Groove binding between ferulic acid and calf thymus DNA: spectroscopic methodology combined with chemometrics and molecular docking studies

Abstract Ferulic acid (FA), a dietary phenolic acid compound, is proved to possess numerous biological activities. Hence, this study was devoted to explore the interaction between FA and calf thymus DNA (ctDNA) by UV − vis absorption, fluorescence, circular dichroism (CD) spectroscopy combined with multivariate curve resolution-alternating least-squares (MCR − ALS) and molecular docking studies. The concentration curves and the pure spectra of compositions (FA, ctDNA and FA − ctDNA complex) were obtained by MCR − ALS approach to verify and monitor the interaction of FA with ctDNA. The groove binding mode between FA and ctDNA was confirmed by the results of melting analysis, viscosity measurements, single-stranded DNA experiments, and competitive studies. The binding constant of FA − ctDNA complex was 4.87 × 104 L mol−1 at 298 K. The values of enthalpy (ΔH°) and entropy (ΔS°) changes in the interaction were −16.24 kJ mol−1 and 35.02 J mol−1 K−1, respectively, indicating that the main binding forces were hydrogen bonds and hydrophobic interactions. The result of CD spectra suggested that a decrease in right-handed helicity of ctDNA was induced by FA and the DNA conformational transition from the B-form to the A-form. The results of docking indicated that FA binding with ctDNA in the minor groove. These findings may be conducive to understand the interaction mechanism of FA with ctDNA and the pharmacological effects of FA. Communicated by Ramaswamy H. Sarma