A pinanyl-based open-type fluorescent probe for detecting bisulfite, and its preparation method and application

Abstract

The present invention discloses a pinanyl-based open-type fluorescent probe for detecting bisulfite, and its preparation method and application. The probe is 3-(2-(2-methoxy-7,7-dimethyl-5,6,7,8-tetrahydro-6,8-methylenequinazoline-4-yl)vinyl)-1-methylquinolin-1-ium trifluoromethanesulfonate (TQZQ-TfO). The present invention uses 7,7-dimethyl-4-(2-(quinoline-3-yl)vinyl)-5,6,7,8-tetrahydro-6,8-methylenequinazoline-2-ol (abbreviated as TQZQ) as raw material, and undergoes quaternization reaction with methyl trifluoromethanesulfonate to prepare TQZQ-TfO. The compound can undergo a specific addition reaction with bisulfite. Under ultraviolet light with a wavelength of 365nm, the solution of TQZQ-TfO has no fluorescence. After adding bisulfite, the solution emits strong yellow fluorescence. Therefore, TQZQ‑TfO can be used as an open-type fluorescent probe for the detection of bisulfite, with many advantages such as good selectivity, high sensitivity (low detection limit of 12 nM), fast response speed (within 5 s), and a wide pH range (4‑12), showing good application prospects.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorescent probes and relates to a nopinyl open-type fluorescent probe for detecting bisulfite and a preparation method and application thereof. Background Art

[0002] Bisulfite is a widely used food additive with excellent properties, including bleaching, preservation, antioxidant properties, bacterial inhibition, and enzymatic reaction control. Small amounts of bisulfite can be naturally metabolized by the human body and ultimately excreted through the urinary system. However, excessive bisulfite intake can easily cause symptoms such as respiratory distress, acute allergic reactions, pulmonary edema, and coma, which can be harmful to human health. Therefore, developing a method for detecting bisulfite in food samples and living systems is of great significance.

[0003] Currently, the main methods for detecting bisulfite include mass spectrometry, electrochemical methods, high-performance liquid chromatography, and colorimetry. However, these methods suffer from drawbacks such as time-consuming and high-cost detection. In recent years, fluorescent probes have emerged as an ideal detection tool. Compared with other detection methods, fluorescent probes offer advantages such as good selectivity, high sensitivity, ease of use, and non-invasiveness. They have been widely used in fields such as environmental science, life science, and chemistry.

[0004] To address the common problems of slow response time, low sensitivity, narrow detection range, and high cytotoxicity in existing fluorescent probes for detecting bisulfite, the present invention aims to provide a fluorescent probe for detecting bisulfite with a fast response time, high sensitivity, a wide detection range, and the ability to be applied to cell imaging. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a pinanyl-based open-type fluorescent probe for detecting bisulfite, which has the characteristics of fast response, high sensitivity, wide detection range, and wide pH adaptability. It can perform qualitative and quantitative detection of bisulfite in water, soil, plants, and animals, and can be applied to fluorescence imaging of bisulfite in cells.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a pinanyl open-type fluorescent probe for detecting bisulfite, the structural formula of which is:

[0007]

[0008] The fluorescent probe has the molecular formula: C 25 H 26F3N3O4S, named as: 3-(2-(2-methoxy-7,7-dimethyl-5,6,7,8-tetrahydro-6,8-methanoquinazolin-4-yl)vinyl)-1-methylquinolin-1-ium trifluoromethanesulfonate, referred to as TQZQ-TfO.

[0009] The method for preparing a pinanyl-based open-type fluorescent probe for detecting bisulfite uses 7,7-dimethyl-4-(2-(quinolin-3-yl)vinyl)-5,6,7,8-tetrahydro-6,8-methanoquinazolin-2-ol (TQZQ for short) as a starting material, which is reacted with methyl trifluoromethanesulfonate to form a quaternary ammonium salt to produce TQZQ-TfO. The method specifically comprises the following steps:

[0010] (1) Dissolve 340-510 g (1-1.5 mol) of TQZQ in anhydrous dichloromethane. Add 3-4 mol of methyl trifluoromethanesulfonate dropwise to the reaction solution under nitrogen protection and react in an ice bath for 10-12 h.

[0011] (2) The reaction solution was filtered to obtain a crude TQZQ-TfO product:

[0012] (3) The crude TQZQ-TfO product was washed three times with 1000-1500 mL of cold dichloromethane and dried to obtain yellow powder TQZQ-TfO.

[0013] The compound TQZQ-TfO can specifically react with bisulfite. Under 365nm ultraviolet light, the probe solution exhibits strong yellow fluorescence. TQZQ-TfO detects the content of bisulfite in the solution with a detection range of 0-7.5×10 -5 mol / L, with a detection limit as low as 1.2×10 -8 mol / L.

[0014] Beneficial Effects: Compared with the prior art, the present invention uses TQZQ as a raw material and reacts with methyl trifluoromethanesulfonate to form a quaternary ammonium salt to obtain the compound TQZQ-TfO. This compound can specifically recognize bisulfite and sensitively detect the bisulfite content in a solution. As a fluorescent probe for bisulfite detection, it has many advantages, such as convenient synthesis, good selectivity, and high sensitivity, and has good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the fluorescence spectrum of TQZQ-TfO reacting with different concentrations of bisulfite;

[0016] Figure 2 It is the fluorescence spectrum of TQZQ-TfO interacting with different analytes such as metal ions, anions, bioactive small molecules and reactive oxygen species. DETAILED DESCRIPTION

[0017] The present invention will be further described below with reference to specific embodiments.

[0018] Example 1

[0019] The preparation of TQZQ-TfO, the reaction formula is as follows:

[0020]

[0021] The specific steps are as follows:

[0022] Preparation of TQZQ-TfO:

[0023] 1 mmol of TQZQ was dissolved in 10-15 mL of anhydrous dichloromethane. Under nitrogen protection, 4 mmol of methyl trifluoromethanesulfonate was dropped into the reaction solution. The reaction was carried out in an ice bath for 10-12 h. The reaction solution was filtered to obtain a crude TQZQ-TfO product. The crude TQZQ-TfO product was washed three times with cold dichloromethane and dried to obtain a yellow powder TQZQ-TfO. 1 H NMR (600MHz, DMSO-d6): δ9.96 (dd, J=7.4, 1.9Hz, 1H), 9.57-9.52 (m, 1H), 8.58-8.49 (m, 2H), 8 .34 (ddt, J=8.6, 7.0, 1.5Hz, 1H), 8.20--8.10 (m, 2H), 7.61 (ddt, J=26.6, 16.4Hz, 1H), 4.70 (s, 3 H), 3.60 (d, J=78.8Hz, 3H), 3.05 (td, J=15.5, 14.8, 3.2Hz, 1H), 3.01-2.89 (m, 2H), 2.84 (dq, J= 11.2, 5.7Hz, 1H), 2.45 (dtd, J=8.9, 5.6, 3.1Hz, 1H), 1.51-1.42 (m, 4H), 0.87 (d, J=2.7Hz, 3H). 13 C NMR (151MHz, DMSO-d6): δ149.82, 149.75, 149.06, 145.23, 138.08, 136.64, 136.39, 131.02, 130.70, 128.91, 128.50, 121.75, 121.44, 119 .61, 119.42, 110.12, 46.65, 45.75, 45.65, 40.06, 38.59, 38.16, 33.28, 28.54, 27.38, 26.66, 25.32, 25.19, 21.31, 21.25.HRMS (m / z): [M] +calculated for C 24 H 26 N3O + :372.2070, found:372.2080.

[0024] Example 2

[0025] TQZQ-TfO was made into 1×10 -5 mol / L PBS buffer solution (pH = 7.4, 10mmol / L) and bisulfite was dissolved in PBS buffer to prepare concentrations of 0, 0.5×10 -5 , 1.0×10 -5 , 1.5×10 -5 , 2.0×10 -5 , 2.5×10 -5 , 3.0×10 -5 , 3.5×10 -5 , 4.0×10 -5 , 4.5×10 -5 , 5.0×10 -5 , 5.5×10 -5 , 6.0×10 -5 , 7.0×10 -5 , 7.5×10 -5 mol / L solution. The fluorescence emission spectra of TQZQ-TfO in the presence of different concentrations of bisulfite were measured on a fluorescence spectrophotometer using fluorescence spectrometry. Figure 1 The results show that as the concentration of bisulfite in the solution gradually increases from 0 mol / L to 7.5×10 -5 mol / L, the fluorescence emission intensity of the compound at 545 nm gradually increased, indicating that the compound can be used as an open-type fluorescent probe for sensitive detection of bisulfite.

[0026] Example 3

[0027] TQZQ-TfO was prepared into 1×10 -5 mol / L PBS buffer solution (pH = 7.4, 10% EtOH, 10 mmol / L), and different analytes such as metal ions, anions, biothiols and reactive oxygen species were dissolved in PBS buffer to a concentration of 7.5×10 -5 mol / L solution. The fluorescence emission spectra of TQZQ-TfO in the presence of different analytes such as metal ions, anions, biothiols and reactive oxygen species were measured on a fluorescence spectrophotometer using fluorescence spectrometry. Figure 2As shown. After the compound reacts with bisulfite, it produces an obvious fluorescence emission peak at 545nm, and the addition of metal ions (Fe 3+ , Fe 2 + , Cu 2+ , Mg 2+ , Ca 2+ , Zn 2+ , Ni 2+ , Cu + ), anion (HPO4 2- , Cl - , SO4 2- , Br - , NO2 - , S x 2- , HS - ), biothiols (Cys, Hcy, GSH) and reactive oxygen species (H2O2, ONOO - ) and other analytes, the fluorescence spectrum of the compound did not change significantly. This indicates that the compound can be used as an open-type fluorescent probe for the selective detection of bisulfite.

Claims

1. A pinanyl-based open-type fluorescent probe, characterized in that: The structural formula of the fluorescent probe is:

2. The method for preparing the pinanyl open-type fluorescent probe according to claim 1, wherein: 7,7-Dimethyl-4-(2-(quinolin-3-yl)vinyl)-5,6,7,8-tetrahydro-6,8-methanoquinazolin-2-ol (TQZQ) was used as the starting material and reacted with methyl trifluoromethanesulfonate to undergo simultaneous etherification and quaternization to obtain 3-(2-(2-methoxy-7,7-dimethyl-5,6,7,8-tetrahydro-6,8-methanoquinazolin-4-yl)vinyl)-1-methylquinolin-1-ium trifluoromethanesulfonate (TQZQ-TfO).

3. The method for preparing the pinanyl open-type fluorescent probe according to claim 2, wherein: The specific preparation method of TQZQ-TfO includes: (1) Dissolve 340-510 g (1-1.5 mol) of TQZQ in anhydrous dichloromethane. Add 3-4 mol of methyl trifluoromethanesulfonate dropwise to the reaction solution under nitrogen protection and react in an ice bath for 10-12 h. (2) The reaction solution is filtered to obtain a crude TQZQ-TfO product; (3) The crude TQZQ-TfO product was washed three times with 1000-1500 mL of cold dichloromethane and dried to obtain yellow powder TQZQ-TfO.

4. Use of the nopinanyl open-type fluorescent probe according to claim 1 for the qualitative and quantitative detection of bisulfite in water, soil, plants, animals, and cells for non-disease treatment and diagnosis purposes.

5. The use according to claim 4, characterized in that: TQZQ-TfO can specifically undergo addition reaction with bisulfite, and the solution exhibits strong yellow fluorescence under 365nm ultraviolet light.

6. The use according to claim 4, characterized in that: The linear detection range of this fluorescent probe for bisulfite is 0-7.5 μM, the response time is within 5 s, the detection limit is 12 nM, and the applicable pH range is 4-12.

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