A hERG potassium channel inhibitor based on IR780 derivatives and its preparation method and application

Abstract

The present invention discloses a hERG potassium channel inhibitor based on IR780 derivatives and its preparation method and application, belonging to the field of drug synthesis. The general structural formula of the hERG potassium channel inhibitor based on IR780 derivatives is shown in formula (I) or formula (II); #imgabs0# The hERG potassium channel inhibitor of the present invention uses IR780 as a singlet oxygen generating group, the recognition group is a ligand with high binding activity to the hERG potassium channel (such as astemizole and E4031), the recognition group and the fluorophore are connected through an alkyl chain, and a novel hERG potassium channel inhibitor is rationally designed and constructed, and its biological activity is evaluated. On this basis, the application of the probe molecule in tumor treatment is further evaluated, providing a novel therapeutic candidate drug molecule for tumor treatment.

Description

Technical Field

[0001] The invention belongs to the field of drug synthesis, and specifically relates to a hERG potassium channel inhibitor based on IR780 derivatives and a preparation method and application thereof. Background Art

[0002] Cancer has become the second leading cause of death after cardiovascular disease. Although there are currently a variety of treatments for cancer, such as surgery, radiotherapy and various chemotherapy drugs, there has been no breakthrough in the treatment of cancer. Currently, clinical practice still requires anti-tumor drugs with novel treatment mechanisms.

[0003] The hERG potassium channel is a voltage-gated potassium channel that mediates the fast phase component of the delayed rectifier potassium current of phase III repolarization of the cardiac action potential. In addition to its distribution in cardiac tissue, it is also distributed in smooth muscle tissue, nerve tissue, pancreas, liver and other tissues. In recent years, more and more studies have shown that the hERG potassium channel is upregulated in tumor cells of various tissue origins, while it is not expressed or expressed at very low levels in the corresponding normal tissues, such as colon cancer cells, neuroblastoma cells, endometrial cancer cells, leukemia cells, breast cancer cells, melanoma cells, gastric cancer cells, etc. Subsequently, people have conducted a large number of mechanistic studies on how the hERG potassium channel participates in regulating the occurrence and development of tumors, and found that the hERG potassium channel plays an important role in the generation, proliferation, metastasis, invasion, apoptosis, and angiogenesis of tumor cells. At the same time, the expression level of the hERG potassium channel is positively correlated with the malignancy of the tumor, and patients with high expression levels of the hERG potassium channel have a poor prognosis. More and more in vivo experiments have shown that hERG potassium channel blockers have good anti-tumor effects. Therefore, hERG potassium channel is a potential anti-tumor drug target with good development prospects. Summary of the invention

[0004] In order to solve the deficiencies of the prior art, the purpose of the present invention is to provide a hERG potassium channel inhibitor based on IR780 derivatives and a preparation method and application thereof, so as to provide a novel structural candidate drug molecule for the treatment of tumors.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] The first aspect of the present invention provides a hERG potassium channel inhibitor based on an IR780 derivative, wherein the general structural formula of the hERG potassium channel inhibitor is as shown in formula (I) or formula (II);

[0007]

[0008] Wherein, R1 is an aliphatic hydrocarbon group, R2 is a monosubstituted or disubstituted electron-withdrawing, electron-donating or neutral group, and n=0-8. The hERG potassium channel inhibitor of the IR780 fluorophore of the present invention can exist in a free form or in a salt form.

[0009] The second aspect of the present invention provides a method for preparing the hERG potassium channel inhibitor based on the IR780 derivative, comprising the following steps:

[0010] Preparation of compounds of formula (I):

[0011] The synthetic route of the compound of formula (I) is as follows:

[0012]

[0013] S1. Dissolve compound Ia and N-(bromoalkyl)phthalimide in an organic solvent, add an acid binding agent, and reflux at high temperature; after the reaction is completed, cool the reaction solution and extract, combine the organic layers, dry, filter, concentrate, and purify to obtain intermediate product Ⅰb-1;

[0014] S2. The intermediate product Ⅰb-1 is subjected to hydrazinolysis. After the hydrazinolysis is completed, the reaction solution is concentrated and purified to obtain the intermediate product Ⅰb;

[0015] S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅰb are reacted in an organic solvent at high temperature and in the dark; after the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅰ);

[0016] Or, the preparation of the compound of formula (II):

[0017] The synthetic route of the compound of formula (II) is as follows:

[0018]

[0019]

[0020] S1. Dissolve N-(4-(piperidin-4-yl)phenyl)methanesulfonamide and an acid-binding agent in an organic solvent, slowly dropwise add N-(bromoalkyl)carbamic acid tert-butyl ester solution, and reflux at high temperature; after the reaction is completed, cool the reaction solution and extract, combine the organic layers, dry, filter, concentrate, and purify to obtain intermediate product Ⅱb-1;

[0021] S2. The intermediate product Ⅱb-1 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, stirred, and dried to obtain a yellow oil, which was dissolved in distilled water and neutralized by adding solid sodium bicarbonate, washed with dichloromethane, and the aqueous phase was collected and dried; the obtained solid was dissolved in methanol, filtered, and the filtrate was collected and dried to obtain the intermediate product Ⅱb;

[0022] S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅱb are reacted in an organic solvent at high temperature and in the dark. After the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅱ).

[0023] The third aspect of the present invention provides the use of the hERG potassium channel inhibitor based on IR780 derivatives in the preparation of anti-tumor drugs.

[0024] The fourth aspect of the present invention provides a pharmaceutical composition for treating cancer, comprising the above-mentioned hERG potassium channel inhibitor based on IR780 derivatives or a pharmaceutically acceptable salt thereof.

[0025] The beneficial effects of the present invention are:

[0026] hERG potassium channel is a potential anti-tumor drug target with good development prospects. Photodynamic therapy is currently a very effective in situ tumor treatment strategy, which uses the reactive oxygen generated after irradiating the compound with light to kill tumor cells. The hERG potassium channel inhibitor of the present invention uses IR780 as a singlet oxygen generating group, the recognition group is a ligand with high binding activity to the hERG potassium channel (such as astemizole and E4031), the recognition group and the fluorophore are connected by an alkyl chain, and a novel hERG potassium channel inhibitor is rationally designed and constructed, and its biological activity is evaluated, and its application in tumor treatment is further evaluated on this basis. Experiments have proved that the novel hERG potassium channel inhibitor constructed by the present invention has high inhibitory activity on hERG potassium channel; it has a strong singlet oxygen generation ability in solution or in cells; it has a strong anti-tumor activity at the cellular level, and the inhibitory effect of hERG potassium channel combined with laser-mediated photodynamic therapy exerts a stronger anti-tumor effect, providing a novel therapeutic candidate drug molecule for the treatment of tumors. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0028] Figure 1 The inhibitory activity of the compound on hERG potassium channel was determined by radioligand assay;

[0029] Figure 2 is a curve of wavelength and absorbance of compound I-A8;

[0030] Figure 3 is the singlet oxygen generating ability of compound I-A8 in dichloromethane;

[0031] Figure 4is the singlet oxygen generating ability of compound I-A8 in U87 cells;

[0032] Figure 5 is the antiproliferative activity of compound I-A8 on GBM tumor cells;

[0033] Figure 6 is the antiproliferative activity of compound I-A8 on lung cancer cells A549;

[0034] Figure 7 The combined antitumor effect of compound I-A8 and 660 nm laser irradiation;

[0035] Figure 8 This is a diagram showing the tumor growth after treatment with PBS, ApoE-Lipo@A8, and ApoE-Lipo@A8+660nm laser irradiation;

[0036] Fig. 9 This is a graph showing the changes in tumor size over time during the treatment cycle of different treatment methods;

[0037] Fig.10 The tumor inhibition rate after one cycle of treatment with different treatment methods;

[0038] Fig.11 This is a statistical chart of the survival of mice after one cycle of treatment with different treatment methods. DETAILED DESCRIPTION

[0039] Considering that hERG potassium channel is a potential target for anti-tumor drugs and has good development prospects, the present invention provides a hERG potassium channel inhibitor based on IR780 derivatives and a preparation method and application thereof.

[0040] A typical embodiment of the present invention provides a hERG potassium channel inhibitor based on an IR780 derivative, wherein the general structural formula of the hERG potassium channel inhibitor is as shown in formula (I) or formula (II);

[0041]

[0042] Wherein, R1 is an aliphatic hydrocarbon group, R2 is a monosubstituted or disubstituted electron-withdrawing, electron-donating or neutral group, and n=0-8.

[0043] In some examples of this embodiment, R1 is methyl, ethyl, propyl, allyl, butylene, propargyl or butylene; and R2 is halogen, methyl, sulfonic acid or hydrogen.

[0044] In some examples of this embodiment, the hERG potassium channel inhibitor is selected from compounds having the following structural formula:

[0045]

[0046] A second typical embodiment of the present invention provides a method for preparing the hERG potassium channel inhibitor based on the IR780 derivative, comprising the following steps:

[0047] (1) Preparation of the compound of formula (I):

[0048] S1. Dissolve compound Ia and N-(bromoalkyl)phthalimide in an organic solvent, add an acid binding agent, and reflux at high temperature; after the reaction is completed, cool the reaction solution and extract, combine the organic layers, dry, filter, concentrate, and purify to obtain intermediate product Ⅰb-1;

[0049] S2. The intermediate product Ⅰb-1 is subjected to hydrazinolysis. After the hydrazinolysis is completed, the reaction solution is concentrated and purified to obtain the intermediate product Ⅰb;

[0050] S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅰb are reacted in an organic solvent at high temperature and in the dark; after the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅰ);

[0051] The structure of compound Ⅰa is as follows:

[0052]

[0053] Or, the preparation of the compound of formula (II):

[0054] S1. Dissolve N-(4-(piperidin-4-yl)phenyl)methanesulfonamide and an acid-binding agent in an organic solvent, slowly dropwise add N-(bromoalkyl)carbamic acid tert-butyl ester solution, and reflux at high temperature; after the reaction is completed, cool the reaction solution and extract, combine the organic layers, dry, filter, concentrate, and purify to obtain intermediate product Ⅱb-1;

[0055] S2. The intermediate product Ⅱb-1 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, stirred, and dried to obtain a yellow oil, which was dissolved in distilled water and neutralized by adding solid sodium bicarbonate, washed with dichloromethane, and the aqueous phase was collected and dried; the obtained solid was dissolved in methanol, filtered, and the filtrate was collected and dried to obtain the intermediate product Ⅱb;

[0056] S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅱb are reacted in an organic solvent at high temperature and in the dark. After the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅱ).

[0057] In some examples of this embodiment, the alkyl chain length of the N-(bromoalkyl)phthalimide is 2-10 carbons.

[0058] In some examples of this embodiment, the alkyl chain length of the tert-butyl N-(bromoalkyl)carbamate is 2-10 carbons.

[0059] In some examples of this embodiment, the acid binding agent includes anhydrous potassium carbonate, anhydrous sodium acetate, and anhydrous sodium carbonate; preferably, the acid binding agent is anhydrous potassium carbonate.

[0060] The third typical embodiment of the present invention provides the use of the hERG potassium channel inhibitor based on IR780 derivatives in the preparation of anti-tumor drugs.

[0061] A fourth exemplary embodiment of the present invention provides a pharmaceutical composition for treating cancer, the pharmaceutical composition comprising the above-mentioned hERG potassium channel inhibitor based on IR780 derivatives or a pharmaceutically acceptable salt thereof. Pharmaceutically acceptable salts include conventional non-toxic salts, including quaternary ammonium salts formed by bases of such compounds and inorganic or organic acids.

[0062] In some examples of this embodiment, the cancer includes but is not limited to glioma, glioblastoma multiforme, lung cancer, gastrointestinal cancer, pancreatic cancer, lymphoma, liver cancer, kidney cancer, bladder cancer, prostate cancer, breast cancer, head and neck cancer, nasopharyngeal cancer, oral cancer, and skin cancer.

[0063] In some examples of this embodiment, the pharmaceutical composition is a hydrate or a solvate. The preparation method of the hydrate is to freeze-dry the pharmaceutical composition and water to form a hydrate; the preparation method of the solvent composition is to concentrate the pharmaceutical composition and a suitable organic solvent in a solution to form a solvate.

[0064] In some examples of this embodiment, the pharmaceutical composition comprises a therapeutic amount of an IR780 derivative-based hERG potassium channel inhibitor or a pharmaceutically acceptable salt thereof, and one or more pharmaceutically acceptable carriers and / or excipients.

[0065] Wherein, the carrier is solid or liquid.

[0066] Typical solid carriers include lactose, gypsum, sucrose, talc, gelatin, agar, pectin, gum arabic, magnesium stearate, stearic acid and the like. Solid carriers may include one or more substances that may simultaneously act as flavoring agents, lubricants, solubilizers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrants; they may also be encapsulating materials. In powders, the carrier is a finely pulverized solid, which is mixed with finely pulverized active ingredients. In tablets, the active ingredient is mixed with a carrier having the necessary compression properties in a suitable ratio and compressed in the desired shape and size. Powders and tablets preferably contain up to 99% active ingredients. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugar, lactose, dextrin, starch, gelatin, cellulose, methylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone, low melting wax and ion exchange resins.

[0067] Typical liquid carriers include syrups, peanut oil, olive oil, water, etc. Liquid carriers are used to prepare solutions, suspensions, emulsions, syrups, tinctures and sealed compositions. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of the two, or a pharmaceutically acceptable oil or fat. The liquid carrier can include other suitable pharmaceutical additives such as solubilizers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickeners, pigments, viscosity modifiers, stabilizers or osmotic pressure-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (partially including additives such as those described above, such as cellulose derivatives, preferably carboxymethyl cellulose sodium salt solutions), alcohols (including monohydric alcohols and polyhydric alcohols, such as ethylene glycol) and their derivatives, oils (such as fractionated coconut oil and peanut oil). Carriers for parenteral administration can also be fats and oils such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used for sterile liquid compositions for parenteral administration. The liquid carrier for pressurized composition can be a halogenated hydrocarbon or other pharmaceutically acceptable propellant. Sterile solution or suspension liquid pharmaceutical composition can be used for injection, for example, intravenous, intramuscular, intraperitoneal or subcutaneous injection. The injection can be a single push or gradually injected, such as intravenous drip. The compound can also be administered orally in the form of a liquid or solid composition.

[0068] The carrier or excipient may include time-delay materials known in the art, such as monostearate glyceryl or distearate glyceryl, and may also include wax, ethylcellulose, hydroxypropylmethylcellulose, methyl methacrylate, etc. When the formulation is for oral administration, it is recognized that 0.01% Tween 80 in PHOSALPG-50 is used for the preparation of acceptable oral formulations of other compounds, which can be adapted to the preparation of various compounds of the present invention. A wide variety of pharmaceutical forms can be used when administering the compounds of the present invention. If a solid carrier is used, the formulation can be in the form of a tablet, a powder or a small pill placed in a hard capsule, or in the form of a lozenge or a lozenge. The amount of the solid carrier varies greatly, but preferably from about 25 mg to about 1.0 g. If a liquid carrier is used, the formulation can be a syrup, an emulsion, a soft capsule, or a sterile injection solution or suspension in an ampoule, a vial or a non-aqueous liquid suspension.

[0069] In order to obtain a stable water-soluble dosage form, the hERG potassium channel inhibitor or a pharmaceutically acceptable salt thereof can be dissolved in an aqueous solution of an organic or inorganic acid, a 0.3M succinic acid or citric acid solution. If a soluble form is not available, the compound can be dissolved in a suitable cosolvent or a combination thereof. Examples of such suitable cosolvents include, but are not limited to, ethanol, propylene glycol, polyethylene glycol 300, polysorbate 80, glycerol, polyoxyethylene fatty acid esters, fatty alcohols or glycerol light fatty acid esters, etc., in a concentration range of 0-60% total volume.

[0070] In some examples of this embodiment, the pharmaceutical composition can be in the form of liquid, suspension, emulsion, tablet, pill, capsule, sustained release formulation, suppository, powder, liposome and micelle. Oral formulations can include standard carriers such as pharmaceutical grade mannitol, lactose, starch, magnesium stearate, sodium saccharin, cellulose and magnesium carbonate, etc. Depending on the formulation required, the formulation can be designed to mix, granulate and compress or dissolve the components. In another approach, the composition can be formulated into nanoparticles.

[0071] In some embodiments of this embodiment, the release system of the pharmaceutical composition is known and can be used for the administration of compounds or other various preparations, including tablets, capsules, injectable solutions, liposomes, micelles, microparticles, microcapsules, etc. The method of introduction includes but is not limited to skin, intradermal, intramuscular, intraperitoneal, intravenous, subcutaneous, intranasal, lung, epidural, eyes and (usually preferred) oral route. The pharmaceutical composition can be administered by any convenient or other appropriate route, such as by epithelial or mucosal route (for example, oral mucosa, rectum and intestinal mucosa, etc.) absorption or by the stent loaded with medicine and can be administered with other bioactive agents. Can be systemic or topical administration. When used for the treatment or prevention of nose, bronchial or lung diseases, the preferred route of administration is oral, nasal administration or bronchial aerosol or sprayer.

[0072] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in conjunction with specific embodiments.

[0073] Example 1

[0074] A hERG potassium channel inhibitor Ⅰ-A4 based on an IR780 derivative, the structure of which is shown below:

[0075]

[0076] The synthetic route is as follows:

[0077]

[0078] The preparation method of compound Ⅰ-A4 comprises the following steps:

[0079] (1) Synthesis of intermediate Ib-4

[0080] Compound Ia (0.36 g, 1.0 mmol) and N-(4-bromobutyl)phthalimide (0.56 g, 2 mmol) were dissolved in a mixed solution of 50 mL of dry acetonitrile and 4 mL of dry DMF, anhydrous potassium carbonate (0.41 g, 3.0 mmol) was added, and refluxed at 80°C for 12 h; after the reaction solution was cooled, it was extracted with dichloromethane, washed with distilled water, the organic layers were combined, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by silica gel column to obtain 0.28 g of light yellow solid product Ib-4-1 with a yield of 47.5%.

[0081] ESI-MS: m / z calcd for C 31 H 32 FN5O2[(M+H) + ]:526.2618; found:526.2648. 1 H NMR (400MHz, CDCl3) δ7.72 (dd, J=5.0, 3.1Hz, 2H), 7.64–7.55 (m, 2H), 7.39 (d, J=7. 7Hz,1H),7.01(dd,J=7.7,5.1Hz,3H),6.91(dd,J=15.5,6.8Hz,4H),4.97(s,2H),4. 12(s,1H),3.81(d,J=39.0Hz,2H),3.59(t,J=6.9Hz,2H),2.68(d,J=8.6Hz,1H),2.3 6–2.20(m,2H),2.15–1.90(m,4H),1.67–1.53(m,2H),1.40(dd,J=19.8,9.3Hz,4H).

[0082] The intermediate Ib-4-1 (0.38 g, 0.72 mmol) was dissolved in 30 mL of anhydrous ethanol, and 5 mL of hydrazine hydrate with a mass fraction of 50% was added, and the mixture was refluxed at 80°C for 5 h. The reaction solution was dried by vortexing, and 30 mL of dichloromethane was added to precipitate white flocculent hydrazide, which was filtered by suction, and the filtrate was collected and dried by vortexing under reduced pressure. Dichloromethane was added again to precipitate white flocculent, which was filtered by suction, and the filtrate was dried by vortexing under reduced pressure again, and dried to obtain 0.23 g of white solid product Ib-4 with a yield of 81.0%.

[0083] ESI-MS: m / z calcd for C 23 H 30 FN5[(M+H) + ],396.2563; found 396.2616. 1HNMR (400MHz, DMSO) δ7.25–7.18(m,3H),7.14(t,J=8.9Hz,2H),7.05(d,J=7.4 Hz, 1H), 6.92 (td, J=7.6, 1.1Hz, 1H), 6.82 (td, J=7.6, 1.1Hz, 1H), 6.57 (d, J=7. 5Hz,1H),5.27(s,2H),3.74(dd,J=14.5,3.4Hz,1H),2.84(d,J=11.4Hz,2H),2. 62–2.46(m,3H),2.30–2.18(m,2H),1.96(t,J=10.6Hz,4H),1.64–1.27(m,7H).

[0084] (2) Synthesis of Compound I-A4

[0085] Under nitrogen protection, Ic (17.9 mg, 0.035 mmol) and intermediate Ib-4 (27.6 mg, 0.070 mmol) were dissolved in 6 mL DMF and reacted at 80°C in the dark for 2 h. The reaction solution was cooled to room temperature, dried by spin drying, and purified by silica gel column to obtain 16 mg of dark blue solid product I-A4 with a yield of 52.6%.

[0086] ESI-MS: m / z calcd for C 57 H 69 FN7 + [M + ],870.5593;found 870.5660. 1 HNMR(400MHz,CD3OD_SPE)δ7.77(d,J=13.0Hz,2H),7.37(d,J=7.3Hz,2H),7.34–7.27(m ,3H),7.18–6.95(m,12H),5.84(d,J=13.0Hz,2H),5.30(s,1H),3.99(dd,J=13.7,6.6Hz, 5H),3.83(t,J=6.1Hz,2H),3.48(s,2H),3.02(d,J=33.5Hz,4H),2.55(t,J=6.2Hz,4H), 2.25(d,J=12.4Hz,2H),1.89–1.81(m,5H),1.67(s,12H),1.31(dd,J=16.3,9.2Hz,10H).

[0087] Example 2

[0088] A hERG potassium channel inhibitor Ⅰ-A8 based on an IR780 derivative, the structure of which is shown below:

[0089]

[0090] The synthetic route is as follows:

[0091]

[0092] The preparation method of compound I-A8 comprises the following steps:

[0093] (1) Synthesis of intermediate Ib-8

[0094] Compound Ⅰa (0.36 g, 1.0 mmol) and 2-(8-bromooctyl)isoindoline-1,3-dione (0.34 g, 1.0 mmol) were dissolved in 20 mL of dry acetonitrile, anhydrous potassium carbonate (0.41 g, 3.0 mmol) was added, and refluxed at 80°C for 4 h; the reaction solution was cooled and extracted with dichloromethane, washed with distilled water, and the organic layers were combined, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified on a silica gel column to obtain 0.12 g of a white solid product Ib-8-1 with a yield of 20.7%.

[0095] ESI-MS: m / z calcd for C 35 H 40 FN5O2[(M+H) + ],582.3244; found 582.3242. 1 H NMR (400MHz, CD3OD_SPE) δ7.87–7.81(m,1H),7.81–7.75(m,1H),7.33(d,J=8.5Hz,1H),7.13(dd,J=8.7,5.3Hz,1H),7.10–6.93(m,3H),5.29(s,1H), 4.01(s,1H),3.66(t,J=7.1Hz,1H),3.08(dd,J=20.1,12.0Hz,2H),2.30(d ,J=13.0Hz,1H),1.91(s,1H),1.69(dd,J=18.5,11.4Hz,2H),1.38(s,4H).

[0096] The intermediate Ib-8-1 (0.12 g, 0.20 mmol) was dissolved in 10 mL of anhydrous ethanol, and 1.6 mL of 50% hydrazine hydrate was added, and refluxed at 80°C for 5 h. The reaction solution was concentrated under reduced pressure and purified by silica gel column to obtain 0.037 g of white solid product Ib-8 with a yield of 40.0%.

[0097] ESI-MS: m / z calcd for C 27 H 38 FN5[(M+H)+ ],452.3189; found 452.3253. 1 HNMR(400MHz,CD3OD_SPE)δ7.29(d,J=7.8Hz,1H),7.12(dd,J=8.7,5.3Hz,2H),7.06–6.97(m,4H),6.95–6.90(m,1H),5.23(s,2H),3.80(s,1H), 2.93(d,J=10.8Hz,2H),2.67–2.56(m,2H),2.39–2.30(m,2H),2.15(t,J =11.8Hz,2H),2.05(d,J=11.6Hz,2H),1.67–1.42(m,7H),1.33(m,10H).

[0098] (2) Synthesis of Compound I-A8

[0099] Under nitrogen protection, Ic (22.7 mg, 0.044 mmol) and intermediate Ib-8 (20.0 mg, 0.044 mmol) were dissolved in 6 mL DMF and reacted at 80°C in the dark for 2 h. The reaction solution was cooled to room temperature, dried by spin drying, and purified by silica gel column to obtain 26.8 mg of dark blue solid product I-A8 with a yield of 65.7%.

[0100] ESI-MS: m / z calcd for C 61 H 77 FN7 + [M + ],926.6219; found 926.6279. 1 H NMR (400MHz, CD3OD_SPE) δ7.76 (d, J=13.0Hz, 2H), 7.43–7.24 (m, 5H), 7.15 (dd, J=8.7 ,5.3Hz,2H),7.12–6.96(m,10H),5.83(d,J=13.0Hz,1H),5.31(s,2H),3.99(dd,J=13 .8,6.7Hz,4H),3.77(t,J=6.8Hz,2H),3.12–3.05(m,2H),2.54(t,J=6.3Hz,4H),2.28 (d,J=12.7Hz,2H),1.89–1.71(m,7H),1.65(s,10H),1.42(s,8H),1.37–1.24(m,15H).

[0101] Example 3

[0102] A hERG potassium channel inhibitor II-E4 based on an IR780 derivative, the structure of which is shown below:

[0103]

[0104] The synthetic route is as follows:

[0105]

[0106] The preparation method of compound II-E4 comprises the following steps:

[0107] (1) Synthesis of Intermediate IIb-4

[0108] Compound IIa (0.76 g, 2.38 mmol) and anhydrous potassium carbonate (0.66 g, 4.76 mmol) were dissolved in 15 mL of dry acetonitrile, and then tert-butyl N-(4-bromobutyl)carbamate (0.30 g, 1.19 mmol) in acetonitrile (10 mL) was slowly added dropwise to the above solution, and the mixture was refluxed at 80°C for 2 h. After the reaction solution was cooled to room temperature, it was extracted with dichloromethane, washed with distilled water, and the combined organic layers were dried over anhydrous sodium sulfate, filtered, concentrated in vacuo, and purified on a silica gel column to obtain 0.10 g of a white solid product IIb-4-1 with a yield of 18.5%.

[0109] ESI-MS: m / z calcd for C 12 H 35 N3O5S[(M+H) + ],454.2376; found 454.2439. 1 H NMR (400MHz, CDCl3) δ7.82(d,J=8.7Hz,2H),7.29(d,J=8.7Hz,2H),5.56(s,1H),5.29(s,1H),3.19(dd,J=13.3,6.0Hz,1H),3 .01(d,J=7.7Hz,7H),2.42(t,J=7.1Hz,2H),2.22(s,2H),1.82(s,4H),1.64–1.50(m,2H),1.45(d,J=6.6Hz,2H),1.36(s,9H).

[0110] The intermediate IIb-4-1 (0.10 g, 0.22 mmol) was dissolved in a mixed solution of 4 mL of dichloromethane and 1 mL of trifluoroacetic acid and stirred at room temperature for 1 h. The mixture was spin-dried to obtain a yellow oil, which was dissolved in distilled water and neutralized with solid sodium bicarbonate. The mixture was washed with dichloromethane, and the aqueous phase was collected and spin-dried. The obtained solid was dissolved in methanol, filtered, and the filtrate was collected and spin-dried to obtain 0.04 g of a white solid product IIb-4 with a yield of 51.3%.

[0111] ESI-MS: m / z calcd for C 17 H 27 N3O3S[(M+H) + ],354.1851; found 354.1870. 1 H NMR (400MHz, CD3OD_SPE) δ7.75(d,J=8.8Hz,2H),7.02(d,J=8.8Hz,2H),3.10–2.88(m,3H),2.83(s,3H),2.63(t,J=7.0Hz, 1H),2.43–2.32(m,2H),2.13(td,J=11.4,2.9Hz,2H),1.89–1.63(m,5H),1.60–1.35(m,5H),1.26(dd,J=16.0,5.0Hz,2H).

[0112] (2) Synthesis of Compound II-E4

[0113] Under nitrogen protection, Ic (20.0 mg, 0.039 mmol) and intermediate IIb-4 (27.6 mg, 0.078 mmol) were dissolved in 6 mL DMF and reacted at 80°C in the dark for 2 h. The reaction solution was cooled to room temperature, dried under reduced pressure, and purified by silica gel column to obtain 13.8 mg of dark blue solid with a yield of 42.7%.

[0114] ESI-MS: m / z calcd for C 51 H 66 N5O3S + [M + ],828.4881; found 828.4846. 1HNMR(400MHz, CDCl3) δ7.95(s,2H),7.83(d,J=8.8Hz,1H),7.62(d,J=12.7Hz,1H),7.40(d,J=8.7Hz,1H),7.25–7. 17(m,3H),6.99(t,J=7.3Hz,1H),6.79(d,J=7.8Hz,1H),5.54(d,J=12.4Hz,1H),3.88–3.72(m,3H),3.40–3.33(m, 1H),3.13–3.05(m,1H),3.01(s,2H),2.89(s,6H),2.82(s,6H),2.72(s,2H),2.64(s,1H),2.55(d,J=7.0Hz,1H),2 .42(t,J=6.2Hz,3H),1.91(dd,J=16.6,7.9Hz,4H),1.80–1.69(m,3H),1.63(d,J=16.9Hz,7H),1.32–1.12(m,15H).

[0115] Example 4

[0116] A hERG potassium channel inhibitor II-E6 based on an IR780 derivative, the structure of which is shown below:

[0117]

[0118] The synthetic route is as follows:

[0119]

[0120] The preparation method of compound II-E4 comprises the following steps:

[0121] (1) Synthesis of Intermediate IIb-6

[0122] Compound IIa (0.32 g, 1.0 mmol) and anhydrous potassium carbonate (0.41 g, 3.0 mmol) were dissolved in 15 mL of dry acetonitrile, and tert-butyl (6-bromohexyl)carbamate (0.28 g, 1.0 mmol) was dissolved in 5 mL of dry acetonitrile, and then added to the acetonitrile solution of compound IIa at 80°C. After the addition was complete, the mixture was refluxed for 2 h. The reaction solution was cooled to room temperature, extracted with dichloromethane, washed with distilled water, and the organic layers were combined, dried over anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and purified by silica gel column to obtain 0.10 g of white solid product IIb-6-1 with a yield of 20.7%.

[0123] ESI-MS: m / z calcd for C 24 H 39 N3O5S[(M+H)+ ],482.2689; found 482.2758. 1 H NMR (400MHz, CD3OD_SPE) δ7.95(d,J=8.8Hz,2H),7.30(d,J=8.8Hz,2H),3.41(t,J=11.1Hz,1H),3.09(d,J=11.9Hz,2H),3.05–2.97(m,5 H),2.52–2.42(m,2H),2.31(t,J=10.8Hz,2H),1.82(dt,J=21.8,12.3Hz,4H),1.57(s,2H),1.44(d,J=18.5Hz,12H),1.38–1.26(m,5H).

[0124] The intermediate IIb-6-1 (0.10 g, 0.21 mmol) was dissolved in a mixed solution of 4 mL of dichloromethane and 1 mL of trifluoroacetic acid, and stirred at room temperature for 1 h. The mixture was spin-dried to obtain a yellow oil, which was dissolved in distilled water and neutralized with solid sodium bicarbonate, washed with dichloromethane, and the aqueous phase was spin-dried, dissolved in methanol, filtered, and the filtrate was collected and spin-dried to obtain 0.04 g of white solid IIb-6 with a yield of 49.5%.

[0125] ESI-MS: m / z calcd for C 19 H 31 N3O3S[(M+H) + ],382.2164; found 382.2190.

[0126] (2) Synthesis of Compound II-E6

[0127] Under nitrogen protection, Ic (26.8 mg, 0.052 mmol) and compound IIb-6 (20.0 mg, 0.052 mmol) were dissolved in 6 mL DMF and reacted at 80°C in the dark for 2 h. The reaction solution was cooled to room temperature, dried by spin drying, and purified by silica gel column to obtain 623.78 mg of dark blue solid II-E with a yield of 53.4%.

[0128] ESI-MS: m / z calcd for C 53 H 70 N5O3S + [M + ],325.1216; found 856.5260.

[0129] Application Examples

[0130] 1. Determination of the inhibitory activity of compounds on hERG potassium channels

[0131] The present invention determines the inhibitory activity of the synthesized compound on hERG potassium channel by radioligand binding experiment. The experimental results are as follows Figure 1 As shown in Figure 2, compound I-A8 has the strongest inhibitory effect on hERG potassium channels, IC 50 The value was 3.62 nM (Table 1), so probe I-A8 was selected for further activity evaluation.

[0132] Table 1

[0133] Compound <![CDATA[IC 50 (nM)]]> Ⅰ-A4 30.36 Ⅰ-A8 3.62 II-E4 29.96 II-E6 9.59 Dofetilide 2.30

[0134] 2. Singlet oxygen generation ability of probe I-A8

[0135] The IR780 fluorophore has a good ability to generate singlet oxygen, so the ability of compound I-A8 to generate singlet oxygen was further evaluated.

[0136] 2.1. Using DPBF (singlet oxygen indicating fluorescent probe) to detect the ability of compound I-A8 to generate singlet oxygen in solution

[0137] DPBF, DPBF+I-A8, and DPBF+IR780 solutions were prepared in dichloromethane, and the absorbance of DPBF at 415nm was adjusted to about 1.0, and the absorbance of I-A8 and IR780 was adjusted to about 0.2. Then, the above solutions were irradiated with monochromatic light of 660nm for different times, and their absorption spectra were immediately measured. The decomposition rate was quantified by the decrease in the absorbance of DPBF at 415nm. The experimental results showed that after irradiation with 660nm monochromatic light, the absorbance of DPBF at 415nm in the mixed system of DPBF and I-A8 decreased rapidly ( Figure 2 , Figure 3 ), which indicates that compound I-A8 has a strong ability to generate singlet oxygen in solution.

[0138] 2.1. The singlet oxygen production ability of compound I-A8 was further verified at the cellular level by DCFH-DA (reactive oxygen detection kit)

[0139] U87 cells were treated with 1 μM compound I-A8 for 1 h, then 10 μM DCFH-DA was added and incubated for 15 min. The treated cells were then irradiated with 660 nm monochromatic light for 1 min and carefully washed three times with PBS. Immediately, they were imaged with SP8. Obvious fluorescence was observed in the cells treated with laser ( Figure 4 ), indicating that compound I-A8 still has the ability to produce singlet oxygen in cells.

[0140] 3. Evaluation of antitumor activity of compound I-A8 at the cellular level

[0141] 3.1. Evaluation of the antitumor activity of compound I-A8 at the cellular level using various GBM cell lines (U87 / A172 / LN229) and lung cancer cell line A549

[0142] After the tumor cells were treated with I-A8 for 72 hours, the CCK8 kit was used to evaluate its effect on cell proliferation. The results showed that I-A8 inhibited the proliferation of the three GBM tumor cells in a dose-dependent manner, and its half-maximal inhibitory concentration was calculated to be about 1 μM ( Figure 5 ). At the same time, normal human astrocytes were selected to evaluate the selectivity of compound I-A8 for normal cells. The results showed that I-A8 had little effect on normal cell proliferation and its toxicity to normal cells was significantly lower than that to GBM tumor cells. At the same time, A549 cells were used to evaluate the anti-tumor activity of I-A8 against lung cancer cells. The results showed that I-A8 also had good anti-tumor activity against lung cancer cells, and its half-inhibitory concentration was also around 1μM ( Figure 6 ).

[0143] 3.2. Evaluation of the effect of I-A8 and laser combined action on tumor cell proliferation using U87 cells

[0144] U87 tumor cells were divided into two groups. One group was treated with I-A8 for 48 hours. The other group was treated with A8 for 24 hours in advance, then irradiated with 660nm monochromatic light for 5 minutes, and the cells were returned to the incubator for another 24 hours. Finally, the CCK8 kit was used to evaluate the effects of I-A8 alone and the combined effects of I-A8 and laser on cell proliferation. The experimental results showed that compared with I-A8 alone, the combination of I-A8 and laser can exert a stronger anti-tumor effect ( Figure 7 ).

[0145] In summary, the novel hERG potassium channel probe I-A8 constructed in the present invention has strong anti-tumor activity at the cellular level and can exert a stronger anti-tumor effect in combination with laser therapy.

[0146] 4. Evaluation of the in vivo antitumor activity of compound I-A8

[0147] The U87-luc cell line was used to construct an intracranial orthotopic mouse tumor model with glioblastoma multiforme to study the anti-tumor activity of I-A8 at the in vivo level.

[0148] In order to improve the delivery efficiency of I-A8 to the brain, the present invention selects liposomes as delivery carriers, and loads I-A8 onto liposomes to obtain ApoE-Lipo@A8. The specific synthesis method of ApoE-Lipo@A8 is as follows:

[0149] 1) Soybean lecithin, cholesterol, DSPE-PEOz and DSPE-PEG2000 were prepared in a molar ratio of 60:30:12:2 and dissolved in methanol to adjust the final solution concentration to 1 mg / mL; I-A8 was dissolved in methanol and added to the above liposome solution to control the mass ratio of I-A8:liposome = 3:100. 16 mL of the mixed solution was placed in a 100 mL eggplant-shaped bottle for rotary evaporation to form a phospholipid bilayer film, and vacuum dried overnight;

[0150] 2) Add 1.6 mL of physiological saline containing 1.6 mg of DSPE-PEG3400-ApoE to the above liposome film for hydration, shake by hand until the film layer is completely detached, then ultrasonicate at 25-35° C. for 30 min, and then ultrasonicate at 50° C. for 30 min to obtain a blue liposome solution;

[0151] 3) The liposome solution was sequentially passed through 0.45um and 0.22um aqueous filter membranes for three times each, and then extruded using a liposome extruder. During extrusion, it was extruded back and forth through a 100nm filter membrane ten times to obtain ApoE-Lipo@A8, which was stored in a 4°C refrigerator for subsequent experiments.

[0152] Ten days after tumor inoculation, nude mice bearing tumors were randomly divided into three groups and treated with PBS, ApoE-Lipo@A8 (dosage of 3 mg / kg), and ApoE-Lipo@A8 (dosage of 3 mg / kg) + 660nm laser irradiation. The administration method was tail vein injection, once every two days, for a total of five times. At the same time, starting from the tenth day of tumor inoculation, the growth of the tumor was monitored every two days using a small animal live imaging device.

[0153] The results are as follows Figure 8-11 As shown, ApoE-Lipo@A8 can effectively inhibit the growth of intracranial in situ tumor cells, and ApoE-Lipo@A8 combined with 660nm laser irradiation almost completely inhibits the growth of tumors; more importantly, the median survival time of mice in the treatment group was significantly prolonged, and the survival time was twice that of the control group, and the survival rate within 40 days was significantly improved. In summary, the new hERG potassium channel inhibitor I-A8 constructed by the present invention shows effective anti-GBM tumor activity in U87 tumor-bearing mice, and can effectively cross the blood-brain barrier after being encapsulated in liposomes, inhibit the growth of intracranial in situ tumors and significantly prolong the survival of mice.

[0154] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A hERG potassium channel inhibitor based on an IR780 derivative, wherein the general structural formula of the hERG potassium channel inhibitor is as shown in formula (I) or formula (II); in, R1 is methyl, ethyl, propyl, allyl, butylene, propargyl or butylene; R2 is halogen, methyl, sulfonic acid or hydrogen, and n=0-8.

2. The hERG potassium channel inhibitor based on IR780 derivatives as claimed in claim 1, characterized in that The hERG potassium channel inhibitor is selected from compounds having the following structural formula: 。 3. The method for preparing the hERG potassium channel inhibitor based on IR780 derivatives according to claim 1, characterized in that: The following steps are involved: (1) Preparation of the compound of formula (I): S1. Compound Ia and N-(bromoalkyl)phthalimide are dissolved in an organic solvent, an acid binding agent is added, and the mixture is refluxed at high temperature. After the reaction is completed, the reaction solution is cooled and extracted, and the organic layers are combined, dried, filtered, concentrated, and purified to obtain intermediate product Ⅰb-1; S2. The intermediate product Ⅰb-1 is subjected to hydrazinolysis. After the hydrazinolysis is completed, the reaction solution is concentrated and purified to obtain the intermediate product Ⅰb; S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅰb are reacted in an organic solvent at high temperature and in the dark; after the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅰ); The structure of compound Ⅰa is as follows: ； Or, the preparation of the compound of formula (II): S1. Dissolve N-(4-(piperidin-4-yl)phenyl)methanesulfonamide and an acid-binding agent in an organic solvent, slowly dropwise add N-(bromoalkyl)carbamic acid tert-butyl ester solution, and reflux at high temperature; after the reaction is completed, cool the reaction solution and extract, combine the organic layers, dry, filter, concentrate, and purify to obtain intermediate product Ⅱb-1; S2. The intermediate product Ⅱb-1 was dissolved in a mixed solution of dichloromethane and trifluoroacetic acid, stirred, and dried to obtain a yellow oil, which was dissolved in distilled water and neutralized by adding solid sodium bicarbonate, washed with dichloromethane, and the aqueous phase was collected and dried; the obtained solid was dissolved in methanol, filtered, and the filtrate was collected and dried to obtain the intermediate product Ⅱb; S3. Under nitrogen protection, compound Ⅰc and intermediate product Ⅱb are reacted in an organic solvent at high temperature and in the dark. After the reaction is completed, the reaction solution is cooled to room temperature, dried by rotation, and purified to obtain a compound of formula (Ⅱ).

4. The method for preparing a hERG potassium channel inhibitor based on an IR780 derivative as claimed in claim 3, characterized in that: The alkyl chain length of the N-(bromoalkyl)phthalimide is 2-10 carbons.

5. The method for preparing a hERG potassium channel inhibitor based on an IR780 derivative as claimed in claim 3, characterized in that: The alkyl chain length of the tert-butyl N-(bromoalkyl)carbamate is 2 to 10 carbons.

6. The method for preparing a hERG potassium channel inhibitor based on an IR780 derivative as claimed in claim 3, characterized in that: The acid binding agent includes anhydrous potassium carbonate, anhydrous sodium acetate and anhydrous sodium carbonate.

7. The method for preparing a hERG potassium channel inhibitor based on an IR780 derivative as claimed in claim 6, characterized in that: The acid binding agent is anhydrous potassium carbonate.

8. Use of the hERG potassium channel inhibitor based on IR780 derivatives according to claim 1 in the preparation of anti-tumor drugs; The tumor is one of glioma, glioblastoma multiforme or lung cancer.

9. A pharmaceutical composition for treating cancer, characterized in that: The pharmaceutical composition comprises the hERG potassium channel inhibitor based on the IR780 derivative according to claim 1 or a pharmaceutically acceptable salt thereof.

10. The pharmaceutical composition according to claim 9, characterized in that The cancers include glioma, glioblastoma multiforme, lung cancer, digestive tract cancer, pancreatic cancer, lymphoma, liver cancer, kidney cancer, bladder cancer, prostate cancer, breast cancer, head and neck cancer, nasopharyngeal cancer, oral cancer, and skin cancer.

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