Drug–DNA interactions and their study by UV–Visible, fluorescence spectroscopies and cyclic voltametry

Synthesis, DNA-Binding and Antibacterial Activity of the Cell-Penetrating Peptide HIV-1 Tat (49-57)

“…Hypochromism was due to the electrostatic interaction of DNA phosphate groups with the side chains of Tat (49-57). This interaction tightened the double strands of DNA to prevent aromatic bases from becoming increasingly exposed and resulted in the reduced absorption intensity [20,21] . With the increase in the concentration of Tat (49-57), when the groove of ct-DNA was padded by Tat (49-57), the interaction of side chains containing guanidine and amino groups of Tat (49-57) destabilized the base pairs of DNA, caused the aromatic bases to become exposed, and resulted in hyperchromism of DNA [22] .…”

Synthesis, structural characterization and cytotoxic activity of ternary copper(II)–dipeptide–phenanthroline complexes. A step towards the development of new copper compounds for the treatment of cancer

“…The Kb value is given by the ratio of the slope to the intercept [26]. Solutions of CT-DNA in buffer gave a ratio of UV absorbance A 260 /A 280 of 1.8-1.9, indicating that the DNA was sufficiently free of protein [26]. The stock solution of DNA prepared in buffer was kept at 4°C and used within 4 days.…”

Spectroscopic Studies on the Interaction of Anti Cancer Rosemary With ctDNA

“…The extent of fluorescence quenching of EtBr bound to DNA was applied to determine the extent of binding between the second molecule and ctDNA (12). The Stern-Volmer Equation was was as follows, (2) F0/F = 1 + Kr Where F 0 and F are the fluorescence intensities in the absence and presence of complex, respectively, K is a linear Stern-Volmer quenching constant and r is the ratio of total concentration of complex to that of DNA (12); the Stern-Volmer constant value for rosemary extract was 0.39 (mg/mL) -1 . Since, EtBr intercalates DNA through interaction with the minor groove; the displacement of EtBr by the titration of a second molecule is suggestive of an intercalative or minor groove binding (15).…”

“…Non-covalent drug-DNA interaction has been classified into three types including intercalation, groove and external bindings. These interactions can change DNA conformation and torsional tension, and also dissociate protein-DNA interactions lightly and may break DNA strands (1,2). There are various anticancer agents derived from herbs that interact with DNA such as mitoxantrone (3), curcumin (4), quercetin (5) and saffron metabolites (6,7).…”