Studies On The Interaction Of Flavonoids With Biological Molecular

The molecular interactions between molecule and biological molecular have become of an important research field in chemistry, life sciences and clinical medicine. DNA and proteins are key biological moleculars. DNA is the primary target molecular for most of anticancer and antivirus therapies. The investigation of the interaction of DNA with drugs is helpful to understand the mechanism by anticancer and antivirus medicines act and provide theoretical guidance for designing the effective drugs. Protein serves as a transport carrier for drugs, the binding of drugs with protein has a great influence not only upon the distribution of the drugs in the body but also upon their patterns of metabolism and excretion. The studies on this aspect may provide information of the structural features that determine the therapeutic effectiveness of drug. On the basis of the previous research, the fluorescence spectroscopy, UV-visible absorption spectroscopy and CD spectroscopy were used to investigate the interaction of drug with biological molecular.This paper consists of four sections as follows:Chapter 1: The methods and actuality about the research of the interaction between small molecular substances and biological molecular were summarized.Chapter 2: The binding of chrysin with HSA has been investigated by spectroscopy. The fluorescence and CD spectroscopy indicated that the conformation of HSA changed due to the binding of chrysin. Theα-helix contents of HSA in the absence and presence of chrysin were calculated by quantitative analysis of the CD spectra data. In addition, the binding constant, the number of binding sites, thermodynamic parameters and the distance between the binding location and tryptophan residue were calculated.Chapter 3: The interaction between puerarin and lysozyme has been studied using fluorescence and CD spectroscopy. The binding constant and the number of binding sites at three different temperature were calculated. The mainly intermolecular force induced by drugs binding was obtained according to the thermodynamic parameters. The effects of puerarin on Lysozyme secondary structure were investigated by CD spectroscopy.Chapter 4: This study was designed to examine the interaction between puerarin and DNA under simulated physiological conditions. The binding mode of puerarin and DNA was determined through UV-visible absorption spectroscopy, fluorescence polarization measurement and CD measurement. The binding constant and the number of binding sites were calculated from the data obtained from fluorescence experiments.