Study Interaction Between The Macrocyclic Complexes And DNA

In the dissertation, The development direction and prospects of the coordination compound were expatiated. The interaction between small molecule and nucleic acid was also described, including interaction modes, research methods and research techniques.Firstly, we prepared four novel phenol-based compartmental macrocycles homodinuclear and heterodinuclear complexs. [Cu₂(L¹)Cl₂]·CH₃CN 1 [Cu₂(L²)Cl₂]·CH₃CN 2 [CuZn(L¹)(OAc)](ClO₄)·CH₃CN·H₂O 3 [CuZn(L²)(OAc)](ClO₄)·2CH₃CN·H₂O 4. The ligand H₂L¹ was prepared through the Mannich reaction. the reagents were 5-chlosalicyladehyde N,N'-bis(2-furyl)-1, 2-diaminoethane and paraformaldehyde, H₂L² was Synthesis as same as H₂L¹, but 5-bromosalicyladehyde in stead of 5-chlosalicyladehyde. 1 and 2 were homodinuclear complex, 3 and 4 were heterodinuclear complex. The X-ray results tell that: all metal ions have five coordinated atoms with distorted square-pyramidal configuration. The interaction between the complex and calf thymus (CT) DNA was investigated by UV-vis absorption, viscosity experiment and CD spectroscopy. The following results were obtained: firstly, when add CT-DNA to the four complexs the absorption value was descended clearly under the spectroscopic, the highest hypochromicity shifts were 85% and with bathochromic shift. the binding constants between the four complexs and the DNA derived from the spectroscopic methods, K1= 6.2×105,K2= 7.2×105,K3= 4.7×105,K4= 5.0×105 respectively; Secondly, the fuor complexs can unwind the DNA helix and bind to CT-DNA in an unclassical intercalative mode. Thirdly, the complex exhibited efficient cleavage of supercoiled DNA (pBR322DNA) in the absence of any external agents. The mechanism of the cleavage process was also studied. It is proposed that DNA cleavage occur via oxidative mechanism.Secondly, The complexs 5 and 6 were Synthesised, The two complexs were open-loop structure. The X-ray results show that: all metal ions have six coordinated atoms with distorted octahedron-pyramidal configuration. Studied them activity of cleavage pBR322DNA with different temperature and pH, The results revealed that temperature and pH had an effect on the cleavage activity.