Study On New L,3，4-oxadiazole Fluorescent Probes Containing Two Functional Fluophores

It is well-known that some heterocyclic compounds which contain O,N and S elements，are valuable in many fields. For example,1,3,4-oxadiazole derivatives are reported to be withbiological activities such as pesticides, antifungal, antibacterial, and cancer treatmentmaterials. Besides,1,3,4-oxadiazoles are integrated with the hole transport and used as classesof electroluminescent materials. Meanwhile, coumarin derivatives are reported to possess theactivity of anti-cancer, blood pressure, anti-arrhythmia, antibacterial and other biologicalactivities, as well as with the unique photo physical property as a good fluorescent group.Based on the connecting principle of active biological groups and the bioisosterism,some new compounds which contain double functional units of1,3,4-oxadiazole andcoumarin group in each molecule are designed and synthesized. The reaction was connectedwith many steps such as esterification, hydrazinolysis, and cyclization reaction. The desiredstructures were characterized by1H-NMR, IR ways and their optical properties are measuredby UV and fluorescence spectroscopy.The effect of2-(2’-chlorophenyl)-5-(2’-hydroxyphenyl)-1,3,4-oxadiazole (HOXD) on thebehavior of DNA was evaluated by the fluorescence quenching method. From the results ofstudied factors, such as incubation temperature, incubation time, and ionic strength, it can beseen that the interaction of HOXD and DNA might be a static quenching process whichmeans that HOXD has strong affinity with DNA.Two compounds of1,3,4-oxadiazole with sulfo-ether structure are synthesized and thepreliminary bioassay showed that the inhibitory rates against Escherichia coli were as high as95％. The effects of inhibitory against Staphylococcus aureus and Bacillus subtilis were alsoover80％, which exhibited a certain extent antibacterial activities.