Synthesis and characterization of a new oxovanadium Schiff base of salicylaldehyde-arginine- hydroxyquinoline: antibacterial and antifungal activities determination

A new oxovanadium complex, [VO(Sal-Arg)(Hq)] (Sal = salicylaldehyde, Arg = L-arginine, and Hq = 8-hydroxyquinoline), was synthesized in methanol and characterized by 1 HNMR, UV–Vis, and FTIR spectroscopy as well as cyclic voltammetry and elemental analysis techniques. These results suggest an octahedral geometry, with a 1:1 molar ratio of tridentate Schiff base and bidentate quinoline ligands coordinated with vanadium (V) and formed a stable complex in the air.To investigate the in vitro antimicrobial activity of the Schiff Base, the title complex was compared with complex [VO(C 9 H 6 NO) 2 (CH 3 O)] (as an oxovanadium complex coordinated with two chelating quinolin-8-olate ligands) against some gram-positive (Staphylococcus aureus, Enterococcus faecalis (Group D Streptococcus), Bacillus subtilis), gram-negative bacteria (Escherichia coli), and fungal strains (Candida albicans, Aspergillus Niger). The Schiff base oxovanadium complex showed significant activity against most tested microorganisms, with varying degrees of inhibition zone diameters compared to the [VO(C 9 H 6 NO) 2 (CH 3 O)] complex. The presence of the azomethine group in the[VO(Sal-Arg)(Hq)] structure inhibits enzyme activity in the bacterial membrane.