Design,Synthesis And Characterization Of Coumarin,Juronidine,Dihydronaphthothiophene Directed Fluorescent Probes For The Detection Of Mitochondrial Hypochlorite

As an important reactive oxygen species(ROS),hypochlorous acid(HCl O)plays pivotal role in the human immune system and ensures the normal function of the organisms.HCl O is derived from mitochondria and can regulate intracellular redox balance.Nevertheless,abnormal HCl O levels is related to immune system,disorders,neurodegenerative injury and cancer.Therefore,fast and sensitive monitoring HCl O in mitochondria is extremely significant for some diseases indication.In this paper,three small molecular fluorescent probes with targeted mitochondria for the detection of HClO were designed and synthesized based on coumarin,juronidine and dihydrobenzothiophene as the framework,and their optical properties and biological applications were studied.The specific research contents are as follows:1.Coumarin dyes are applied in the design of fluorescent probes because of their good photostability,good biocompatibility,high molar absorption coefficient and large Stokes shift.The probe HDCl was designed and synthesized using coumarin as fluorophore,quaternary ammonium pyridinate as mitochondrial targeting site and dimethyl thiocarbamate as HCl O recognition site.The probe HDCl had almost no fluorescence,and after recognition of HCl O,dimethyl thiocarbamate leaves,thus emitting red fluorescence.Probe HDCl had an extremely low detection limit(2.8 n M),high sensitivity,high selectivity,and rapid response(<5 s),along with a large Stokes shift(176 nm).In addition,probe HDCl had low cytotoxicity,and probe HDCl could detect HCl O in the mitochondria of He La cells and zebrafish.2.Juronidine fluorophore was used to design and synthesize a near infrared targeted mitochondrial fluorescence probe PTCl.The oxonium part of the probe PTCl could target mitochondria and the sulfur part could recognize HCl O.After responding to HCl O,the fluorescence intensity of the probe at 660 nm was significantly enhanced.The probe had low detection limit of 58 n M,high sensitivity,high selectivity and fast response(<15 s),accompanied by a large Stokes shift(115nm).In addition,cytotoxicity experiments of probe PTCl showed low cytotoxicity,and bioimaging experiments demonstrated that probe PTCl could detect HClO in mitochondria of He La cells and zebrafish.3.A targeted mitochondrial fluorescent probe HPTM was designed using dihydronaphthothiophene as the skeleton to detect HCl O.1,1,2,3-tetramethyl-1h-benzoindole-3-onium as mitochondrial target.When the probe HPTM reacted with HCl O,the fluorescence intensity at 600 nm increased significantly.HPTM had the characteristics of low detection limit(0.883 μM),high sensitivity,high selectivity and rapid response HCl O(<15 s)with a large Stokes shift(150 nm).The cytotoxicity of probe HPTM showed low cytotoxicity,and probe HPTM had been successfully applied to imaging HClO in the mitochondria of HeLa cells and zebrafish.