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.

In this study, we have synthesized a new molecule labeled HBPA. Its molecular structure was determined by spectroscopic methods such as: FT-IR, NMR ( 1 H, 13 C and 31 P); 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 K b ). 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 (M pro ).