Design, Synthesis And Application Of Fluorescent Probes For Methylglyoxal And Hydrazine

In this thesis, we have designed and synthesized fluorescent probes which utilized photoinduced electron transfer (PET) effect for methylglyoxal detection, and fluorescent probes based on protection-deprotection mechanism for hydrazine detection, respectively.Methylglyoxal with a reactive dicarbonyl group is a highly toxic compound. Many diseases could cause the accumulation of methylglyoxal in vivo, while the impact of methylglyoxal on cellular processes remains poorly understood. We designed and synthesized fluorescent probes compound 1,2 and 3 to detect methylglyoxal. These three probes contain o-phenylenediamine (OPD) structure, which could quench the fluorescence of the fluorophore due to the PET effect. An addition reaction could take place between OPD and methylglyoxal, which inhibit the PET effect, along with an enhancement of fluorescent intensity. There would be a 33-fold fluorescence enhancement when 1 reacted with methylglyoxal, and the specificity of 1 for methylglyoxal to other aldehydes, ions, peroxide and nitric oxide is satisfactory, which is better than those of 2 and 3. The mechanism of the reaction between 1 and methylglyoxal was evaluated by NMR spectroscopy, mass spectrometry (MS) and high resolution mass spectrometry (HRMS). Imaging methylglyoxal in living cells by fluorescent probe 1 is also accomplished with high sensitivity and low cytotoxicity.Hydrazine can act as an important reducing agent or reactant in organic synthesis, and it is also used as eikonogen and efficient rockets fuels. Hydrazine is a highly toxic reagent, which could cause healthy and environmental problems. We designed and synthesized fluorescent probes compound 4,5 and 6, which consist of different fluorophores and protecting groups, respectively. We screened and found that compound 6 could detect hydrazine effectively. The selective deprotection of the ester group of the probe 6 by hydrazine led to a 10-fold enhancement of fluorescent intensity, as well as a remarkable color change from colorless to pink, which could be distinguished by naked eye. The fluorescence enhancement showed decent linear relationship with hydrazine concentration ranging from 0 to 50?M. The sensing mechanism of 6 and hydrazine was evaluated by high performance liquid chromatography (HPLC), MS and density functional theory (DFT). Moreover, we have utilized 6 for imaging hydrazine in living cells, and the fluorescence enhancement was observed when the cells were incubated with hydrazine (100?M) for 30 min.