Use of a compound in the manufacture of a medicament for the prevention or treatment of a cardiac disorder

Abstract

The present application discloses the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof in the manufacture of a medicament for the prevention or treatment of a cardiac disorder, in particular an arrhythmia.

Description

Technical Field

[0001] This invention relates to the use of a compound in the preparation of a medicament for the prevention or treatment of heart disease. The invention also relates to a pharmaceutical composition and its use in the preparation of a medicament for the prevention or treatment of heart disease. Background Technology

[0002] The compound of formula (I) is a compound known in the prior art and is known to have antitumor activity.

[0003]

[0004] However, the inventors of this invention unexpectedly discovered that the compound of formula (I) has a very good effect on heart disease, especially arrhythmia, and can meet the needs of prevention and treatment, thus completing this invention. Summary of the Invention

[0005] One aspect of the present invention provides the use of a compound of formula (I) or a pharmaceutically acceptable salt thereof in the preparation of a medicament for the prevention or treatment of heart disease.

[0006] In one embodiment, the compound of formula (I) is a compound of formula (IA) or formula (IB) (or a pharmaceutically acceptable salt thereof), or a mixture of both:

[0007]

[0008] In one embodiment, the compound of formula (I) is a mixture of compounds of formula (IA) and formula (IB) (or pharmaceutically acceptable salts thereof). The compound of formula (IA) or its pharmaceutically acceptable salt, based on the weight of the free base, comprises 5% to 95% by weight of the total amount of the compound of formula (IA) or its pharmaceutically acceptable salt and the compound of formula (IB) or its pharmaceutically acceptable salt, for example, about 5% by weight, about 10% by weight, about 15% by weight, about 20% by weight, about 25% by weight, about 30% by weight, about 35% by weight, about 40% by weight, about 45% by weight, about 50% by weight, about 55% by weight, about 60% by weight, about 65% by weight, about 70% by weight, about 75% by weight, about 80% by weight, about 85% by weight, about 90% by weight, or about 95% by weight.

[0009] In one embodiment, the compound of formula (I) is a mixture of compounds of formula (IA) and formula (IB) (or pharmaceutically acceptable salts thereof). The compound of formula (IA) or its pharmaceutically acceptable salt, by weight of the free base, comprises about 30% to 90% by weight, preferably about 40% to 80% by weight (e.g., about 40% to 60% by weight or about 60% to 80% by weight), and more preferably about 50% to 70% by weight (e.g., about 50% by weight or about 70% by weight).

[0010] In one embodiment, the cardiac disease is an arrhythmia. In another embodiment, the arrhythmia is a ventricular arrhythmia.

[0011] Another aspect of the invention provides a pharmaceutical composition comprising a compound of formula (IA) or a pharmaceutically acceptable salt thereof, a compound of formula (IB) or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier.

[0012] In one embodiment of the pharmaceutical composition, the compound of formula (IA) or a pharmaceutically acceptable salt thereof, based on the weight of the free base, accounts for 5% to 95% by weight of the total amount of the compound of formula (IA) or a pharmaceutically acceptable salt thereof and the compound of formula (IB) or a pharmaceutically acceptable salt thereof, for example, about 5% by weight, about 10% by weight, about 15% by weight, about 20% by weight, about 25% by weight, about 30% by weight, about 35% by weight, about 40% by weight, about 45% by weight, about 50% by weight, about 55% by weight, about 60% by weight, about 65% by weight, about 70% by weight, about 75% by weight, about 80% by weight, about 85% by weight, about 90% by weight, and about 95% by weight.

[0013] In one embodiment of the pharmaceutical composition, the compound of formula (IA) or a pharmaceutically acceptable salt thereof, based on the weight of the free base, accounts for about 30% to 90% by weight, preferably about 40% to 80% by weight (e.g., about 40% to 60% by weight or about 60% to 80% by weight), more preferably about 50% to 70% by weight (e.g., about 50% by weight or about 70% by weight).

[0014] Another aspect of the invention provides the use of the aforementioned pharmaceutical composition in the preparation of a medicament for the prevention or treatment of heart disease. In one embodiment, the heart disease is an arrhythmia, preferably a ventricular arrhythmia. Detailed Implementation

[0015] The present invention is further illustrated below with specific embodiments. It should be understood that the embodiments are not intended to limit the scope of the invention. The raw materials, reagents, etc. used in the embodiments are substances known to those skilled in the art and obtainable by commercially available or literature methods; the experimental or characterization methods used are also methods known to those skilled in the art.

[0016] Example 1: Preparation and separation of compounds of formula (I), (IA), and (IB)

[0017]

[0018] Step 1: Synthesis of intermediate M-1

[0019] Under nitrogen protection and stirring at 0°C, tert-butyl nitrite (15.47 g, 0.15 mol) was slowly added dropwise to 200 ml of THF solution containing sophoridine (24.82 g, 0.10 mol) and potassium tert-butoxide (39.27 g, 0.35 mol). After the addition was complete (0–10°C), the reaction was allowed to continue for 0.5–1.0 h until complete. The reaction was confirmed by TLC, and 700 ml of 3N hydrochloric acid solution (pH = 1–2) was added. The mixture was stirred at room temperature for 0.5–1.0 h. The mixture was filtered, and the filter cake was dried to give M-1 (30.00 g, yield 96%). LCMS [M+H] + 278.36(C 15 H 23 N3O2: 277.36).

[0020] Step 2: Synthesis of compound (I)

[0021] Under stirring conditions at 20–30 °C, zinc powder (18.31 g, 0.28 mol) was added in portions to 125 ml of an aqueous solution containing M-1 (25.10 g, 0.08 mol) and ammonium chloride (25.67 g, 0.48 mol), and the reaction was continued for 3–5 h until complete. The reaction was detected by TLC. The mixture was filtered at room temperature, and oxalic acid (14.41 g, 0.16 mol) was added to the filtrate. The mixture was stirred for 0.5–1.0 h, and 75 ml of 30% sodium hydroxide (pH = 9–10) was added dropwise. The mixture was stirred for 0.5–1.0 h, filtered, and the filtrate was extracted with dichloromethane (300 ml × 3). The extract was dried over anhydrous sodium sulfate, and the filtrate was evaporated to dryness under reduced pressure to obtain compound (I) (20.00 g, yield 95%). LCMS [M+H] + 264.38(C 15 H 25 N3O: 263.38).

[0022] Step 3: Separation of compounds of formula (IA) and formula (IB)

[0023] The obtained compound of formula (I) (20.00 g, 0.076 mol) was purified and separated by silica gel (300-400 mesh) column chromatography (V 二氯甲烷 V 甲醇 =30:1 to 5:1), to obtain compound (IA) (8.00 g, 40% yield) and compound (IB) (8.00 g, 40% yield).

[0024] Compound of formula (IA): LCMS[M+H] + 264.38(C 15 H 25 N3O: 263.38). 1 HNMR (400MHz, D2O) δ3.92-3.79 (m, 2H), 3.58-3.45 (m, 1H), 3.30-3.12 (m, 1H), 2.96-2.89 (m, 2H) , 2.89-2.80 (m, 1H), 2.63-2.05 (m, 4H), 2.01-1.65 (m, 4H), 1.62-1.48 (m, 6H), 1.35-1.04 (m, 2H).

[0025] Compounds of formula (IB): LCMS[M+H] + 264.38(C 15 H 25 N3O: 263.38). 1 HNMR (400MHz, D2O) δ3.92-3.79 (m, 2H), 3.58-3.45 (m, 1H), 3.30-3.12 (m, 1H), 2.96-2.89 (m, 2H) , 2.89-2.80 (m, 1H), 2.63-2.05 (m, 4H), 2.01-1.65 (m, 4H), 1.62-1.48 (m, 6H), 1.35-1.04 (m, 2H).

[0026] In the following text, compounds of formula (IA) will sometimes be referred to as "H208A" and compounds of formula (IB) as "H208B".

[0027] Step 4: Single-crystal diffraction tests of compounds of formula (IA) and (IB).

[0028] To determine the stereoconfigurations of compounds (IA) (H208A) and (IB) (H208B), single-crystal diffraction experiments were performed on both. H208A was prepared as a single crystal using the free base of the compound, while H208B, being an oily substance, was difficult to crystallize. Therefore, conventional methods were used to prepare H208B as a dihydrochloride, and the experiments were conducted using the single crystal of the dihydrochloride.

[0029] instrument

[0030] Detector: Rigaku Oxford Diffraction XtaLAB Synergy four-cycle diffractometer, equipped with HyPix-6000HE area detector.

[0031] Cooling system: Oxford Cryostream 800

[0032] Other parameters:

[0033] 50W, microfocus source with multi-layer mirror (μ-CMF)

[0034] Distance from crystal to CCD detector: d = 35mm

[0035] Tube voltage: 50kV

[0036] Tube current: 1mA

[0037] Crystal culture

[0038] 20 mg of H2O8A sample was dissolved in 0.6 mL of dichloromethane / n-hexane (1:5) at room temperature. The sample solution was placed in a 4 mL semi-sealed sample bottle and allowed to evaporate slowly at 45 °C. Colorless prismatic crystals were obtained the next day.

[0039] 20 mg of H2O8B dihydrochloride sample was dissolved in 1.1 mL of ethanol / n-heptane (5:6) at room temperature. The sample solution was placed in a 4 mL semi-sealed sample bottle and allowed to evaporate slowly at room temperature. Colorless blocky crystals were obtained the next day.

[0040] Data collection

[0041] For H208A, a diffraction experiment collected 62,194 diffraction points, of which 11,225 were independent diffraction points (Rint = 0.0682). The diffraction collection range was 2θ = 4.416 to 133.18°, and the diffraction index range was -6 ≤ h ≤ 6, -37 ≤ k ≤ 31, -23 ≤ l ≤ 23. Structural analysis was performed using SHELXT (Sheldrick, GM2015. ActaCryst. A71, 3-8), and structural refinement was performed using SHELXL (against F...). 2 (Sheldrick, GM2015. ActaCryst. C71, 3-8). Of the 11225 independent diffraction points, 896 parameters participated in the structure refinement. After refinement, S = 1.065, R1 = 0.0361, wR2 = 0.0914. The residual electron density values ​​are 0.12 and...

[0042] For H2O8B dihydrochloride, diffraction experiments collected 40,390 diffraction points, of which 3,331 were independent diffraction points (Rint = 0.1071). The diffraction range was 2θ = 8.102 to 133.17°, and the diffraction index range was -11 ≤ h ≤ 11, -11 ≤ k ≤ 8, -51 ≤ l ≤ 51. Structural analysis was performed using SHELXT (Sheldrick, GM2015. ActaCryst. A71, 3-8), and structural refinement was performed using SHELXL (against F...). 2 (Sheldrick, GM2015. ActaCryst. C71, 3-8). Of the 3331 independent diffraction points, the parameter used for structure refinement was 215. After refinement, S = 1.128, R1 = 0.0727, wR2 = 0.1722. The residual electron density values ​​were 0.69 and...

[0043] Test results

[0044] For H208A, the results are shown in Tables I to V; for H208B dihydrochloride, the results are shown in Tables VI to XI. The results verify that H208A and H208B possess the configurations shown in formulas (IA) and (IB) of this application, respectively. Table I: Summary of X-ray crystallography data for H208A single crystals.

[0045]

[0046] Table II: Atomic coordinates of H2O8A single crystal (x10) 4 and equivalent isotropic displacement parameters (A) 2 x10 3 )

[0047]

[0048]

[0049]

[0050] Table III: Bond Lengths of H2O8A Single Crystals

[0051]

[0052]

[0053]

[0054] Table IV: Bond Angles (°) of H2O8A Single Crystal

[0055]

[0056]

[0057]

[0058] Table V: Twist angle (°) of H208A single crystal

[0059]

[0060]

[0061]

[0062]

[0063] Table VI: Summary of X-ray crystallization data for H2O8B dihydrochloride single crystals

[0064]

[0065] Table VII: Atomic coordinates (x10) of H2O8B dihydrochloride single crystal 4 and equivalent isotropic displacement parameters (A) 2 x10 3 )

[0066]

[0067] Table VIII: Bond Lengths of H2O8B Dihydrochloride Single Crystals

[0068]

[0069]

[0070] Table IX: Bond Angles (°) of H208B Dihydrochloride Monocrystals

[0071]

[0072] Table X: Hydrogen Bonds of H208B Dihydrochloride Monocrystals

[0073]

[0074]

[0075] 1 1 + X, + Y, + Z: 2 -1 / 2 - X, -1 / 2 + Y, 3 / 4 - Z; 3 1 / 2 - X, -1 / 2 + Y, 3 / 4 - Z, 4 3 / 2 - Y, 1 / 2 + X, -1 / 4 + Z

[0076] Table XI: Torsion Angles (°) of H208B Dihydrochloride Monocrystals

[0077]

[0078] Example 2: Effects on Isolated Heart Electrocardiogram (ECG) and Conduction System

[0079] 1 Materials

[0080] 1.1 Animals Dunkin Hartley (DH) guinea pigs, 12, male, purchased from Beijing Jinmuyang Experimental Animal Breeding Co., Ltd., license number: SCXK(Beijing) 2020 - 0002.

[0081] 1.2 Drug H208B (purity: over 98%).

[0082] 2 Methods

[0083] 2.1 Grouping and Administration of Experimental Animals:

[0084] Animals were randomly divided into 2 groups, a control group and an H208B group, 6 animals per group. The administration concentrations of H208B were set as 0, 200, 400 μM groups and an elution group ("elution" means after evaluation with 400 μM H208B addition, the drug was eluted with K - H solution without the drug), and the control group was parallelly given K - H solution.

[0085] 2.2 Experimental Procedures:

[0086] Before the start of the experiment, the compounds in the formula were accurately weighed according to the following table to prepare the K - H solution used in the experiment.

[0087] Table 1: Formula of K - H Solution Used in Example 2

[0088]

[0089] Add the solution to ultrapure water and bring the volume to 1L. Use a magnetic stirrer to aid dissolution, aerate for 30 minutes, and adjust the pH to 7.4±0.05. Turn on the thermostatic circulation pump of the isolated heart perfusion device and maintain the system temperature at 37℃. Pour the prepared KH solution into the thermostatic bath to equilibrate to physiological temperature, and continuously aerate it. Fill the tubing with KH solution (ensuring no air bubbles are present in the tubing). Turn on the main unit and amplifier power, open the software, set the corresponding parameters, and set it for later use. After anesthetizing the guinea pigs, heparin was injected, the thoracic cavity was quickly opened, the heart was removed and placed in pre-cooled KH solution, and the aorta was connected to the perfusion system in the shortest possible time. The heart was then fixed with sutures, the perfusion system was turned on, and the ex vivo heart perfusion began. The heart resumed normal beating within minutes. After the rhythm stabilized, two ECG probes were placed at the apex and right atrium, respectively, for ECG monitoring. Two mapping electrodes were attached to the left atrium and left ventricle of the heart, respectively. After the signal stabilized, the pre-drug data was recorded, and the drug was administered. The data changes after different drug concentrations were recorded.

[0090] 2.3 Statistical analysis results The results indicate that SPSS software was used for ANOVA analysis and Dunnett's test, and nonparametric tests were used for data that did not conform to a normal distribution.

[0091] 3 Results

[0092] 3.1 Heart rate: Compared with the control group, H2O8B slowed the heart rate and could be eluted by drug-free KH solution, p<0.05 (see Table 2).

[0093] 3.2 Prolonged PR interval: Compared with the control group, H2O8B slowed the heart rate and could be eluted by drug-free KH solution, p<0.05 (see Table 2).

[0094] 3.3 QT interval: Compared with the control group, no significant drug-related changes were observed after H208B administration intervention (see Table 2).

[0095] 3.4 Left ventricular conduction: Compared with the control group, H2O8B slowed down the conduction velocity of the ventricles and could be eluted by drug-free KH solution, p<0.05, p<0.01 (see Table 3).

[0096] 3.5 Atrioventricular delay: Compared with the control group, H2O8B can prolong the atrioventricular delay time and can be eluted by drug-free KH solution, p<0.05 (see Table 3).

[0097] Table 2. Effects of H2O8B on ECG parameters of isolated hearts, rate of change (n=6)

[0098]

[0099] Note: The data in the above table are percentage values relative to those before drug administration, and are expressed as mean ± standard deviation.

[0100] Table 3. Effects of H208B on isolated heart conduction, rate of change (n = 6)

[0101]

[0102] Note: The data in the above table are percentage values relative to those before drug administration, and are expressed as mean ± standard deviation.

[0103] 4 Conclusions

[0104] H208B can slow down the heart rate of isolated hearts, prolong the PR interval, and has no obvious effect on the QT interval; it can significantly slow down the conduction velocity of the left ventricle and the atrioventricular delay. Taken together, the compound involved in the present invention can regulate the ECG and conduction system of isolated hearts, has the characteristics of a multi-ion channel blocker, and shows anti-arrhythmic activity.

[0105] Example 3: Effects on myocardial cell action potentials and ion channels

[0106] 1 Materials

[0107] 1.1 Animals DH guinea pigs, 30 males, purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd., license number: SCXK (Beijing) 2016-0011.

[0108] 1.2 Drugs H208B (purity: over 98%).

[0109] 2 Methods

[0110] 2.1 Acute isolation of guinea pig myocardial cells

[0111] Guinea pigs were intraperitoneally injected with 1000 IU·kg of sodium heparin -1 , anesthetized intraperitoneally after heparinization, the heart was removed, and retrograde cannulation was performed through the aorta to start perfusion with calcium-free Tyrode's solution. After rinsing the blood in the heart, it was perfused with calcium-free Tyrode's solution (containing 50 μmol / L of CaCl2) containing 19 mg / 50 ml of collagenase II in a circulating manner. After the outflow rate of the perfusion fluid was significantly accelerated, the heart was removed and put into KB solution and cut into pieces, gently and repeatedly pipetted and allowed to stand still with a thick pipette to make the surviving myocardial cells sediment. Before the electrophysiological experiment, the air in the pipeline system was exhausted. The output end of the drug delivery system was moved to the vicinity of the selected cells in the cell bath by a micromanipulator, and after adding the drug at the corresponding concentration to the drug delivery tube, perfusion drug delivery was carried out.

[0112] 2.2 Liquids required for isolating myocardial cells

[0113] 2.2.1 Preparation of calcium-free desktop solution

[0114] Table 4. Composition of calcium-free benchtop solution (adjust pH to 7.4 ± 0.05)

[0115]

[0116] 2.2.2KB liquid preparation

[0117] Table 5. Composition of KB solution (adjust pH to 7.4 ± 0.05)

[0118]

[0119] 3. Recording of action potentials in guinea pig cardiomyocytes

[0120] 3.1 Preparation of internal electrolyte for electrodes

[0121] Prepare the electrode internal solution according to the concentrations shown in the table below, adjust the pH, dispense, and store below -18℃. Take it out on the day of use and add MgATP (4 mmol / L).

[0122] Table 6. Composition of the internal solution of the action potential electrode (adjusted pH to 7.2 ± 0.05)

[0123]

[0124] 3.2 Preparation of extracellular fluid

[0125] Table 7. Composition of extracellular fluid in action potentials (pH adjusted to 7.4 ± 0.05)

[0126]

[0127]

[0128] 3.3 Recording of action potentials and administration of H2O8B concentration

[0129] Action potentials (APDs) of guinea pig ventricular myocytes were recorded using the I-clamp patch-clamp technique. The current was clamped to 0, and an intracellular current was injected. The stimulation was maintained for 3 ms, and the APDs were recorded. Changes in APD duration (APD90) before and after drug administration were analyzed. Three drug concentrations were administered: 30, 100, and 300 μmol / L, with n = 4 replicates at each concentration.

[0130] 3.4 Data Processing

[0131] All obtained data results are used The results indicate that the paired t-test method was used with Origin 8.0 statistical software for analysis.

[0132] 3.5 Results

[0133] H2O8B at concentrations of 100 μmol / L and 300 μmol / L can significantly prolong the action potential duration of cardiomyocytes (p<0.05 or p<0.01), as shown in Table 8.

[0134] 3.6 Conclusion

[0135] H208B can prolong the action potential duration of cardiomyocytes.

[0136] Table 8. Effects of H₂O₈B at different concentrations on action potential APD90

[0137]

[0138] Recording of 4 potassium currents

[0139] 4.1 Preparation of internal electrolyte for electrodes

[0140] Prepare the electrode internal solution according to the concentrations shown in the table below, adjust the pH, dispense, and store below -18℃. Take it out on the day of use and add MgATP (4 mmol / L).

[0141] Table 9. Composition of the internal solution of the potassium current electrode (adjusted pH to 7.2 ± 0.05)

[0142]

[0143] 4.2 Preparation of extracellular fluid

[0144] Table 10. Composition of extracellular fluid in potassium current (adjusted pH to 7.4 ± 0.05)

[0145]

[0146]

[0147] 4.3 Recording of potassium current and administration of H2O8B concentration

[0148] Potassium current was recorded. Cells were clamped at -80 mV and gradually depolarized from -60 mV to +40 mV in 5 mV increments. The stimulation voltage was maintained for 450 ms. Changes in current before and after drug administration at +40 mV were analyzed. The drug concentrations were 10, 30, 100, 300, and 500 μmol / L, with n = 3 replicates at each concentration.

[0149] 4.4 Data Processing

[0150] All obtained data results are used The results indicate that the paired t-test method was used with Origin 8.0 statistical software for analysis.

[0151] 4.5 Results

[0152] H2O8B can significantly suppress potassium current at concentrations of 100 μmol / L, 300 μmol / L, and 500 μmol / L (p<0.05 or p<0.01), as shown in Table 11.

[0153] 4.6 Conclusion

[0154] H2O8B has an inhibitory effect on potassium current.

[0155] Table 11. Effects of H₂O₈B at different concentrations on potassium current

[0156]

[0157]

[0158] Recording of calcium current

[0159] 5.1 Preparation of internal electrolyte for electrodes

[0160] Table 12. Composition of the internal solution of the calcium current electrode (pH adjusted to 7.2 ± 0.05)

[0161]

[0162] 5.2 Preparation of extracellular fluid

[0163] Table 13. Composition of extracellular fluid in calcium current (adjusted pH to 7.4 ± 0.05)

[0164]

[0165] 5.3 Recording of calcium current and administration of H2O8B concentration

[0166] Calcium currents were recorded with cells clamped at -80 mV. The cells were then gradually depolarized from -60 mV to +60 mV in 10 mV increments, with the stimulation voltage maintained for 200 ms. Changes in the 0 mV current before and after drug administration were analyzed. Drug concentrations were 10, 30, 100, 300, and 500 μmol / L, with n = 4 replicates at each concentration.

[0167] 5.4 Data Processing

[0168] All obtained data results are used The results indicate that the paired t-test method was used with Origin 8.0 statistical software for analysis.

[0169] 5.5 Results

[0170] H208B inhibited calcium current at concentrations of 30 μmol / L, 100 μmol / L, 300 μmol / L, and 500 μmol / L (p < 0.01 or p < 0.001), as shown in Table 14.

[0171] 5.6 Conclusion

[0172] H208B inhibited calcium current.

[0173] Table 14. Effects of H208B at different concentrations on calcium current

[0174]

[0175] The data of this example indicate that the compound involved in the present invention can regulate the action potential and ion channels of cardiomyocytes, and thus can improve arrhythmia.

[0176] Example 4: Effects on the isolated heart ischemia-reperfusion model

[0177] 1 Materials

[0178] 1.1 Animals: 30 male SD rats were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd., with the license number: SCXK (Beijing) 2016-0011.

[0179] 1.2 Drug: H208B (purity: over 98%). [[ID=二十九]]

[0180] 2 Methods

[0181] 2.1 Grouping and administration of experimental animals:

[0182] The animals were randomly divided into 5 groups: sham operation group, model control group, and H208B-125, 250, 500 μM groups, with 6 animals in each group. The sham operation and model groups were given an equal volume of K-H solution.

[0183] 2.2 Experimental procedures:

[0184] Before the start of the experiment, the compounds in the formula were accurately weighed according to the following table to prepare the K-H solution required for the experiment.

[0185] Table 15: Formula of the K-H solution used in Example 4

[0186]

[0187] Add the solution to ultrapure water and bring the volume to 1L. Use a magnetic stirrer to aid dissolution, aerate for 30 minutes, and adjust the pH to 7.4±0.05. Turn on the thermostatic circulation pump of the isolated heart perfusion device and maintain the system temperature at 37℃. Pour the prepared KH solution into the thermostatic bath to equilibrate to physiological temperature, and continuously aerate. Fill the tubing with KH solution (ensuring no air bubbles are present in the tubing). Turn on the main unit and amplifier power, open the software, set the corresponding parameters, and set aside. After anesthetizing guinea pigs, heparin was injected, the thoracic cavity was quickly opened, the heart was removed and placed in pre-cooled KH solution, and the aorta was connected to the perfusion system in the shortest possible time. The heart was then secured with sutures, the perfusion system was turned on, and perfusion of the isolated heart began. The heart resumed normal beating within minutes. After the rhythm stabilized, two ECG probes were placed at the apex and right atrium, respectively, to monitor the ECG. After recording the data before drug administration, the heart was perfused for 15 minutes at the predetermined drug concentration. The left anterior descending coronary artery was ligated, and after 30 minutes of ischemia, the sutures were removed, and ischemia-reperfusion was performed. The time of onset of arrhythmias after ischemia-reperfusion was recorded. In the sham surgery group, only sutures were threaded, without ligation or reperfusion.

[0188] 2.3 Statistical analysis results The results indicate that SPSS software was used for ANOVA analysis and Dunnett's test, and nonparametric tests were used for data that did not conform to a normal distribution.

[0189] 3 Results

[0190] Compared with the sham-operated group, all six animals in the model control group developed arrhythmias such as ventricular tachycardia and ventricular fibrillation. Compared with the model control group, the onset time of arrhythmias was significantly delayed and the duration of attacks was significantly shortened in the H208B-125, 250, and 500 μM drug perfusion groups (see Table 16).

[0191] Table 16. Effects of H2O8B on ischemia-reperfusion-induced arrhythmias in isolated hearts (n=6)

[0192]

[0193] 4. Conclusion

[0194] H208B pre-administration can significantly delay the onset of ischemia-reperfusion-induced arrhythmias in isolated hearts and shorten the duration of arrhythmia.

[0195] The data in this embodiment show that the compounds involved in this invention can regulate the heart rhythm in an isolated heart ischemia-reperfusion model, thereby improving arrhythmias.

[0196] Example 5: Effects on a rat aconitine model

[0197] 1. Materials

[0198] 1.1 Animals

[0199] 30 male SD rats were purchased from Beijing Vital River Laboratory Animal Technology Co., Ltd., with the license number: SCXK(Beijing) 2016-0011.

[0200] 1.2 Drugs: H208B (purity: over 98%).

[0201] 2 Methods

[0202] 2.1 Grouping and administration of experimental animals

[0203] The animals were randomly divided into 4 groups, namely the model control group and three H208B treatment groups (administered H208B at 25, 50, and 75 mg / kg respectively), with 10 animals in each group. Administration method: single injection. The model control group was given an equal volume of vehicle (0.9% sodium chloride injection).

[0204] 2.2 Experimental procedures

[0205] The animals were quarantined and grouped in advance. On the day of the experiment, the rats were anesthetized intraperitoneally with 25% urethane, and then connected to the Powerlab electrophysiological recording system to monitor the animals' ECG. After the signal was stable, the corresponding dosage of H208B (treatment groups) or an equal volume of vehicle (model control group) was injected into the tail vein once. 5 minutes later, an aconitine solution (30 μg / kg) was rapidly injected into the femoral vein. The time was marked at the moment of administration and model establishment, and the ECG was continuously recorded to observe the appearance and end time of typical arrhythmia waveforms such as premature ventricular contractions. Evaluation indexes: the appearance time of arrhythmia (calculated relative to the time of model establishment) and the attack time (i.e., the time from appearance to end).

[0206] 2.3 Statistical analysis

[0207] The results were expressed as and analyzed by ANOVA and Dunnett's test using SPSS software. Non-parametric tests were used for data that did not conform to the normal distribution.

[0208] 3 Results

[0209] Compared with the model control group, the appearance time of arrhythmia in the three H208B treatment groups was significantly delayed, and the attack time was significantly shortened, as shown in Table 17.

[0210] Table 17. Effects of H208B injection on aconitine-induced arrhythmia in rats (n = 10, mean ± standard deviation)

[0211]

[0212] 4 Conclusions

[0213] H208B injection significantly delayed the onset of aconitine-induced arrhythmias in rats and shortened the duration of arrhythmia.

[0214] The rat aconitine model is a commonly used animal model of cardiac arrhythmias (especially ventricular arrhythmias) in this field. Data from this embodiment show that the compounds involved in this invention can regulate the heart rhythm of the rat aconitine model, thereby improving cardiac arrhythmias, particularly ventricular arrhythmias.

Claims

1. Use of a compound of formula (I) or a pharmaceutically acceptable salt thereof in the preparation of a medicament for the prevention or treatment of arrhythmias:

2. The use according to claim 1, wherein the compound of formula (I) is a compound of formula (IA) or formula (IB), or a mixture of both:

3. The use according to claim 1 or 2, wherein the arrhythmia is a ventricular arrhythmia.

4. Use of pharmaceutical compositions comprising a compound of formula (IA) or a pharmaceutically acceptable salt thereof, a compound of formula (IB) or a pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, in the preparation of a medicament for the prevention or treatment of arrhythmias:

5. The use according to claim 4, wherein, based on the weight of the free base, the compound of formula (IA) or a pharmaceutically acceptable salt thereof accounts for 5% to 95% by weight of the total amount of the compound of formula (IA) or a pharmaceutically acceptable salt thereof and the compound of formula (IB) or a pharmaceutically acceptable salt thereof.

6. The use according to claim 4, wherein, based on the weight of the free base, the compound of formula (IA) or a pharmaceutically acceptable salt thereof accounts for 30% to 90% by weight of the total amount of the compound of formula (IA) or a pharmaceutically acceptable salt thereof and the compound of formula (IB) or a pharmaceutically acceptable salt thereof.

7. The use according to claim 4, wherein, based on the weight of the free base, the compound of formula (IA) or a pharmaceutically acceptable salt thereof accounts for 40% to 80% by weight of the total amount of the compound of formula (IA) or a pharmaceutically acceptable salt thereof and the compound of formula (IB) or a pharmaceutically acceptable salt thereof.

8. The use according to any one of claims 4-7, wherein the arrhythmia is a ventricular arrhythmia.

Images