DNA Interaction Studies of a New Platinum(II) Complex Containing Different Aromatic Dinitrogen Ligands

• Main Authors: Nahid Shahabadi, Somaye Mohammadi, Robabeh Alizadeh
• Format: Article
• Language: English
• Published: Hindawi Limited 2011-01-01
• Series: Bioinorganic Chemistry and Applications
• Online Access: http://dx.doi.org/10.1155/2011/429241

A new mononuclear Pt(II) complex, [Pt(DMP)(DIP)]Cl2.H2O, in which DMP is 4,4-dimethyl-2,2-bipyridine and DIP is 4,7-diphenyl-1,10-phenantroline, has been synthesized and characterized by physicochemical and spectroscopic methods. The binding interaction of this complex with calf thymus DNA (CT-DNA) was investigated using fluorimetry, spectrophotometry, circular dichroism, viscosimetry and cyclic voltametry (CV). UV-VIS spectrum showed 4 nm bathochromic shift of the absorption band at 280 nm along with significant hypochromicity for the absorption band of the complex. The intrnisic binding constant (𝐾𝑏=2×104M−1) is more in keeping with intercalators and suggests this binding mode. The viscosity measurements showed that the complex-DNA interaction can be hydrophobic and confirm intercalation. Moreover, the complex induced detectable changes in the CD spectrum of CT-DNA. The fluorescence studies revealed that the probable quenching mechanism of fluorescence of the complex by CT-DNA is static quenching. The thermodynamic parameters (Δ𝐻>0 and Δ𝑆>0) showed that main interaction with hydrogenic forces occurred that is intercalation mode. Also, CV results confirm this mode because, with increasing the CT-DNA concentration, shift to higher potential was observed.