Mononuclear discrete Ag(I) complexes of aryl substituted (E)-N-phenyl-1-(pyridin-3-yl)methanimine: In vitro biological activities and interactions with biomolecules

Abstract

The synthesis of three pyridinyl imines (L1-L3) with electron-donating and electron-withdrawing functional groups, as well as their silver(I) complexes (1a-3a, 1b-3b and 1c-3c), resulted from our ongoing search for novel metallodrugs with potential pharmacological activity. Various analytical and spectroscopic analyses were used to characterize the Ag(I) complexes. The single crystal X-ray diffraction analysis of complexes 3a and 3b in the solid state confirmed their linear geometry around the Ag(I) center. In vitro antibacterial properties of the complexes evaluated using the minimum inhibitory concentration (MIC) method revealed that complexes containing either a Me- or an F-substituent exhibited greater activity. The ferric-reducing antioxidant power (FRAP) experiment revealed that complexes with hydroxyl substituents have high antioxidant potential. These complexes with IC50 values ranging from 0.86 to 2.47 mg mL-1 outperformed ascorbic acid, with an IC50 of 2.68 mg mL-1. The reported complexes bound to CT-DNA via intercalation mode with significant binding constants for complexes whose ligands bore the OH- substituent. Bovine serum albumin (BSA) binding affinity to the complexes ranges from moderate to high. The studied complexes with methyl substituents are promising anti-cervical cancer candidates.