Synthesis And Application Of Fluorescent Probes For Some Bioactive Molecules

Reactive sulfur species?RSS?and reactive nitrogen species?RNS?are two kinds of bioactive molecules,including thiols,H₂S and NO.Thiols in cells are usually present in millimolar levels,while Sec is a cysteine?Cys?analogue with a selenol group,which is the active site of selenoproteins?SePs?.Hydrogen sulfide?H₂S?and nitric oxide?NO?are considered as the members of the three most important gasotransmitters.As a result,detection of these bioactive compounds is of great significance in biological field.In this paper,several fluorescent probes were designed and applied to detect the targets in solutions and living system.In the chapter 2,we synthesized two Michael-type fluorescent probes for thiols,QMAs and QMEs.The sensing reactions of QMAs and QMEs occur in distinct pH ranges,QMAs are activated in acidic solutions?pH<pKa3?,which is different from QME and most of the Michael probes.After the selection of QMA with different substituents,two QMAs?NEt2,OH?can label lysosomes in live cells,which are the first case compounds for labeling lysosomes in a reaction-based sensing mode.In the chapter 3,a two-input AND fluorescent probe?QME-N₃?based on quinoline scaffold with azido group was reported.QME-N₃ was specific acceptors of RSH and H₂S respectively,and can be converted into the luminescent product with low cytotoxicity and a high two-photon absorption cross section.Compared to single input,dual-analyte fluorescent probes have emerged as promising analytical tools and can be applied in more complex biological systems.In the chapter 4,a new red fluorophore?B-BODIPY?was synthesized and constructed into two selective and sensitive fluorescent probes for Sec,Sel-pl and Sel-p2.The detection of exogenous Sec,selenite-induced Sec in living cells can be achieved with Sel-p2,so does the fluorescent imaging of Sec in mice.It makes possilble for sel-p2 to uncover the function of selenium in cancer prevention or treatment.In the chapter 5,NO-a5 and NO-a6 are fluorescent probes for NO which possesses obvious advantages of simple synthesis,rapid response and high selectivity and sensitivity.NO-a5 showed a turn-on fluorescent response mode with NO under two-photon microscopy;treated with NO,the blue fluorescence of NO-a6 turned into green one,which is the first rationmetric fluorescent probe with AD to the best of our knowledge.Furthermore,exogenous and endogenous NO in RAW 264.7 cells can be detected with the application of NO-a5 and NO-a6.