Water-soluble BODIPY photosensitizer as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of preparation of antitumor drugs, and particularly relates to a water-soluble BODIPY photosensitizer as well as a preparation method and application thereof, and a BODIPY structure is modified with a COX-2 targeting unit and a PEG chain to obtain a nano probe I-M-BDP which can be self-assembled and has amphipathy. The I-M-BDP shows specific affinity to tumor cells of the overexpressed COX-2, and has good biocompatibility. Compared with a contrast compound M-BDP, the compound provided by the invention has better imaging effect and phototoxicity, and also shows better PDT in a tumor-bearing Balb / c mouse model. The concentration of the photosensitizer in the tumor tissue is improved due to the specific enrichment of I-M-BDP on the tumor.

Description

Technical Field

[0001] The invention belongs to the technical field of anti-tumor drug preparation, and specifically relates to a water-soluble BODIPY photosensitizer and a preparation method thereof and application thereof in the preparation of anti-tumor targeted drugs. Background Art

[0002] Cancer remains the leading cause of death worldwide. Cancer treatment has always faced huge challenges. Traditional treatments have certain side effects. Therefore, it is urgent to study safe and effective cancer treatment strategies. Photodynamic therapy (PDT) is a very promising minimally invasive light therapy that has been used to treat various cancers. PDT has the advantages of tumor selectivity, repeated treatment and low drug resistance, and has attracted widespread attention. PDT is based on the fact that photosensitizers (PS) are excited by light of a specific wavelength to produce cytotoxic reactive oxygen species (ROS), especially singlet oxygen ( 1 O2), thereby inducing tumor cell death. In recent years, organic molecules have been widely used in the field of photodynamic therapy due to their safety and easy modification. In addition, their photophysical and therapeutic properties can be precisely controlled by molecular structure. However, there are still many key issues to be solved in organic photosensitizers: (1) Lack of specificity. Due to the nonspecific distribution of organic photosensitizers in the body, it is difficult to distinguish between tumor cells and normal cells, and tumor-specific treatment cannot be achieved; (2) Organic molecules themselves have poor water solubility and are prone to aggregation in aqueous solutions, resulting in the inability to be transported to tumor tissues through the blood, and aggregation-induced fluorescence quenching (ACQ) will occur; (3) The excitation wavelength of traditional photosensitizers is short. Therefore, solving these problems is currently the key to improving the therapeutic effect of organic photosensitizers.

[0003] Studies have shown that the amount of certain enzymes in tumor cells increases significantly. Taking advantage of this property, researchers have designed photosensitizers (PS) targeting these enzymes to improve the specificity of PS in cancer tissues. Cyclooxygenase-2 (COX-2) is significantly overexpressed in many cancer types, such as gastric cancer, colorectal cancer, and pancreatic cancer. In contrast, the expression level of COX-2 in normal cells is relatively low. As a prostaglandin-peroxisomal synthase, the high expression of COX-2 in tumor tissues and cells reveals its potential role in cancer progression, and its overexpression is associated with all stages of cancer and increases with the progression of cancer. Therefore, COX-2 has been developed as a fluorescent probe to distinguish cancer cells from normal cells. However, there are few reports on improving the selectivity of photosensitizers by targeting COX-2. Indomethacin (IMC) is a commercially available nonsteroidal anti-inflammatory drug. IMC has been shown to bind to the large hydrophobic side pocket of COX-2 homodimers. Therefore, IMC was selected as the specific recognition part of COX-2 imaging probe, and its dual targeting to tumors and subcellular has been verified. However, only a few photosensitizers have been developed and combined with IMC, mainly because of the weak absorbance in the long wavelength (near infrared) region, resulting in low photodynamic therapy efficiency and insufficient affinity with tumor tissue.

[0004] Since general photosensitizers have obvious limitations in terms of light penetration, water solubility and selectivity, and their performance is significantly affected in anoxic environments, designing and synthesizing highly efficient biological photosensitizers remains a challenging task. Generally, biological photosensitizers have poor hydrophilicity and are prone to aggregation, which leads to the formation of larger photosensitizer particles that cannot effectively pass through the cell membrane, thereby affecting the cell's uptake efficiency. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention uses indomethacin, N-(6-aminohexyl) tert-butyl carbamate, triethylene glycol monomethyl ether, 3,4,5-trihydroxybenzaldehyde, 2.4-dimethylpyrrole, methyl p-formylbenzoate and benzenesulfonyl chloride as main raw materials, and adopts a step-by-step synthesis method to synthesize N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide, 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde and 4-(5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborol-10-yl)benzoic acid, through Knoevenagel condensation and amidation of photosensitizer; a water-soluble BODIPY photosensitizer (IM-BDP) is constructed. The water-soluble BODIPY photosensitizer of the present invention utilizes the hydrophilicity of PEG and the specific targeting of indomethacin to tumors to achieve specific enrichment of the IM-BDP photosensitizer in tumor cells and achieve specific targeting to tumors.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A water-soluble BODIPY photosensitizer IM-BDP targeting cyclooxygenase-2, wherein the photosensitizer IM-BDP is a spherical nanoparticle, and a hydrophilic PEG chain is introduced into the BODIPY matrix, and then coupled with hydrophobic indomethacin, and self-assembles to form nanoparticles with good dispersion effect in water through hydrophilic and hydrophobic interactions. The molecular formula of the IM-BDP is: C 101 H 137 BClF2I2N5O 28 , the structural formula is as follows:

[0008]

[0009] The present invention also provides a method for synthesizing the IM-BDP, and the specific steps are as follows:

[0010] Under the conditions of acetic acid and piperidine, 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid and 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde underwent Knoevenagel condensation to give 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid; 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is then subjected to amidation reaction with N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide under HATU conditions to finally obtain IM-BDP;

[0011]

[0012] The 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 The structural formula of -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is:

[0013] The structural formula of the 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde is:

[0014]

[0015] The structural formula of the N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide is:

[0016]

[0017] Preferably, the 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid and 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde in a molar ratio of 1:2.5;

[0018] Preferably, the 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 The molar ratio of -dipyrrolic[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid to N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide and HATU is 1:1.5:1.

[0019] Preferably, the synthesis method of the N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide is as follows:

[0020]

[0021] Under HATU catalysis and DIPEA conditions, N-(6-aminohexyl)carbamic acid tert-butyl ester and indomethacin are subjected to amidation reaction (preferably, the molar ratio of indomethacin to N-(6-aminohexyl)carbamic acid tert-butyl ester=5:7.5); then, under trifluoroacetic acid conditions, de-BOC is carried out to finally obtain N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide;

[0022] The N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide has a strong effect on COX-2 because COX-2 has a hydrophobic cavity that interacts with indomethacin, allowing it to be firmly embedded in COX-2.

[0023] Preferably, the synthesis method of the 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde is as follows:

[0024] Triethylene glycol monomethyl ether and benzenesulfonyl chloride undergo a substitution reaction to obtain a sulfonylated product, and the sulfonylated product reacts with 3,4,5-trihydroxybenzaldehyde under a nitrogen atmosphere and a weak base (preferably, the molar ratio of the sulfonylated product to 3,4,5-trihydroxybenzaldehyde is 1:4) to finally obtain 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde;

[0025] The 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde molecule has three long ether chains and can form multiple hydrogen bonds with water molecules, so it has good water solubility.

[0026] Preferably, the 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 The synthesis method of -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is as follows:

[0027] (1) In the presence of trifluoroacetic acid in a protective gas atmosphere, 2,4-dimethylpyrrole reacts with methyl paraformylbenzoate, DDQ is added and stirred to react completely, and then triethylamine and boron trifluoride-ether complex are added to react to obtain methyl 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoate;

[0028] (2) In a protective gas atmosphere, under alkaline conditions, methyl 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrole [1,2-c: 2',1'-f][1,3,2]diazaborolidine indol-10-yl) benzoate was dissolved and refluxed to obtain 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid; under iodic acid conditions, 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid reacts with iodine to give 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid;

[0029] Preferably, the molar ratio of the 2,4-dimethylpyrrole to methyl paraformylbenzoate and DDQ is 2:1:1; the 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid to iodine and iodic acid in a molar ratio of 1:2.5:2;

[0030] The IM-BDP molecule contains indomethacin and multiple ether chains, which enable it to have good water solubility in aqueous solution and the ability to target COX-2 overexpressed cancer cells, and can generate a large amount of ROS under light conditions, and has a good PDT treatment effect;

[0031] Therefore, the present invention also provides the use of the above IM-BDP or the IM-BDP obtained by the above synthesis method in the preparation of COX-2 fluorescent probes or anti-tumor targeted drugs.

[0032] Compared with the prior art, the technical solution of the present invention has the following advantages and beneficial effects:

[0033] 1. The novel BODIPY photosensitizer designed and synthesized by the present invention is synthesized by convergent reaction, which has the advantages of high yield, NIR (mainly in the first near infrared NIR-I window, 650-900nm) fluorescence emission and excellent ROS generation performance, which is beneficial to its application in the biomedical field.

[0034] 2. The novel amphiphilic small molecule (IM-BDP) designed and synthesized by the present invention has tumor cell targeting and self-assembly properties, and can self-assemble to form core-shell nanomicelles in aqueous solution.

[0035] 3. The average particle size of the IM-BDP photosensitizer micelle is 134nm, and it has EPR (high permeability and long retention) effect, and has great application potential in biological fields such as the preparation of drug carriers and controlled drug release.

[0036] 4. The present invention uses BODIPY as a photosensitizer matrix and modifies functional functional groups to synthesize a near-infrared water-soluble BODIPY photosensitizer with tumor targeting ability. By coupling BODIPY with indomethacin to enhance the targeting ability of the photosensitizer, and introducing a PEG chain to enhance its water solubility, a photosensitizer IM-BDP with targeting ability to tumor cells overexpressing cyclooxygenase (COX-2) is obtained. The results show that IM-BDP has good targeting ability and low cytotoxicity to tumor cells. The breast cancer mouse model is used to demonstrate the practical application of the PDT treatment platform based on IM-BDP, and good results have been achieved. The commonly used BODIPY photosensitizer is not water-soluble, while the photosensitizer with a PEG chain has good water solubility. Compared with commonly used polymer micelles, the molecules themselves can self-assemble micelles, which have the advantages of non-toxicity, good biocompatibility and functional diversity, and the photosensitizer encapsulated by amphiphilic polymers must consider the issue of encapsulation content. By coupling indomethacin to the molecule, the molecule can be more targeted and retained in tumors, providing new research ideas for accurate visual tumor diagnosis and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 The IM-BDP synthesized in Example 1 1 H NMR spectrum;

[0038] Figure 2 This is the MALDI-TOF MS spectrum of IM-BDP synthesized in Example 1;

[0039] Figure 3 The absorption and emission spectra of IM-BDP synthesized in Example 2;

[0040] Figure 4 TEM and DLS spectra of IM-BDP synthesized in Example 3;

[0041] Figure 5 This is a graph showing the ROS generation performance test results of IM-BDP in Example 4;

[0042] Figure 6 This is a diagram showing the experimental results of cellular uptake of IM-BDP in Example 5;

[0043] Figure 7 The figure is the result of the dark cytotoxicity and phototoxicity experiment of IM-BDP in Example 5; Figure 8 This is a diagram showing the results of the tumor cell targeting inhibition experiment of IM-BDP in Example 5;

[0044] Fig. 9 This is a diagram showing the results of the cell co-localization experiment of IM-BDP in Example 5;

[0045] Fig.10 This is a graph showing the results of the cell live-dead staining experiment of IM-BDP in Example 5;

[0046] Fig.11 This is a graph showing the experimental results of the ROS production performance of IM-BDP in tumor cells in Example 5;

[0047] Fig.12 This is a diagram showing the results of the IM-BDP tumor-bearing mouse imaging experiment in Example 6;

[0048] Fig.13 This is a graph showing the results of the IM-BDP tumor-bearing mouse treatment experiment in Example 6. DETAILED DESCRIPTION

[0049] The applicant will describe the technical solution of the present invention in detail below in conjunction with specific embodiments and drawings, so that those skilled in the art can clearly understand the present invention. However, the following embodiments should not be interpreted in any way as limiting the scope of protection claimed in the claims of the present invention.

[0050] The reagents used in the following examples are all common commercially available products, and the purity level is all analytical grade.

[0051] In the following examples, the ratios between the liquids during extraction and elution refer to volume ratios.

[0052] Example 1. Synthesis of IM-BDP

[0053]

[0054] (1) Synthesis of Compound 1

[0055] Indomethacin (5mmol), tert-butyl N-(6-aminohexyl)carbamate (7.5mmol), HATU (5mmol) were added to a round-bottom flask, and DMF (20mL) was added, and N,N-diisopropylethylamine DIPEA (5mmol) was added dropwise, and stirred at room temperature (25°C, the same below) overnight (the specific time of overnight in the present invention refers to 12h). The reaction was monitored by thin layer chromatography (developing agent ethyl acetate / petroleum ether = 4:1, v / v). After the raw materials reacted, the reaction was stopped, and the mixture was extracted with a mixed solution of dichloromethane (50mL) and water (dichloromethane / water = 1 / 10), and the organic layer was taken and dried with anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure. The crude product was purified by silica gel column chromatography using dichloromethane as an eluent to obtain a light yellow solid, namely compound 1, and the yield of this step was 55%.

[0056] 1 H NMR(400MHz,Chloroform-d)δ7.71–7.63(m,2H),7.54–7.45(m,2H),6.93–6.83(m,2H),6.71(dd,J=9.0,2.5Hz,1H),5.77(s,1H),4.55(d ,J=6.9Hz,1H),3.83(s,3H),3.65(s,2H),3.20(q,J=6.7Hz,2H),3.10–2.95(m,2H),2.40(s,3H),1.31-1.42(m,13H),1.15-1.26(m,4H).

[0057] (2) Synthesis of compound 2-(N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide)

[0058] Compound 1 (1.77 mmol) and DMF (10 mL) were added to a round-bottom flask, and trifluoroacetic acid (18 mmol) was added dropwise. The mixture was reacted at room temperature for 30 min. The reaction mixture was distilled under reduced pressure to remove the solvent. The crude product was purified by silica gel column chromatography using (dichloromethane / methanol = 1:50) as the eluent to obtain (N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide) as a white solid. The yield of this step was 85%. 1H NMR (600MHz, DMSO-d6) δ7.71–7.63(m,4H),7.12(d,J=2.6Hz,1H),6.93(d,J=9.0Hz,1H),6.71(dd,J=9.0,2.6Hz,1H),3.76(s,3H),3 .49(s,2H),3.05(q,J=6.6Hz,2H),2.78–2.72(m,2H),2.23(s,3H),1.48(q,J=7.5Hz,2H),1.39(q,J=7.1Hz,2H),1.26–1.24(m,4H).

[0059] (3) Synthesis of Compound 3

[0060] In a round-bottom flask, triethylene glycol monomethyl ether (60.9 mmol) was dissolved in 50 mL of tetrahydrofuran, stirred evenly at 0°C in a cold trap, 30 mL of sodium hydroxide aqueous solution (20%) was added, and then benzenesulfonyl chloride solution (12 g of benzenesulfonyl chloride was dissolved in 50 mL of THF) was added dropwise under constant pressure. After 30 min of complete addition, the mixture was stirred at room temperature for 12 h, the pH was adjusted to 7.0 with 3 mol / L hydrochloric acid, and then extracted with 50 mL of dichloromethane. The organic layer was washed three times with deionized water (300 mL each time), dried with anhydrous sodium sulfate, filtered, and the filtrate was distilled under reduced pressure to obtain a pale yellow oily crude product, which was purified by silica gel column chromatography using (petroleum ether / dichloromethane=10 / 1) as an eluent to obtain a sulfonylated product, i.e., compound 3, which was a colorless oily liquid for standby use. The yield of this step was 54%. 1 H NMR(600MHz,Chloroform-d)δ7.85–7.80(m,2H),δ7.20–7.32(m,1H)7.05–6.99(m,2H),4.24–4.20(m,2H),3 .91–3.88(m,2H),3.77–3.74(m,2H),3.71–3.68(m,2H),3.67–3.64(m,2H),3.57–3.53(m,2H),3.38(s,3H).

[0061] (4) Synthesis of compound 4-(3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde)

[0062] 150 mL of N,N-dimethylformamide was added to a three-necked flask and nitrogen was passed through for 30 min. 3,4,5-trihydroxybenzaldehyde (7.85 mmol) was added thereto. The sulfonylated product (31.41 mmol) and potassium carbonate (47.11 mmol) obtained in step (3) were added under nitrogen. The mixture was stirred evenly and heated to 90° C. for reaction for 24 h. The mixture was cooled to room temperature and extracted with 100 mL of dichloromethane. The organic layer was washed three times with saturated sodium chloride aqueous solution (200 mL each time), dried over anhydrous sodium sulfate, filtered, and the filtrate was concentrated by distillation under reduced pressure. The filtrate was purified by silica gel column chromatography using (petroleum ether / dichloromethane=2 / 1) as the eluent to obtain a light brown oily liquid - compound 4, which was used for later use. 1 H NMR(600MHz,Chloroform-d)δ9.75(s,1H),7.07(s,2H),4.20(t,J=4.6Hz,2H),4.16(t,J=4.5Hz,4H),3.81(t,J=4.5Hz, 4H), 3.74 (d, J=4.7Hz, 3H), 3.69–3.63 (m, 6H), 3.58 (ddt, J=15.5, 10.7, 4.5Hz, 12H), 3.47 (q, J=4.4Hz, 6H), 3.31 (s, 9H).

[0063] (5) Synthesis of Compound 5

[0064] Under nitrogen protection, add 2,4-dimethylpyrrole (6.25mL, 60.96mmol) and methyl p-formylbenzoate (5g, 30.48mmol) to a 1L three-necked flask, add appropriate amount of dichloromethane to dissolve, stir for 15min, add 0.4mL trifluoroacetic acid, stir well overnight at room temperature to obtain a mixed solution. Add dichlorodicyanobenzoquinone DDQ (7g, 30.48mmol) to the mixed solution, and continue stirring at room temperature for 4h. Add triethylamine (76.2mL, 60.96mmol) to it, stir for 20min, then add boron trifluoride-ether complex (76.2mL, 60.96mmol), continue the reaction for 12h and then stop the reaction. The reaction solution obtained above was washed with saturated brine, and the organic phase was collected and concentrated by evaporation. The mixture was separated and purified by silica gel column chromatography using dichloromethane as eluent. The bright green fluorescent solution was collected and concentrated by evaporation to obtain a bright green solid, namely compound 5. The yield of this step was 17.17%. 1 H NMR (600MHz, Chloroform-d) δ8.18(d,J=7.8Hz,2H),7.41(d,J=7.8Hz,2H),5.99(s,2H),3.97(s,3H),2.56(s,6H),1.36(s,6H).

[0065] (6) Synthesis of Compound 6

[0066] Compound 5 (1 g, 2.6 mmol) was added to a three-necked flask containing methanol (150 mL) under nitrogen conditions, and 15 mL of a 15% NaOH solution was added dropwise. The above mixture was refluxed at 80°C for 4 hours. TLC (developing agent ethyl acetate / petroleum ether = 4:1, v / v) was used for monitoring. After the raw materials were completely reacted, the reaction was stopped. After cooling to room temperature, a 15% HCl solution was added to the solution to acidify it, and the pH was adjusted to 3-4, and a solid precipitated. Filter, wash the filter cake repeatedly with distilled water until the pH of the filtrate is 7, and dry to obtain a red crude product. Using (chloroform / methanol = 95:5, v / v) as the eluent, the crude product was purified by silica gel column chromatography to obtain a red solid, namely compound 6, with a yield of 93% in this step. 1 H NMR (600MHz, DMSO-d6) δ8.14–8.06(m,2H),7.57–7.47(m,2H),6.20(s,2H),2.46(s,6H),1.33(s,6H).

[0067] (7) Compound 7 (4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -Bipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid)

[0068] Under nitrogen, compound 6 (1 g, 3.08 mmol) and iodine (1.95 g, 7.69 mmol) and ethanol (50 mL) were added to a round-bottom flask. Stir at room temperature, dissolve iodic acid (2.5 g, 6.11 mmol) in water (5 mL), and add dropwise to the above round-bottom flask. Heat to 60 ° C and stir for 1 h. Monitor the reaction by TLC (developing agent ethyl acetate / petroleum ether = 4:1, v / v), and stop the reaction after the raw material point disappears completely. Extract with a mixed solution of 100 mL of dichloromethane and 300 mL of water, take the organic layer, add anhydrous sodium sulfate to dry, concentrate under reduced pressure, use dichloromethane as the eluent, and purify the crude product by silica gel column chromatography to obtain a red solid, i.e., compound 7, with a yield of 60% in this step. 1 H NMR (600MHz, DMSO-d6) δ8.11(d,J=7.7Hz,2H),7.52(d,J=7.7Hz,2H),2.55(s,6H),1.33(s,6H).

[0069] (8) M-BDP (4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 Synthesis of dipyrrolic acid (1,2-dipyrrolic acid [1,2-c:2',1'-f] [1,3,2] diazaboryl] benzoic acid)

[0070] In a three-necked flask, 50 mL of anhydrous toluene was added, and after nitrogen was passed for 30 min, compound 7 (1 g, 1.6 mmol) was added, followed by compound 4 (2.4 g, 4.03 mmol), followed by 1 mL of acetic acid, and finally 1 mL of piperidine. Under nitrogen protection, the mixture was heated to 120° C. and stirred overnight. The mixture was cooled to room temperature and extracted with a mixture of 100 mL of dichloromethane and 300 mL of water. The organic layer was taken and dried over anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure. The crude product was purified by silica gel column chromatography using (dichloromethane / methanol=20 / 1) as the eluent to obtain 200 mg of a gray-green oily liquid, namely M-BDP. The yield of this step was 37%. 1 H NMR(600MHz,Chloroform-d)δ7.91(d,J=16.5Hz,2H),7.41(d,J=16.5Hz,2H),7.32(s,3H),6.84(d,5H),4.23(t,J=5.5Hz,12 H),3.87(t,J=4.7Hz,8H),3.81(m,6H),3.78–3.70(m,12H),3.68–3.61(m,24H),3.54(dd,J=5.9,3.5Hz,12H),3.37(s,18H).

[0071] (9)IM-BDP synthesis

[0072] Compound M-BDP (1mmol), compound 2 (1.5mmol), HATU (1mmol) were added to a round-bottom flask, 7mL DMF was added, DIPEA (5mmol) was added dropwise, and the mixture was stirred at room temperature overnight. The reaction was monitored by thin layer chromatography (developing agent ethyl acetate / petroleum ether = 4:1, v / v). After the reaction of the raw materials was completed, the reaction was stopped, and a mixed solution of 100mL dichloromethane and 300mL water was used for extraction. After the organic layer was taken, anhydrous sodium sulfate was added for drying, and the solvent was removed by vacuum distillation. Dichloromethane was used as an eluent, and the crude product was purified by silica gel column chromatography to obtain a compound as a green colloid, namely IM-BDP, with a yield of 35% in this step.

[0073] 1H NMR(600MHz,Chloroform-d)δ8.02(d,J=8.1Hz,2H),7.95(d,J=16.5Hz,2H),7.69–7.66(m,4H),7.49(dd,J= 9.2,2.0Hz,6H),6.85(s,5H),4.21(t,J=13.1,5.2Hz,12H),3.86(t,J=5.0Hz,11H),3.82–3.78(m,8H),3.72 (m,J=11.5,2.9Hz,12H),3.64(m,J=14.0Hz,24H),3.54(dd,J=15.0Hz,12H),3.39–3.33(s,18H),3.25(m,2H ),3.11(t,2H),2.40(s,3H),1.44(s,2H).CalcdforC101H137BClF2I2N5O28[M]+,2206.732; found,2206.32.

[0074] The molecular weight was determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the actual molecular weight was 2206.327. Figure 2 , which is consistent with the theoretical value (theoretical molecular weight is 2206.732). 1 H NMR data ( Figure 1 ), proving that the IM-BDP photosensitizer was successfully synthesized.

[0075] Example 2: UV absorption spectrum and fluorescence spectrum characterization

[0076] The concentration of photosensitizer IM-BDP was prepared to 1.0×10 -2 The photophysical properties of the photosensitizer were measured in 10 mM pH = 7.4 PBS buffer, and the photosensitizer was diluted to 10 μM before each spectral measurement. The photophysical properties of IM-BDP were characterized by UV-visible absorption spectroscopy and fluorescence spectroscopy. Figure 3 As shown, IM-BDP has an obvious absorption peak at 665nm, and the maximum emission wavelength of IM-BDP is around 720nm, which indicates that the photosensitizer has good absorption and emission in the near-infrared region.

[0077] Example 3: Material Characterization Experiment

[0078] The photosensitizer IM-BDP was prepared with deionized water to a concentration of 100 mM, and the sample morphology was characterized by transmission electron microscopy (TEM) and the sample particle size was measured by dynamic light scattering (DLS). Figure 4As shown in A, the hydrodynamic average particle size of IM-BDP detected by DLS is 134nm. The TEM image (4B) shows that IM-BDP is a spherical particle with uniform size, with a particle size of about 80-120nm. The difference in size between TEM and DLS may be due to the shrinkage of the water layer during the drying process of TEM sample preparation.

[0079] Example 4: Photodynamic performance test

[0080] In vitro IM-BDP 1 The O2 yield was tested using 1,3-diphenylisobenzofuran (DPBF) as a scavenger. The photodynamic properties of the compounds were evaluated using UV-visible absorption spectroscopy. 2 ) as the excitation source. The mixed aqueous solution containing IM-BDP (10 μM) and DPBF (50 μM) was transferred to a quartz cuvette and excited with 660 nm (40 mW / cm 2 ) for a certain period of time, and the absorbance of DPBF at 418 nm was monitored, with an aqueous solution of DPBF (50 μM) as a control. Figure 5 (A) and (C) Figure 5 (C), A0 is the original absorbance value of each group before laser irradiation). As the laser irradiation time increases, the absorption peak intensity of the DPBF solution with IM-BDP added at 418 nm continues to decrease, while the absorption peak intensity of the DPBF solution without IM-BDP at 418 nm remains basically unchanged ( Figure 5 (B) and (C)), indicating that IM-BDP has singlet oxygen ( 1 O2) production capacity.

[0081] Select TEMP as 1 Spin trapping agent for O2, further verified by electron paramagnetic resonance (EPR) spectroscopy 1 O2 is produced. Figure 5 (D) shows the electron paramagnetic resonance signal (red line) and the EPR signal (black line) of a mixed aqueous solution containing IM-BDP (1 mM) and TEMP (100 μM) after 660 nm laser irradiation. 1 O2 matches the characteristic paramagnetic adduct, indicating that the ROS generated is 1 O2.

[0082] Example 5. Evaluation of the therapeutic efficacy of IM-BDP at the cellular level

[0083] 4T1 cells (Wuhan Punosai Company, other subsequent cells were purchased from the company) were cultured in DMEM medium (1% penicillin / streptomycin and 10% fetal bovine serum) and incubated in a 37°C cell culture incubator containing 5% CO2. Before fluorescence imaging, the cells were seeded into confocal dishes at an appropriate density and cultured in a 37°C cell culture incubator containing 5% CO2 for 24 hours to obtain 4T1 cell suspensions, and the following detection experiments were performed.

[0084] Unless otherwise specified, the following cell cultures were all cultured at 37° C. in a cell culture incubator containing 5% CO 2 ; the culture medium used was DMEM culture medium (1% penicillin / streptomycin and 10% fetal bovine serum).

[0085] IM-BDP cell uptake experiment: 4T1 cells were seeded in a confocal dish and placed in a (37°C, 5% CO2) incubator for 24 hours. After the cells adhered to the wall, the dish was washed with PBS (10mM pH=7.4 PBS buffer, the same below), and 1mL of culture medium containing 10μM IM-BDP was added for continued incubation. The confocal imaging results of 4T1 cells at different incubation times were collected. Figure 6 As shown, with the increase of incubation time, IM-BDP can be taken up by tumor cells, and the fluorescence intensity reaches the maximum value at 120min to 150min, which provides a reference for the incubation time of cells on the material during subsequent treatment.

[0086] IM-BDP cytotoxicity test: The phototoxicity and dark toxicity of IM-BDP were detected by CCK8 assay.

[0087] 4T1 cells were suspended at 5×10 3 The cells were inoculated into a 96-well plate at a density of 100 μM / well and cultured in a cell culture incubator for 24 h. After the cells adhered to the wall, the culture medium was removed and IM-BDP solutions with concentrations of 0, 0.5, 1, 2.5, 5, and 10 μM were prepared with DMEM culture medium and 100 μL was added to each well. After incubation for 2 h, the cells were illuminated with a 660 nm laser (40 mW / cm 2 ) irradiate each well for 10 min, incubate for another 12 h, aspirate the medium, add 100 μL of fresh medium and 10 μL of CCK8 solution to each well, and incubate in a 5% CO2 incubator for 1 h, then record the absorbance at 450 nm with a microplate reader. Calculate cell viability according to the following equation:

[0088] Cell Viability(%)=

[0089] ((ODsample-ODbackground) / (ODcontrol-ODbackground))*100%;

[0090] ODsample: experimental group (culture medium containing cells, CCK8, IM-BDP);

[0091] ODcontrol: control group (medium containing cells, CCK8, and no IM-BDP);

[0092] ODbackground: blank group (medium without cells and IM-BDP, CCK8);

[0093] A control group was set up in the dark (-light, without laser irradiation).

[0094] The cell viability of 4T1 cells after incubation with different concentrations of IM-BDP (0-10 μM) for 2 h was determined using the CCK8 kit. Figure 7 As shown in Figure 2, under dark conditions (-light), as the concentration of the photosensitizer increases, when the concentration of IM-BDP reaches 10 μM, the cell survival rate is still above 90%, indicating good biocompatibility. 2 ) laser irradiation for 10 minutes, with the continuous increase of IM-BDP concentration, the survival rate of cells continued to decrease. When the concentration reached 10μM, the survival rate of 4T1 cells was less than 20%. This result shows that IM-BDP can effectively kill tumor cells under laser irradiation. IM-BDP has high phototoxicity and has a good inhibitory effect on the growth of tumor cells.

[0095] Cell-targeted inhibition experiment: cells were seeded in a small dish and placed in a (37°C, 5% CO2) incubator for 24 hours. After the cells adhered to the wall, the dish was washed with PBS, and then a medium containing 15 μM Aceclofenac was added and incubated for 2 hours. After that, the medium was aspirated, 1 mL of a medium containing 10 μM IM-BDP was added, and the dish was placed in a (37°C, 5% CO2) incubator for 2 hours. After washing with PBS three times, confocal imaging was performed. Figure 8 As shown in the figure, the IM-BDP group is a control group without "adding medium containing 15μM Aceclofenac and incubating for 2h". IM-BDP has obvious fluorescence signals in different types of tumor cells, while the fluorescence signal in normal cells is very weak and negligible. After being treated with the COX-2 inhibitor Aceclofenac, the fluorescence signals of different types of cells are very weak. The results show that IM-BDP can stain tumor cells well, is insensitive to normal cells, and has fluorescence signals only when it interacts with COX-2 in cells.

[0096] Organelle co-localization experiment:

[0097] 4T1 cells were seeded in a small dish and placed in a (37°C, 5% CO2) incubator for 24 hours. After the cells adhered to the wall, the dish was washed with PBS, 1 mL of culture medium containing 10 μM IM-BDP (or 10 μM M-BDP) was added, and the dish was placed in a (37°C, 5% CO2) incubator for 1 hour. The 4T1 cells were then treated with Golgi-Tracker Green for 30 minutes, and then washed with PBS three times before imaging. Fig. 9 As shown, the photosensitizer IM-BDP and Golgi-Tracker Green have good overlap, with the Pearson coefficient reaching 0.685, while the Pearson coefficient of M-BDP and Golgi-Tracker Green is only 0.210, which indicates that the Pearson coefficient of the photosensitizer IM-BDP is much larger than that of M-BDP, and IM-BDP can be preferentially distributed in the Golgi apparatus, laying the foundation for subsequent treatment.

[0098] Live and dead cell staining:

[0099] The AM-PI live / dead cell staining kit was used to stain 4T1 cells treated with different conditions. Calcein-AM (green) and propidium iodide (PI, red) were used to detect live cells and dead cells, respectively.

[0100] 4T1 cells were seeded in a confocal dish and cultured for 24 h. The culture medium was aspirated and 1 mL of 10 μM IM-BDP DMEM solution was added and incubated for 2 h. 2 ) laser irradiated cells for 10 min and continued to culture for 12 h. PBS (1 mL) containing AM (4 μM) and PI (6 μM) was added to stain the cells for 20 min and confocal imaging was performed. The following control groups were set up at the same time: IM-BDP (without laser irradiation), light (with laser irradiation, without IM-BDP) and PBS control group (without laser irradiation, without IM-BDP).

[0101] like Fig.10 As shown, the IM-BDP, light and PBS control groups have green fluorescence in the green channel and no obvious red fluorescence in the red channel, indicating that the cells can still survive well after being treated with these three conditions. After being treated with IM-BDP+light (laser irradiation), there is no obvious green fluorescence in the green channel, but there is obvious red fluorescence in the red channel. This shows that IM-BDP can almost completely kill 4T1 cells under 660nm laser irradiation. The results show that when co-incubated with IM-BDP and treated with light, the cytotoxicity is the greatest and the treatment effect is the best.

[0102] Intracellular 1 O2 detection: using DCFH-DA probe to detect intracellular 1 4T1 cells were treated with IM-BDP in DMEM (10 μM) for 2 h at 37°C and then illuminated with a 660 nm laser (40 mW / cm 2 ) irradiate the cells for 10 min and continue culturing for 12 h. Aspirate the original culture medium, incubate with culture medium containing 20 μM DCFH-DA for 30 min, wash with PBS three times and perform confocal imaging. Set up the following control groups: Control control group (no laser irradiation, no IM-BDP); IM-BDP+Aceclofenac+light treatment group (refer to the cell targeted inhibition experiment, after incubation with Aceclofenac for 2 hours, add DMEM solution of IM-BDP and incubate for 2 hours, then use 660nm 40mW / cm 2 Laser irradiation of cells for 10 min), light (laser irradiation, without IM-BDP), Aceclofenac (refer to the cell-targeted inhibition experiment for Aceclofenac incubation for 2 hours), and IM-BDP (without laser irradiation).

[0103] like Fig.11 As shown, in the control group, IM-BDP, Aceclofenac, light and IM-BDP+

[0104] The Aceclofenac+light treatment group had a very low green fluorescence signal, indicating that the amount of ROS generated in this process was very small and negligible. When treated with IM-BDP+light and irradiated with a 660nm laser, 4T1 cells showed bright green fluorescence, indicating that a large amount of ROS was generated in this process. These results show that IM-BDP can produce ROS that damage cells under 660nm laser irradiation. This once again proves that IM-BDP can kill tumor cells by producing ROS under light conditions.

[0105] Example 6: In vivo fluorescence imaging and photodynamic therapy

[0106] 4T1 cells (1×10 6 The 4T1 tumor-bearing mouse model was established by subcutaneously injecting 100 cells into the back of each mouse. 3 For in vivo imaging, IM-BDP solution prepared with PBS was injected into Balb / c mice bearing 4T1 tumors via tail vein injection. Fig.12As shown in the figure, 10 minutes after injection, fluorescence was observed at the tumor through the in vivo imaging device, indicating that the photosensitizer accumulated near the tumor. As the injection time increased, the fluorescence gradually increased, and then the fluorescence intensity at the tumor peaked, and then the fluorescence intensity showed a slow downward trend. The time when the IM-BDP fluorescence intensity reached the peak was 4 hours, indicating that 4 hours after injection was the best illumination time.

[0107] Balb / c mice bearing 4T1 tumors were randomly divided into 6 groups: a) PBS group (100 μL); b) PBS (100 μL) + light group; c) M-BDP (5×10 -3 μM, 100 μL) group; d) IM-BDP (5×10 -3 μM, 100μL); e) M-BDP (5×10 -3 μM, 100 μL)+light group; f) IM-BDP (5×10 -3 μM, 100μL)+light group, the above “+light” refers to 660nm200mW / cm 2 Irradiate with laser for 15 minutes. Fig.13 As shown, in groups e) and f), 4 h after the tail vein injection of the material, continuous light (660 nm 200 mW / cm 2 )15min. The mice continued to be fed for 14 days, and the weight and tumor volume of the mice were monitored every day. After 14 days of treatment, the weight of the mice showed a slow upward trend. At the same time, the tumor volume of the PBS group, M-BDP group and PBS+light group increased by about 5.5 times compared with the original tumor volume, the tumor volume of the IM-BDP group increased by about 4.5 times compared with the original tumor volume, the tumor volume of the M-BDP+light group increased by about 3.8 times compared with the original tumor volume, and the tumor volume of the IM-BDP+light group increased by about 0.3 times compared with the original tumor volume. This shows that M-BDP has a poor inhibitory effect on tumor growth under 660nm laser irradiation, while IM-BDP can effectively inhibit tumor growth under 660nm laser irradiation. This is because IM-BDP introduces indomethacin, which can interact with the hydrophobic pocket of COX-2, so that IM-BDP can be enriched in tumor tissue and can exist in cells for a long time without being metabolized. Because IM-BDP has these properties, the inhibitory effect on tumors is very significant. Therefore, IM-BDP has a good photodynamic effect.

[0108] The present invention prepares a photosensitizer IM-BDP that can target tumor cells for tumor PDT treatment. IM-BDP is selective for tumor cells overexpressing COX-2 and produces 1O2 under a 660nm laser. In vitro cell confocal, cytotoxicity and live-dead staining experiments show that IM-BDP can target tumor cells and has good phototoxicity. The killing rate of IM-BDP on 4T1 cells can reach 84%. At the same time, tumor-bearing mice are used to evaluate the therapeutic effect of IM-BDP in vivo, and excellent tumor inhibition effects are shown in tumor-bearing mouse experiments. The above experiments are sufficient to prove that after the IM-BDP photosensitizer is coupled with indomethacin, it has the targeting of tumor cells and the PDT therapeutic performance triggered by near-infrared light.

Claims

1. A water-soluble BODIPY photosensitizer IM-BDP targeting cyclooxygenase-2, wherein the photosensitizer IM-BDP is a spherical nanoparticle, and the molecular formula of the IM-BDP is: C 101 H 137 BClF2I2N5O 28 , whose structural formula is shown in the following formula (1):

2. A method for synthesizing the IM-BDP according to claim 1, comprising the following steps: Under the conditions of acetic acid and piperidine, 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid and 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde underwent Knoevenagel condensation to give 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid; 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is then subjected to amidation reaction with N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide under HATU conditions to finally obtain IM-BDP; The 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 The structural formula of -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is formula (2): The structural formula of the 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde is formula (3): The structural formula of the N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide is formula (4):

3. The synthesis method according to claim 2, characterized in that The 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid and 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde in a molar ratio of 1:2.5; and / or The 4-[5,5-difluoro-2,8-diiodo-1,9-dimethyl-3,7-bis[(E)-3,4,5-tris[2-(2-(2-methoxyethoxy)ethoxy)ethoxy]phenyl]-5H-4λ 4 ,5λ 4 The molar ratio of -dipyrrolic[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid to N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide and HATU is 1:1.5:

1.

4. The synthesis method according to claim 2, characterized in that The synthesis method of the N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide is as follows: Under the catalysis of HATU and the condition of DIPEA, tert-butyl N-(6-aminohexyl)carbamate and indomethacin were subjected to amidation reaction; then, under the condition of trifluoroacetic acid, de-BOC was carried out to finally obtain N-(6-aminohexyl)-2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetamide.

5. The synthesis method according to claim 2, characterized in that The synthesis method of the 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde is as follows: Triethylene glycol monomethyl ether and benzenesulfonyl chloride undergo substitution reaction to obtain a sulfonylated product, and the sulfonylated product reacts with 3,4,5-trihydroxybenzaldehyde under a nitrogen atmosphere and weak base conditions to finally obtain 3,4,5-tris[2-[2-(2-methoxyethoxy)ethoxy]ethoxy]benzaldehyde.

6. The synthesis method according to claim 2, characterized in that The 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 The synthesis method of -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid is as follows: (1) In the presence of trifluoroacetic acid in a protective gas atmosphere, 2,4-dimethylpyrrole reacts with methyl paraformylbenzoate, DDQ is added and stirred, and then triethylamine and boron trifluoride-ether complex are added to react to obtain methyl 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoate; (2) In a protective gas atmosphere, under alkaline conditions, methyl 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrole [1,2-c: 2',1'-f][1,3,2]diazaborolidine indol-10-yl) benzoate was dissolved and refluxed to obtain 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid; under iodic acid conditions, 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid reacts with iodine to give 4-[5,5-difluoro-2,8-diiodo-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 -dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaboryl]benzoic acid.

7. The synthesis method according to claim 6, characterized in that The molar ratio of the 2,4-dimethylpyrrole to methyl paraformylbenzoate and DDQ is 2:1:1; the 4-(5,5-difluoro-1,3,7,9-tetramethyl-5H-4λ 4 ,5λ 4 The molar ratio of 1,2-dipyrrolo[1,2-c:2',1'-f][1,3,2]diazaborolidine indol-10-yl)benzoic acid to iodine and iodic acid is 1:2.5:

2.

8. Use of the IM-BDP according to claim 1 or the IM-BDP obtained by the synthesis method according to any one of claims 2 to 7 in the preparation of a COX-2 fluorescent probe.

9. Use of the IM-BDP according to claim 1 or the IM-BDP obtained by the synthesis method according to any one of claims 2 to 7 in the preparation of anti-tumor targeted drugs.

Images