Study On The Interaction Of DNA With Small Molecules By Molecular Spectroscopy And The Application Of Derivative Fluorescence Spectrum

Although the nucleic acids are few, they are the most important biomacromolecules in the organisms. Nucleic acids include DNA and RNA. As biological genetic material Deoxyribonucleic acid (DNA) dominate the process of all information of life, which can decides not only the form, composition and function of the cells, but also the reproduction, change and variation. Therefore, we have carried out researches on the structures, configurations of DNA and the interactions between small molecules (such as drugs, ions, surfactants) and DNA. Moreover, we have also learned the way of the combination between DNA and small molecules, the changes occurred from their structures and the functions. In conclusion, these researches are helpful to explain the relationship between functions and structures of DNA and also cognize the nosoqenesis of disease and some treatment mechanism of drugs. It has meaningful sense of studying chemical essence of macromolecule systems and provides guided information for manufacturing new kinds of high-efficiency drugs. As a result, they have recently become the focus of biology, chemistry, medicine, pharmacy, physics and computer science.In this thesis, the binding mode, binding constant, quenching type and interaction force type between several small molecules and DNA were studied to reveal the action mode by using a series of spectroscopic methods such as absorption spectrometry and molecular fluorescent spectrometry, which provided a new effective clue for developing new drugs.The thesis mainly includes the following aspects:1. In the first, the following parts were elaborated:The structure features of DNA; The chemical and physical properties of DNA itself; the type of the force between small molecular antenna the research methods and the development prospect; At last prospect the future of the fluorescence analysis.2. In the second part of the paper, the effect of rare earth metal ions and many kinds of surfactants on DNA-BR mixed system as well as the interaction mechanisms were studied by the method of fluorescence spectrometry using berberine hydrochloride as a classical fluorescence probe. It is of significance for investigating the toxic effects of surfactants in bioaccumulation, the combination principle between DNA and metal ions and their influences on biological functions of DNA.3. In the third, the interaction mechanisms of DNA with Hesperidin and Naringenin was discussed by using berberine hydrochloride as a fluorescence probe. The UV-Vis spectrum, fluorescence spectrometry, phosphate effect and salt effect, Scat chard equation, melting curve were also studied. The results disclosed that under the condition of Physiological acidity, Hesperidin and Naringenin interacted with DNA both by intercalation and electrostatic gravity; the quenching model of Naringenin and Hesperidin were both dynamic and static quenching procedure; we also calculated the binding constants of Naringenin and Hesperidin with DNA.4. Under physiological condition, we have studied the interaction mechanism of Curcumin and Artemisinin with DNA by means of fluorescence spectroscopy, UV-Vis absorption spectroscopy and melting curve, etc. The research showed that the quenching model of Curcumin and Artemisinin were both dynamic quenching procedure, and they interacted with DNA mainly by intercalation. At last we calculated the associating constant of Curcumin and Artemisinin with DNA.5. In chapter five,2-alpha-naphthol and Amino phenol in Environment water were simultaneously determined by using first-derivative fluorescence, which solved the problem that the conventional fluorescence spectra of two substances overlapped each other. The linear range of2-alpha-naphthol was2×10-8mol·L-1～8×10-5mol·L-1, with R=0.9997; Meanwhile, the linear range for Amino phenol was1×10-7mol·L-1～6×10-4mol·L-1, with R=0.9997. The detection limit of2-alpha-naphthol and Amino phenol was8.11×10-9mol·L-1and3.21×10-8mol·L-1, respectively. This provides a good method for eliminating the interference caused from overlap of fluorescence spectrum between2-alpha-naphthol and amino phenol without separation, the method was accurate, simple and satisfying.