A naphthalene dianhydride molecular compound and its preparation and application

Abstract

The present invention discloses a naphthalene dianhydride molecular compound and its preparation and application. The chemical structural formula of the novel naphthalene dianhydride molecular compound is shown in formula (1). The preparation thereof is specifically to carry out an alkylation reaction with pentylamine under the catalysis of phosphorus tribromide to prepare an intermediate product A; to carry out a cyclization reaction by replacing the bromine atoms on one side of the intermediate product A with 1,5-diaminonaphthalene to obtain an intermediate product B; to replace the bromine atoms on the remaining side of the intermediate product B with 2-aminothiophenol, and to obtain a novel naphthalene dianhydride molecule after cyclization. The preparation process of the nanoparticles is to take the novel naphthalene dianhydride molecule, dissolve it in a DMSO solvent, and then drop DSPE-PEG 2000 After coating, DMSO is removed by rotary evaporation, and the nanoparticles are uniformly dispersed in a pure aqueous solution. The present invention can effectively improve the deficiencies of the prior art, including enhancing the ultraviolet absorption of the second near-infrared window, improving the photothermal conversion rate of naphthalene dianhydride molecules, and achieving effective killing of tumor cells. #imgabs0#

Description

Technical Field

[0001] The invention relates to the field of cancer photodiagnostic agents, in particular to a novel second near-infrared window naphthalene dianhydride molecular compound based on tetrabromonaphthalene dianhydride, a preparation method thereof and application of the compound in nano photosensitizers. Background Art

[0002] At present, cancer is still one of the major diseases threatening human health. At present, the number of people diagnosed with cancer is getting younger and younger, and the number is increasing year by year. The existing methods of treating cancer are mainly radiotherapy and chemotherapy. The problem is that they attack the internal tissues of the body indiscriminately, causing patients to suffer from sequelae of varying degrees, including systemic neurotoxicity, anorexia, dizziness, etc., which further damages the patient's already fragile body.

[0003] With the development of scientific and technological research, in the 1990s, John Funkouser proposed the cancer treatment strategy of Theranostics. That is, by designing a reasonable nanomaterial structure, the nanomaterial can be actively or passively targeted to concentrate on the tumor in the body, and the corresponding treatment methods and diagnostic signal transmission are used to achieve the application of integrated diagnosis and treatment. For example, photothermal therapy (PTT) and photodynamic therapy (PDT).

[0004] As a non-invasive treatment, phototherapy has the ability to accurately diagnose the location of the tumor to achieve precise treatment of the tumor area, reduce the treatment damage to normal tissues, and has no obvious sequelae. It has attracted the attention of a large number of researchers and has become a research hotspot in the field of cancer treatment. The principle of photothermal therapy is to enrich the photosensitizer in the tumor site, realize photothermal conversion under the excitation of near-infrared light, generate high temperature in the tumor site to induce rapid necrosis of tumor cells, and apoptosis to achieve the purpose of inhibiting tumors. The results reported in the literature show that the effect of temperature on tumor cells is: at 37-41°C, it can accelerate blood flow and enhance the permeability of cell membranes; at 41-48°C, it causes the protein folding and deformation of tumor cells, which can improve the therapeutic effect of chemotherapy and radiotherapy, and at temperatures above 43°C, most tumor cells are inactivated; at 48-60°C, the protein damage in tumor cells is irreversible, and the tumor cells are completely necrotic. However, the presence of heat shock proteins in tumor cells makes the heat resistance of tumor cells continue to increase, which increases the probability of damaging the normal tissues around the tumor cells due to the increase in the temperature of photothermal therapy. The principle of photodynamic therapy is to selectively excite the photosensitizer through a suitable light source, which is mainly a photosensitization reaction involving oxygen molecules. Free radicals react with oxygen to generate reactive oxygen species (ROS) such as superoxide ions (O2-), hydrogen peroxide (H2O2) and hydroxyl radicals (·OH), or to transfer energy to produce singlet states ( 1O2) induces cell apoptosis. The problem with photodynamic therapy is that a large amount of oxygen molecules are required during the treatment process, but the tumor microenvironment is characterized by hypoxia, which cannot support the continuous progress of photodynamic therapy. In addition, the light source of current photodynamic therapy is mainly blue light or ultraviolet light, with a wavelength of only a few hundred nanometers, which has the disadvantage of weak tissue penetration depth, which also makes the therapeutic effect of photodynamic therapy only reflected at the level of cell therapy.

[0005] In view of the shortcomings of phototherapy, researchers have solved them by designing effective synergistic effects. For example, in photothermal therapy, by doping heat shock protein inhibitors in nanophotosensitizers, the heat resistance of tumor cells is reduced by inhibiting the expression of heat shock proteins, killing tumor cells at lower temperatures and reducing damage to normal tissues; in photodynamic therapy, by combining oxygen-producing carriers such as calcium peroxide, the problem of hypoxia during photodynamic therapy with photosensitizers is solved; by designing a reasonable small molecule structure, the absorption of small molecules is red-shifted so that they can be excited by near-infrared light with deeper tissue penetration ability.

[0006] In photodiagnosis and treatment, the choice of light source determines the diagnostic and therapeutic effects of tumor-bearing mice. Since biological tissues are highly scattering tissues, most of the energy of the light source is absorbed by the tissue and scattered on the surface, resulting in less light source energy that can be absorbed by the photosensitizer, resulting in poor treatment results and poor quality of fluorescence imaging. In current research, light is divided into visible light, near-infrared region 1 (650-900nm) and near-infrared region 2 (1000-1700nm) according to the wavelength of light. In visible light and near-infrared region 1, due to the short wavelength, there is a problem of poor tissue penetration. The difference is that in the near-infrared region 2, due to avoiding the absorption range of water to the light source, the penetration of tissues is greatly enhanced, the scattering of photons is reduced, and it also means the potential for high-quality fluorescence imaging. In summary, the absorption results close to the near-infrared region 2 obtained by designing the structure of organic small molecules can solve the shortcomings of the current integrated diagnosis and treatment applications, which has also become a hot issue in the field of phototherapy.

[0007] Compared with inorganic materials, organic small molecule dyes have the advantages of good biocompatibility, high reactivity, and easy metabolism in the body, and have broad application prospects in the field of clinical tumor treatment. By modifying different ligands to increase the π-π conjugated structure of organic small molecule dyes, their absorption and emission in the near-infrared region II can be achieved, which is especially beneficial for the accurate diagnosis and treatment of deep tumors.

[0008] For example, in 2015, the research groups of Dai Hongjie, Cheng Zhen and Hong Xuechuan jointly reported for the first time the near-infrared region II organic small molecule CH1055, which constructed a DAD structure through the acceptor BBTD and the donor triphenylamine (TPA), but the absorption peak was only around 700nm, the wavelength of the laser excitation light source was short, and the tissue penetration ability was weak;

[0009]

[0010] For example, in 2018, the research group of Dai Hongjie and Cheng Zhen constructed the nanoparticle PDFT1023 based on diketopyrrolopyrrole. The reasonable DAD architecture made its absorption peak reach 809nm, and it absorbed efficiently and stably at 809nm. The good water solubility, biocompatibility and low in vivo toxicity also enabled PDFT1023 to be used in the treatment of osteosarcoma models and in vivo tumor imaging monitoring.

[0011] The present invention designs a novel near-infrared zone II window photosensitizer based on tetrabromonaphthalene dianhydride, and achieves a lower energy gap and higher ultraviolet absorption by introducing 1,5-diaminonaphthalene and 2-aminothiophenol to enhance the π-π conjugated system. Test results show that the absorption wavelength peak of the novel naphthalene dianhydride molecule is located near 900nm, and it can utilize the centimeter-level penetration ability of the near-infrared zone II light source to improve the fluorescence imaging of the photosensitizer in deep tumors and enhance the photothermal conversion efficiency of the photosensitizer, which has broad application prospects in the field of light therapy for cancer. Summary of the invention

[0012] The present invention aims at the deficiencies of the prior art and provides a novel naphthalene dianhydride molecule of the second near-infrared window based on tetrabromonaphthalene dianhydride, as well as a preparation method thereof and an application in a nano photosensitizer, which can effectively enhance the ultraviolet absorption of the second near-infrared window, achieve an improvement in the photothermal conversion efficiency of the naphthalene dianhydride molecule and effectively kill tumors.

[0013] In order to solve the above technical problems, the technical solutions adopted by the present invention are as follows:

[0014] In the first aspect, the present invention provides a novel naphthalene dianhydride molecular compound having the chemical structural formula:

[0015]

[0016] In a second aspect, the present invention provides a novel process for preparing a naphthalene dianhydride molecular compound, which specifically comprises the following steps:

[0017] Step S1, using pentylamine to replace the oxygen atom of tetrabromonaphthalene dianhydride to prepare intermediate product A;

[0018] Step S2, using 1,5-diaminonaphthalene to replace the bromine atom on one side of the intermediate product A to carry out a cyclization reaction to obtain the intermediate product B;

[0019] Step S3, using 2-aminothiophenol to replace the remaining bromine atoms on the intermediate product B, and then cyclizing to obtain a novel naphthalene dianhydride molecular compound represented by formula (1): 1HNMR (500MHz, DMSO-D6, ppm): δ7.74-6.90(m,9H),3.14(t,4H),1.70(m,4H),1.30(m,8H),0.87(t,6H).);

[0020] Preferably, step S1 specifically comprises:

[0021] 3-4 molar portions of tetrabromonaphthalene dianhydride, 6-10 molar portions of pentylamine and 15-30 molar portions of acetic acid are added to dry toluene and dry N,N-dimethylformamide under a nitrogen atmosphere, and stirred for 30 minutes under a nitrogen atmosphere at 100°C; 20-40 molar portions of PBr3 are then added to the solution; the reaction mixture is refluxed for 12 hours, the mixture is cooled to room temperature, and then poured into water; the reaction mixture is extracted with toluene; the combined organic matter is vacuum concentrated to obtain a crude product, which is then passed through a column to obtain an intermediate product A;

[0022] More preferably, step S1 is specifically: adding 4 molar portions of tetrabromonaphthalene dianhydride, 8.8 molar portions of pentylamine and 20 molar portions of acetic acid to dry toluene and dry N,N-dimethylformamide, and stirring for 30 minutes under a nitrogen atmosphere at 100°C; then adding 40 molar portions of PBr3 to the solution; reflux the reaction mixture for 12 hours, cool the mixture to room temperature, and then pour it into water; extract the reaction mixture with toluene; vacuum concentrate the combined organic matter to obtain a crude product, and the eluent is n-hexane: dichloromethane = 2:1 (v / v) to obtain an intermediate product A after column chromatography;

[0023] Preferably, step S2 specifically comprises:

[0024] 3-6 mole parts of intermediate product A, 0.5-1 mole parts of 1,5-diaminonaphthalene, and 6-12 mole parts of potassium carbonate are added into a three-necked flask, evacuated, backfilled with nitrogen, and tetrahydrofuran is added, stirred at 80°C for 8h, cooled to room temperature, and the brown-green reaction liquid is diluted with petroleum ether, washed with water, and dried to obtain intermediate product B;

[0025] More preferably, step S2 specifically comprises:

[0026] 4 mole parts of intermediate product A, 0.72 mole parts of 1,5-diaminonaphthalene, and 10 mole parts of potassium carbonate were added into a three-necked flask, vacuumed, backfilled with nitrogen, and tetrahydrofuran was added, stirred at 80°C for 8 hours, cooled to room temperature, and the brown-green reaction solution was diluted with petroleum ether, washed with water, and dried to obtain intermediate product B;

[0027] Preferably, step S3 specifically comprises:

[0028] 2-4 molar portions of intermediate product B, 0.5-1 molar portions of 2-aminothiophenol, and 3-6 molar portions of potassium carbonate are added to toluene, heated at 110°C for 12 hours, cooled to room temperature, diluted with petroleum ether, and then washed with water three times. The organic solution is dried over anhydrous sodium sulfate, and then the solvent is removed in a vacuum. After column chromatography, a novel naphthalene dianhydride molecular compound ( 1 HNMR (500MHz, DMSO-D6, ppm): δ7.74-6.90 (m, 9H), 3.14 (t, 4H), 1.70 (m, 4H), 1.30 (m, 8H), 0.87 (t, 6H).).

[0029] More preferably, step S3 specifically comprises:

[0030] 2 molar portions of intermediate product B, 6 molar portions of 2-aminothiophenol, and 8 molar portions of potassium carbonate were added to toluene, heated at 110° C. for 12 h, cooled to room temperature, diluted the reaction mixture with petroleum ether, and then rinsed with water three times. The organic solution was dried over anhydrous sodium sulfate, and then the solvent was removed in vacuo to obtain a crude product. The eluent was n-hexane: dichloromethane = 2:1 (v / v). After column chromatography, a novel naphthalene dianhydride molecular compound ( 1 H NMR (500MHz, DMSO-D6, ppm): δ7.74-6.90 (m, 9H), 3.14 (t, 4H), 1.70 (m, 4H), 1.30 (m, 8H), 0.87 (t, 6H).).

[0031] Preferably, after the intermediate product A and 1,5-diaminonaphthalene undergo cyclization reaction, petroleum ether is added to dilute the brown-green reaction solution, and the eluent is n-hexane: dichloromethane: ethyl acetate = 8:2:1 (v / v / v) and the reaction efficiency is higher after passing through the column.

[0032] In a third aspect, a novel naphthalene dianhydride molecular compound nanoparticle is provided, wherein the novel naphthalene dianhydride molecular compound represented by formula (1) is dissolved in DMSO, and DSPE-PEG is added dropwise. 2000 After sufficient stirring, remove the DMSO.

[0033] As a preferred method, DSPE-PEG is added dropwise 2000 Then stir thoroughly at a speed of 1200r / min for 1h.

[0034] In a third aspect, the present invention provides the use of the novel naphthalene dianhydride molecular compound nanoparticles as a second near-infrared window photosensitizer.

[0035] The beneficial results of the present invention are:

[0036] (1) Through the rational design of the molecular structure, the ultraviolet absorption peak of the new naphthalene dianhydride molecule reaches 900nm, which helps to enhance the ability to penetrate biological tissues;

[0037] (2) Through the excitation of 808nm laser light source, the new naphthalene anhydride nanoparticles can achieve efficient photothermal conversion;

[0038] (3) Using new naphthalene anhydride nanoparticles as the second near-infrared window photosensitizer, combined with efficient photothermal conversion capabilities, under the excitation of an 808nm laser light source, the temperature can be raised to 45°C within 3-5 minutes, achieving effective killing of tumor cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 It is the absorption spectrum diagram of the novel naphthalene dianhydride molecule of the present invention.

[0040] Figure 2 This is a TEM image of the novel naphthalene dianhydride molecular nano photosensitizer of the present invention.

[0041] Figure 3 This is a photothermal temperature rise result diagram of different concentrations of the novel naphthalene dianhydride molecular nano photosensitizer of the present invention.

[0042] Figure 4 This is a graph showing the results of an in vitro toxicity experiment on 4T1 using the novel naphthalene dianhydride molecular nanophotosensitizer of the present invention.

[0043] Figure 5 This is a graph showing the results of an in vitro toxicity experiment on CT26 using the novel naphthalene dianhydride molecular nanophotosensitizer of the present invention. DETAILED DESCRIPTION

[0044] The present invention is further analyzed below in conjunction with specific embodiments.

[0045] Example 1

[0046] 4 molar portions of tetrabromonaphthalene dianhydride, 8.8 molar portions of pentylamine and 20 molar portions of acetic acid are added to dry toluene and dry N,N-dimethylformamide, and stirred for 30 minutes under a nitrogen atmosphere at 100°C; 40 molar portions of PBr3 are then added to the solution; the reaction mixture is refluxed for 12 hours, the mixture is cooled to room temperature, and then poured into water; the reaction mixture is extracted with toluene; the combined organic matter is vacuum concentrated to obtain a crude product, and the eluent is n-hexane: dichloromethane = 2:1 (v / v) and then passed through a column to obtain an intermediate product;

[0047] 4 mole parts of intermediate product A, 0.72 mole parts of 1,5-diaminonaphthalene, and 10 mole parts of potassium carbonate were added into a three-necked flask, vacuumed, backfilled with nitrogen, and tetrahydrofuran was added, stirred at 80°C for 8 hours, cooled to room temperature, and the brown-green reaction solution was diluted with petroleum ether, washed with water, and dried to obtain intermediate product B;

[0048] 2 molar portions of intermediate B, 6 molar portions of 2-aminothiophenol, and 8 molar portions of potassium carbonate were added to toluene, heated at 110°C for 12 hours, cooled to room temperature, diluted the reaction mixture with petroleum ether, and then rinsed with water three times. The organic solution was dried over anhydrous sodium sulfate, and then the solvent was removed in vacuo to obtain a crude product. The eluent was n-hexane: dichloromethane = 2:1 (v / v). After column chromatography, a novel naphthalene anhydride molecule ( 1 HNMR (500MHz, DMSO-D6, ppm): δ7.74-6.90 (m, 9H), 3.14 (t, 4H), 1.70 (m, 4H), 1.30 (m, 8H), 0.87 (t, 6H).).

[0049] The new naphthalene anhydride molecule was dissolved in DMSO and DSPE-PEG was added dropwise 2000 , fully stirred at a speed of 1200r / min. After 1h, DMSO was removed by rotary evaporation, and the nanoparticles were uniformly dispersed in a pure aqueous solution to obtain a new type of naphthalene anhydride nano photosensitizer.

[0050] The absorption spectrum of the novel naphthalene dianhydride molecule of the present invention is shown in Figure 1 , TEM image see Figure 2 .

[0051] Experimental study on the photothermal conversion of novel naphthalene anhydride nano-photosensitizer

[0052] The prepared novel naphthalene anhydride nanophotosensitizer was quantitatively dissolved in pure water at 0, 25, 50, 100, and 200 μg / mL. 1 mL of the novel naphthalene anhydride nanophotosensitizer solution of different concentrations was added to a quartz dish and irradiated with a NIR laser (808 nm, 1.5 W / cm 2 ) for 5 minutes, and use a thermal imager to record the temperature change of the solution during the heating process. Figure 3 .

[0053] In vitro toxicity test of novel naphthalene anhydride nanophotosensitizer

[0054] 4T1 and CT26 cells were used to test the dark toxicity and laser toxicity of different concentrations of the new naphthalene anhydride nanophotosensitizer. The specific implementation steps are as follows: the cultured 4T1 cells were added to a 96-well plate at 6000 / well, and placed in a cell culture incubator for further incubation for 24 hours. The new naphthalene anhydride nanophotosensitizer was dissolved in PBS solution, diluted with 1640 culture medium to quantify the photosensitizer at different concentrations (0, 15, 30, 45, 60, 75, 90 μg / mL), and then added to the 96-well plate incubated with 4T1 and CT26 at 100 μL / well for further incubation for 8 hours. The 96-well plate for testing laser toxicity was then taken out and irradiated with NIR laser (808 nm, 1.5 W / cm 2 ) for 10 minutes, and the 96-well plate for dark toxicity testing was kept away from light. After completion, it was incubated for 4 hours. Then, the MTT colorimetric method was used for determination. 20 μL / well of MTT solution (5 mg / mL) was added to the 96-well plate incubated with 4T1, and the incubation was continued for 4 hours in the same atmosphere. Then, DMSO solution was added, and the absorption value at 490 nm was determined using a Bio-Tek microplate microplate reader. The results of the in vitro toxicity experiment of the new naphthalene dianhydride molecular nanophotosensitizer for 4T1 and CT26 can be found in Figure 4-5 .

[0055] Example 2

[0056] This case is improved on the basis of Example 1. After the intermediate product A and 1,5-diaminonaphthalene are subjected to cyclization reaction, petroleum ether is added to dilute the brown-green reaction liquid. The eluent is n-hexane: dichloromethane: ethyl acetate = 8:2:1 (v / v / v). After column passage, the reaction efficiency is higher. It is calculated that the yield of the intermediate product B is increased by 8% compared with that in Example 1.

Claims

1. A naphthalene anhydride molecular compound, characterized in that The chemical structural formula of the compound is as follows:

2. A method for preparing a naphthalene anhydride molecular compound according to claim 1, characterized in that The method comprises the following steps: Step S1, using pentylamine to replace the oxygen atom of tetrabromonaphthalene dianhydride to prepare intermediate product A; Step S2, using 1,5-diaminonaphthalene to replace the bromine atom on one side of the intermediate product A to carry out a cyclization reaction to obtain the intermediate product B; Step S3, using 2-aminothiophenol to replace the remaining bromine atoms on the intermediate product B, and obtaining a novel naphthalene dianhydride molecular compound represented by formula (1) after cyclization.

3. The method according to claim 2, characterized in that Step S1 specifically includes: Under a nitrogen atmosphere, 3 to 4 molar portions of tetrabromonaphthalene dianhydride, 6 to 10 molar portions of pentylamine and 15 to 30 molar portions of acetic acid are added to dry toluene and dry N,N-dimethylformamide, and stirred for 30 minutes under a nitrogen atmosphere at 100°C; then 20 to 40 molar portions of PBr3 are added to the solution; the reaction mixture is refluxed for 12 hours, the mixture is cooled to room temperature, and then poured into water; the reaction mixture is extracted with toluene; the combined organic matter is vacuum concentrated to obtain a crude product, which is then passed through a column to obtain an intermediate product A.

4. The method according to claim 3, characterized in that Step S1 specifically comprises: adding 4 molar portions of tetrabromonaphthalene dianhydride, 8.8 molar portions of pentylamine and 20 molar portions of acetic acid to dry toluene and dry N,N-dimethylformamide, and stirring for 30 minutes under a nitrogen atmosphere at 100°C; then adding 40 molar portions of PBr3 to the solution; reflux the reaction mixture for 12 hours, cool the mixture to room temperature, and then pour it into water; extract the reaction mixture with toluene; vacuum concentrate the combined organic matter to obtain a crude product, the eluent is a mixture of n-hexane and dichloromethane in a volume ratio of 2:1, and obtain an intermediate product A after column chromatography.

5. The method according to claim 2, characterized in that Step S2 specifically includes: 3-6 mole parts of intermediate product A, 0.5-1 mole parts of 1,5-diaminonaphthalene and 6-12 mole parts of potassium carbonate are added into a three-necked flask, evacuated, backfilled with nitrogen, and tetrahydrofuran is added. The mixture is stirred at 80°C for 8 hours, cooled to room temperature, and the brown-green reaction liquid is diluted with petroleum ether. The intermediate product B is obtained after washing with water and drying.

6. The method according to claim 5, characterized in that Step S2 specifically includes: 4 mol of intermediate product A, 0.72 mol of 1,5-diaminonaphthalene and 10 mol of potassium carbonate were added into a three-necked flask, vacuumed, backfilled with nitrogen, and tetrahydrofuran was added. The mixture was stirred at 80°C for 8h, cooled to room temperature, and the brown-green reaction solution was diluted with petroleum ether. The intermediate product B was obtained after washing with water and drying.

7. The method according to claim 2, characterized in that Step S3 specifically includes: 2 to 4 molar portions of intermediate product B, 0.5 to 1 molar portion of 2-aminothiophenol, and 3 to 6 molar portions of potassium carbonate are added to toluene, heated at 110° C. for 12 hours, cooled to room temperature, and then the reaction mixture is diluted with petroleum ether, then rinsed three times with water, the organic solution is dried over anhydrous sodium sulfate, and then the solvent is removed in a vacuum, and after passing through a column, a novel naphthalene dianhydride molecular compound represented by formula (1) is obtained.

8. The method according to claim 7, characterized in that Step S3 specifically includes: 2 molar portions of intermediate product B, 6 molar portions of 2-aminothiophenol, and 8 molar portions of potassium carbonate are added to toluene, heated at 110° C. for 12 h, cooled to room temperature, diluted the reaction mixture with petroleum ether, and then rinsed with water three times. The organic solution is dried over anhydrous sodium sulfate, and then the solvent is removed in vacuo to obtain a crude product. The eluent is a mixture of n-hexane and dichloromethane in a volume ratio of 2:

1. After column chromatography, a novel naphthalene dianhydride molecular compound represented by formula (1) is obtained.

9. A novel naphthalene dianhydride molecular compound nanoparticle, characterized in that The novel naphthalene dianhydride molecular compound described in claim 1 is dissolved in DMSO, and DSPE-PEG is added dropwise 2000 After sufficient stirring, remove the DMSO.

10. Use of the naphthalene dianhydride molecular compound nanoparticles according to claim 9 as a second near-infrared window photosensitizer.

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