Synthesis and electrochemical investigation of chiral amine bis(phenolate)- boron complexes: In vitro antibacterial activity screening of boron compounds

Abstract

A new class of low-cost, easily-synthesizable and modifiable chiral amine bis(phenolate) ligand (L), its chiral boron complex (LB), and five different salen groups (1-(3-Aminopropyl) imidazole (LB1), N,N-Diethyl-p-phenylenediamine (LB2), 2-Picolylamine (LB3), 4′-Aminoacetophenone (LB4), and 4-Amino-2,2,6,6-tetramethyl piperidine (LB5)) containing chiral boron complexes were synthesized in this study. These newly synthesized chiral compounds were fully characterized by 1H and 13C NMR, FT-IR, UV–Vis, and LC-MS/MS spectroscopy, melting point, elemental analysis, and cyclic voltammetry techniques. The in vitro antibacterial activity of the synthesized different chiral boron complexes was tested against four pathogenic bacteria strains using the resazurin-based broth microdilution method, and the MIC values of each boron complex were determined. Based on the overall results, the N, N-Diethyl-p-phenylenediamine group containing chiral boron complex (LB2) showed the highest activity against all bacterial strains, with the lowest MIC value of 4 µg/mL which is nearly in the range of values for commercial antibacterial drugs.