Spectroscopic Study of the Interaction of Trans_Aco Base (curcuminato) Exo Zirconium IV Hydrate and Curcumin with DNA

Binding interaction of novel six-coordinate complex of zirconium with curcumin ligand (trans-[ZrO(curcumin)2(H2O)].H2O) and curcumin with calf thymus (CT-DNA) were investigated using UV–Vis absorption spectroscopy and fluorescence spectrophotometry. The appearance of hypochromicity effect and the blue shift in UV-Vis spectrum of complex and curcumin were due to the interaction with CT-DNA. The binding constants (K) were determined from the changes in the optical absorption spectra at various CT-DNA concentrations. The values of K were 8.50 104 M-1 and 2.25 104 M-1 for complex and curcumin, respectively, at 25 ºC. The UV–Vis and fluorescence results suggested that complex and curcumin prefer to bind on the minor groove of CT-DNA.