Synthesis and Anticancer Activity of Gold(I)-Chloroquine Complexes

Abstract

Two new gold(I) -chloroquine complexes, Au(CQ)(Cl) (1) and Au(CQ)(tgta) (2), were prepared and their most probable structure were established through a combination of different spectroscopic and analytical techniques. Their interaction with two important targets of action, DNA and thioredoxin reductase (TrxR), were nvestigated. These studies showed that complexes 1 and 2 displayed two types of interaction with DNA, covalent binding through the metal center, and additionally a non-covalent interaction that is electrostatic in the case of complex 1, but intercalative for complex 2, which is similar to that displayed by free CQ. The experimental data indicated that these gold-CQ complexes also possess the ability to inhibit TrxR. These results led us to test their cytotoxicity against 6 tumor cell lines. The complexes displayed cytotoxic activity against the PC-3, SKBR-3, HT-29, LoVo and B16/BL6 lines. These finding suggest that gold(I)-CQ compounds, particularly [Au(CQ)(PPh₃)]PF₆, are promising chemotherapeutic alternatives in the search of anticancer agents.