Synthesis and Antitumor Activity Evaluation of Cyclometalated <i>2H‐</i>Indazole Ruthenium(II) and Iridium(III) Complexes
R. Nishanth Rao, Rajeeva Lochana Panchangam, Venkatraman Manickam, M. M. Balamurali, Kaushik Chanda
Abstract
Abstract In this work, a series of novel C−N cyclometalated 2 H ‐indazole Ru(II) and Ir(III) complexes were synthesized, wherein chelating ligands with substituents like H, and isopropyl group in the R 4 position of the phenyl ring of the 2 H ‐indazole chelating ligand are present. The cytotoxicity of Ru(II) and Ir(III) complexes has been evaluated against different human cancer cell lines (HeLa, MCF‐7, and A549) in a concentration‐dependent manner. The new iridium complex with isopropyl substituent in the phenyl ring of the 2 H ‐indazole moiety showed good cytotoxic activity against MCF‐7 cells with an IC 50 value 3.5 μM. The complex also exhibited cytotoxicity comparable to that of cisplatin. The ability of this compound inducing apoptosis was tested by nuclear condensation, cell membrane blebbing and caspase 3/7 activation. Further, this iridium complex is capable of inhibiting cancer cell migration when tested in MCF‐7 cell line. Subsequently, we have studied the DNA binding and protein binding ability of the newly synthesized iridium complex.