Mixed ligand copper(<scp>ii</scp>)-diimine complexes of 2-formylpyridine-<i>N</i><sup>4</sup>-phenylthiosemicarbazone: diimine co-ligands tune the<i>in vitro</i>nanomolar cytotoxicity
Radhakrishnan Kartikeyan, Dhanashree Murugan, Tamilarasan Ajaykamal, Manikandan Varadhan, Loganathan Rangasamy, Marappan Velusamy, Mallayan Palaniandavar, Venugopal Rajendiran
Abstract
at 48 h. 4 shows (57.2 nM) higher cytotoxicity than 1 (181.5 nM) at 24 h incubation; however, notably, 1 demonstrates phenomenal cytotoxicity (7.0 nM) higher than 4 (13.6 nM) at 48 h incubation. The selectivity index (SI) reveals that complexes 1 and 4 are 53.5 and 37.3, respectively, times less toxic to HEK293 normal cells than to cancerous cells. Except for [CuL]+, all the complexes generate ROS to different extents at 24 h, with 1 producing the highest amount, which is consistent with their redox properties. Also, 1 and 4 exhibit, respectively, sub-G1 and G2-M phase cell arrest in the cell cycle. Therefore, complexes 1 and 4 have the potential to emerge as promising anticancer agents.