Antifungal activity, DNA and lysozyme binding affinity of Pd(II) and Pt(II) complexes bearing N,N-pyridylbenzimidazole ligand

The lysozyme- and DNA-binding affinities of the biologically active cisplatin analogues, Pd(II) (1) and Pt(II) (2) complexes of functionalized N,N-pyridylbenzimidazole ligand, are reported. The electronic transitions were studied by time-dependent density functional theory. Complex 1 exhibits interesting antifungal activity against Candida albicans (MIC = 32 μg mL⁻¹; 64 nM) and Cryptococcus neoformans (MIC = 16 μg mL⁻¹, 32 nM). Complex 1 is covalently bound to DNA and lysozyme via the elimination of the chloride ligand(s). When complex 2 interacts with lysozyme, two adduct peaks are observed in the mass spectrum corresponding to binding of Pt(II) ion to lysozyme.