Synthesis, characterization and cell viability test of six vanadyl complexes with acetylacetonate derivatives

Vanadium compounds are known to display a number of therapeutic effects, namely insulin-mimetic and cardiovascular effects. Evidence of the antiproliferative and proapoptotic activity of a number of vanadyl complexes, together with their low toxicity, establishes these metal compounds as promising antitumoral therapeutic agents. In the present work, we describe the synthesis and full characterization of six new vanadyl complexes with acetylacetonate derivatives bearing asymmetric substitutions on the β-dicarbonyl moiety: the complexes were characterized in the solid state as well as in solution. Our results show that all complexes are in square pyramidal geometry; cis isomers in the equatorial plane are favored in the presence of strongly coordinating solvents. EPR evidence suggests that all complexes are in the bis-chelate form, although in two cases the mono-chelated complex seems to be present as well. Preliminary tests carried out on non-tumor and tumor cell lines show that these complexes are effective in suppressing cell viability and elicit a distinct response of tumor and non-tumor cells.