Small Organic Molecule Fluorescent Probe For Detecting Cellular Redox-active Species

Small molecule fluorescent probes are a class of active molecules containing specific recognition sites for target objects.This dissertation synthesized a series of reaction-based organic probes and studied their interaction with various analytes,including thiols,HCl O and H₂O₂ in vitro and in live cells.This dissertation consists of six chapters,which are summarized as follows.Chapter Ⅰ:Introduction.This chapter focuses on basic concepts of small molecule probes and the mechanisms of fluorescence sensing.Recent developments of fluorescent probes for Cys,thiols and H₂O₂ are also introduced.Chapter Ⅱ:Three fluorescent probes containing bromomaleimide were designed and evaluated in detecting vicinal-dithiol-containing proteins（VDPs）.After a series of tests,we found that these probes which containing maleimide could react with Cys with high selectivity.Further research showed that the mechanism of the reaction is based on the addition/rearrangement-cyclization.Finally,we successfully apply the probes to detect Cys in biological samples.Chapter Ⅲ:Based on the results in Chapter II,we designed and synthesized a novel fluorescent probe Naph-EA-Mal,in which maleimide is indirectly connected to naphthalimide by ethylenediamine linker.Spectral test showed that this probe could detect thiols in aqueous solution with an ultrafast rate.Then we made it to be a protein thiol labeling reagent,and successfully applied it to detect various reversible protein thiol modifications.Chapter Ⅳ:Two new kinds of fluorescent probes containing sulfide structure were designed and tested for HCl O detection.After carefully studying the reaction products of the probe with HCl O,the mechanism of recognition of HCl O was proposed.Chapter Ⅴ:We synthesized a series of thiol fluorescent probes containing thiazoline and oxazolone scaffold.After isolating and analyzing the reaction products,we proposed two mechanisms for sensing thiols.Chapter Ⅵ:This chapter is about the conclusions and the prospects of this dissertation.Main innovative points of this dissertation are summarized here.Several future plans based on the current results t are proposed.