RP-TLC chromatogram of investigated compounds and ethidium bromide (EB) (1.6 mM) (A), of compounds 1A, 1B, 2A, and 2B, and EB incubated with ctDNA (1.6 mM) for 60 min at 37°C (B), of compounds 1A, 1B, 2A, 2B and EB (1.6 mM) spotted directly on the spot of ctDNA (1.6 mM) (C) and of ctDNA (1.6 mM) (D). Plate: silanized silica gel 60F254 (0.25 mm). Mobile phase: methanol/sodium hydrogen phosphate (50 mM; pH 7.4) mixture (8:2 v/v). ctDNA was visualized by spraying with anisaldehyde, compounds, and E.B. were visualized by U.V. illumination.