Affiliation:
1. Centre for Organometallic Chemistry, School of Chemistry Bharathidasan University Tiruchirappalli India
2. School of Chemistry University of Hyderabad Gachibowli Telangana India
Abstract
New half‐sandwich dinuclear arene ruthenium complexes of the general formula [(η6‐p‐cymene)Ru(k2‐S‐arylthiourea)Cl] (1–3) have been synthesized. The structural characterization of the ruthenium complexes has been established using analytical and various spectroscopic techniques. The bidentate coordination of the ligands and pseudo‐octahedral geometry around the ruthenium(II) ion are confirmed by the single‐crystal X‐ray diffraction technique. In vitro antiproliferative activity of the complexes has been studied by MTT (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyl tetrazolium bromide) assay against lung (A549), breast (MCF‐7), cervical (HeLa), ovarian (A2780) cancer cells, and non‐cancerous NIH‐3T3 mouse embryonic fibroblast cells. The results show that all the complexes exhibit excellent cytotoxicity towards all the cancer cells, with a low IC50 concentration compared with cisplatin. Further, the mode of cancer cell death has been examined by AO–EB (acridine orange/ethidium bromide), and DAPI (4',6‐diamidino‐2‐phenylindole) staining studies demonstrate the apoptosis‐associated cell morphological changes. Furthermore, the quantitative differentiation of late apoptosis has been elucidated by flow cytometry employing dual staining of Annexin V‐FITC and propidium iodide, which involves the transfer of phosphatidylserine to the external leaflet of the cytoplasmic membrane.