Drug-DNA Interaction Studies of Acridone-Based Derivatives.

N10-alkylated 2-bromoacridones are a novel series of potent antitumor compounds. DNA binding studies of these compounds were carried out using spectrophotometric titrations, Circular dichroism (CD) measurements using Calf Thymus DNA (CT DNA). The binding constants were identified at a range of K=0.3 to 3.9×10(5) M(-1) and the percentage of hypochromism from the spectral titrations at 28-54%. This study has identified a compound 9 with the good binding affinity of K=0.39768×10(5) M(-1) with CT DNA. Molecular dynamics (MD) simulations have investigated the changes in structural and dynamic features of native DNA on binding to the active compound 9. All the synthesized compounds have increased the uptake of Vinblastine in MDR KBChR-8-5 cells to an extent of 1.25- to1.9-fold than standard modulator Verapamil of similar concentration. These findings allowed us to draw preliminary conclusions about the structural features of 2-bromoacridones and further chemical enhancement will improve the binding affinity of the acridone derivatives to CT-DNA for better drug-DNA interaction. The molecular modeling studies have shown mechanism of action and the binding modes of the acridones to DNA.