| ABSTRACT
Chromium(III) chloride mediates DNA-DNA cross-linking. Some
chromium complexes promote programmed cell death in specific ligand environment through binding to DNA. One strategy
that can be supposed for reduction of Cr3+ binding affinity to
DNA is using curcumin as a chelator. In the current study, the
[Cr(Curcumin)(EtOH)2](NO3)2 (CCC) was synthesized and characterized by UV/Vis, FT-IR, CHN and spectrophotometric titration
techniques. The mole ratio plot revealed a 1:1 complex between
Cr3+ and curcumin in solution. Binding interaction of this complex
with calf thymus-DNA (CT-DNA) was investigated using UV/Vis,
circular dichroism (CD), FT-IR and cyclic voltammetry. The intrinsic binding constants of CCC with DNA, measured by UV/Vis and
cyclic voltammetry, were 1.60 × 105 and 1.13 × 105, respectively.
The thermodynamic studies showed that the reaction is enthalpy
and entropy favoured. CD analysis revealed that only -CCC interacts with DNA and -CCC form has no tendency towards DNA.
Based on FT-IR studies, it was understood that CCC interacts with
DNA via minor groove binding. The docking simulation was carried out for finding the binding mode of CCC to DNA, too. All of
data demonstrated that the curcumin significantly reduced the
affinity of Cr3+ to the DNA and the form of -CCC has no interaction with DNA. |