Electrochemical and Spectroscopic Investigations of Protonated Ferrocene-DNA Intercalation

Voltammetric and viscometric studies of flavonoids interactions with DNA at physiological conditions

“…DNA was extracted from chicken blood using Falkon method [9]. All conducting samples were prepared using (a) 0.1 M acetic acid-sodium acetate buffer solution, containing 50 mM KCl with pH = 4.7 and (b) 0.1 M sodium phosphate buffer solution with pH = 7.4.…”

“…Stock solution of each flavonoid (1 mM) was prepared in buffered ethanol:water mixture with 1:1 (v:v) ratio. Concentration of chicken blood ds.DNA in distilled water was determined spectrophotometrically at 260 nm using molar extinction coefficient ε260 = 6600 cm -1 M -1 [9]. The ratio of the absorbance at 260 nm to that at 280 nm, A260/A280> 1.8, indicated that DNA was sufficiently pure and free from protein [10].…”

“…The changes in current upon addition of DNA can be explained in terms of diffusion of an equilibrium mixture of free and bound flavonoid to the electrode and which can be used to quantify the binding of flavonoids to DNA. The diffusion coefficient of all three flavonoids in the absence and presence of DNA were evaluated by using Randles sevcik equation [9,11,13]:…”

“…A simple site binding model was used to fit the cyclic voltammetric data acquired from the interaction between flavonoids and DNA. Binding site size of flavonoid-DNA interaction has been evaluated from the following equation [9,15]:…”

“…Furthermore, the possible binding modes between flavonoids and DNA were determined by viscommetric measurements. Such studies yield information about the mechanism of intercalation and the conformation of flavonoid-DNA complex [9]. These investigations form a theoretic guide for the design of new drugs and chemical treatments of tumor and virus.…”