Time-Dependent Cytotoxic Properties of Terpyridine-Based Copper Complexes.

Five copper complexes supported by terpyridine ligands were prepared and characterized, viz. [Cu3 Cl4 (naphtpy)2 ][CuCl2 ] (1), [Cu2 Cl2 (naphtpy)2 ](ClO4 )2 (2), [CuCl2 (naphtpy)]2 (MeOH)3 (H2 O) (3), [CuCl2 (Cltpy)] (4) and [Cu(Cltpy)2 ](ClO4 )2 (5); (where naphtpy stands for 4'-((naphthalen-2-yl)methoxy)-2,2':6',2''-terpyridine and Cltpy for 4'-chloro-2,2':6',2''-terpyridine). Their ability to interact with DNA was investigated, and their cytotoxic behaviour was examined with three cells lines, namely human ovarian carcinoma cells (A2780), their derived cisplatin-resistant line (A2780cis), and human cervix adenocarcinoma cells (HeLa). All compounds show good cytotoxic properties (especially after 72 h of incubation). Remarkably, two compounds, 4 and 5, are still almost inactive after 24 h (particularly 4), but are highly active after 72 h, with IC50 values in the low-micromolar to sub-micromolar range. Compounds 1 and 2 induce necrosis, whereas late apoptosis is observed with 3-5, 4 exhibiting a behaviour close to that of cisplatin.