A biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY and its preparation method

Abstract

The present invention belongs to the technical field of organic synthesis and discloses a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY and a preparation method thereof. The present invention adopts dimethylpyrrole and 4,4'-biphenyldicarboxaldehyde to react to synthesize the biphenyl-containing BODIPY dimer, and then introduces iodine atoms into the biphenyl-containing BODIPY dimer. The introduced BODIPY dimer serves as an electron acceptor and the biphenyl serves as an electron donor. The biphenyl introduced in the present invention can effectively increase the length distance of the compound, so that it can more accurately bind to biomarkers; it also enhances the photoinduced electron transfer ability of the BODIPY compound and improves the generation efficiency of singlet oxygen; the BODIPY dimer has greatly enhanced photosensitivity compared to the BODIPY monomer; iodine acts as an electron acceptor, which enhances the electron-withdrawing ability of BODIPY, so that it has high photodynamic activity and significantly increases the generation level of ROS.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic synthesis and relates to the synthesis of a sterilization fluorescent probe, in particular to a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY and its preparation method. Background Art

[0002] Bacterial infections continue to threaten human health and cause millions of deaths annually. Among the diverse bacterial infections, effective treatment of Gram-positive infections, particularly Staphylococcus aureus, remains a significant challenge. This presents a significant risk of long-term infection in patients with compromised immune systems, placing a significant burden on both patients and hospitals. With the discovery of antibiotics such as penicillin and streptomycin, bacterial infections were once believed to be permanently curable. However, the overuse of these antibiotics has led to the emergence of drug-resistant bacteria, and bacterial resistance has become increasingly robust. To address this, researchers have developed novel antimicrobial technologies, such as antimicrobial photodynamic therapy (aPDT), aiming to provide more sustainable, cost-effective, and effective antimicrobial treatments. aPDT utilizes photosensitizers (PSs) under irradiation with light of appropriate wavelengths to generate reactive oxygen species (ROS). ROS are generated by internal conversion of PSs after photon absorption, generating singlet oxygen. These ROS kill bacteria by inducing oxidative damage to proteins, lipids, and nucleic acids, and disrupting cellular metabolic function. Compared with traditional antimicrobial therapies, aPDT reduces the development of bacterial resistance and exhibits fewer side effects.

[0003] Boron-dipyrrole (BODIPY) is a highly promising PS with excellent photophysical and chemical properties. Its properties can be controlled to meet specific requirements by modifying its parent structure. However, few studies have revealed the relationship between antibacterial efficacy and BODIPY structure. Therefore, it is of great significance to study and design BODIPY probes with photodynamic sterilization capabilities. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY, which exhibits high sensitivity, strong fluorescence performance and good sterilization performance. Another purpose of the present invention is to provide a method for preparing the probe.

[0005] The present invention is achieved through the following technical solutions:

[0006] A biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY has a molecular structure as shown below:

[0007]

[0008] A further improvement of the present invention is:

[0009] A method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY comprises the following steps:

[0010] (1) reacting dimethylpyrrole with 4,4'-biphenyldicarboxaldehyde and boron trifluoride etherate to produce DB-BODIPY;

[0011] (2) causing DB-BODIPY to undergo iodination reaction to generate DBI-BODIPY;

[0012] The reaction equation is as follows:

[0013]

[0014] A further improvement of the present invention is:

[0015] In step (1), dichloromethane is used as solvent, 2,3-dimethyl-5,6-dicyanobenzoquinone is used as catalyst, and triethylamine is used as complexing agent.

[0016] Furthermore, the molar ratio of dimethylpyrrole, 4,4'-biphenyldicarboxaldehyde, boron trifluoride ethyl etherate, 2,3-dimethyl-5,6-dicyanobenzoquinone and triethylamine is 1-6.6:0.3-2.3:1-3:0.03-0.23:0.3-2.3.

[0017] Furthermore, in step (2), dichloromethane is used as solvent and N-iodosuccinimide is used as iodine reagent.

[0018] Furthermore, the molar ratio of DB-BODIPY to N-iodosuccinimide is 0.1-1.1:0.4-8.8.

[0019] Furthermore, the specific process of step (1) is as follows: dimethylpyrrole and 4,4'-biphenyldicarboxaldehyde are mixed and dissolved in dichloromethane, an equivalent amount of triethylamine is added, and the mixture is stirred at room temperature for 0.5h to 6h, boron trifluoride ether is slowly added dropwise in an ice bath, and the mixture is stirred for 0.5h to 6h, 2,3-dimethyl-5,6-dicyanobenzoquinone is added, and the reaction is continued until the raw materials react completely, extracted with dichloromethane, dried over anhydrous Na2SO4, and the solvent is removed in vacuo. The mixture is separated and purified by a chromatography column to obtain a light yellow solid, namely DB-BODIPY.

[0020] Furthermore, the specific process of step (2) is: DB-BODIPY and N-iodosuccinimide are mixed and dissolved in dichloromethane, stirred and reacted at room temperature for 1 hour to 6 hours, and after the reaction, separated and purified to obtain a solid product, namely DBI-BODIPY.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention uses dimethylpyrrole and 4,4'-biphenyldicarboxaldehyde to react to synthesize a biphenyl-containing BODIPY dimer, and then introduces an iodine atom into the biphenyl-containing BODIPY dimer. The introduced BODIPY dimer serves as an electron acceptor, and the biphenyl serves as an electron donor. The biphenyl introduced in the present invention can effectively increase the length distance of the compound, allowing it to more accurately bind to biomarkers; it also enhances the photoinduced electron transfer ability of the BODIPY compound and improves the generation efficiency of singlet oxygen; the BODIPY dimer has greatly enhanced photosensitivity compared to the BODIPY monomer; iodine acts as an electron acceptor, enhancing the electron-withdrawing ability of BODIPY, giving it higher photodynamic activity and significantly increasing the level of ROS generation.

[0023] The present invention uses dimethylpyrrole and aldehyde compounds to undergo Knoevenagel condensation reaction, and finally performs iodination reaction on the β position of BODIPY to synthesize it. Bacterial infectious diseases have become one of the biggest challenges in the world and seriously threaten human health. Relevant studies have shown that bacteria can also indirectly promote the occurrence and development of other diseases such as cancer. Compared with traditional antibacterial therapies, antibacterial photodynamic therapy (aPDT) uses photosensitizers (PSs) to produce reactive oxygen species (ROS) under light of appropriate wavelengths, killing bacteria by inducing oxidative damage to proteins, lipids and nucleic acids, and cellular metabolic dysfunction, thereby reducing the occurrence of bacterial resistance. BODIPY is a fluorescent dye that can be used for PDT. The modified BODIPY can convert oxygen into singlet oxygen under the irradiation of light to fight bacteria, thereby achieving a sterilization effect. The introduction of biphenyl as an electron-donating group in DBI-BODIPY enhances the photoinduced electron transfer ability of the BODIPY compound and improves the efficiency of singlet oxygen generation. Furthermore, DBI-BODIPY contains two BODIPY cores substituted with tetraiodine. Iodine acts as an electron acceptor, enhancing BODIPY's electron-withdrawing capacity, resulting in high photodynamic activity and significantly increasing ROS production. This fluorescent probe, designed with modified electron groups and iodine substitution in mind, can generate singlet oxygen upon illumination, thereby achieving sterilization. Furthermore, the compound exhibits mild preparation conditions and simple steps, suggesting promising potential applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the H NMR spectrum of DBI-BODIPY prepared in Example 1 of the present invention;

[0025] Figure 2The antibacterial performance of DBI-BODIPY obtained in Example 1 of the present invention against Staphylococcus aureus under different illumination conditions in vitro; wherein, a: blank control group, no illumination, no BODIPY; b: BODIPY added, no illumination; c: BODIPY added, natural illumination; d: BODIPY added, 24W fluorescence (λ=395nm);

[0026] Figure 3 This is the fluorescence staining of Aβ fibers by the DBI-BODIPY compound obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0027] The present invention is described in detail below with reference to specific embodiments.

[0028] The preparation method of the fluoroboron dipyrrole compound DB-BODIPY fluorescent dye used in the embodiment of the present invention is as follows:

[0029] 840 mg (4.0 mmol) of 4,4'-biphenyldicarboxaldehyde was weighed and dissolved in 200 mL of freshly distilled dichloromethane. 1520 mg (16 mmol) of 2,4-dimethylpyrrole was injected with a syringe, and 3 ml of triethylamine was added. The mixture was stirred magnetically at high speed, protected from light, and stirred at room temperature overnight. Under nitrogen protection, 3 mL of boron trifluoride etherate was slowly added dropwise in an ice bath and stirred for 10 minutes. Then, 45.4 mg (0.2 mmol) of 2,3-dimethyl-5,6-dicyanobenzoquinone was added under stirring. After TLC tracking until the reaction of the raw materials was complete, column chromatography was performed, the solvent was removed by distillation under reduced pressure, and the mixture was extracted with dichloromethane. The mixture was dried over anhydrous Na2SO4, and the solvent was removed in vacuo at 50°C. The product was separated and purified by chromatography to obtain the fluoroboron dipyrrole fluorescent dye DB-BODIPY.

[0030] Example 1

[0031] 646 mg (1 mmol) of DB-BODIPY and 900 mg (4 mmol) of N-iodosuccinimide (NIS) were mixed and dissolved in dichloromethane (160 mL) and stirred at room temperature for 6 h. The solid product, DBI-BODIPY (920 mg, 80% yield), was isolated and purified by chromatography on a silica gel column (CH2Cl2:n-hexane = 1:1). The H NMR spectrum was as follows: Figure 1 shown.

[0032] Example 2

[0033] 646 mg (1 mmol) of DB-BODIPY and 1800 mg (8 mmol) of N-iodosuccinimide (NIS) were mixed and dissolved in dichloromethane (160 mL) and stirred at room temperature for 6 h. The solid product DBI-BODIPY (989 mg, yield 86%) was separated and purified by chromatography on a silica gel column (CH2Cl2: n-hexane = 1:1). The compound was detected by nuclear magnetic resonance (NMR) 1 The target product was confirmed by HNMR spectrum.

[0034] Example 3

[0035] 646 mg (1 mmol) DB-BODIPY and 1350 mg (6 mmol) N-iodosuccinimide (NIS) were mixed and dissolved in dichloromethane (160 mL) and stirred at room temperature for 6 h. The solid product DBI-BODIPY (943 mg, yield 82%) was separated and purified by chromatography on a silica gel column (CH2Cl2: n-hexane = 1:1). The compound was analyzed by nuclear magnetic resonance. 1 The target product was confirmed by HNMR spectrum.

[0036] Example 4

[0037] In vitro anti-Staphylococcus aureus activity experiment of DBI-BODIPY under different light conditions

[0038] Staphylococcus aureus (S. aureus) was cultured in LB broth for 24 h. The incubated bacterial solution was centrifuged at 6000 rpm for 10 minutes and the supernatant was removed. The bacterial precipitate was washed three times with PBS and redispersed in 4 mL of PBS solution. The DBI-BODIPY sample was prepared at a concentration of 1 mg / mL to treat the bacteria (10 8 One group was set as 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 for 10 8 The bacterial suspension with CFU / mL was incubated with 1mg / mL DBI-BODIPY sample. The culture was shaken at 150 rpm for 24 hours. The three experimental groups were irradiated for 2 hours in the dark, natural light, and 24W fluorescent lamp (λ=395nm) with filter at a distance of 5 cm from the light source. Then, the UV absorbance of the bacteria at 600nm was measured. 600 The bacterial growth curve is drawn with absorbance as the horizontal and vertical coordinates, such as Figure 2 The results showed that the antibacterial effect of DBI-BODIPY was best under the irradiation of 24W fluorescent lamp (λ=395nm).

[0039] Example 5

[0040] DBI-BODIPY analysis of Aβ fiber recognition

[0041] Aβ peptide (10 mg) was dissolved in 45 μL hexafluoroisopropanol, and then 105 μL of water was added by injection. Ultrasonication was performed at room temperature for 5 minutes to allow the Aβ peptide to assemble into Aβ fibers. The hexafluoroisopropanol was dialyzed against water to obtain Aβ fibers that were stored in water for future use. DBI-BODIPY (1 mg) was dissolved in 45 μL hexafluoroisopropanol and added to the Aβ fiber aqueous solution by injection. After 2 hours, red fluorescent labeled Aβ fibers were obtained, as shown in Figure 2. Figure 3 As shown in Figure 4, DBI-BODIPY exhibits fluorescence on Aβ fibers, indicating that DBI-BODIPY compounds have great potential application value in the accurate diagnosis of AD.

[0042] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY, characterized in that: The molecular structure is shown below: 。 2. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 1, characterized in that: The following steps are involved: (1) 2,4-dimethylpyrrole is reacted with 4,4'-biphenyldicarboxaldehyde and boron trifluoride etherate to produce DB-BODIPY; (2) Iodination reaction of DB-BODIPY to generate DBI-BODIPY; The reaction equation is as follows: 。 3. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 2, characterized in that: In step (1), dichloromethane is used as solvent, 2,3-dimethyl-5,6-dicyanobenzoquinone is used as catalyst, and triethylamine is used as complexing agent.

4. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 3, characterized in that: The molar ratio of the 2,4-dimethylpyrrole, 4,4'-biphenyldicarboxaldehyde, boron trifluoride etherate, 2,3-dimethyl-5,6-dicyanobenzoquinone and triethylamine is 1-6.6:0.3-2.3:1-3:0.03-0.23:0.3-2.

3.

5. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 2, characterized in that: In step (2), dichloromethane is used as solvent and N-iodosuccinimide is used as iodination reagent.

6. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 5, characterized in that: The molar ratio of the DB-BODIPY to N-iodosuccinimide is 0.1-1.1:0.4-8.

8.

7. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 2, characterized in that: The specific process of step (1) is as follows: 2,4-dimethylpyrrole and 4,4'-biphenyldicarboxaldehyde are mixed and dissolved in dichloromethane, triethylamine is added, and the mixture is stirred at room temperature for 0.5h~6h. Boron trifluoride ether is slowly added dropwise in an ice bath, and the mixture is stirred for 0.5h~6h. 2,3-dimethyl-5,6-dicyanobenzoquinone is added, and the reaction is continued until the raw materials react completely. The mixture is extracted with dichloromethane, dried over anhydrous Na2SO4, and the solvent is removed in vacuo. The mixture is separated and purified by a chromatography column to obtain a light yellow solid, namely DB-BODIPY.

8. The method for preparing a biphenyl-containing BODIPY dimer photodynamic sterilization probe DBI-BODIPY according to claim 2, characterized in that: The specific process of step (2) is as follows: DB-BODIPY and N-iodosuccinimide are mixed and dissolved in dichloromethane, stirred and reacted at room temperature for 1 hour to 6 hours, and after the reaction, a solid product, namely DBI-BODIPY, is separated and purified.

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