A bodipy dimer compound containing se-se bond and a preparation method thereof

Abstract

The application belongs to the technical field of organic synthesis, and discloses a Se-Se bond-containing BODIPY dimer compound and a preparation method thereof. The SeSe-2TPA-BnOH-BODIPY compound is synthesized by esterification reaction of a linker with a double selenium bond and a BODIPY modified by triphenylamine and benzyl alcohol under certain conditions. The BODIPY modified by triphenylamine and benzyl alcohol has excellent photosensitivity and light stability, and according to the characteristics that the double selenium bond is easy to break in a polar solvent, when the probe enters the cerebrospinal fluid of AD patients, the double selenium bond is broken, and the modified BODIPY can recognize the aggregates formed by the folding of beta-amyloid protein in the brain, so that the early detection of Alzheimer's disease is more accurately realized.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis technology and relates to the preparation of fluorescent probes. Specifically, it relates to a BODIPY dimer compound containing Se-Se bonds (SeSe-2TPA-BnOH-BODIPY) and its preparation method, which has potential application value in the diagnosis and treatment of Alzheimer's disease. Background Technology

[0002] Alzheimer's disease (AD), commonly known as senile dementia, is a degenerative disease of the central nervous system. It has an insidious onset and a chronic, progressive course, and is the most common type of dementia in the elderly. Its main manifestations include progressive memory impairment, cognitive dysfunction, personality changes, and language disorders. Once afflicted, it severely impacts social life and gradually diminishes occupational and daily living functions. In 2022, the National Health Commission of China held a press conference, indicating that this disease has already had a significant impact on the health and quality of life of the elderly. Statistics show that there are approximately 15 million dementia patients aged 60 and above in my country, of whom 10 million are Alzheimer's patients. The National Health Commission has included "a decrease in the rate of increase in the prevalence of dementia among people aged 65 and above" as one of the outcome indicators in the Healthy China Action for Elderly Health Promotion. Research in the field of Alzheimer's disease treatment indicates that due to the lack of accurate and effective diagnostic methods, research on Alzheimer's disease treatment faces numerous difficulties, and the existing drug treatments are not ideal. Therefore, developing new methods is of great significance for research on the diagnosis and treatment of Alzheimer's disease.

[0003] In the brain, β-amyloid protein folds to form fibers, and its deposition is positively correlated with Alzheimer's disease. Since 1959, the fluorescent dye thioflavin-T (ThT) has been the widely used "gold standard" for selectively staining and identifying amyloid fibers, which are the result of protein self-assembly into these large clumps. However, the use of ThT in vivo is limited due to its charge and emission wavelength (less than 650 nm), affecting diagnostic accuracy.

[0004] Therefore, for the early diagnosis of Alzheimer's disease, it is essential to develop new fluorescent probes to identify Aβ fibers in order to improve the sensitivity and accuracy of AD diagnosis. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the main objective of this invention is to provide a long-wavelength, highly sensitive, and highly selective fluorescent probe for the diagnosis of Alzheimer's disease, and to provide a method for preparing the fluorescent probe.

[0006] This invention is achieved through the following technical solution:

[0007] A BODIPY dimer compound containing Se-Se bonds has the following molecular structural formula:

[0008]

[0009] In the formula, the fluoroboron dipyrrole compound is linked by a double selenium bond linker, and there are two N,N-diphenyl-4-vinylaniline groups at positions 3 and 5.

[0010] A further improvement to the present invention is as follows:

[0011] A method for preparing a BODIPY dimer compound containing Se-Se bonds, comprising the following steps:

[0012] (1) Using 2,4-dimethylpyrrole and p-hydroxymethylbenzaldehyde as raw materials, dichloromethane (CH2Cl2) as solvent, 2,3-dimethyl-5,6-dicyanobenzoquinone as catalyst, and boron trifluoride ether (BF3·Et2O) and triethylamine (Et3N) as complexing agents, BnOH-BODIPY compound was prepared.

[0013] (2) Using BnOH-BODIPY and 4-diphenylaminobenzaldehyde obtained in step (1) as raw materials, toluene and piperidine as solvents, and toluenesulfonamide as catalyst, 2TPA-BnOH-BODIPY compound was prepared.

[0014] (3) Using the 2TPA-BnOH-BODIPY obtained in step (2) and the linker containing double selenium bonds as raw materials, chloroform as solvent, and dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) as catalysts, the final product SeSe-2TPA-BnOH-BODIPY compound was prepared.

[0015] The reaction route is shown in the following equation:

[0016]

[0017] Further, the specific process of step (1) is as follows: 2,4-dimethylpyrrole and p-hydroxymethylbenzaldehyde are mixed and dissolved in dichloromethane, triethylamine is added, and the mixture is stirred at room temperature for 1 h to 6 h. Boron trifluoride ether (M:M) is slowly added dropwise in an ice bath, and the mixture is stirred for 0.5 h to 3 h. 1 to 3 equivalents of 2,3-dimethyl-5,6-dicyanobenzoquinone are added, and the mixture is extracted with dichloromethane, dried with anhydrous Na2SO4, and the solvent is removed under vacuum. The mixture is then separated and purified by column chromatography to obtain the orange-yellow solid product BnOH-BODIPY.

[0018] Furthermore, the molar ratio of 2,4-dimethylpyrrole, p-hydroxymethylbenzaldehyde, 2,3-dimethyl-5,6-dicyanobenzoquinone, triethylamine and boron trifluoride diethyl ether is (2-2.3):(1-1.3):(1-3):(1-1.3):(1-3).

[0019] Further, the specific process of step (2) is as follows: BnOH-BODIPY, 4-diphenylaminobenzaldehyde, and toluenesulfonamide are dissolved in a mixed solution of toluene and piperidine (v / v = 1 / 1), placed in a round-bottom flask equipped with a Dean-Stark apparatus, and heated to reflux at 120℃-150℃ until all solvent is collected by the Dean-Stark apparatus. Toluene and piperidine are then added to the reaction medium, and the reaction is repeated 3-5 times. TLC is used to track the reaction until the reactants are completely reacted. After column chromatography and vacuum distillation to remove the solvent, a black solid product 2TPA-BnOH-BODIPY compound is obtained.

[0020] Furthermore, the molar ratio of BnOH-BODIPY, 4-diphenylaminobenzaldehyde, and toluenesulfonamide is (1-1.3):(2-2.3):(0.1-1).

[0021] Further, the specific process of step (3) is as follows: 2TPA-BnOH-BODIPY and the linker containing the diselenium bond are added to a flask, dissolved in chloroform, stirred vigorously, and a mixed solution of dicyclohexylcarbodiimide (DCC) and 4-dimethylaminopyridine (DMAP) is added. The mixture is stirred at 60-100℃ for 1-6 hours, the solvent is removed by vacuum rotary evaporation, and the mixture is purified by column chromatography. After the reaction is completed, the final product SeSe-2TPA-BnOH-BODIPY compound is obtained.

[0022] Furthermore, the molar ratio of 2TPA-BnOH-BODIPY, the linker containing diselenium bonds, DCC, and DMAP is (1-1.3):(1-2.3):(0.1-1):(0.1-1).

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] β-amyloid protein folds to form fibers in the brain, and its deposition is positively correlated with Alzheimer's disease. Because β-amyloid protein deposition contains different major structural variants of peptides, it exhibits polymorphism, thus requiring specific identification. The BODIPY probe formed by triphenylamine and benzyl alcohol has a specific binding function to Aβ fibers, and Aβ fibers can be identified through fluorescence signal output. Furthermore, the fluorescent probe SeSe-2TPA-BnOH-BODIPY of this invention utilizes the characteristic that the diselenium bond is easily broken in polar solvents. When the probe enters the cerebrospinal fluid of an AD patient, the diselenium bond breaks, resulting in double the Aβ fiber recognition effect, thereby better achieving the purpose of Alzheimer's disease diagnosis.

[0025] The fluorescent probe SeSe-2TPA-BnOH-BODIPY of this invention has high sensitivity and selectivity, and its preparation method is simple and easy to operate, making it of great application value in the field of Alzheimer's disease diagnosis and treatment. Attached Figure Description

[0026] Figure 1 This is the 1H NMR spectrum of the SeSe-2TPA-BnOH-BODIPY compound obtained in Example 1 of this invention;

[0027] Figure 2 This is a scanning electron microscope image of the Aβ fiber recognition of the SeSe-2TPA-BnOH-BODIPY compound obtained in Example 1 of this invention. Detailed Implementation

[0028] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0029] The preparation method of the compound 2TPA-BnOH-BODIPY used in the following examples is as follows:

[0030] (1) Add 95 mg (0.1 mmol) of 2,4-dimethylpyrrole and 6.8 mg (0.05 mmol) of p-hydroxymethylbenzaldehyde to an Erlenmeyer flask. Mix and dissolve in dichloromethane (50 ml), add triethylamine (3 ml), stir at room temperature for 1 h to 6 h, slowly add boron trifluoride diethyl ether (3 ml) dropwise in an ice bath, stir for 0.5 h to 3 h, add 22.7 mg (0.1 mmol) of 2,3-dimethyl-5,6-dicyanobenzoquinone, extract with dichloromethane, dry with anhydrous Na2SO4, remove solvent under vacuum, and purify by column chromatography to obtain the orange-yellow solid product BnOH-BODIPY compound.

[0031] (2) Weigh 177 mg (0.5 mmol) BnOH-BODIPY, 273 mg (1.0 mmol) 4-diphenylaminobenzaldehyde, and 17.1 mg (0.1 mmol) toluenesulfonamide sequentially and dissolve them in a mixed solution of 20 ml toluene and 20 ml piperidine (v / v = 1 / 1). Place the solution in a round-bottom flask equipped with a Dean-Stark apparatus and heat under reflux at 120 °C-150 °C until all solvent is collected by the Dean-Stark apparatus. Then add toluene and piperidine to the reaction medium and repeat 3-5 times. Monitor the reaction with TLC until the reactants are completely reacted. Perform column chromatography and remove the solvent by vacuum distillation to obtain the black solid product 2TPA-BnOH-BODIPY compound.

[0032] Example 1

[0033] Add 86.5 mg (0.1 mmol) of 2TPA-BnOH-BODIPY and 58.2 mg (0.15 mmol) of a linker containing a diselenobond to a dried flask, dissolve in 10 mL of chloroform, stir vigorously, add 26 mL of a mixed solution of dicyclohexylcarbodiimide (DCC) and 26 mL of 4-dimethylaminopyridine (DMAP) (DCC / DMAP = 1:1, v / v), stir at 60–100 °C for 1–6 h, remove solvent by vacuum rotary evaporation, and purify by column chromatography. After the reaction, a total of 49.968 mg (0.024 mmol) of the final product SeSe-2TPA-BnOH-BODIPY was obtained, with a yield of 24%. The 1H NMR spectrum of the compound is shown below. Figure 1 As shown.

[0034] Example 2

[0035] 129.75 mg (0.15 mmol) of 2TPA-BnOH-BODIPY and 77.6 mg (0.2 mmol) of a linker containing a diselenobond were added to a dried flask. The mixture was dissolved in 10 mL of chloroform and stirred vigorously. A mixed solution of 30 mL of dicyclohexylcarbodiimide (DCC) and 30 mL of 4-dimethylaminopyridine (DMAP) (DCC / DMAP = 1:1, v / v) was added. The mixture was stirred at 60–100 °C for 1–6 h. The solvent was removed by rotary evaporation under vacuum. The mixture was purified by column chromatography. After the reaction was complete, 68.77 mg (0.033 mmol) of the final product SeSe-2TPA-BnOH-BODIPY was obtained, with a yield of 22%. The compound was identified as the target product by 1H NMR spectroscopy.

[0036] Example 3

[0037] 131.48 mg (0.12 mmol) of 2TPA-BnOH-BODIPY and 58.2 mg (0.15 mmol) of a linker containing a diselenobond were added to a dried flask. The mixture was dissolved in 10 mL of chloroform and stirred vigorously. A mixed solution of 28 mL of dicyclohexylcarbodiimide (DCC) and 28 mL of 4-dimethylaminopyridine (DMAP) (DCC / DMAP = 1:1, v / v) was added. The mixture was stirred at 60–100 °C for 1–6 h. The solvent was removed by rotary evaporation under vacuum. The mixture was purified by column chromatography. After the reaction was complete, 52.47 mg (0.252 mmol) of the final product SeSe-2TPA-BnOH-BODIPY was obtained, with a yield of 21%. The target product was identified by 1H NMR spectroscopy.

[0038] Application of the substance prepared in Example 1

[0039] Analysis of SeSe-2TPA-BnOH-BODIPY for Aβ fiber recognition:

[0040] Aβ peptides were dissolved in hexafluoroisopropanol to a concentration of 1 mM, followed by vacuum removal of the hexafluoroisopropanol. The peptides were resuspended in dimethyl sulfoxide to a concentration of 5 μM, further diluted to 100 μM with F12 (phenol red-free) medium, and incubated at 4°C for 36 hours. The solution was centrifuged at 14000 g for 15 minutes to obtain self-assembled Aβ fibers, and the supernatant was collected for later use. SeSe-2TPA-BnOH-BODIPY (1 mg) was dissolved in 45 μL of hexafluoroisopropanol and injected into the Aβ fiber aqueous solution. After 2 hours, fluorescently labeled Aβ fibers were obtained. Subsequently, samples were placed on silicon wafers and dehydrated for 15 min each with 30%, 50%, 75%, 85%, 95%, and 100% ethanol solutions. After drying for 16 hours, the samples were dehydrated and dried using a vacuum critical freeze dryer, then sprayed with gold using a vacuum sprayer, and examined under a microscope. The results are as follows. Figure 2 As shown, SeSe-2TPA-BnOH-BODIPY has great potential application value for the accurate diagnosis of AD.

[0041] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A BODIPY dimer compound containing Se-Se bonds for the diagnosis and treatment of Alzheimer's disease, characterized in that, It has the following molecular structural formula: 。 2. The method for preparing a BODIPY dimer compound containing Se-Se bonds as described in claim 1, characterized in that, Includes the following steps: (1) Using 2,4-dimethylpyrrole and p-hydroxymethylbenzaldehyde as raw materials, dichloromethane as solvent, 2,3-dimethyl-5,6-dicyanobenzoquinone as catalyst, boron trifluoride ether and triethylamine as complexing agents, BnOH-BODIPY compound was prepared; (2) Using BnOH-BODIPY and 4-diphenylaminobenzaldehyde obtained in step (1) as raw materials, toluene and piperidine as solvents, and toluenesulfonamide as catalyst, 2TPA-BnOH-BODIPY compound was prepared. (3) Using the 2TPA-BnOH-BODIPY obtained in step (2) and the linker containing double selenium bonds as raw materials, chloroform as solvent, and dicyclohexylcarbodiimide and 4-dimethylaminopyridine as catalysts, the final product SeSe-2TPA-BnOH-BODIPY compound was prepared. The reaction route is shown in the following equation: 。 3. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 2, characterized in that: The specific process of step (1) is as follows: 2,4-dimethylpyrrole and p-hydroxymethylbenzaldehyde are mixed and dissolved in dichloromethane, triethylamine is added, and the mixture is stirred at room temperature for 1 h to 6 h. Boron trifluoride ether is slowly added dropwise in an ice bath and stirred for 0.5 h to 3 h. 1 to 3 equivalents of 2,3-dimethyl-5,6-dicyanobenzoquinone are added, and the mixture is extracted with dichloromethane, dried with anhydrous Na2SO4, and the solvent is removed under vacuum. The mixture is then separated and purified by chromatography to obtain the orange-yellow solid product BnOH-BODIPY.

4. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 3, characterized in that: The molar ratio of 2,4-dimethylpyrrole, p-hydroxymethylbenzaldehyde, 2,3-dimethyl-5,6-dicyanobenzoquinone, triethylamine and boron trifluoride ether is (2~2.3):(1~1.3):(1~3):(1~1.3):(1~3).

5. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 2, characterized in that: The specific process of step (2) is as follows: BnOH-BODIPY, 4-diphenylaminobenzaldehyde, and toluenesulfonamide are dissolved in a mixed solution of toluene and piperidine, placed in a round-bottom flask equipped with a Dean-Stark apparatus, and heated to reflux at 120℃-150℃ until all the solvent is collected by the Dean-Stark apparatus. Toluene and piperidine are then added to the reaction medium, and the reaction is repeated 3-5 times. TLC is used to track the reaction until the reactants are completely reacted. After column chromatography and vacuum distillation to remove the solvent, a black solid product 2TPA-BnOH-BODIPY compound is obtained.

6. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 5, characterized in that: The molar ratio of BnOH-BODIPY, 4-diphenylaminobenzaldehyde, and toluenesulfonamide is (1~1.3):(2~2.3):(0.1~1).

7. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 2, characterized in that: The specific process of step (3) is as follows: 2TPA-BnOH-BODIPY and the linker containing the diselenium bond are added to a flask, dissolved in chloroform, stirred vigorously, and a mixed solution of dicyclohexylcarbodiimide and 4-dimethylaminopyridine is added. The mixture is stirred at 60~100℃ for 1h~6h, the solvent is removed by vacuum rotary evaporation, and the mixture is purified by chromatography. After the reaction is completed, the final product SeSe-2TPA-BnOH-BODIPY compound is obtained.

8. The method for preparing a BODIPY dimer compound containing Se-Se bonds according to claim 7, characterized in that: The molar ratio of 2TPA-BnOH-BODIPY, the linker containing a diselenide bond, dicyclohexylcarbodiimide, and 4-dimethylaminopyridine is (1~1.3):(1~2.3):(0.1~1):(0.1~1).

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