Studies On The Interaction Metal Ruthenium(Ⅱ) Complexes With Different Structures Of Nucleic Acids

The medical value of metal ruthenium（II）complexes in anti-cancer have aroused intensive attention by researchers in recent years,and the deep understanding for mechanism of metal ruthenium（II）complexes interaction with nucleic acids is an important aspect in the development of the related anticancer drugs.Hence,the interaction between them has become has become a hot research topic.In order to more clearly understand the significance of binding mechanism,several metal ruthenium（II）complexes were synthesized in this work,and the metal ruthenium（II）complexes interaction with nucleic acids containing different structure sequences were systemically studied.We hope that the type of research can help with the development and design of anti-cancer complexes.Specific content of the full text is divided into four sections:The first chapter for the introduction section,which mainly gives a brief introduction on several relevant basic knowledge of nucleic acids,and the significance of the study,application fields of the binding between metal ruthenium（II）complexes and nucleic acids with different structures.Chapter two offers a brief description on the drugs needed in the experimental process and the synthesis and characterization of intercalative ligands and complexes.this chapter also outlines the assembly of RNA triplex poly（U）·poly（A）*poly（U）and determined structure of CT-DNA and yeast t RNA.In the third chapter,arene metal ruthenium（II）complexes have a shape similar to the“piano stool”was designed and synthesized,which intercalative ligand containing an electron-withdrawing substituent nitro group.The binding characteristics of Ru1with RNA triplex and RNA duplex as well as CT-DNA were explored by a series of biophysical technique and hydrodynamics methods.Which among electronic absorption spectra and fluorescence quenching demonstrates that the binding affinity of complex Ru1 with CT-DNA was the largest,followed by RNA triplex poly（U）·poly（A）*poly（U）,then the duplex RNA poly（A）·poly（U）.Furthermore,melting experiments show that the stabilization effects of Ru1 on nucleic acids with different structure sequences are strikingly different from each other.These results indicate that it is of great importance to the binding of ruthenium（II）complexes with nucleic acids containing different structure sequences.In the fourth chapter,the two classical octahedral ruthenium（II）polypyridyl containing different substituents,[Ru（phen）₂（7-CH₃-dppz）]²⁺（Ru2）and[Ru（phen）₂（7-Br-dppz）]²⁺（Ru3）,have been synthesized and characterized.Whether the complexes Ru2 and Ru3 can serve as molecular“light switches”of nucleic acids of different structure sequences was explored respectively.The results of the study suggested that Ru2 and Ru3 have light switch effect on duplex RNA,yeast t RNA and CT-DNA,but have no light switch effect on single-stranded RNA poly（U）.This means that the complexes Ru2 and Ru3 can be used as fluorescent probes to recognition the duplex RNA,yeast t RNA and CT-DNA.This phenomenon indicates that Ru2 and Ru3 have an excellent recognition effect for nucleic acid with diverse structures and conformations by as the luminescent probe.Moreover,electronic absorption spectra titrations and viscosity experiments indicate that the binding of Ru2 and Ru3 to the duplex RNA via an intercalative mode,and Ru1 has a significantly higher binding strength than that of Ru2.The obtained result of this study further reflects that the interaction between the both complexes and the nucleic acids can be regulated by slight variations in the intercalative ligands 7-CH₃-dppz and 7-Br-dppz when the ancillary ligands are maintaining the same.