New bi-phosphonate derivative: Synthesis, characterization, antioxidant activity in vitro and via cyclic voltammetry mode and evaluation of its inhibition of SARS-CoV-2 main protease

•New bisphosphonate acid was synthesized and identified.•Antioxidant activities as DPPH scavenging and ferric reducing power is performed to elucidate the inhibitory capacity of the investigated compound.•Scavenging superoxide activity via cyclic voltammetry: assessment of IC50 and thermodynamic factors (Gibbs free energy, stability constant Kb).•Molecular docking of the ligand with SARS-CoV-2 main protease, determination of the binding energy attributed to the best conformation ΔG° and of interactions of hydrogen and Hydrophobicbonds, while comparing to chloroquine drug. In this study, we have synthesized a new molecule labeled HBPA. Its molecular structure was determined by spectroscopic methods such as: FT-IR, NMR (1H, 13C and 31P); our compound is subjected to two antioxidant activities assays: DPPH scavenging and ferric reducing antioxidant power (FRAP); in the results, HBPA was expanded remarkable inhibition when compared especially to standard BHT with values of 14.936±0.808 and 7.1486±0.0645 μg/ml, respectively; in addition to the scavenging test of superoxide anion integrated in electrochemical process, it elucidated a strongly stable interaction towards the radical by evaluating the thermodynamic descriptors (Gibbs free energy ΔG° and the binding constant Kb). Besides, the electrochemical behavior of HBPA was distinguished by an irreversible system and for the electrochemical regime adopted at the surface of the electrode; a diffusion governed by a slow charge transfer was deduced. The molecular docking of HBPA was conducted beside Chloroquine and the obtained results were indicated a significant binding with active sites of the SARS-CoV-2 main protease (Mpro). [Display omitted]