Lipid droplet-sensitive AIE fluorescent probe and lipid droplet detection method for monitoring ferroptosis in atherosclerotic plaques

Abstract

The present invention discloses a lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques and a lipid droplet detection method, wherein the AIE fluorescent probe has a compound structure as shown in general formula (I). The AIE fluorescent probe of the present invention is a lipid droplet-sensitive probe that can be used to detect ferroptosis in atherosclerotic plaques. The AIE fluorescent probe of the present invention has a good response to lipid droplets and has very high detection sensitivity and binding ability for lipid droplets, and can achieve rapid detection. In addition, the AIE fluorescent probe of the present invention has high selectivity for lipid droplets, has the ability to detect ferroptosis in the process of atherosclerosis in a complex biological environment, and has the potential to be applied to the clinical diagnosis and treatment of atherosclerosis.

Description

Technical Field

[0001] The present invention relates to a probe and a lipid droplet detection method, and in particular to a lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques and a lipid droplet detection method. Background Art

[0002] Atherosclerosis (AS) is a chronic progressive arterial disease and the basic pathological state of cardiovascular disease. It is characterized by the accumulation of lipids in the arterial lumen and the formation of atherosclerotic plaques on the arterial wall.

[0003] Plaque growth and rupture can easily induce thrombosis and even acute myocardial infarction. Studies have shown that dysregulated ferroptosis plays a key role in the pathogenesis of atherosclerosis. Macrophage foam cell death, including ferroptosis, is the primary cause of the lipid-rich necrotic core and a hallmark of plaque instability. Inhibiting macrophage ferroptosis may offer a novel therapeutic approach for atherosclerosis, and therefore, monitoring the macrophage ferroptosis process is crucial. Excessive lipid peroxidation within cellular lipid droplets (LDs) leads to the conversion of low-density lipoprotein (LD) to oxidized low-density lipoprotein (O-LDL), a highly atherogenic risk factor associated with ferroptosis. Therefore, LDs are an important marker for detecting ferroptosis in atherosclerotic plaques. Fluorescent probes, with their excellent selectivity, high sensitivity, and noninvasive detection, offer a reliable method for monitoring ferroptosis in atherosclerotic plaques. However, the potential applications of most currently developed probes are limited by high background fluorescence interference, complex synthesis, high toxicity, and inability to cross the blood-brain barrier. In 2017, Chinese scholars applied for and disclosed a fluorescent probe that specifically labels cellular lipid droplets (CN106946869A / 2017).

[0004] Although existing fluorescent probes designed to locate lipid droplets in organelles have the characteristics of high specificity, high fluorescence quantum yield, and simple synthesis methods, no one has yet applied lipid droplet-targeted probes to monitor the ferroptosis process in atherosclerosis. Summary of the Invention

[0005] Purpose of the invention: The purpose of the present invention is to provide an anti-interference, highly sensitive lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques; the purpose of the present invention is to provide a lipid droplet detection method.

[0006] Technical solution: The present invention provides a lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques. The AIE fluorescent probe has a compound structure as shown in the general formula (I):

[0007]

[0008] In the formula, R1 is dimethylamino or p-phenylenedimethylamino, and R2 is ethyl or sulfopropyl.

[0009] As a further improvement of the above scheme, the AIE fluorescent probe is any one of compounds FAS1-3:

[0010]

[0011] As a further improvement of the above scheme, compound FAS1 was prepared by the following method:

[0012]

[0013] (1) 2-Methylquinoline was dissolved in organic solvent A, 1,3-propane sultone was added under inert gas protection, and the mixture was heated and stirred until the reaction was complete. The precipitate was collected, and the precipitate, malononitrile, and sodium ethoxide were dissolved in organic solvent B. The mixture was stirred under inert gas protection. After the reaction was completed, the product was collected, which was the intermediate compound 1.

[0014] (2) 4-dimethylamino-2-hydroxybenzaldehyde is dissolved in organic solvent B, and then diethyl malonate and piperidine are added, and the reaction is stirred under the protection of inert gas; after the reaction is completed, the precipitate is filtered, and the precipitate is dissolved in an inorganic solvent, and the reaction is stirred under the protection of inert gas. After the reaction is completed, the precipitate is poured into ice water to quench the reaction; the precipitate is filtered and purified to obtain compound intermediate 3.1; phosphorus oxychloride is added to organic solvent C, and the reaction is stirred under the protection of inert gas; then the compound intermediate 3.1 dissolved in organic solvent C is slowly added and the reaction is stirred; after the reaction is completed, it is poured into ice water to quench the reaction; after the reaction is completed, the product is collected, and the product is intermediate compound 3.

[0015] (3) Dissolve the intermediate compound 1 and the intermediate compound 3 in an organic solvent D, then add piperidine, and heat and stir to react under the protection of an inert gas; after the reaction is completed, collect the product, which is compound FAS1.

[0016] Preferably, the organic solvent A is toluene, the organic solvent B is ethanol, the inorganic solvent is a mixture of glacial acetic acid and hydrochloric acid, the organic solvent C is dimethyl sulfoxide, and the organic solvent D is acetonitrile.

[0017] As a further improvement of the above scheme, compound FAS2 was prepared by the following method:

[0018]

[0019] (1) 2-Methylquinoline and iodoethane are dissolved in an organic solvent D, and the mixture is stirred under an inert gas to react. The precipitate is collected and dissolved in anhydrous ethanol. Malononitrile and sodium ethoxide are then added and stirred to react. After the reaction is completed, the product is collected, which is the intermediate compound 2.

[0020] (2) 4-(Dimethylamino)phenylboronic acid and 4-bromo-2-hydroxybenzaldehyde are dissolved in 1,2-dimethoxyethane, and Pd(PPh3)4 and sodium carbonate aqueous solution are added to the solution under the protection of an inert gas, and the mixture is stirred for reaction. After the reaction is completed, the product is collected, which is the intermediate compound 4.1. Compound 4.1 is then stirred for reaction with ethoxyformylethylenetriphenylphosphine. After the reaction is completed, the product is collected to obtain the intermediate compound 4.2. Phosphorus oxychloride is added to an organic solvent C, and the mixture is stirred for reaction under the protection of an inert gas. Then, the intermediate compound 4.2 is slowly dissolved in the organic solvent C, and the mixture is stirred for reaction. After the reaction is completed, the product is collected, which is the intermediate compound 4.

[0021] (3) Dissolve the intermediate compound 2 and the intermediate compound 4 in an organic solvent D, then add piperidine, and heat and stir to react under the protection of an inert gas. After the reaction is completed, collect the product, which is compound FAS2.

[0022] Preferably, the organic solvent C is dimethyl sulfoxide, and the organic solvent D is acetonitrile.

[0023] As a further improvement of the above scheme, compound FAS3 was prepared by the following method:

[0024]

[0025] (1) 2-Methylquinoline was dissolved in organic solvent A, 1,3-propane sultone was added under inert gas protection, and the mixture was heated and stirred until the reaction was complete. The precipitate was collected, and the precipitate, malononitrile, and sodium ethoxide were dissolved in organic solvent B. The mixture was stirred under inert gas protection. After the reaction was completed, the product was collected, which was the intermediate compound 1.

[0026] (2) 4-(Dimethylamino)phenylboronic acid and 4-bromo-2-hydroxybenzaldehyde are dissolved in 1,2-dimethoxyethane, and Pd(PPh3)4 and sodium carbonate aqueous solution are added to the solution under the protection of an inert gas, and the mixture is stirred for reaction. After the reaction is completed, the product is collected, which is the intermediate compound 4.1. Compound 4.1 is then stirred for reaction with ethoxycarbonylethylidenetriphenylphosphine. After the reaction is completed, the product is collected to obtain the intermediate compound 4.2. Phosphorus oxychloride is added to an organic solvent C, and the mixture is stirred for reaction under the protection of an inert gas. The intermediate compound 4.2 is then slowly dissolved in the organic solvent C, and the mixture is stirred for reaction. After the reaction is completed, the product is collected, which is the intermediate compound 4.

[0027] (3) Dissolve the intermediate compound 1 and the intermediate compound 4 in an organic solvent C, then add piperidine and react under the protection of an inert gas. After the reaction is completed, collect the product, which is compound FAS3.

[0028] Preferably, the organic solvent A is toluene, the organic solvent C is dimethyl sulfoxide,

[0029] On the other hand, the present invention provides a method for detecting lipid droplets, wherein the method uses the above-mentioned AIE fluorescent probe to detect lipid droplets.

[0030] Preferably, the lipid droplets are lipid droplets for detecting ferroptosis in atherosclerotic plaques.

[0031] As a further improvement of the above solution, the detection conditions are: under excitation at a wavelength of 610 nm, collecting the fluorescence emission spectrum in the 500-800 nm band.

[0032] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: The synthesis method of the AIE fluorescent probe of the present invention is simple. The AIE fluorescent probe compound itself does not emit light. In in vitro experiments, different viscosity gradients were used to simulate the increase in lipid droplets during ferroptosis in atherosclerotic plaque cells. It was found that the enhancement of the fluorescence intensity of the compound was positively correlated with the viscosity of the solution, indicating that the compound has a good response to lipid droplets and has a very high detection sensitivity and binding ability for lipid droplets, which can achieve rapid detection. In addition, the compound has a high selectivity for lipid droplets and has the ability to detect the ferroptosis process in the process of atherosclerosis in a complex biological environment. It has the potential to be used in the clinical diagnosis and treatment of atherosclerosis, and provides a new method for the diagnosis and treatment of the disease from the perspective of the ferroptosis mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is the in vitro simulated lipid droplet response test in Example 2.

[0034] Figure 2 This is a diagram of the selectivity experiment in Example 3.

[0035] Figure 3 This is the in vitro simulated lipid droplet response test in Example 4.

[0036] Figure 4 This is the in vitro simulated lipid droplet response test in Example 5. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0038] A lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques, wherein the AIE fluorescent probe has a compound structure as shown in general formula (I):

[0039]

[0040] (I)

[0041] In the formula, R1 is dimethylamino or p-phenylenedimethylamino, and R2 is ethyl or sulfopropyl.

[0042] The AIE fluorescent probe of the present invention is a lipid droplet-sensitive probe that can be used to detect ferroptosis in atherosclerotic plaques. The present invention provides responsive detection of the probe to lipid droplets and selective detection of the probe to lipid droplets. The present invention specifically relates to the following compounds:

[0043] .

[0044] Example 1 Preparation of AIE fluorescent probe

[0045] 1. Synthesis of intermediate compound 1

[0046]

[0047] 2-Methylquinoline (4g, 27mmol) was dissolved in toluene (20mL), and then 1,3-propane sultone (4.87g, 40mmol) was added under nitrogen protection. The mixture was heated at 120°C and stirred for 20 hours. After the reaction was completed, it was cooled to room temperature, the precipitate was filtered and washed with dichloromethane to obtain compound 1.1 as a pink-white solid. Compound 1.1 (200mg, 0.76mmol), malononitrile (187mg, 2.85mmol) and sodium ethoxide (233mg, 3.43mmol) were then dissolved in ethanol (10mL), stirred at 0°C for 0.5 hours under nitrogen protection, and then continued to stir at room temperature. After the reaction was completed, the precipitate was filtered and washed with dichloromethane to obtain pure compound 1 as a yellow solid (172 mg, yield 69%).

[0048] 2. Synthesis of intermediate compound 2:

[0049]

[0050] 2-Methylquinoline (2.86 g, 20 mmol) and iodoethane (3.90 g, 25 mmol) were dissolved in anhydrous acetonitrile (25 mL) and stirred at 85°C for 24 hours under N2 protection. After the reaction was completed, the mixture was cooled to room temperature. A large amount of precipitate formed at the bottom of the flask, which was filtered using a Buchner funnel and washed with glacial acetonitrile. After drying overnight, compound 2.1 was obtained as a white solid (2.18 g, 63% yield), which was used in the next step without purification. Compound 2.1 (1.72 g, 10 mmol) was dissolved in anhydrous ethanol (10 mL), followed by the addition of malononitrile (1 g, 15 mmol) and sodium ethoxide (1.02 g, 15 mmol). The mixture was stirred at 0°C for 0.5 hours and then at room temperature for an additional 3 hours. After the reaction was complete, the precipitate was filtered and washed with cold ethanol (20 mL x 3) to obtain compound 2 as a yellow solid (1.41 g, 60% yield). 1 H-NMR (300MHz, DMSO- d6 ) δ8.90 (d, J =8.3Hz, 1H), 8.06 (d, J =8.7Hz, 1H), 7.91 (t, J =7.7Hz, 1H), 7.59 (s, 1H), 6.80 (s, 1H), 4.48 (d, J =6.9 Hz,2H), 2.67 (s, 3H), 1.35 (t, J =6.9 Hz, 3H).

[0051] 3. Synthesis of intermediate compound 3

[0052]

[0053] 4-(Dimethylamino)-2-hydroxybenzaldehyde (1.0 g, 6.0 mmol) was dissolved in anhydrous ethanol (25 mL), followed by the addition of diethyl malonate (1.57 g, 9.86 mmol) and piperidine (3d). The mixture was stirred at 80°C for 10 hours under nitrogen. After completion of the reaction, the precipitate was filtered and purified without further treatment to yield pure compound 3.1 as an orange solid (1.32 g, 83.5% yield). Compound 3.1 (689 mg, 2.64 mmol) was dissolved in glacial acetic acid (15 mL) and hydrochloric acid (15 mL) and stirred at 110°C for 12 hours under nitrogen. After completion, the reaction was quenched by pouring into ice water, and the pH was adjusted to 3.0 with 50% aqueous sodium hydroxide solution. The precipitate was filtered and purified by silica gel column chromatography to yield compound 3.2 as a yellow solid (399 mg, 80% yield). Phosphorus oxychloride (0.3 mL) was added to anhydrous dimethyl sulfoxide (3 mL) and stirred at 50 ° C for 45 minutes under nitrogen protection. Then, compound 3.2 (150 mg, 0.79 mmol) dissolved in anhydrous dimethyl sulfoxide (1 mL) was slowly added and stirred at 60 ° C for 3 hours. After the reaction was completed, it was poured into ice water to quench the reaction. After the reaction was completed, the precipitate was filtered and purified by silica gel column chromatography to obtain compound 3 as an orange solid (27 mg, yield 74.2%) 1 H-NMR (300 MHz, DMSO- d6 ) δ10.15(s,1H), 8.29(s, 1H), 7.46(d, J =9.0Hz, 1H), 6.67 (dd, J =9.0, 2.4Hz, 1H), 6.50 (d, J =2.3Hz, 1H), 3.17 (s, 6H).

[0054] 4. Synthesis of intermediate compound 4

[0055]

[0056] 4-(Dimethylamino)phenylboronic acid (800 mg, 4.0 mmol) and 4-bromo-2-hydroxybenzaldehyde (850 mg, 5.1 mmol) were dissolved in 1,2-dimethoxyethane (35 mL). Pd (PPh3)4 (287 mg, 0.25 mmol) and aqueous sodium carbonate solution (2M, 41 mL) were added to the solution under nitrogen protection and stirred at 90 ° C for 10 hours. After the reaction was completed, the reaction mixture was cooled to room temperature and transferred to a separatory funnel, and 100 mL of brine was added. The mixture was extracted with ethyl acetate (3 × 100 mL), and the organic layer was dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography to obtain a compound (771 mg, 80% yield) as a yellow solid. Compound 4.1 (400 mg, 1.66 mmol) and ethoxycarbonylethylidenetriphenylphosphine (690 mg, 1.98 mmol) were then stirred at 180 ° C for 1 hour. After the reaction was complete, the precipitate was filtered and washed with methanol to obtain pure compound 4.2 as an orange solid (338.7 mg, 77% yield). Phosphorus oxychloride (0.6 mL) was added to anhydrous dimethyl sulfoxide (3 mL) and stirred at 50°C for 45 minutes under nitrogen. Then, 4.2 (200 mg, 0.75 mmol) was slowly dissolved in anhydrous dimethyl sulfoxide (3 mL) and stirred at 60°C for 3 hours. After the reaction was complete, the mixture was extracted with water and dichloromethane (20 mL × 3) and concentrated under reduced pressure. No further purification was required to obtain pure compound 4 as a light yellow solid (121.6 mg, 55% yield).

[0057] 5. Synthesis of compound FAS1

[0058]

[0059] Compound 1 (100 mg, 0.3 mmol) and compound 3 (68 mg, 0.3 mmol) were dissolved in acetonitrile (30 mL), followed by the addition of piperidine (2d). The mixture was heated at 90°C under nitrogen and stirred for 10 hours. After completion of the reaction, the crude product was concentrated under reduced pressure and purified by column chromatography to afford compound FAS1 (83.7 mg, 52.5% yield) as a dark red solid. 1 H-NMR (300 MHz, DMSO- d6 ) δ 8.94-8.85(m, 2H) , 8.22 (d, J =8.9 Hz, 1H), 7.91 (s, 1H), 7.79 (d, J =15.7 Hz, 1H),7.64-7.51(m, 2H), 7.41 (d, J=15.7 Hz, 1H), 7.08 (s, 1H), 6.82 (s,1H), 6.62 (s, 1H), 4.73 (s, 2H), 3.44 (s, 2H), 3.09 (s, 6H), 2.72 (s, 2H).

[0060] 6. Synthesis of compound FAS2

[0061]

[0062] Compound 2 (93 mg, 0.32 mmol) and compound 4 (63 mg, 0.27 mmol) were dissolved in acetonitrile (10 mL), followed by the addition of piperidine (2d). The mixture was heated at 90°C under nitrogen and stirred for 10 hours. After completion of the reaction, the crude product was concentrated under reduced pressure and purified by column chromatography to afford compound FAS2 (73.4 mg, 45% yield) as an orange solid. 1 H NMR (300 MHz, CDCl3) δ 9.19 (dd, J =8.5, 1.4Hz, 1H), 7.86-7.70 (m, 4H), 7.70-7.59 (m, 3H), 7.57(dd, J =2.7, 1.6Hz, 2H), 7.50 (dd, J =8.5, 6.9Hz, 1H), 7.27-7.12 (m, 3H), 6.45(d, J =9.5Hz, 1H), 4.46 (q, J =7.2 Hz, 2H), 2.91 (s, 6H), 1.62 (d, J =7.2 Hz, 3H).

[0063] 7. Synthesis of compound FAS3

[0064]

[0065] Compound 1 (110 mg, 0.37 mmol) and compound 3 (82 mg, 0.25 mmol) were dissolved in dimethyl sulfoxide (10 mL). Piperidine (2d) was then added. The mixture was heated at 110°C under nitrogen and stirred for 18 hours. After completion of the reaction, the crude product was concentrated under reduced pressure and purified by column chromatography to afford compound FAS3 (70.8 mg, 47% yield) as an orange solid. 1 H-NMR (400 MHz, DMSO- d6 ) δ 8.95 (d, J=8.3Hz, 1H), 8.46 (s, 1H), 8.26(d, J =8.6 Hz,1H), 8.14 (dd, J =17.3, 8.7 Hz, 2H), 7.97-7.74(m, 5H), 7.63 (s, 2H), 7.24 (s,1H), 7.17 (s, 1H), 6.47 (d, J =9.5 Hz, 1H), 4.86 (s, 2H), 2.84 (s, 6H), 2.71 (s, 2H), 2.18 (s, 2H).

[0066] Example 2

[0067] 2.6 mg of the compound FAS1 prepared in Example 1 was weighed and dissolved in 3 ml of dimethyl sulfoxide to prepare a standard solution with a concentration of 1 mM. The solution was diluted with PBS buffer (10 mM, pH 7.4, 1% DMSO) to a final concentration of 10 μM and a solution with a viscosity value increasing from 1.53 cp (100% methanol solution) to 955 cp (100% glycerol) was added. The solution was placed in a quartz cuvette with four sides of light transmission and incubated. Under excitation at a wavelength of 610 nm, the slit width was set to 10.0 / 10.0, the response time was set to 0.1 s, and the PMT was set to 700 V. The fluorescence emission spectrum in the 500-800 nm band was collected. Figure 1 As shown, the fluorescence intensity of the FAS1 probe increases with increasing viscosity, reaching a maximum at the highest viscosity (955 cp, 100% glycerol). This demonstrates that the compound has a high lipid droplet responsiveness and can emit a strong fluorescence signal in an environment that simulates high lipid droplet expression.

[0068] Example 3

[0069] 2.6 mg of the compound FAS1 prepared in Example 1 was weighed and dissolved in 3 ml of dimethyl sulfoxide to prepare a standard solution with a concentration of 1 mM; the solution was diluted with PBS buffer (10 mM, pH 7.4, 1% DMSO) to a final concentration of 10 μM and placed in a quartz cuvette with four sides transparent to light. Different interfering substances simulating the in vivo environment were added thereto for incubation. The interfering substances included potassium ions, sodium ions, calcium ions, bovine serum albumin, magnesium ions, sulfate ions, carbonate ions, glutathione, cysteine, glycine, vitamin C, β-galactosidase (100 μg / mL), catalase (200 U / mL), glucose oxidase (100 μg / mL), NADPH, sulfatase (200 U / mL), hydroxyl radicals, potassium superoxide, hydrogen peroxide, hypochlorite, peroxynitrite, singlet oxygen, and glycerol. Under 610nm wavelength excitation, the slit width was set to 10.0 / 10.0, the response time was 0.1s, and the PMT was set to 700V. The fluorescence emission spectrum in the 500-800nm ​​band was collected, and the fluorescence intensity value of each substance at the emission wavelength of 625nm was recorded. Figure 2 As shown, the probe FAS1 exhibits good selectivity for glycerol. The fluorescence intensity of FAS1 in the glycerol system is significantly enhanced, while the fluorescence intensity of FAS1 in other interfering substances is not significantly enhanced.

[0070] Example 4

[0071] 2.6 mg of the compound FAS2 prepared in Example 1 was weighed and dissolved in 3 ml of dimethyl sulfoxide to prepare a standard solution with a concentration of 1 mM. The solution was diluted with PBS buffer (10 mM, pH 7.4, 1% DMSO) to a final concentration of 10 μM. A solution with a viscosity value increasing from 1.53 cp (100% methanol solution) to 955 cp (100% glycerol) was added and incubated in a quartz cuvette with four sides of light. Under excitation at a wavelength of 610 nm, the slit width was set to 10.0 / 10.0, the response time was set to 0.1 s, and the PMT was set to 700 V. The fluorescence emission spectrum in the 500-800 nm band was collected. Figure 3 As shown, the fluorescence intensity of the probe FAS2 increases with increasing viscosity, reaching a maximum at the highest viscosity (955 cp, 100% glycerol). This demonstrates that the compound has a high lipid droplet responsiveness and can emit a strong fluorescence signal in an environment that simulates high lipid droplet expression.

[0072] Example 5

[0073] 2.9 mg of the compound FAS3 prepared in Example 1 was weighed and dissolved in 3 ml of dimethyl sulfoxide to prepare a standard solution with a concentration of 1 mM. The solution was diluted with PBS buffer (10 mM, pH 7.4, 1% DMSO) to a final concentration of 10 μM. A solution with a viscosity value increasing from 1.53 cp (100% methanol solution) to 955 cp (100% glycerol) was added and incubated in a quartz cuvette with four sides of light. Under excitation at a wavelength of 610 nm, the slit width was set to 10.0 / 10.0, the response time was set to 0.1 s, and the PMT was set to 700 V. The fluorescence emission spectrum in the 500-800 nm band was collected. Figure 4 As shown, the fluorescence intensity of the probe FAS3 increases with increasing viscosity and reaches a maximum at the highest viscosity (955 cp, 100% glycerol). This demonstrates that the compound has a high lipid droplet responsiveness and can emit a strong fluorescence signal in an environment that simulates high lipid droplet expression.

Claims

1. A lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques, characterized in that: The AIE fluorescent probe is any one of compounds FAS1-3: 。 2. The lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques according to claim 1, characterized in that Compound FAS1 was prepared by the following method: (1) 2-Methylquinoline was dissolved in toluene, 1,3-propane sultone was added under inert gas protection, and the mixture was heated and stirred until the reaction was complete. The precipitate was collected, and the precipitate, malononitrile, and sodium ethoxide were dissolved in ethanol, and the mixture was stirred under inert gas protection. After the reaction was completed, the product was collected, which was the intermediate compound 1; (2) Dissolve 4-dimethylamino-2-hydroxybenzaldehyde in ethanol, then add diethyl malonate and piperidine, and stir to react under the protection of inert gas; after the reaction is completed, filter the precipitate, dissolve the precipitate in an inorganic solvent, and stir to react under the protection of inert gas. After the reaction is completed, pour into ice water to quench the reaction; filter the precipitate and purify it to obtain compound intermediate 3.1 ; Add phosphorus oxychloride to dimethyl sulfoxide and stir the reaction under the protection of inert gas; then slowly add the compound intermediate 3.1 dissolved in dimethyl sulfoxide and stir the reaction; after the reaction is completed, pour it into ice water to quench the reaction; after the reaction is completed, collect the product, which is the intermediate compound 3; (3) Dissolve the intermediate compound 1 and the intermediate compound 3 in acetonitrile, then add piperidine, and heat and stir to react under the protection of inert gas; after the reaction is completed, collect the product, which is compound FAS1.

3. The lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques according to claim 1, characterized in that Compound FAS2 was prepared by the following method: (1) 2-Methylquinoline and iodoethane are dissolved in acetonitrile, stirred under inert gas protection, the precipitate is collected, the precipitate is dissolved in anhydrous ethanol, and then malononitrile and sodium ethoxide are added and stirred for reaction; after the reaction is completed, the product is collected, which is the intermediate compound 2; (2) 4-(Dimethylamino)phenylboronic acid and 4-bromo-2-hydroxybenzaldehyde were dissolved in 1,2-dimethoxyethane. Pd(PPh3)4 and sodium carbonate aqueous solution were added to the solution under the protection of inert gas and stirred for reaction. After the reaction was completed, the product was collected, which was the intermediate compound 4.

1. Then, compound 4.1 and ethoxycarbonyl ethylidene triphenylphosphine are stirred and reacted. After the reaction is completed, the product is collected to obtain the intermediate compound 4.2 , adding phosphorus oxychloride to dimethyl sulfoxide, stirring to react under the protection of inert gas, then slowly dissolving the intermediate compound 4.2 in dimethyl sulfoxide and stirring to react. After the reaction is completed, collecting the product, which is the intermediate compound 4; (3) Dissolve the intermediate compound 2 and the intermediate compound 4 in acetonitrile, then add piperidine, and heat and stir to react under the protection of inert gas. After the reaction is completed, collect the product, which is compound FAS2.

4. The lipid droplet-sensitive AIE fluorescent probe for monitoring ferroptosis in atherosclerotic plaques according to claim 1, characterized in that Compound FAS3 was prepared by the following method: (1) 2-Methylquinoline was dissolved in toluene, 1,3-propane sultone was added under inert gas protection, and the mixture was heated and stirred until the reaction was complete. The precipitate was collected, and the precipitate, malononitrile, and sodium ethoxide were dissolved in ethanol, and the mixture was stirred under inert gas protection. After the reaction was completed, the product was collected, which was the intermediate compound 1; (2) 4-(Dimethylamino)phenylboronic acid and 4-bromo-2-hydroxybenzaldehyde were dissolved in 1,2-dimethoxyethane. Pd(PPh3)4 and sodium carbonate aqueous solution were added to the solution under the protection of inert gas and stirred for reaction. After the reaction was completed, the product was collected, which was the intermediate compound 4.

1. Then, compound 4.1 and ethoxycarbonyl ethylidene triphenylphosphine are stirred and reacted. After the reaction is completed, the product is collected to obtain the intermediate compound 4.2 , adding phosphorus oxychloride to dimethyl sulfoxide, stirring to react under the protection of inert gas, then slowly dissolving the intermediate compound 4.2 in dimethyl sulfoxide and stirring to react. After the reaction is completed, collecting the product, which is the intermediate compound 4; (3) Dissolve the intermediate compound 1 and the intermediate compound 4 in dimethyl sulfoxide, then add piperidine and react under the protection of inert gas. After the reaction is completed, collect the product, which is compound FAS3.

5. A method for detecting lipid droplets, characterized in that: The detection method uses the AIE fluorescent probe according to any one of claims 1 to 4 to detect lipid droplets, and the method is not intended for disease diagnosis and / or treatment.

6. The method for detecting lipid droplets according to claim 5, wherein The detected lipid droplets are lipid droplets in the ferroptosis process in atherosclerotic plaques.

7. The method for detecting lipid droplets according to claim 5, wherein The detection conditions are: under the excitation wavelength of 610 nm, collecting the fluorescence emission spectrum in the 500-800 nm band.

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