Design,Synthesis And Evaluation Of Fluorescent Probe For Biothiols

Biothiols and small molecule hydrogen sulfide（H₂S）play important roles in physiological process of human body.The abnormal concentration of biothiols and H₂S is related to the formation of some major diseases.Because of its simple operation and real-time tracking,fluorescence method is an appropriate method for the analysis and detection of biologically active biothiols and H₂S.In this study,four fluorescent probes were designed and synthesized for detection of biothiols and H₂S based on our previous work and the research literature,and their optical properties and bioactivity were evaluated.The main work of this thesis includes:（1）An intermediate DM and a fluorescent probe DM-SH were designed and synthesized through structural modification of dicyanoisophorone,and the relationship between structure and optical properties was evaluated.The fluorescent probe DM-SH was a non-fluorescent substance.The intermediate DM was formed by the reaction with biothiols and H₂S,and its emission wavelength was 675 nm,which fell in the near infrared region and emitted red fluorescence.Besides,the response mechanism of detection of biothiols and H₂S was verified by high resolution mass spectrometry and theoretical calculation methods.This probe has a low detection limit for biothiols and can effectively detect biothiols in simulated physiological environment.The probe DM-SH showed relatively low cytotoxicity and the cell imaging experiment demonstrated that this probe can detect the biothiols in cells in real-time.（2）Two intermediates TH-3 and TH-4 and two fluorescent probes TH-1 and TH-2 were designed and synthesized based on dicyanoisophorone structure.TH-3 to TH-4 were the isomeric compounds of TH-1 to TH-2,respectively.The relationship of four molecules between structure and optical properties was evaluated.The intermediates TH-3 and TH-4show double fluorescence emission in neutral and alkaline p H environment,while the probes TH-1 and TH-2 showed both ratio change（green light area）and enhanced fluorescent change（near infrared light area）after react with an addition of Cys/Hcy in simulated physiological conditions,which belonged to dual-responsive fluorescent probes.The two probes had high selectivity and sensitivity to Cys/Hcy,and could be used as analytical tools to detect Cys/Hcy.（3）The intermediate NR and fluorescent probe NR-SH were designed and synthesized by modifying the structure of Nile-red fluorescent dye.The fluorescent probe NR-SH was a non-fluorescent substance.When it reacted with biothiols and H₂S,the probe emitted significant long wavelength fluorescence.The response speeds of probe NR-SH to biothiols and H₂S were different.Under the same conditions,the probe could recognize H₂S relatively quickly,while the measurement of biothiols needs a long incubation time.The results of cell imaging experiments showed that the probe NR-SH can detect the biothiols in cells in real-time,which provided a reference for the detection of thiols in the human body.