iridium photosensitizer 1-Ir is: C 54 H 45 F6IrN5O4P, the structural formula is: [Ir(L)(bpy)]PF 6。

[0073] Example 3

[0074] This example introduces a test method for a Rhizoma Coptidis alkaloid iridium photosensitizer. Figure 9 The singlet oxygen generating ability of the iridium photosensitizer 1-Ir was tested by ultraviolet absorption spectroscopy and electron spin resonance electron paramagnetic resonance (EPR).

[0075] Firstly, the relative singlet oxygen yield of 1-Ir was tested by chemical method with 9, 10-anthracenediyl-bis(methylene)dimalonic acid (ABDA) as singlet oxygen indicator and Rose Bengal B (RB) as reference, the specific experimental steps are as follows:

[0076] The acetonitrile solution (10 μM) of 1-Ir was mixed with the ABDA solution (10 μM), then irradiated with laser (535 nm, 10 mW / cm -2 ), the absorption spectrum of the mixed solution was detected, and the absorption spectrum and absorbance at 300-400 nm were recorded every 10 min; with Rose Bengal B as reference, the same experiment was carried out.

[0077] Then, the singlet oxygen production ability of 1-Ir was tested by electron EPR technology with 2, 2, 6, 6-tetramethylpiperidine-1-oxyl (TEMP) as singlet oxygen trapping agent.

[0078] The degradation effect of iridium photosensitizer 1-Ir and reference RB on ABDA under the action of laser is shown in FIGS. 9A, 9B and 9C, after laser irradiation, 1-Ir makes ABDA rapidly degrade, and the degradation rate is obviously faster than that of reference RB; and referring to the EPR detection results in FIG. 9D, it can be seen that after 1-Ir is irradiated for different times, the characteristic signal peak of 1:1:1 singlet oxygen can be detected. Figure 9 Figure 9

[0079] In summary, the above prepared iridium photosensitizer 1-Ir has excellent singlet oxygen production ability.

[0080] Example 4

[0081] This example introduces a test method for a Coptis alkaloid iridium photosensitizer, based on the above examples, the toxicity and photodynamic therapy effect of iridium photosensitizer 1-Ir on HepG-2 cancer cells under the action and non-action of laser are detected by MTT method, and the specific experimental steps are as follows:

[0082] The cells in the logarithmic growth phase were inoculated in a 96-well plate at a density of 1×10 5 cells / well, and placed in an incubator (37℃, 5% CO2) for incubation, when the cell density reached 80%, the culture medium containing different concentrations of 1-Ir was added;

[0083] For the laser irradiation group, after 1-Ir was incubated for 16 h, the cells were irradiated with laser (535 nm, 100 mW / cm -2 , 30 min);

[0084] ​​For the group without laser irradiation, the cells were always in the dark, with 0 μM as the control group. After 24 h of incubation, 15 μL of MTT was added to each well, and the incubation was continued for 4 h. The absorbance of the absorption peak at 540 nm was tested by an enzyme marker. The absorbance of 6 wells in each group was averaged, and the standard deviation was calculated to obtain the survival rate of the cancer cells.

[0085] The medium containing different concentrations of iridium photosensitizer 1-Ir was prepared as follows: 1-Ir stock solution with a concentration of 2 mM was prepared using biochemical grade dimethyl sulfoxide. The stock solution was diluted to 2.5 μM, 5 μM, 10 μM, 20 μM, and 40 μM using complete medium (RPMI 1640 containing 10% fetal bovine serum).

[0086] The MTT test results are shown in Table 1. Figure 10 As shown in Table 1, under the action of laser, the survival rate of HepG-2 cells decreased with increasing test concentration. The half-inhibitory concentration IC 50 = 1.65 μM was calculated, which was significantly higher than that in the non-irradiation group, indicating that the prepared iridium photosensitizer 1-Ir had excellent photodynamic therapy effect. Moreover, under the action of laser and without laser, the survival rate of normal liver cancer cells was still high at high concentrations of 1-Ir, indicating that the prepared iridium photosensitizer 1-Ir had excellent biocompatibility.

[0087] Example 5

[0088] This example introduces a test method for a Coptis alkaloid iridium photosensitizer. Based on the above examples, a liver cancer tumor model was established by subcutaneously injecting HepG-2 cells (2 x 10 6 mm in the right flank of mice. When the tumor volume reached 100 mm 3 The tumor-bearing mice were divided into 3 groups (5 mice in each group) for treatment:

[0089] Group 1: no treatment;

[0090] Group 2: injection of iridium photosensitizer 1-Ir through the tail vein;

[0091] Group 3: injection of iridium photosensitizer 1-Ir through the tail vein, and treatment with laser (535 nm, 100 mW / cm -2 , 30 min) 2 h after injection;

[0092] After 14 days of treatment (no mice died during the period), all mice were sacrificed, and tumor and main organ tissues (heart, liver, spleen, lung, kidney) were collected, photographed, weighed, and recorded.

[0093] The H&E staining results of the organs after photodynamic therapy of the iridium photosensitizer 1-Ir on the mouse breast cancer subcutaneous tumor model are shown in Table 2. Figure 11As shown, the main organs of the experimental group have no obvious histopathological changes, which again indicates that the prepared iridium photosensitizer 1-Ir has excellent biocompatibility;

[0094] And, please refer to Figure 12 The results show that the tumor inhibition rate of the laser irradiation group reaches 58.21%, which is higher than that of the non-laser irradiation group 42.85%, indicating that the prepared iridium photosensitizer 1-Ir has excellent photodynamic therapy effect.

[0095] The above only describes the preferred embodiments of the present application, and does not limit the protection scope of the present application. For those skilled in the art, the present application can have various changes and variations. Any changes, modifications, replacements, integrations and parameter changes of these embodiments within the spirit and principles of the present application, which can realize the same functions without departing from the principles and spirit of the present application, fall within the protection scope of the present application.

Claims

1. A Rhizoma Coptidis alkaloid iridium photosensitizer, characterized in that: The chemical structural formula of the Coptis chinensis alkaloid iridium photosensitizer is: 。 2. The method for preparing a Rhizoma Coptidis alkaloid photosensitizer according to claim 1, wherein: The following steps are involved: Step S1, placing jatrorrhizine hydrochloride and 4-bromomethyl-4'-methyl-2,2'-bipyridine in a reaction bottle at a molar ratio of 1:0.9-1.2, and then carrying out a substitution reaction to obtain 9-(4'-methyl-2,2'-bipyridine)methyljatrorrhizine ligand L; Step S2: dissolving the ligand L and dichlorotetrakis[2-(2-pyridyl)phenyl]diiridium(III) in anhydrous methanol solvent at a molar ratio of 1:0.9-1.3, and then undergoing coordination reaction to obtain the target Coptis chinensis alkaloid iridium photosensitizer 1-Ir.

3. The method for preparing a Rhizoma Coptidis alkaloid photosensitizer according to claim 2, wherein: The reaction system in step S1 is in an oxygen-free state.

4. The method for preparing a Rhizoma Coptidis alkaloid photosensitizer according to claim 3, wherein: The reaction temperature of the reaction system in step S1 is 65-90° C., and the reaction time is 4-6 hours.

5. The method for preparing a Rhizoma Coptidis alkaloid photosensitizer according to claim 2, wherein: The reaction system in step S2 is in an oxygen-free and water-free state.

6. The method for preparing a Rhizoma Coptidis alkaloid photosensitizer according to claim 5, characterized in that: The reaction temperature of the reaction system in step S2 is 65-90° C., and the reaction time is 8-24 hours.

7. Use of the coptis alkaloid iridium photosensitizer according to claim 1 in the preparation of drugs for tumor photodynamic therapy.

8. The use of a Coptis chinensis alkaloid iridium photosensitizer according to claim 7, characterized in that: The tumor is a subcutaneous tumor.

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