Proposed binding mechanism of galbanic acid extracted from Ferula assa-foetida to DNA

•Galbanic acid was extracted from Ferula assa-foetida.•The galbanic acid has cytotoxic effect.•Binding of GA to DNA was studied by voltammetry, spectroscopy, molecular docking.•The GA is binding to DNA through the partial intercalations.

Recently, galbanic acid (GA), a sesquiterpenoid coumarin, has been introduced as an apoptotic and geno/cytotoxicity agent. In the present study, GA has been extracted from Ferula assa-foetida, a native medicinal plant in Iran, and characterized by 1H NMR, mass spectroscopy. Additionally, spectroscopic studies have been performed in order to investigate its DNA-interaction mode. The electrochemical behavior of GA has been studied by cyclic voltammetry (CV) in various scan rates. In neutral media (pH = 7.3) one irreversible cathodic peak was obtained at − 1.46 V, while in higher scan rates an irreversible one was determined at − 1.67 V. According to the voltametric data GA can be easily reduced by 2e−/2H+ mechanism at hanging mercury drop electrode (HMDE). The interaction of GA with ct-DNA was evaluated by CV, differential pulse voltammetry (DPV), enhancement fluorescence, UV-Vis, FT-IR spectroscopy and molecular docking. The molecular docking study shows that the GA interacts to DNA on partial intercalation mode via DNA groove binding and forms a complex by van der Waals and electroastatic interactions. In addition, the thermodynamic parameters of GA-DNA complex were investigated with ΔH°, ΔS° and ΔG° values of 15.81 KJ mol− 1, 133.95 J mol− 1 and − 23.10 KJ mol− 1, respectively. All data revealed that the GA is binding to DNA by van der Waals and electrostatic interactions through the partial intercalations from the DNA's grooves.

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