Design, Synthesis And Application Of Single/two-photon Nitric Oxide Photo-controlled Release Molecules

As an important gasotransmitters,Nitric oxide(NO)plays regulating role in many physiological activities,such as vasodilation,neurotransmission and immune response.In numerous clinical studies,some NO donors have long been used as conventional exogenous NO reagents,including diazeniumdiolates(NONOates),nitrosothiols,etc.The biological functions of NO greatly depend on its location,flux,and transformation.In order to further explore the role of NO in physiological and pathological activities,a lot of effort has been put into the designing of NO photoreleasers,which release NO with a high spatiotemporal control by light irradiation.In the meanwhile,self-lighting donors with fluorescence turn-on will result in the direct visualization or tracking of NO release in biological systems,which is important for NO-related biomedical research and diagnostic treatment.In addition,the NO release system with ratiometric fluorescence signal is more suitable for quantitative application without being affected by the donor concentration,distribution and variation in excitation light power.Therefore,ratiometric NO photoreleasers are promising and are expected to greatly widen the application scope of NO donors.Subcellular NO release is another research with controlling modulation of NO level in some cellular compartments.This can strongly help fulfill the fundamental interrogations of NO-mediated biology.Therefore,this thesis carried out the following two aspect of the research work:(1)Based on the fluorescence resonance energy transfer(FRET)mechanism,a ratiometric fluorogenic NO photoreleaser,CNNO,was designed and synthesized.NO can be released from CNNO by irradiation of both single-photon 365 nm and two-photon 800 nm.Importantly,the NO release is accompanied by dramatic fluorescence ratiometric variation.Experiments show that CNNO has the advantages of rapid release,large ratiometric variation,and satisfied stability for in vitro and intracellular NO release.Moreover,CNNO exhibits the merits of spatiotemporal controlling in both the site-specific NO release in the selected cell culture region and the controllable vasodilation of mouse aorta ex vivo.The design concept of this ratiometric NO photoreleaser opens up a new path for the design and application of novel NO donors.(2)In this section,lysosomal targeting group N-(2-aminoethyl)morpholine was incorporated into naphthalamide to obtain a new donor LyNO.LyNO localized in lysosomal of cardiomyocytes and release NO upon irradiation.Controlling release of NO in subcellularcompartments contributes to the level regulation of NO and can strongly help fulfill the fundamental interrogations of NO-mediated biology.