A systematic comparative study of the binding of antitumor Morin and its complexes with DNA has been
investigated in the Britton-Robison (BR) buffer solutions using voltammetric and spectroscopic meth-
ods. The results show that Morin molecule, acting as an intercalator, is inserted into the cavity of the
-cyclodextrin (-CD) as well as into the base stacking domain of the DNA double helix. The interaction
ofMorin–Cu complex or the inclusion complex ofMorin–-CDwith ds-DNA causes hypochromismin the
absorption spectra, along with pronounced changes in the electrochemical behavior of the Morin com-
plexes. An isobestic point and a newspectrumband appeared indicating the formation of the newsystem
of Morin–Cu–DNA at m = 391 nm and Morin–-CD–DNA at m = 375 nm. The intercalation of Morin–Cu
and Morin–-CD complexes with DNA produces an electrochemically inactive supramolecular complex.
The binding constants were calculated from the increase of the solubility, the strong hypochromism, and
the decrease in peak current of Morin and its complexes upon the addition of the host molecules. Cal-
culation of the thermodynamic parameters of the interaction of the inclusion complex of Morin–-CD
with DNA, including Gibbs free energy change, Helmholz free energy and entropy change shows that the
complexation is a spontaneous process of association.