Spectroscopic analysis on the resveratrol–DNA binding interactions at physiological pH

The interaction of resveratrol with calf thymus deoxyribonucleic acid (ctDNA) under physiological conditions (Tris–HCl buffer solutions, pH 7.4) was studied by spectroscopy, fluorescence spectroscopy and viscosity measurement method, respectively. Results indicated that a complex of resveratrol with ctDNA was formed with a binding constant of K17 °C = 5.49 × 103 L mol−1 and K37 °C = 1.90 × 104 L mol−1. The fluorescence quenching mechanism of acridine orange (AO)-ctDNA by resveratrol was shown to be a static quenching type. The thermodynamic parameters of the complex were calculated by a double reciprocal method: ΔrHms=4.64×104 J mol−1, ΔrSms=231.8 J K−1 mol−1 and ΔrGms=−2.54×104 J mol−1 (37 °C). Spectroscopic techniques together with viscosity determination provided evidences of intercalation mode of binding for the interaction between resveratrol and ctDNA.

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► Resveratrol could binds to ctDNA with a high affinity at physiological pH.
► The fluorescence quenching mechanism of AO-ctDNA by resveratrol was a static quenching type.
► The viscosity of ctDNA was enhanced with increasing concentration of resveratrol.
► The interaction between resveratrol and ctDNA might occur via intercalative mode.