Interaction of diplacone and eriodictyol with DNA by multi-spectroscopic and molecular modelling methods

Abstract

Diplacone was a C-geranylated flavanone derivative with great antioxidation and anti-inflammatory activity. Its structure could be identified as eriodictyol with a C10 side chain (geranyl) substituted at the C-6 position, and the geranyl was considered as the active group. Interaction properties with ctDNA of diplacone and eriodictyol were investigated simultaneously by two spectral fluorescent probes of ethidium bromide (EB) and methyl green (MG), as well as UV–vis absorption, DNA melting techniques (Tm), viscosity measurements and molecular docking analysis. The groove binding of these two flavanone derivatives was confirmed by UV–vis absorption and dye displacement studies using fluorophores conjugated ctDNA systems and agreed with the changes of Tm and viscosity. Results also indicated that these two compounds all had a strong interaction with ctDNA, and the binding ability of diplacone was stronger than that of eriodictyol possibly because of its geranyl substituent group. Molecular docking provided detailed computational interaction of diplacone and eriodictyol with DNA, which proved the groove binding of diplacone/eriodictyol -DNA complex and the geranyl group could supply extra interaction with DNA and enhance the affinity of diplacone.