Binding of a double-chain surfactant-cobalt(III) complex to CT DNA: effect of β-cyclodextrin in the medium.

The interaction of cis-Co(phen)2(HA)23, a cationic surfactant complex (phen=1,10-phenanthroline, HA=hexadecylamine), with calf thymus DNA has been studied by UV-vis absorption, fluorescence spectroscopy, cyclic voltammetry, circular dichroism, and viscosity measurements. The spectroscopic studies together with cyclic voltammetry and viscosity experiments support that the surfactant-cobalt(III) complex binds to calf thymus DNA (CT DNA) by intercalation through the aliphatic chain present in the complex into the base pairs of DNA. The presence of phenanthroline ligand with larger π-frame work may also enhance intercalation. Besides the effect of binding of surfactant cobalt(III) complex to DNA in presence of β-cyclodextrin has also studied. In presence of β-cyclodextrin the binding occurs through surface and (or) groove binding. The complex was investigated as one of the potential selective anticancer prodrugs. The complex was tested also in vitro on human monolayer tumor cell lines: HepG2 (human hepatocellular liver carcinoma).