Spectroscopic studies on the interaction of β-cyclodextrin-8-Hydroxyquiuoline inclusion complex with herring sperm DNA

In this paper the interaction mechanism between β-cyclodextrin-8-Hydroxyquiuoline complex and DNA was studied through spectrometry and thermodynamic methods, as well as viscosity measurements. All of the studies were carried out under the condition of pH 7.4, which is maintained by Tris–HCl buffer solution. From the experimental we know that the β-cyclodextrin-8-Hydroxyquiuoline inclusion complex has a 1:1 stoichiometry. From the result of probe experiment, we found that β-cyclodextrin-8-Hydroxyquiuoline complex could compete with EB for intercalates into DNA thus changing their molecular configuration. The binding constants between β-cyclodextrin-8-Hydroxyquiuoline and DNA are K300.15KΘ=4.225×105L/mol,K310.15KΘ=4.057×105L/mol, and the corresponding thermodynamic parameters are ΔrHmΘ=3.14×103J/mol, ΔrGm300.15KΘ=-3.23×104J/mol, ΔrSmΘ=97.2J/(mol K). The further experiment results suggested that there exist electrostatic interaction besides partial intercalation binding.

Highlight► The β-CD was used to research the interaction between the micromolecule and DNA. ► The β-CD-HQ interactions with DNA studied by fluorescence and viscosity methods. ► The thermodynamics of the β-CD-HQ interactions with DNA was studied. ► The EB as probe have been used to study the interaction between of β-CD-HQ and DNA.