Kilicaslan_2025_Int.J.Biol.Macromol__140314

This study investigated the binding mechanism of taxifolin (TA), daidzein (DA), and S-equol (SQ) flavonoids with fish sperm double helix DNA (dsDNA) under the simulated physiological pH condition using UV-Vis and photoluminescence spectroscopy, as well as viscometric methods. Binding constants (K(b)) for the flavonoids to dsDNA were determined as 1.8 x 10(4) M(-1) for SQ, 1.6 x 10(4) M(-1) for DA and 1.7 x 10(4) M(-1) for TA, indicating moderate affinity. The groove binding mode was confirmed by competitive binding studies with ethidium bromide or rhodamine B, UV-Vis spectrophotometry and viscosity evaluation. Additionally, the compounds showed high cholinesterase (ChE) inhibitory activity, with TA being the most potent, particularly against BChE (IC50 = 2.93 microM) and AChE (IC50 = 6.42 microM). Antioxidant activities were also evaluated using DPPH and ABTS assays, with TA showing the lowest IC50 values. Additionally, molecular docking studies were performed to assess the interactions and binding affinities of all compounds with AChE and BChE enzymes. As a result, the studied compounds were found to prefer minor groove binding. This research analyzed the contribution of the structure-activities of natural flavones in terms of their biological properties, which is important for their future application against diseases.