Synthesis and cytotoxicity evaluation of copper(II) complexes with polypyridines and 5-benzyltetrazole

In the present study, four new mixed-ligand copper(II) complexes with 5-benzyltetrazole (HL) and polypyridine ligands (phen - 1,10-phenanthroline, dmphen - 4,7-dimethyl-1,10-phenanthroline, bipy - 2,2'-bipyridine, dmbipy - 2,2'-bi-4-picoline), namely, [Cu-2(bipy)(2)(L)(4)] (1), [Cu-2(dmbipy)(2)(L)(4)]center dot H2O(2 center dot H2O), [Cu(phen)(L)(2)] (3), [Cu(dmphen)(L)(2)] (4), have been synthesized. Complexes have been characterized by EPR and IR-spectroscopy, elemental, thermogravimetric and powder X-ray diffraction analysis. Two crystal structures of the copper(II) complexes with 5-benzyltetrazole, namely [Cu-2(bipy)(2)(L)(4)] (1) and [Cu-2(dmbipy)(2) (L)(4)] (2), were established for the first time by a single-crystal X-ray diffraction study. All complexes have been screened in vitro for their cytotoxic activity against two cancer cell lines: larynx carcinoma (Hep2), hepatocellular carcinoma (HepG2) and breast adenocarcinoma (MCF-7). The order of efficacy was 4 > 3 > 2 center dot H2O > 1. Complexes [Cu(phen)(L)(2)] (3) and [Cu(dmphen)(L)(2)] (4) demonstrated the highest cytotoxicity. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

In this study, four new mixed-ligand copper(II) complexes were synthesized and characterized. Two crystal structures of the complexes with 5-benzyltetrazole were established for the first time. The complexes were screened for cytotoxic activity against three cancer cell lines, with [Cu(phen)(L)(2)] and [Cu(dmphen)(L)(2)] showing the highest cytotoxicity.