A new dinuclear Ag(I)–<i>N</i>-heterocyclic carbene complex derived from <i>para</i>-xylyl linked <i>bis</i>-imidazolium salt: synthesis, crystal structure, and <i>in vitro</i> anticancer studies

Abstract

This manuscript describes synthesis, spectral (FT-IR and NMR), and structural studies of a new para-xylyl linked bis-imidazolium salt (1) and the dinuclear Ag(I)–N-heterocyclic carbene complex (2). Both 1 and 2 were tested for their potential against human colon cancer (HCT 116) and breast cancer (MCF-7) cell lines. According to cell viability measurements using MTT assay, the test compounds showed dose-dependent cytotoxic activities against both cell lines. The complex displayed significant activity (IC50 = 20.9 μM for HCT 116 and 2.4 μM for MCF-7) compared to their respective imidazolium salt (IC50 > 200 μM for HCT 116 and = 137 μM for MCF-7). The photomicrographs of the cells treated with 2 revealed that the cytotoxic efficacy of 2 is mainly by deposition of silver in the cytoplasm of the affected cells since clear signs of black silver deposits in the cytoplasm of the affected cells were observed.