DNA-Harmalol interaction: The effects of Harmalol on the solution structure of calf-thymus DNA studied by FTIR spectroscopy

The interaction of hamalol with calf-thymus DNA was investigated at physiological pH with drug/DNA (phosphate) molar ratio(r) of 1/40. Fourier transform infrared difference spectroscopy were used to establish correlations between spectral changes and drug binding mode, sequence selectivity, DNA conformation and structural properties of harmalol-DNA complexes in aqueous solution. Spectroscopic results indicated that harmalol is a weak intercalator with affinity for A-T rich regions. At low drug concentration (r=1/40), the A-T region is the main target of drug intercalation.