Interaction of β-Carbolines with DNA: Spectroscopic Studies, Correlation with Biological Activity and Molecular Docking

Quantitative interaction of twelve beta-carboline derivatives with calf thymus deoxyribonucleic acid (ctDNA) using spectroscopic techniques was evaluated. The values of the binding constants (K-b) obtained for the complexes formed with the ctDNA ranged from 3.30 x 10(2) to 1.82 x 10(6) mol L-1, being the beta-carbolines with the N, N-dimethylaminophenyl group at position 1 the ones which presented the highest Kb values. The binding mode between the beta-carbolines evaluated and ctDNA was proposed from the KI assay, competition with ethidium bromide, and DNA thermal denaturation profile (T-m), where it was possible to infer that the evaluated alkaloids interact with ctDNA preferably via intercalation. Additionally, the correlation of K-b values obtained with the IC50 of seven human cancer cell lines was carried out. From this study, it was possible to observe a linear relation among most of the evaluated derivatives, obtaining r(2) values from 0.5360 to 0.9600. In addition, in silico molecular docking was performed to corroborate the experimental results.