Antibacterial Activity of Pyridine Nucleus-Containing Schiff Bases and their Copper and Cobalt Complexes

Abstract

Pyridine is a valuable nitrogencontaining heterocyclic compound widely
present in numerous naturally occurring
bioactive molecules and extensively utilized in
pharmaceutical drug design and development.
In this study, three pyridine-based Schiff bases,
namely 2-((pyridine-4-ylimino)methyl)phenol
(L1), 4-nitro-2-((pyridine-4-ylimino)methyl
)phenol (L2) and 4-bromo-2-((pyridine-4-
ylimino)methyl)phenol (L3). Their
corresponding copper and cobalt complexes
were synthesized and characterized using
melting point determination, FTIR
spectroscopy, NMR spectroscopy, and
elemental analysis. The Schiff bases acted as
bidentate ligands, coordinating through the
imine nitrogen and phenolic oxygen atoms. The
in vitro antibacterial activity of the synthesized
compounds was evaluated against
Staphylococcus aureus, Enterococcus faecalis,
Escherichia coli, and Pseudomonas
aeruginosa. Results revealed that antibacterial
activity increased with concentration. Notably,
the cobalt complexes demonstrated
pronounced antibacterial efficacy, particularly
against S. aureus, suggesting their potential as
promising candidates for further development
as antibacterial agents. However, additional
toxicological and formulation studies would be
required before considering practical
applications such as hospital antiseptic
formulations.