Experimental and Computational Studies on the Interaction between DNA and BSA with a Couple of Isomeric [Pd(daf)(Leu)]+, and [Pd(daf)(Ile)]+ Antitumor Complexes, Their Synthesis and Spectral Characterization

Abstract

Abstract A pair of isomeric and unreported complexes, [Pd(daf)(Leu)]Cl (I) and [Pd(daf)(Ile)]Cl (II) (daf, Leu and Ile are dafone, leucine and isoleucine respectively) have been prepared and characterized. They showed in-vitro cytotoxic activities against MCF-7 and HCT-116 cancer cells much higher than a well known anticancer drug i.e. carboplatin. In-detail interaction of these agents with calf thymus DNA (CT-DNA) and bovine serum albumin (BSA) have been investigated by fluorescence, electronic absorption, circular dichroism, and gel electrophoresis techniques. Docking analysis of both metal complexes with DNA and BSA was applied as a supplementary route for the prediction of binding sites and orientation during the interaction processes. Results obtained from all above approaches agreed with good interaction of the metal complexes with DNA grooves and BSA via H-binding and van der Waals forces. In the fluorescence quenching studies of BSA emission, peculiar and unpublished processes to date were observed. Leucine complex initially quenches statically at lower concentration and in combination of static and dynamic at higher, while isoleucine complex affects the fluorescence emission of BSA at its three different concentration ranges: static and combined at lower-, de-quenching at moderate- and again static quenching at higher-concentration ranges.