Antibacterial activity and molecular studies of non-symmetric POCOP-Pd (II) pincer complexes derived from 2,4-dihydroxybenzaldehyde (2,4-DHBA)

A series of non-symmetric POCOP-Pd(II) pincer complexes including an aldehyde group in the meta-position of the aromatic pincer-backbone were prepared and characterized. The molecular structure of complex 1-Pd was unambiguously determined by single crystal X-ray diffraction analysis, showing a square-planar geometry around the metal fragment and the presence of the aldehyde functionality at the pincer ligand backbone. The evaluation of the antibacterial activities of complexes 2-Pd and 3-Pd against gram-positive and gram-negative strains was performed. Complex 3-Pd was the most active against S. aureus ATCC 25923 strain with a MIC value of 8 mu g center dot mL(-1). We also determined by molecular docking studies, that pincer complexes 2-Pd and 3-Pd may interact with some key bacterial enzymes such as KPC-2 and PBP2A.