High antitumor activity of 5,7-dihalo-8-quinolinolato tin(IV) complexes

Abstract

Three tin(IV) complexes [Sn(ClQ)2Cl2] (1), [Sn(BrQ)2Cl2] (2) and [Sn(ClIQ)2Cl2] (3) were prepared (H-ClQ = 5,7-dichloro-8-hydroxylquinoline, H-BrQ = 5,7-dibromo-8-hydroxylquinoline, H-ClIQ = 5-chloro-7-iodo-8-hydroxylquinoline) and their in vitro cytotoxicities against BEL7404, SKOV-3, NCI-H460, HL-7702 cell lines were evaluated. The complexes showed high anti-proliferative activity toward the tested cell lines with IC50 values ranging from 20 nM to 5.11 μM. Compared with 5,7-dihalo-8-quinolinol, most complexes exhibited significantly enhanced cytotoxicity (except 2 against SKOV-3 and NCI-H460). They also displayed some selective cytotoxicity favoring the tested tumor cells over the normal human liver HL-7702 cells. Compared with their quinolinol ligands, complexes 1-3 bind more strongly with DNA. Intercalation is the most probable binding mode for both the complexes and their quinolinol ligands.