Design,Preparation And Application Of Peroxynitrosyl Radical And Biothiol Dual Response Fluorescence Probe

In recent years,fluorescence imaging methods based on organic small molecule fluorescent probes have become a powerful analysis tool due to their high selectivity,high sensitivity,and good spatiotemporal resolution.It realizes the visual detection of active substances such as active oxygen,active nitrogen and active sulfur in biological systems,and has played an important role in the physiological and pathological research of organisms.At present,most fluorescent probes can only detect a single specie,but in view of the fact that multiple active substances are involved in the process of physiological and pathological changes,it is more meaningful to develop fluorescent probes that can respond to two or more active species simultaneously.,This will provide more effective information to the investigation of related molecular events.Peroxynitrite?ONOO^–?an active nitrogen species with high oxidizing and nitrifying ability,is widely involved in various physiological and pathological processes.ONOO^–plays an auxiliary regulatory role in the body's immune system and causes oxidative stress that will damage cells and tissues.Biothiols,which typically include glutathione?GSH?,cysteine?Cys?,and homocysteine?Hcy?,play an important role in the antioxidant processes.At the same time,hydrogen sulfide?H₂S?has similar characteristics to biothiols and plays an important role in signal transduction and regulation.Therefore,a suitable fluorescent probe with reasonable design and reactivity regulation that can achieve the simultaneous detection of ONOO^–and biothiols?including H₂S?in cells is important to interpret the intracellular related physiological and pathological processes as well as the molecular event mechanisms.Based on the above considerations,in this thesis,we designed and synthesized two dual-responsive small-molecule fluorescent probes to detect ONOO^–and biothiols.The specific research content is as follows:?1?A fluorescent probe BCN for the simultaneous detection of ONOO^–and biothiols was designed and synthesized.The probe is based on the benzopyran-coumarin?BC?skeleton with a electron withdrawing group of nitro,which can detect ONOO^–and biothiol respectively by colorimetry.Meanwhile,it can specifically respond to ONOO^–with fluorescence enhancement.Using BCN,the fluctuation of ONOO^–in cells,mouse liver and brain tissue induced by the drug acrylamide?AA?was investigated.Experimental results show that AA can induce the upregulation of ONOO^–level in cells and mouse organs.?2?A dual-response probe BCO was designed and synthesized based on BCN.By changing the substituent group,BCO respond to ONOO^–and biothiol simultaneously through both colorimetric and fluorescence mode.The probe is proved to be highly sensitive and fast responsive,and can be used to image ONOO^–and biothiol in live cells.The results provide a good analytical tool for exploring the interaction and synergistic changes of ONOO^–and biothiols in the redox process of biological systems.