Ratio type single benzene ring fluorescent probe for detecting biological enzyme and preparation method and application thereof
阅读说明：本技术 一种用于检测生物酶的比率型单苯环荧光探针及其制备方法和应用 (Ratio type single benzene ring fluorescent probe for detecting biological enzyme and preparation method and application thereof ) 是由 袁智勤 张凯 田明策 于 2020-12-01 设计创作，主要内容包括：本发明公开了一种用于检测生物酶的比率型单苯环荧光探针及其制备方法和应用。本发明利用分子内氢键的断裂/生成所引起的荧光发射的变化,通过对单苯环分子上的羟基基团进行化学修饰,得到了具有良好水溶性的单苯环荧光探针。荧光探针与酶反应后,释放出羟基并与相邻基团生成分子内氢键,从而产生荧光发射红移。本发明制备的单苯环荧光探针具有高选择性,高稳定性,高灵敏度,较低的检出限和良好的生物相容性,可用于内源性酶的检测。此外,本发明设计的单苯环荧光探针,制备方法简单,原料廉价易得,成本低,制备的产品产率高,适合大规模推广应用。(The invention discloses a ratio type single benzene ring fluorescent probe for detecting biological enzyme and a preparation method and application thereof. The invention utilizes the change of fluorescence emission caused by the breakage/generation of intramolecular hydrogen bonds, and obtains the single benzene ring fluorescent probe with good water solubility by chemically modifying hydroxyl groups on the single benzene ring molecules. After the fluorescent probe reacts with enzyme, hydroxyl is released and generates intramolecular hydrogen bond with adjacent groups, thereby generating fluorescence emission red shift. The single-benzene-ring fluorescent probe prepared by the invention has high selectivity, high stability, high sensitivity, lower detection limit and good biocompatibility, and can be used for detecting endogenous enzymes. In addition, the single-benzene-ring fluorescent probe designed by the invention is simple in preparation method, cheap and easily available in raw materials, low in cost, high in yield of prepared products, and suitable for large-scale popularization and application.)
1. A ratio type single-benzene-ring fluorescent probe for detecting biological enzymes is characterized in that the structural formula of the single-benzene-ring fluorescent probe is as follows:
2. the method for preparing a ratiometric single-benzene-ring fluorescent probe for detecting biological enzymes according to claim 1, which comprises the following steps:
(1) respectively carrying out carboxyl protection reaction on 4, 6-dihydroxy isophthalic acid or 2, 5-dihydroxy terephthalic acid;
(2) respectively carrying out phosphorylation reaction, amidation reaction and esterification reaction on the carboxyl protection product obtained in the step (1);
(3) and (3) respectively carrying out deprotection reactions on the products obtained in the step (2) to correspondingly obtain the ratio type single benzene ring fluorescent probe for detecting the biological enzyme shown in the formula (I), the formula (II), the formula (III), the formula (IV), the formula (V) and the formula (VI).
3. The production method according to claim 2,the specific operation steps of the carboxyl protection reaction in the step (1) are as follows: to a round bottom flask containing 4, 6-dihydroxyisophthalic acid or 2, 5-dihydroxyterephthalic acid was added anhydrous DMF and NaHCO3Stirring for 10-30 minutes at room temperature; adding benzyl bromide, stirring at 55-60 deg.C for 2-8 hr, quenching with water, extracting organic compound with DCM, mixing organic layers, washing with saturated saline, and adding anhydrous Na2SO4Drying, filtering, and finally performing rotary evaporation to remove the solvent to obtain a carboxyl protection product; wherein 4, 6-dihydroxy isophthalic acid or 2, 5-dihydroxy terephthalic acid, NaHCO3And benzyl bromide in a molar ratio of 1:2-4: 3-5.
4. The method according to claim 2, wherein the phosphorylation reaction in step (2) is carried out by the following steps: adding CCl to the THF solution of the carboxyl protected product obtained in step (1)4Cooled to 0 ℃ and then in N2Dropwise adding N, N-diisopropylethylamine, mixing and stirring for 10-30 minutes, dropwise adding a THF solution of 4-dimethylaminopyridine and dibenzyl phosphonate, heating to room temperature after dropwise adding, and stirring for reacting for 2-8 hours; quenching the reaction with sodium dihydrogen phosphate buffer solution, stirring for 10-50 min, extracting with DCM, washing the organic layer with brine, anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the carboxyl protection product obtained in the step (1), CCl4The molar ratio of N, N-diisopropylethylamine, 4-dimethylaminopyridine and dibenzyl phosphonate is 1:8-12:0.5-1.5:0.08-0.2: 1-3.
5. The process according to claim 2, wherein the amidation reaction in step (2) is carried out by the following steps: adding 4-dimethylaminopyridine and diethyl-carbamoyl chloride into THF solution of the carboxyl protection product obtained in the step (1) at 0- (-20) DEG C, heating to room temperature and stirring for reaction for 2-8 hours, quenching the reaction by phosphate buffer solution of sodium dihydrogen phosphate, continuing stirring for 10-50 minutes, finally extracting by DCM, washing the organic layer by brine, and anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the molar ratio of the carboxyl protection product obtained in the step (1), 4-dimethylaminopyridine and diethyl-carbamoyl chloride is 1:1-3: 1-2.
6. The preparation method according to claim 2, wherein the esterification reaction in step (2) comprises the following specific steps: dropwise adding N, N-diisopropylethylamine into the THF solution of the carboxyl protection product obtained in the step (1), stirring for 10-50 minutes, then continuously dropwise adding the THF solution containing 4-dimethylaminopyridine and acetic anhydride, stirring for reacting for 2-8 hours, quenching the reaction by using phosphate buffer solution of sodium dihydrogen phosphate, continuously stirring for 10-50 minutes, finally extracting by using DCM, washing an organic layer by using brine, and obtaining anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the molar ratio of the carboxyl protection product obtained in the step (1), N-diisopropylethylamine, 4-dimethylaminopyridine and acetic anhydride is 1:0.5-2:1-3: 1-3.
7. The preparation method according to claim 2, wherein the operation steps of the deprotection reaction in step (3) are as follows: adding catalyst into methanol solution of phosphorylation reaction product, stirring at room temperature for 1-5 days, filtering to remove catalyst, washing with methanol, evaporating to remove solvent, and washing with diethyl ether.
8. The preparation method according to claim 2, wherein the operation steps of the deprotection reaction in step (3) are as follows: adding a catalyst into a methanol solution of the amidation reaction product, stirring the mixture at room temperature for reaction for 1 to 5 days, filtering the mixture to remove the catalyst, washing the mixture with methanol, evaporating the solvent, and finally washing the mixture with dichloromethane.
9. The preparation method according to claim 2, wherein the operation steps of the deprotection reaction in step (3) are as follows: adding a catalyst into an isopropanol solution of an esterification reaction product, stirring and reacting for 1-5 days at room temperature in a hydrogen atmosphere, filtering to remove the catalyst, washing with methanol, evaporating to remove the solvent, and finally washing with dichloromethane.
10. The use of the ratiometric single-benzene-ring fluorescent probe for detecting a biological enzyme according to claim 1 for detecting a biological enzyme or screening for an inhibitor of enzyme activity.
Technical Field
The invention belongs to the technical field of fluorescent probes, and particularly relates to a ratio type single benzene ring fluorescent probe for detecting biological enzyme, and a preparation method and application thereof.
Background
The regulation of cellular metabolism is the basis of vital activities, most of which are controlled catalytically by enzymes. Biological enzymes play a key role in maintaining normal cell physiological activities by regulating the rate of biochemical reactions in cells and controlling the progress of various physiological processes. Without the presence of enzymes, many important biochemical reactions will proceed at a rate that is not life sustaining. Studies show that the abnormal activity of certain enzymes is closely related to the occurrence of some serious diseases such as cancer and the like, and is often used as a biomarker for related disease diagnosis and drug discovery. Therefore, the development of a rapid, sensitive and accurate analysis method for detecting the activity of the biological enzyme is of great significance for early diagnosis and accurate treatment of diseases. The fluorescent probe based on the organic micromolecules has the advantages of high sensitivity, high selectivity, quick response time, no damage to organisms and the like, and is widely concerned in the detection of biological enzymes.
Most of the organic small-molecule fluorescent probes reported at present are organic small-molecule fluorescent probes with multiple benzene rings, and compared with multiple benzene rings, the single-benzene-ring organic small-molecule fluorescent probes with the advantages of easiness in preparation, high stability, low cost and the like are not suitable for fluorescent sensing because the fluorescent emission of the single-benzene-ring organic small-molecule fluorescent probes is mostly in an ultraviolet region. But the smaller size of the single benzene ring molecule may allow more sensitive binding to targets (e.g., proteins and DNA). In other words, a single benzene ring molecule may be used as a novel organic probe, providing a new approach for the detection of analytes. Therefore, it is crucial to design and synthesize a single benzene ring molecule with visible or near infrared fluorescence emission.
Disclosure of Invention
The invention utilizes intramolecular hydrogen bonds to regulate and control the fluorescence property of single benzene ring molecules, thereby providing a ratio type single benzene ring fluorescent probe for detecting biological enzyme and a preparation method thereof, and the single benzene ring fluorescent probe is successfully applied to biological imaging of alkaline phosphatase in HeLa cells, the optical stability of the probe is good, and the optical signal is stable in living cell imaging.
The structural formula of the ratio type single benzene ring fluorescent probe for detecting the biological enzyme is as follows:
the preparation method of the ratio type single benzene ring fluorescent probe for detecting the biological enzyme comprises the following steps:
(1) respectively carrying out carboxyl protection reaction on 4, 6-dihydroxy isophthalic acid or 2, 5-dihydroxy terephthalic acid;
(2) respectively carrying out phosphorylation reaction, amidation reaction and esterification reaction on the carboxyl protection product obtained in the step (1);
(3) and (3) respectively carrying out deprotection reactions on the products obtained in the step (2) to correspondingly obtain the ratio type single benzene ring fluorescent probe for detecting the biological enzyme shown in the formula (I), the formula (II), the formula (III), the formula (IV), the formula (V) and the formula (VI).
The reaction of the steps is shown as the following reaction formula:
the specific operation steps of the carboxyl protection reaction in the step (1) are as follows: to a round bottom flask containing 4, 6-dihydroxyisophthalic acid or 2, 5-dihydroxyterephthalic acid was added anhydrous DMF and NaHCO3Stirring for 10-30 minutes at room temperature; then adding benzyl bromideStirring at 55-60 deg.C for 2-8 hr, quenching with water, extracting organic compound with DCM, mixing organic layers, washing with saturated saline, and adding anhydrous Na2SO4Drying, filtering, and finally performing rotary evaporation to remove the solvent to obtain a carboxyl protection product; wherein 4, 6-dihydroxy isophthalic acid or 2, 5-dihydroxy terephthalic acid, NaHCO3And benzyl bromide in a molar ratio of 1:2-4: 3-5.
The specific operation steps of the phosphorylation reaction in the step (2) are as follows: adding CCl to the THF solution of the carboxyl protected product obtained in step (1)4Cooled to 0 ℃ and then in N2Dropwise adding N, N-diisopropylethylamine, mixing and stirring for 10-30 minutes, dropwise adding a THF solution of 4-dimethylaminopyridine and dibenzyl phosphonate, heating to room temperature after dropwise adding, and stirring for reacting for 2-8 hours; quenching the reaction with sodium dihydrogen phosphate buffer solution, stirring for 10-50 min, extracting with DCM, washing the organic layer with brine, anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the carboxyl protection product obtained in the step (1), CCl4The molar ratio of N, N-diisopropylethylamine, 4-dimethylaminopyridine and dibenzyl phosphonate is 1:8-12:0.5-1.5:0.08-0.2: 1-3.
The amidation reaction of the step (2) comprises the following specific operation steps: adding 4-dimethylaminopyridine and diethyl-carbamoyl chloride into THF solution of the carboxyl protection product obtained in the step (1) at 0- (-20) DEG C, heating to room temperature and stirring for reaction for 2-8 hours, quenching the reaction by phosphate buffer solution of sodium dihydrogen phosphate, continuing stirring for 10-50 minutes, finally extracting by DCM, washing the organic layer by brine, and anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the molar ratio of the carboxyl protection product obtained in the step (1), 4-dimethylaminopyridine and diethyl-carbamoyl chloride is 1:1-3: 1-2.
The esterification reaction of the step (2) comprises the following specific operation steps: adding N, N-diisopropylethylamine dropwise into the THF solution of the carboxyl protection product obtained in the step (1), stirring for 10-50 minutes, and then continuously adding dropwise a mixture containing 4-dimethylaminopyridine and acetic acidStirring anhydride in THF solution for 2-8 hr, quenching with sodium dihydrogen phosphate buffer solution, stirring for 10-50 min, extracting with DCM, washing the organic layer with brine, and removing anhydrous Na2SO4Drying, filtering, evaporating off the solvent and purifying the residue with an eluent; wherein the molar ratio of the carboxyl protection product obtained in the step (1), N-diisopropylethylamine, 4-dimethylaminopyridine and acetic anhydride is 1:0.5-2:1-3: 1-3.
The specific operation steps of the deprotection reaction in the step (3) are as follows: adding catalyst into methanol solution of phosphorylation reaction product, stirring at room temperature for 1-5 days, filtering to remove catalyst, washing with methanol, evaporating to remove solvent, and washing with diethyl ether.
The specific operation steps of the deprotection reaction in the step (3) are as follows: adding a catalyst into a methanol solution of the amidation reaction product, stirring the mixture at room temperature for reaction for 1 to 5 days, filtering the mixture to remove the catalyst, washing the mixture with methanol, evaporating the solvent, and finally washing the mixture with dichloromethane.
The specific operation steps of the deprotection reaction in the step (3) are as follows: adding a catalyst into an isopropanol solution of an esterification reaction product, stirring and reacting for 1-5 days at room temperature in a hydrogen atmosphere, filtering to remove the catalyst, washing with methanol, evaporating to remove the solvent, and finally washing with dichloromethane.
The eluent is a mixed solvent of EA and hexane with the volume ratio of 1 (1.5-2.0).
The catalyst is Pd/C.
The application of the ratiometric single-benzene-ring fluorescent probe for detecting the biological enzyme in the detection of the biological enzyme.
The ratiometric single-benzene-ring fluorescent probe for detecting the biological enzyme is used for screening enzyme activity inhibitors.
The invention utilizes the change of fluorescence emission caused by the breakage/generation of intramolecular hydrogen bonds, obtains the single benzene ring fluorescent probe with good water solubility by chemically modifying hydroxyl groups on the single benzene ring molecule, and releases hydroxyl groups after the fluorescent probe reacts with enzyme to generate intramolecular hydrogen bonds with adjacent groups, thereby generating fluorescence emission red shift. The single-benzene-ring fluorescent probe prepared by the invention has high selectivity, high stability, high sensitivity, lower detection limit and good biocompatibility, and can be used for detecting endogenous enzymes. In addition, the single-benzene-ring fluorescent probe designed by the invention is simple in preparation method, cheap and easily available in raw materials, low in cost, high in yield of prepared products, and suitable for large-scale popularization and application.
Drawings
FIG. 1 shows fluorescence excitation spectrum and fluorescence emission spectrum of single-benzene-ring fluorescence probe PDHTA prepared in example 1.
FIG. 2 shows fluorescence excitation spectrum and fluorescence emission spectrum of single-benzene-ring fluorescent probe2 prepared in example 2.
FIG. 3 shows fluorescence excitation spectrum and fluorescence emission spectrum of the single-benzene-ring fluorescent probe Esterase-probe prepared in example 3.
FIG. 4 shows fluorescence emission spectra before and after adding alkaline phosphatase to a single-benzene-ring fluorescent probe PDHTA solution in application example 4.
FIG. 5 is a graph showing the change of emission spectrum of single-benzene-ring fluorescent probe PDHTA with the increase of alkaline phosphatase activity in application example 7 and the fluorescence ratio.
FIG. 6 is a graph showing the fluorescence ratio of a single-benzene-ring fluorescent probe PDHTA for detecting alkaline phosphatase and an interfering substance in application example 10.
FIG. 7 is a graph showing the change of the emission spectrum of a single-benzene-ring fluorescent probe PDHTA with the increase of the concentration of an enzyme activity inhibitor in application example 13 and a fluorescence ratio.
FIG. 8 shows the cytotoxicity of single-benzene-ring fluorescent probe PDHTA at various concentrations.
FIG. 9 is a confocal imaging detection diagram of alkaline phosphatase in living cells by using a single-benzene-ring fluorescent probe PDHTA.
Detailed Description
In order to more clearly illustrate the present invention, the following examples are given, but the scope of the present invention is not limited to the following examples.
Example 1
The structure of the single-benzene-ring fluorescent probe PDHTA is as follows:
the synthesis of the single-benzene-ring fluorescent probe PDHTA comprises the following steps:
(1) to a round bottom flask containing 2, 5-dihydroxyterephthalic acid (500mg,2.52mmol) was added anhydrous DMF (5.0mL) and NaHCO3(530mg,6.31mmol), and the mixture was stirred at room temperature for 10 minutes. Benzyl bromide (1.29g,7.57mmol) was then added and the reaction mixture was heated to 60 ℃ and stirred for 5 h. The reaction was quenched with water (10mL) and the organic compound was extracted with DCM (50 mL. times.3). The combined organic layers were then washed with saturated brine and anhydrous Na2SO4Drying, filtration and removal of the solvent by rotary evaporation gave the carboxy-protected product (800mg, 84%).
Mass spectrum and nuclear magnetic characterization of the carboxyl protection product:
1H NMR(600MHz,CDCl3)δ(ppm):10.07(s,2H),7.52(s,2H),7.46-7.38(m,10H),5.39(s,4H).13C NMR(100MHz,CDCl3)δ:168.93,153.12,134.84,128.89,128.53,118.56,117.97,67.76.
MS(ESI-):m/z＝377.1,calcd 377.1.
(2) to a solution of the carboxy-protected product (500mg,1.32mmol) in THF (10mL) was added CCl4(1.27mL,13.21mmol) and the reaction cooled to 0 ℃. Then, in N2Next, N-diisopropylethylamine (0.75mL,0.92mmol) was added dropwise to the solution and the reaction mixture was stirred for 10 minutes. A solution of 4-dimethylaminopyridine (16mg,0.132mmol) and dibenzyl phosphonate (0.43mL,1.92mmol) in THF (3mL) was added dropwise to the reaction mixture, after which the solution was warmed to room temperature and stirred for 3 hours. The reaction was quenched with sodium dihydrogen phosphate (30mL,1M) in phosphate buffer. After stirring for another 30min, the mixture was extracted with DCM (30 mL. times.3), and the organic layer was washed with brine, anhydrous Na2SO4And (5) drying. After filtration, the solvent was removed by evaporation and the residue was purified using EA and hexane (1/2) as eluents to give the phosphorylation reaction product (700mg, 83%).
1H NMR(400MHz,CDCl3)δ:10.46(s,2H),7.69(d,J＝1.52,2H),7.33(s,1H)7.29-7.11(m,20H),5.23(s,2H),5.16(s,2H),4.97(s,2H),4.95(s,2H).13C NMR(100MHz,CDCl3)δ:168.68,163.71,158.26,140.85,140.78,135.62,135.56,135.44,134.86,130.31,130.26,129.18,128.91,128.74,128.71,128.67,128.64,128.58,128.56,128.54,128.37,128.20,127.81,127.13,125.44,122.85,122.82,120.68,115.45,115.44,70.32,70.26,67.77,67.53.31P NMR(162MHz,CDCl3)δ:6.12.
MS(ESI-):m/z＝637.2,calcd 637.2.
(3) To a methanol solution (50mL) containing the phosphorylated reaction product (400mg,0.626mmol) was added Pd/C catalyst (15mg, 5% by mass of Pd), and after the reaction mixture was stirred at room temperature for 2 days, the catalyst was removed by filtration and washed with methanol. The solvent was removed by evaporation and washed with ether (20mL) to give the fluorescent probe PDHTA (150mg, 90%).
1H NMR(400MHz,d6-DMSO)δ:7.73(s,1H),7.13(s,1H).13C NMR(100MHz,d6-DMSO)δ:170.45,166.01,156.28,141.03(d),132.43(d),122.67,118.11,115.60.31P NMR(162MHz,CDCl3)δ:5.40.
MS(ESI-):m/z＝277.0,calcd 277.0.
Example 2
The structure of the single-benzene-ring fluorescent probe2 is as follows:
the synthesis of the single-benzene-ring fluorescent probe2 comprises the following steps:
(1) to a THF solution (10mL) of the carboxy-protected product (500mg,1.32mmol) obtained in step (1) of example 1 was added 4-dimethylaminopyridine (156mg,1.98mmol) and diethylcarbamoyl chloride (0.2mL,1.59mmol) at 0 ℃. Then, after the resulting solution was warmed to room temperature and stirred for 3 hours, the reaction was quenched with sodium dihydrogen phosphate (30mL,1M) in phosphate buffer. After stirring for a further 30min, the mixture was extracted with DCM (30 mL. times.3)And the organic layer was washed with brine, then anhydrous Na2SO4And (5) drying. After filtration, the solvent was removed by evaporation and the residue was purified using EA and hexane (1/2) as eluent to give the amidation reaction product (250mg, 40%).
1H NMR(400MHz,d6-DMSO)δ:13.26(bs,1H),7.46(s,1H),7.30(s,1H),3.39(bs,2H),3.25(bs,2H),1.19(bs,3H),1.08(bs,3H).13C NMR(100MHz,d6-DMSO)δ:170.17,165.30,157.35,153.40,141.58,131.09,124.85,118.73,117.15,41.65,41.33,13.91,13.27.
MS(ESI-):m/z＝476.2,calcd 477.2.
(2) To a methanol solution (50mL) containing the amidation reaction product (100mg,0.21mmol) was added the catalyst Pd/C (15mg, 5%), and after the reaction mixture was stirred at room temperature for 2 days, the catalyst was removed by filtration and washed with methanol. The solvent was removed by evaporation and washed with dichloromethane to give probe 2(55mg, 88%).
1H NMR(400MHz,d6-DMSO)δ:13.26(bs,1H),7.46(s,1H),7.30(s,1H),3.39(bs,2H),3.25(bs,2H),1.19(bs,3H),1.08(bs,3H).13C NMR(100MHz,d6-DMSO)δ:170.17,165.30,157.35,153.40,141.58,131.09,124.85,118.73,117.15,41.65,41.33,13.91,13.27.
MS(ESI-):m/z＝296.1,calcd 297.1.
Example 3
The structure of the single-benzene-ring fluorescent probe Esterase-probe is as follows:
the synthesis of the single-benzene-ring fluorescent probe Esterase-probe comprises the following steps:
(1) to a THF solution (10mL) of the carboxy-protected product (500mg,1.32mmol) obtained in step (1) of example 1 was added dropwise N, N-diisopropylethylamine (0.75mL,0.92mmol), and the reaction mixture was stirred for 10 minutes. A THF solution (10mL) containing 4-dimethylaminopyridine (156mg,1.98mmol) and acetic anhydride (196mg,1.92mmol) was added dropwise to the reaction mixture, followed by stirring for 3 hours. With sodium dihydrogen phosphateThe reaction was quenched (30mL,1M) in phosphate buffer. After stirring for another 30min, the mixture was extracted with DCM (30 mL. times.3) and the organic layer was washed with brine, then anhydrous Na2SO4And (5) drying. After filtration, the solvent was removed by evaporation and the residue was purified using EA and hexane (1/2) as eluent to give the esterification product (92%).
(2) To an isopropanol solution (50mL) of the esterification reaction product (500mg,0.98mmol) was added catalyst Pd/C (15mg, 5%), and after stirring the reaction mixture under a hydrogen atmosphere for 2 days, the catalyst was removed by filtration and washed with methanol. The solvent was removed by evaporation and washed with dichloromethane to give Esterase-probe (70%).
Application example 1
Study of the fluorescence properties of the molecular PDHTA prepared in example 1:
to 4-hydroxyethylpiperazine ethanesulfonic acid (HEPES) buffer solution (pH 7.4), PDHTA was added at an initial concentration of 1mM such that the final concentration of PDHTA in the solution was 10 μ M. Then, the fluorescence excitation spectrum and the emission spectrum were measured by a fluorescence spectrophotometer, and the results are shown in FIG. 1. From the results, it can be seen that there is a clear optical difference between the molecule PDHTA and the molecule 2, 5-dihydroxyterephthalic acid (DHTA), indicating the feasibility of the prepared molecule PDHTA to be used as a fluorescent probe.
Application example 2
Investigation of fluorescence properties of molecular probe2 prepared in example 2:
to a PBS buffer solution (pH 7.4), probe2 was added at an initial concentration of 1mM so that the final concentration of probe2 in the solution was 10 μ M. The fluorescence excitation spectrum and the emission spectrum were then measured by a fluorescence spectrophotometer, and the results are shown in FIG. 2. As can be seen from the results, the molecular probe2 has a significant optical difference from the molecular DHTA, which indicates the feasibility of the prepared molecular probe2 as a fluorescent probe.
Application example 3
Study of the fluorescence properties of the molecule Esterase-probe prepared in example 3:
in a PBS buffer solution (pH 7.4), an initial concentration of 1mM of Esterase-probe was added so that the final concentration of Esterase-probe in the solution was 10. mu.M. The fluorescence excitation spectrum and the emission spectrum were then measured by a fluorescence spectrophotometer, and the results are shown in FIG. 3. As can be seen from the results, the molecular Esterase-probe has obvious optical difference with the molecular DHTA, which indicates the feasibility of the prepared molecular Esterase-probe as a fluorescent probe.
Application example 4
Feasibility study of the fluorescent probe PDHTA for the detection of alkaline phosphatase in example 1:
to HEPES buffer solution (pH 7.4), PDHTA was added at an initial concentration of 1mM such that the final concentration of PDHTA in the solution was 5 μ M. Then, alkaline phosphatase was added so that the concentration of alkaline phosphatase in the solution was 3U/L. After incubation at 37 ℃ for 50min, fluorescence emission spectra were measured with a spectrofluorometer at an excitation wavelength of 353nm, as shown in FIG. 4, from which it can be seen that the PDHTA probe can be used for the detection of alkaline phosphatase.
Application example 5
Feasibility study of the fluorescent probe2 of example 2 for the detection of acetylcholinesterase:
to a HEPES buffer solution (pH 7.4), probe2 was added at an initial concentration of 1mM so that the final concentration of probe2 in the solution was 5 μ M. Then, acetylcholinesterase was added so that the concentration of acetylcholinesterase in the solution was 5U/L. After incubation at 37 ℃ for 40min, fluorescence emission spectra were measured with a spectrofluorometer at an excitation wavelength of 353nm, from which it was shown that the probe2 was used for the detection of acetylcholinesterase.
Application example 6
Feasibility study of the fluorescent probe Esterase-probe for Esterase detection of example 3:
in HEPES buffer solution (pH 7.4), an initial concentration of 1mM of Esterase-probe was added so that the final concentration of Esterase-probe in the solution was 5. mu.M. Then, esterase was added so that the concentration of esterase in the solution was 4U/L. After incubation at 37 ℃ for 40min, the fluorescence emission spectrum was measured with a spectrofluorometer at an excitation wavelength of 353nm, from which it was shown that the Esterase-probe can be used for the detection of esterases.
Application example 7
Detection of the fluorescent probe PDHTA of example 1 for different concentrations of alkaline phosphatase:
to HEPES buffer solution (pH 7.4), PDHTA was added at an initial concentration of 1mM such that the final concentration of PDHTA in the solution was 5 μ M. Then, alkaline phosphatase was added in this order so that the concentrations of alkaline phosphatase in the solution were 0U/L,0.005U/L,0.01U/L,0.04U/L,0.08U/L,0.1U/L,0.2U/L,0.4U/L,0.6U/L,0.8U/L,1U/L,2U/L,3U/L, and 4U/L, respectively. The ratio detection of alkaline phosphatase was achieved by incubating at 37 ℃ for 50min and then measuring the change in fluorescence emission intensity at 463nm and 533nm with a spectrofluorometer at an excitation wavelength of 353nm, the results of which are shown in FIGS. 5A and 5B, from which it can be seen that the PDHTA probe responded well to alkaline phosphatase.
Application example 8
Detection of different concentrations of acetylcholinesterase with the fluorescent probe2 of example 2:
in a PBS buffer solution (pH 7.4), probe2 was added at an initial concentration of 1mM so that the final concentration of probe2 in the solution was 5 μ M. Then, acetylcholinesterase was added in sequence to make the concentration of acetylcholinesterase in the solution 0U/L,0.01U/L,0.04U/L,0.06U/L,0.1U/L,0.2U/L,0.4U/L,0.6U/L,0.8U/L,1U/L,2U/L,3U/L,4U/L,5U/L,6U/L, respectively. The probe2 is incubated at 37 ℃ for 40min, and then the change of fluorescence emission intensity at 441nm and 533nm is measured by a fluorescence spectrophotometer under the excitation wavelength of 353nm, so that the ratio detection of acetylcholinesterase is realized.
Application example 9
Detection of Esterase at different concentrations with the fluorescent probe Esterase-probe of example 3:
in a PBS buffer solution (pH 7.4), an initial concentration of 1mM of Esterase-probe was added so that the final concentration of Esterase-probe in the solution was 5. mu.M. Then, the esterase was added in order to give a solution containing the esterase at concentrations of 0U/L,0.005U/L,0.01U/L,0.02U/L,0.04U/L,0.08U/L,0.1U/L,0.2U/L,0.4U/L,0.6U/L,0.8U/L,1U/L,2U/L,4U/L, and 6U/L, respectively. The Esterase-probe is incubated for 40min at 37 ℃, and then the change of fluorescence emission intensity at 435nm and 533nm is measured by a fluorescence spectrophotometer under the excitation wavelength of 353nm, so that the ratio detection of Esterase is realized.
Application example 10
Selectivity test of the fluorescent probe PDHTA of example 1:
PDHTA was added to HEPES buffer (pH 7.4) at an initial concentration of 1mM under the same test conditions, such that the concentration of PDHTA in the solution was 5 μ M, as described in application example 7. Then, K was added to the solution in order to give a final concentration of 1mM+,Ca2+,Mg2+,Zn2+L-alanine (Ala), L-aspartic acid (Asp), arginine (Arg), serine (Ser), glycine (Gly), Glutathione (GSH) and glucose (glucose) and Bovine Serum Albumin (BSA) and Lysozyme (LZM) at a final concentration of 100 mg/L. Changes in fluorescence emission intensity at 463nm and 533nm in the presence/absence of alkaline phosphatase (5U/L) were measured with a fluorescence spectrophotometer at an excitation wavelength of 353 nm. The results are shown in fig. 6, and it can be seen from the results that other metal ions and organic biological small molecules do not interfere with the detection results, which indicates that the single-benzene-ring fluorescent probe PDHTA prepared by the invention has higher selectivity for alkaline phosphatase.
Application example 11
Selectivity test of fluorescent probe2 of example 2:
probe2 was added to a PBS buffer solution (pH 7.4) at an initial concentration of 1mM under the same test conditions so that the concentration of probe2 in the solution was 5 μ M, as described in application example 8. Then, K was added to the solution in order to give a final concentration of 1mM+,Ca2+,Mg2+,Zn2+Ala, Asp, Arg, Ser, Gly, GSH and glucose and BSA and LZM at a final concentration of 100 mg/L. Changes in fluorescence emission intensity at 441nm and 533nm were measured with/without acetylcholinesterase (5U/L) by a fluorescence spectrophotometer at an excitation wavelength of 353 nm. According to the results, other metal ions and organic biological small molecules do not interfere the detection results, and the probe2 has high selectivity on acetylcholinesterase.
Application example 12
Selective assay of the fluorescent Probe Esterase-Probe of example 3:
as described in application example 9, under the same test conditions, an initial concentration of 1mM of Esterase-probe was added to PBS buffer (pH 7.4) so that the concentration of Esterase-probe in the solution was 5. mu.M. Then, K was added to the solution in order to give a final concentration of 1mM+,Ca2+,Mg2+,Zn2+Ala, Asp, Arg, Ser, Gly, GSH and glucose and BSA and LZM at a final concentration of 100 mg/L. Changes in fluorescence emission intensity at 435nm and 533nm were measured with a fluorescence spectrophotometer at an excitation wavelength of 353nm in the presence/absence of esterase (5U/L). According to the results, other metal ions and organic biological small molecules do not interfere the detection result, and the Esterase-probe has higher selectivity on Esterase.
Application example 13
Study of inhibition efficiency of enzyme activity inhibitor by fluorescent probe PDHTA of example 1:
mixing ALP (3U/L) with sodium orthovanadate (Na) of different concentrations3VO4) (0, 2, 4,6, 8, 10, 25, 50, 75, 100, 250, 500 and 1000. mu.M) at 37 ℃ for 30 min. Then, the solution is passed through Na3VO4Treated ALP was added to HEPES buffer (10mM, pH 7.4) containing PDHTA (5. mu.M). After incubation at 37 ℃ for 50min, the change in fluorescence emission intensity at 463nm and 533nm was measured with a fluorescence spectrophotometer at an excitation wavelength of 353 nm. The results are shown in FIG. 7, from which it can be seen that they have a lower IC50The PDHTA probe was demonstrated to have higher sensitivity.
Application example 14
Study of the cytotoxicity of the fluorescent probe PDHTA of example 1:
at 37 ℃ and containing CO2(5%) HeLa cells were cultured in a medium containing 10% Fetal Bovine Serum (FBS), streptomycin (100. mu.g/mL) and penicillin (100. mu.g/mL) in air. HeLa cells were then seeded in 96-well plates overnight, and 10. mu.L of thiazolium blue (MTT) solution (5mg/mL) was added to each well after PDHTA was added at a concentration of 5 to 20. mu.M). After 4 hours of incubation, 100 μ L of dimethyl sulfoxide (DMSO) was added, after which the absorbance was measured at 570nm using a multimode plate reader and the cell activity was calculated. The results are shown in FIG. 8: as can be seen from the results, the PDHTA probe had lower cytotoxicity.
Application example 15
Examination of cytotoxicity of Probe2, a fluorescent probe of example 2:
at 37 ℃ and containing CO2(5%) HeLa cells were cultured in a medium containing 10% Fetal Bovine Serum (FBS), streptomycin (100. mu.g/mL) and penicillin (100. mu.g/mL) in air. HeLa cells were further seeded in a 96-well plate overnight, and after adding probe2 at a concentration of 5 to 20. mu.M, 10. mu.L of MTT solution (5mg/mL) was added to each well. After 4 hours of incubation, 100 μ L DMSO was added, after which the absorbance was measured at 570nm using a multimode plate reader and cell activity was calculated. As can be seen from the results, the probe2 had low cytotoxicity.
Application example 16
Examination of the cytotoxicity of the fluorescent probe Esterase-probe of example 3:
at 37 ℃ and containing CO2(5%) HeLa cells were cultured in a medium containing 10% Fetal Bovine Serum (FBS), streptomycin (100. mu.g/mL) and penicillin (100. mu.g/mL) in air. HeLa cells were then seeded in 96-well plates overnight, and after addition of 5 to 20. mu.M Esterase-probe, 10. mu.L of MTT solution (5mg/mL) was added to each well. After 4 hours of incubation, 100 μ L DMSO was added, after which the absorbance was measured at 570nm using a multimode plate reader and cell activity was calculated. As can be seen from the results, the Esterase-probe had low cytotoxicity.
Application example 17
Detection of alkaline phosphatase in HeLa cells by the fluorescent probe PDHTA of example 1:
firstly, dividing HeLa cells into three groups for culture, taking the first group of HeLa cells as a blank group, and only adding a culture medium; in the second group, a medium containing a fluorescent probe PDHTA (5 μ M) dissolved therein was added to HeLa cells; then in the third group, HeLa cells were first treated with the enzyme inhibitor Na3VO4Incubation for 30 minutes and then addition of the fluorescent probe PDHTA (5 μ M) to HeLa cells; after that, the cells were incubated at 37 ℃ for 30 minutes and washed three times with PBS buffer solution, and finally imaged under a confocal laser microscope. Fluorescence imaging was observed simultaneously in the blue channel (425-475nm) and the green channel (520-625nm) under excitation of a 405nm laser source, and the results are shown in FIG. 9: no fluorescence was observed for both the green and blue channels for the first set, significant fluorescence was observed for the green channel for the second set, and almost no fluorescence was observed for the blue channel; for the third group, almost no fluorescence was observed for the green channel, while there was significant fluorescence in the blue channel. The single benzene ring fluorescent probe PDHTA prepared by the invention has good potential for imaging the intracellular alkaline phosphatase.