Synthesis and anticancer activities of novel Pt (II) and Pd (II) complexes with 4‐(2,2′:6′,2″‐terpyridin‐4′‐yl)phenol as ligand

Abstract

Traditional platinum (Pt)‐based drugs have limited use in cancer treatment because of their toxicity, which generates the need for new Pt complexes with effective anticancer activity. Two potent prospective anticancer small molecule drug complexes, PtLCl (1) and PdLCl (2) (L:4‐[2,2′:6′,2′‐terpyridin‐4′‐yl]phenol), were synthesized via a low‐temperature solvothermal method. The structures of the complexes are characterized by a four‐coordinated rhombus plane, according to single‐crystal X‐ray diffraction studies. The complexes 1 and 2 were further characterized using several techniques including powder X‐ray diffraction, infrared spectroscopy, and cyclic voltammetry. Cytotoxicity was assessed using flow cytometry and morphological observations of HeLa cells. The findings demonstrate that both complexes were highly effective at inducing cell death, and the tumor inhibition rate of 1 was greater than that of 2, with total tumor inhibition of 92.3% and 72.3%, respectively, after 24 h. In addition, fluorescence and UV–vis spectroscopy showed that these complexes interacted with DNA through the embedding methods. The four‐coordinated planar structure and π–π stacking could prevent DNA transfer and replication, which has the potential for more effective cancer cell eradication through intercalation. Therefore, these two complexes are promising candidates for the development of new Pt‐ and Pd‐based anticancer drugs.