Chemical, spectroscopic characterization, DFT studies and initial pharmacological assays of a silver(I) complex with N-acetyl-l-cysteine

A new silver(I) complex with N-acetyl-l-cysteine (NAC) of composition AgC5H8NO3S·H2O was synthesized and characterized by a set of chemical and spectroscopic measurements. Solid-state 13C nuclear magnetic resonance (SSNMR) and infrared (IR) analyses indicate the coordination of the ligand to Ag(I) through the sulfur atom. The Ag–NAC complex is slightly soluble in dimethyl sulfoxide. It is insoluble in water, methanol, ethanol, acetone and hexane. Antibacterial activity of the silver complex with N-acetyl-l-cysteine (Ag–NAC) was evaluated by antibiogram assays using the disc diffusion method. The compound showed an effective antibacterial activity against Staphylococcus aureus (Gram-positive), Escherichia coli and Pseudomonas aeruginosa (Gram-negative) bacterial cells. Biological analysis for evaluation of a potential cytotoxic effect of Ag–NAC was performed using HeLa cells derived from human cervical adenocarcinoma. The complex presented a significant cytotoxic activity, inducing 80% of cell death at a concentration of 200 μmol L−1.

Optimized geometry and geometric parameters for silver(I) complex with N-acetyl-l-cysteine: Ag (light gray); S (yellow); O (red); N (blue); C (gray) and H (white).Figure optionsDownload as PowerPoint slideResearch highlights
► A novel silver(I) complex with N-acetyl-L-cysteine.
► IR and Solid-state NMR studies permitted to confirm sulfur coordination.
► The compound shows biological activities against Gram-negative and positive bacteria.
► The complex also exhibits cytotoxic activities against HeLa tumorigenic cells.