DNA Fluorescent Probes Based On Novel Hemicyanine Dyes

In this paper, a series of novel hemicyanine dyes based on quinolizinium weresynthesized and characterized. Furthermore, the interaction of the hemicyanine dyes and calfthymus DNA (ctDNA) was investigated in details. This thesis is divided into the followingsections:First, we synthesized hemicyanine dye L, and its chemical structure was confirmed byNMR spectroscopy, elemental analysis and other analytical tools. The interaction of L andctDNA was conducted in phosphate buffer (pH=7.4) by UV-visible absorption andfluorescent spectroscope titration experiments. The binding constant of L and ctDNA wasestimated to be4.27×107M-2(R=0.9996), and its detection limit was8.04×10-8M; inaddition, experiments of the thermal denaturation of ctDNA in the absence and presence of Land L competing with EB demonstrated that the interaction of L and ctDNA was mainlyintercalative interaction; the hydrolysis of DNA catalysted by DNase indicated that L can beapplied to monitor the deoxyribonuclease activity and hydrolysis process; L might be used forimaging of nucleic acids with cells; finally, addition of ctDNA could result in an obviouschange of solution so that DNA can be detected in naked eyes.Subsequently, the hemicyanine dye TPTP was synthesized and its chemical structurewas confirmed by NMR spectroscopy, elemental analysis and other analytical tools. Theinteraction of TPTP and ctDNA was conducted in phosphate buffer (pH=7.4) by UV-visibleabsorption and fluorescent spectroscope titration experiments. The binding constant of TPTPand ctDNA was estimated to be2.92×107M-2(R=0.9910), and its detection limit was1.13×10-7M; in addition, the thermal denaturation experiment of ctDNA in the presence of TPTPwas also carried out. The results showed that the interaction of TPTP and ctDNA was mainlyintercalative interaction; the hydrolysis of DNA catalysted by DNase indicated that TPTPcan be applied to monitor the activity of deoxyribonuclease I and DNA hydrolysis process;TPTP can be used for selective imaging of nucleic acids within dead cells; finally, TPTP alsoexhibited the ability to act as a reagent for DNA staining in electrophoresis analysis.Finally, we also synthesized hemicyanine dyes C1and C2, and their chemical structureswere confirmed by NMR spectroscopy, elemental analysis and other analytical tools. Theinteraction of C1and C2with ctDNA was conducted in ultrapure water by UV-visibleabsorption and fluorescent spectroscope titration experiments. The binding constants of C1and C2with ctDNA were estimated to be3.13×108M-2(R=0.9987) and2.96×108M-2(R=0.9954), and the detection limits were1.13×10-7M and1.30×10-7M respectively; inaddition, studies of the thermal denaturation of ctDNA and C1and C2competing with EBwere also implemented. The results showed that the interaction of C1and C2with ctDNAwas mainly intercalative interaction; the hydrolysis of DNA catalysted by DNase indicatedthat C1and C2can be applied to monitor the deoxyribonuclease activity and hydrolysis process.In content, through a system research, a series of DNA fluorescent probes (L, TPTP, C1,C2) based on the quinolizium hemicyanine dyes have been developed. Their molecularrecognition behaviors have been investigated detailly.