Boronic modified quercetin molecules: Synthesis and biological investigations with molecular docking verification

Abstract

Quercetin is an essential compound belonging to the flavanol group, which is a derivative of bioflavonoids found in fruits and vegetables. Quercetin has various pharmacological properties such as anticancer, antioxidant, anti-inflammatory, antiviral, antihistamine, and antitumor. Based on these important properties, the quercetin compound was modified with various boronic acids and new types of quercetin-based boronic (QB) compounds were synthesized. In the current study, we have synthesized quercetin-based boronic compounds to obtain more effective molecules by doping the biological activity properties of quercetin naturally in its structure. In this purpose, 6‑methoxy naphthalene boronic acid, 1,4-phenyl diboronic acid, 4‑methoxy phenylboronic acid, 6‑methoxy-3-pyridinylboronic acid, 3-formyl-4-methoxyphenyl boronic acid compounds were used. The synthesized compounds were structurally enlightened by mass, 13C NMR, 1H NMR, and FTIR spectroscopy. Then, the antioxidant, anticholinesterase, antiurease, antityrosinase and toxic-cytotoxic effects of these molecules were tested. QB compounds synthesized and examined in vitro in the study were also analyzed by molecular docking. Molecular docking, one of the structure-based drug design methods, has been applied to support experimental data. It was determined that QB compounds showed more significant efficacy than the reference substance employed in antioxidant and enzyme activity studies. As a result of molecular docking analysis, the binding energy parameter values and active binding site amino acid residues of the compounds were determined. Obtained novel boronic compounds might be associated as drug candidate due to consistent results both in experimental and molecular docking results.