Design,Synthesis And Cell Imaging Of Organic Small Molecule Formaldehyde Fluorescent Probes

Formaldehyde(FA)is a reactive carbonyl substance classified as a Group 1carcinogen by the International Agency for Research on Cancer(IARC)in 2004.In addition,clinical studies have shown that elevated FA levels are associated with different kinds of diseases,such as neurodegenerative diseases,diabetes,and chronic liver and heart disease.However,in addition to the direct inhalation of FA into the environment,most organisms can also produce endogenous FA through demethylases and oxidases during the metabolism of amino acids and exogenous substances.Since FA plays an important role in physiological and pathological processes,it is crucial to develop reliable and efficient methods to monitor FA levels in biological samples.Organic small molecule fluorescent probes have application advantages in the field of formaldehyde detection and bioimaging in vitro and in vivo due to their high sensitivity,high selectivity,visualization and in situ detection.Reaction-based fluorescent probes provide a reliable method for FA detection and real-time visualization in living organisms.In this thesis,based on the 2-aza-Cope rearrangement principle,five FA probe structures with different reaction units(FA-1,FA-2,FA-3,FA-4,FA-5)were developed and designed and synthesized and characterized by(~1H NMR,¹³C NMR and ESI-MS),and the selectivity,sensitivity,and kinetic tests of the probes at different p H values were completed in the buffer solution detection,and their performance in FA was systematically evaluated.Overall power at the time of detection.The results showed that under the same conditions,the FA-2 probe with 6-(pyrrolidin-1-yl)-2-naphthaldehyde fluorophore and 4-nitrobenzylamine group exhibited the highest sensitivity(detection was 0.65?M),selectivity and reaction kinetics.The experiment further introduced a morpholine moiety for lysosome targeting to the probe FA-2,that is,the probe FA-Lyso.In the in vitro test,FA-Lyso maintained the same kinetics and sensitivity to FA as FA-2.Finally,the exogenous and endogenous FA fluctuations in live lysosomes were successfully monitored in live cell imaging,indicating that the probe FA-Lyso has potential biological application value for discovering the multiple functions of FA in physiological and pathological processes.This function provides an advantageous tool.