Equilateral triangle BODIPY photodynamic sterilization fluorescent probe and preparation method thereof

Abstract

The application belongs to the technical field of organic synthesis, and discloses an equilateral triangle BODIPY photodynamic sterilization fluorescent probe (Tri-TPA-I-BODIPY) and a preparation method thereof. The Tri-TPA-I-BODIPY is an equilateral triangle structure composed of two triphenylamine and one fluoroboron dipyrryl. The triphenylamine group has unique free radical properties, and the introduction of the group into the BODIPY can enhance the photocatalytic activity of the BODIPY. The unique equilateral triangle structure greatly enhances the light stability of the Tri-TPA-I-BODIPY. After modification by heavy atom iodine, the photosensitivity of the BODIPY can be improved, and the yield of reactive oxygen species (ROS, mainly singlet oxygen) can be improved. The singlet oxygen can resist eradication of bacteria, so the Tri-TPA-I-BODIPY can effectively achieve the purpose of photodynamic sterilization treatment of Alzheimer's disease.

Description

An equilateral triangular BODIPY photodynamic sterilization fluorescent probe and its preparation method Technical Field

[0001] This invention belongs to the field of organic synthesis technology and relates to the synthesis of sterilization fluorescent probes, specifically to an equilateral triangular BODIPY photodynamic sterilization fluorescent probe and its preparation method. Background Technology

[0002] Alzheimer's disease (AD) is a typical neurodegenerative disease of the central nervous system, clinically characterized by progressive cognitive decline reflecting underlying synaptic loss and neurodegenerative changes. This leads to cognitive impairment, progressive memory loss, behavioral and social impairments, and dementia. Therefore, it seriously threatens the health of the elderly population, imposing a heavy burden on society and the economy, and is considered a global public health threat. Research on Alzheimer's disease has been ongoing for over a century, resulting in various drugs and methods based on different pathological mechanisms, but none have achieved satisfactory therapeutic effects. Therefore, there is an urgent need for research into new and effective treatments.

[0003] Antimicrobial photodynamic therapy (aPDT) utilizes photosensitizers to generate reactive oxygen species (ROS, primarily singlet oxygen) under irradiation with light of appropriate wavelengths (typically from visible to near-infrared). This ROS induces oxidative damage to proteins, lipids, and nucleic acids, and disrupts cellular metabolic function, thus killing bacteria. Compared to other treatments, aPDT does not require specific targeting of bacteria. The multi-target nature of ROS oxidizing biomolecules minimizes the development of drug resistance, and it is non-invasive and has good applicability. In addition to directly killing pathogens by disrupting their structure, ROS can also inactivate some bacterial virulence factors, further enhancing the sterilization effect.

[0004] Therefore, for research on the treatment of Alzheimer's disease, there is a great need to develop new fluorescent probes to enhance the ability of photosensitizers to generate singlet oxygen, thereby improving the photodynamic sterilization effect. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an equilateral triangular BODIPY photodynamic sterilization fluorescent probe, which has the advantages of long wavelength, high affinity, and high selectivity, and is suitable for the diagnosis of Alzheimer's disease. Another objective of the present invention is to provide a method for preparing the fluorescent probe.

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

[0007] An equilateral triangular BODIPY photodynamic sterilization fluorescent probe and its preparation method are disclosed, which has the following molecular structural formula:

[0008]

[0009] In the formula, the fluoroboron dipyrrole compound has a benzene substituent at the 8 position, two methyl groups at the 1,7-position, and two N,N-diphenyl-4-vinylaniline groups at the 3,5-position.

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

[0011] An equilateral triangular BODIPY photodynamic sterilization fluorescent probe and its preparation method, comprising the following steps:

[0012] (1) Using 2,4-dimethylpyrrole and benzoyl chloride as raw materials, dichloromethane (CH2Cl2) as solvent, and triethylamine (Et3N) and boron trifluoride ether (BF3·Et2O) as complexing agents, the B-BODIPY compound was obtained.

[0013] (2) Using the B-BODIPY compound obtained in step (1) and 4-diphenylaminobenzaldehyde as raw materials, and toluene as solvent, Tri-TPA-BODIPY compound was obtained under the catalysis of acetic acid and piperidine.

[0014] (3) Using the Tri-TPA-BODIPY compound obtained in step (2) and N-iodosuccinimide (NIS) as raw materials and dichloromethane as solvent, the final product Tri-TPA-I-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: under N2 protection, 2,4-dimethylpyrrole, benzoyl chloride and dry CH2Cl2 solution are added to a three-necked flask, refluxed for 3-6 h, cooled to room temperature and then Et3N and BF3·Et2O are added dropwise. The reaction is carried out at room temperature for 2-6 h, extracted with CH2Cl2, washed three times with water, the organic phases are combined, dried with MgSO4, filtered and concentrated and then column chromatography is performed to obtain red solid B-BODIPY compound.

[0018] Furthermore, the molar ratio of the 2,4-dimethylpyrrole, benzoyl chloride, triethylamine, and boron trifluoride diethyl ether complex is (1-3.3):(0.3-2.3):(1-3):(1-3).

[0019] Further, the specific process of step (2) is as follows: Under N2 protection, B-BODIPY obtained in step (1) and 4-diphenylaminobenzaldehyde are added to dry toluene, and then the mixture is heated to 110-150°C. A catalyst amount of acetic acid and piperidine is then added to the solution. During the reaction, water formed during the reaction is removed using a Dean-Stark apparatus, and the mixture is refluxed for 16 hours. The reaction progress is monitored by TLC. When the reaction is complete, the solvent is removed by a rotary evaporator. The product is purified by silica gel chromatography, eluted with dichloromethane and ethyl acetate, to obtain a black solid, Tri-TPA-BODIPY compound.

[0020] Furthermore, the molar ratio of B-BODIPY, 4-diphenylaminobenzaldehyde, acetic acid, and piperidine is (1–2.2):(2–4.8):(2–5):(2–5):

[0021] Further, the specific process of step (3) is as follows: the Tri-TPA-BODIPY compound and N-iodosuccinimide (NIS) are dissolved in CH2Cl2 and stirred at room temperature for 3-6 h. The final product Tri-TPA-I-BODIPY compound is obtained by separation and purification by silica gel column chromatography (CH2Cl2:n-hexane = 1:1).

[0022] Furthermore, the molar ratio of Tri-TPA-BODIPY to NIS is (1-1.5):(2-6).

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

[0024] In Alzheimer's disease, fungal infections can occur in the brains of patients, and inhibiting these fungi can be an effective treatment. This invention uses BODIPY as a photosensitizer probe, which enhances its photostability and photocatalytic activity by replacing triphenylamine with a triangular structure. Under specific wavelengths of light, it reacts to produce singlet oxygen, which can react with biomolecules. This singlet oxygen induces oxidative damage to proteins, lipids, and nucleic acids, and disrupts cellular metabolic function, thereby killing bacteria and effectively eliminating lesions, achieving the goal of treating Alzheimer's disease. In addition to directly killing pathogens by disrupting their structure, ROS can also inactivate some bacterial virulence factors, further enhancing the sterilization and therapeutic effect.

[0025] The photodynamic sterilization fluorescent probe Tri-TPA-I-BODIPY of this invention possesses high affinity 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 is the 1H NMR spectrum of the Tri-TPA-I-BODIPY compound obtained in Example 1 of the present invention;

[0027] Figure 2 shows the antibacterial performance of Tri-TPA-I-BODIPY obtained in Example 1 of the present invention against Staphylococcus aureus under different light conditions in vitro;

[0028] Wherein, a: blank control group, no light, no BODIPY; b: with BODIPY, no light; c: with BODIPY, natural light; d: with BODIPY, 24W fluorescence (λ=395nm). Detailed Implementation

[0029] 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.

[0030] The preparation method of Tri-TPA-BODIPY used in the following examples is as follows:

[0031] (1) Under N2 protection, 2,4-dimethylpyrrole (1 mL, 0.924 mmol), benzoyl chloride (0.56 mL, 0.005 mol) and dry CH2Cl2 (50 mL) solution were added to a three-necked flask and refluxed for 3 h. After cooling to room temperature, Et3N (3 mL) and BF3·Et2O (3 mL) were added dropwise and reacted at room temperature for 4 h. The mixture was extracted with CH2Cl2 (30 mL × 3), washed three times with water, and the organic phases were combined, dried with MgSO4, filtered and concentrated, and then subjected to column chromatography (PE:DCM = 2:1) to obtain 452 mg (28.4%) of red solid B-BODIPY compound.

[0032] (2) Under N2 protection, B-BODIPY (100 mg, 0.308 mmol) and 4-diphenylaminobenzaldehyde (175 mg, 0.641 mmol) were added to dry toluene (20.0 mL), and the mixture was heated to 110 °C. Catalytic amounts of acetic acid (38 μL) and piperidine (38 μL) were then added to the solution. Water formed during the reaction was removed using a Dean-Stark apparatus, and the mixture was refluxed for 16 hours. The reaction progress was monitored by TLC. When the reaction was complete, the solvent was removed by rotary evaporator. The product was purified by silica gel chromatography, eluting with dichloromethane and ethyl acetate (dichloromethane:ethyl acetate = 20:1, v / v), to give 41.15 mg (0.049 mmol, 16%) of the black solid Tri-TPA-BODIPY compound.

[0033] Example 1

[0034] Compound Tri-TPA-BODIPY (83.5 mg, 0.1 mmol) and N-iodosuccinimide (NIS) (90 mg, 0.4 mmol) were added to a reaction flask and dissolved in CH2Cl2 (10 mL). The mixture was stirred at room temperature for 6 h. The target compound Tri-TPA-I-BODIPY was purified by silica gel column chromatography (CH2Cl2:n-hexane = 1:1) to obtain a total yield of 30.436 mg (0.028 mmol), representing 28%. The 1H NMR spectrum of the compound is shown in Figure 1.

[0035] Example 2

[0036] Compound Tri-TPA-BODIPY (125.25 mg, 0.15 mmol) and N-iodosuccinimide (NIS) (135 mg, 0.6 mmol) were added to a reaction flask and dissolved in CH2Cl2 (10 mL). The mixture was stirred at room temperature for 6 h. A total of 44.84 mg (0.041 mmol) of the target compound Tri-TPA-I-BODIPY was obtained by separation and purification using a silica gel column chromatography (CH2Cl2:n-hexane = 1:1), with a yield of 27.5%. The target product was identified by 1H NMR spectroscopy.

[0037] Example 3

[0038] Compound Tri-TPA-BODIPY (108.55 mg, 0.13 mmol) and N-iodosuccinimide (NIS) (90 mg, 0.4 mmol) were added to a reaction flask and dissolved in CH2Cl2 (10 mL). The mixture was stirred at room temperature for 6 h. A total of 40.98 mg (0.038 mmol) of the target compound Tri-TPA-I-BODIPY was obtained by separation and purification using a silica gel column chromatography (CH2Cl2:n-hexane = 1:1), with a yield of 29%. The target product was identified by 1H NMR spectroscopy.

[0039] Example 4

[0040] In vitro anti-Staphylococcus aureus activity of Tri-TPA-I-BODIPY under different light conditions

[0041] Staphylococcus aureus was cultured in LB broth for 24 h. The incubated bacterial solution was centrifuged at 6000 rpm for 10 min to remove the supernatant. The bacterial precipitate was washed three times with PBS and redispersed in 4 mL of PBS solution to prepare a 1 mg / mL Tri-TPA-I-BODIPY sample treatment for the bacteria (10... 8CFU / mL). One group was set up as a blank bacterial control group (a), and the other three experimental groups (b: no light, c: natural light, d: 24W fluorescent lamp with filter (λ=395nm)) were used at 10... 8 CFU / mL bacterial suspensions were co-incubated with 1 mg / mL Tri-TPA-I-BODIPY samples. After 24 h of shaking incubation at 150 rpm, the three experimental groups were irradiated for 2 h at a distance of 5 cm from the light source under darkness, natural light, and a 24W fluorescent lamp (λ = 395 nm) with a filter, respectively. Samples were then taken to measure the UV absorbance at 600 nm for each group. Different light conditions and OD values ​​were then used to further analyze the bacterial absorption. 600 The bacterial growth curve was plotted using absorbance as the x and y axes, as shown in Figure 2. The results showed that Tri-TPA-I-BODIPY exhibited the best antibacterial effect under irradiation with a 24W fluorescent lamp (λ = 395 nm).

[0042] 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. An equilateral triangular BODIPY photodynamic sterilization fluorescent probe, characterized in that, It has the following molecular structural formula: 。 2. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe as described in claim 1, characterized in that, Includes the following steps: (1) Using 2,4-dimethylpyrrole and benzoyl chloride as raw materials, CH2Cl2 as solvent, and Et3N and BF3·Et2O as complexing agents, B-BODIPY compound was obtained; (2) Using the B-BODIPY compound obtained in step (1) and 4-diphenylaminobenzaldehyde as raw materials, and toluene as solvent, Tri-TPA-BODIPY compound was obtained under the catalysis of acetic acid and piperidine; (3) Using the Tri-TPA-BODIPY compound obtained in step (2) and NIS as raw materials, and dichloromethane as solvent, the final product Tri-TPA-I-BODIPY compound was prepared; the reaction route is shown in the following formula: 。 3. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 2, characterized in that: The specific process of step (1) is as follows: Under N2 protection, 2,4-dimethylpyrrole, benzoyl chloride and dry CH2Cl2 solution are added to a three-necked flask, refluxed for 3-6 h, cooled to room temperature and then Et3N and BF3·Et2O are added dropwise. The reaction is carried out at room temperature for 2-6 h, extracted with CH2Cl2, washed three times with water, the organic phases are combined, dried with MgSO4, filtered and concentrated and then column chromatography is performed to obtain red solid B-BODIPY compound.

4. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 3, characterized in that: The molar ratio of the complex of 2,4-dimethylpyrrole, benzoyl chloride, triethylamine and boron trifluoride ether is (1~3.3):(0.3~2.3):(1~3):(1~3).

5. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 2, characterized in that: The specific process of step (2) is as follows: Under N2 protection, B-BODIPY obtained in step (1) and 4-diphenylaminobenzaldehyde are added to dry toluene. The mixture is then heated to 110~150℃. A catalyst amount of acetic acid and piperidine is added to the solution. During the reaction, the water formed during the reaction is removed using a Dean-Stark apparatus. The mixture is refluxed for 16~20 hours. The reaction progress is monitored by TLC. When the reaction is complete, the solvent is removed by a rotary evaporator. The product is purified by silica gel chromatography and eluted with dichloromethane and ethyl acetate to obtain the black solid Tri-TPA-BODIPY compound.

6. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 5, characterized in that: The molar ratio of B-BODIPY, 4-diphenylaminobenzaldehyde, acetic acid and piperidine is (1~2.2):(2~4.8):(2~5):(2~5).

7. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 2, characterized in that: The specific process of step (3) is as follows: the Tri-TPA-BODIPY compound and NIS are dissolved in CH2Cl2 and stirred at room temperature for 3-6 hours. The final product Tri-TPA-I-BODIPY compound is obtained by separation and purification by chromatographic silica column. The eluent of the chromatographic silica column is CH2Cl2:n-hexane = 1:

1.

8. The method for preparing an equilateral triangular BODIPY photodynamic sterilization fluorescent probe according to claim 7, characterized in that: The molar ratio of Tri-TPA-BODIPY to NIS is (1~1.5):(2~6).

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