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

Abstract EN

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=2×104 M-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.