Design Synthesis And Bioimaging Of Fluorescent Probes For ONOO~-,HOCL And Lipid Droplets

Peroxynitrite(ONOO~-)and hypochlorous acid(HOCl)are important active oxide of organisms and play an important role in maintaining the intracellular redox balance,Lipid Droplets(LDs)is an important biological organelle,which plays an important role in regulating the energy homeostasis of cells and protecting cells from of lipid apoptosis.The production,distribution and concentration or quantity change of above bioactive substances and organelles are the key to maintain metabolism stability and cause disease.Organic small molecule fluorescent probes have the advantages of high sensitivity,good specificity and low biological toxicity,and are widely used in various research fields such as biomarker detection and biological imaging.This paper focuses on the visual detection of ONOO~-,HOCl and LDs in cells,and designs and synthesizes four kinds of organic small molecule fluorescent probes.The optical properties and biological imaging properties of them are studied in detail.The specific contents and results are as follows:1.Based on TICT mechanism,the ONOO~-fluorescent probe ZL-1 with coumarin as fluorophore and diketone as recognition group was design and constructed.The recognition mechanism of ZL-1 was investigated by high resolution mass spectrometry.Under the simulated physiological environment,ZL-1 can identify ONOO~-within 1min,without interference from biological matrix and other active substances,and the detection limit is 19.3 n M.ZL-1 has low cytotoxicity and has been successfully applied to the real-time fluorescence imaging monitoring of exogenous and endogenous ONOO~-in cells and ONOO~-in the process of cell damage and heat shock,providing a quick and simple method for clinical monitoring of ONOO~-.2.Based on the fluorescence performance and mitochondrial targeting of 4-(2-(6-hydroxynaphthalene)vinyl)-1-methyl-pyridine iodized salt and the specific recognition performance of dimethyl thiocarbamate(DMTC)for HOCl,the fluorescence probe ZL-2 targeting HOCl in mitochondria was constructed.The probe ZL-2 is not interfered by other active oxides and biological matrix,and can have specific reaction with HOCl within 1 min.Moreover,it has low cytotoxicity and mitochondrial targeting,and has successfully achieved fluorescence imaging of HOCl in mitochondria.The probe ZL-2 provides a reference for the real-time monitoring of mitochondrial HOCl.3.Based on the AIE properties of triphenylamine compound and the near-infrared luminescence properties of malononitrile derivatives,the near-infrared fluorescent probe ZL-3 for targeting lipid droplets(LDs)was designed and synthesized.The probe has a simple synthesis step,and the pure product can be obtained by one-step reaction without column chromatography separation.Compared with commercial LDs dyes,it not only has near-infrared emission,ultra-wide stoker displacement(180 nm),excellent anti-photobleaching performance,but also has photodynamic therapeutic effect.Under white light irradiation,it can generate reactive oxygen and kill cancer cells,which provides an important reference for the design and clinical diagnosis and treatment of near-infrared LDs fluorescent probe.4.A novel aggregation-induced(AIE)fluorescent probe ZL-4 targeting LDs was designed with indoles[1,2-a]quinoline as the core.The luminescence and imaging properties of the probe were studied by fluorescence spectroscopy,dynamic light scattering and confocal fluorescence imaging.Zl-4 has a good AIE two-photon performance,a stokes displacement of 155 nm,low cytotoxicity and good cell permeability,and has been successfully applied to real-time imaging monitoring of intracellular LDs.This study is the first to create indoles[1,2-a]quinolines as the core structure of AIE,which provides a new idea for the construction of high-performance targeted LDs fluorescent probes.