Study On Nitrosyl Hydrogenation Probes Based On BODIPY Dye

In this paper, we design and synthesize a series of new organic small molecule fluorescent probes for researching nitroxyl(HNO) specifically and exploring the probe molecules selectively positioned in specific organelles. Based on monitoring the HNO, we can achieve the in situ, real-time and dynamic fluorescence imaging analysis within the three levels of molecules, cells and in vivo. The experimental results will reveal the generation and mechanisms of the HNO. This dissertation consisted of five chapters summarized as follows.In chapter 1, we briefly introduce the basic concept of small molecular fluorescent probe, the design ideas, and the recognition mechanism. Small organic fluorescent probes are becoming popular because of their ease of application in solution as well as their high selectivity and sensitivity for analytes with spatial and temporal resolution. Therefore, fluorescence imaging is nowadays indispensable tools in many fields of modern science and medicine, including clinical diagnostics, biochemistry, and analytical and environmental chemistry. Among many classes of the fluorophores, A BF2-chelated tetraarylazadipyrromethane(Aza-BODIPY) has been recognized as the promising fluorophore for the probe design, because of their outstanding photophysical properties, including high tolerance to environment, small stokes shift, big molar extinction coefficient, and high fluorescence quantum yield. Nitroxyl(HNO), the one-electron reduced and protonated analogue of nitric oxide(NO), have received a few attention due to its potential bio-pharmacological effects. Some reports suggested that HNO can increase systolic force and decrease diastolic pressure in both normal and failing canine hearts. Thus, HNO may provide a powerful therapeutic agent for heart failure. Development of reliable methods for HNO detection is great significance.In chapter 2, based on aza-ylide intramolecular ester aminolysis reaction with HNO, we have presented a near-infrared fluorescent probe Lyso-JN for the detection of nitroxyl(HNO) in cells and in vivo. Lyso-JN is comprised of three moieties: an Aza-BODIPY fluorophore, a HNO-response modulator diphenylphosphino-benzoyl, and a lysosomal locator alkylmorpholine. The probe exhibits high selectivity, good sensitivity and low cytotoxicity when detect HNO. Besides, the probe holds ability to capture lysosomal HNO in RAW 264.7 cells, and also successfully employed to visualize HNO in mice.In chapter 3, BODIPY-based fluorescent probe for the mitochondrial HNO was designed and synthesized. Mito-JN is comprised of three moieties: an Aza-BODIPY fluorophore, a HNO-response modulator diphenylphosphino-benzoyl, and a cationic triphenylphosphonium group for mitochondrial targeting. The probe has been used successfully for HNO detection in RAW264.7 cells and realized the BALB/c mice imaging. What’s more, we attempted to measure the intracellular generation of HNO.In chapter 4, we describe the synthesis, properties, and application of probes Cyto-JN, for HNO sensing in living cells and in vivo. Its reaction equivalent with HNO is 1:1, which will benefit for the little dosage of probe in bioassays. The Cyto-JN exhibits high sensitivity and selectivity toward HNO and low cytotoxic effect to cells. Fluorescence bioimaging illustrated that the probe can be used for the detection of intracellular HNO changes. Besides, Cyto-JN can detect HNO in living mice without interference from background fluorescence. The flow cytometric analysis highlighted the probe can detect intracellular HNO qualitatively and quantitatively.In chapter 5, the last paragraph is a brief summary of this dissertation main ideas and conclusions.