Antimony(V) and bismuth(V) complexes of lapachol: Synthesis, crystal structure and cytotoxic activity

Abstract

Antimony(V) and bismuth(V) complexes of lapachol have been synthesized by the reaction of Ph 3SbCl 2 or Ph 3BiCl 2 with lapachol (Lp) and characterized by several physicochemical techniques such as IR, and NMR spectroscopy and X-ray crystallography. The compounds contain six-coordinated antimony and bismuth atoms. The antimony(V) complex is a monomeric derivative, (Lp)(Ph 3Sb)OH, and the bismuth(V) complex is a dinuclear compound bridged by an oxygen atom, (Lp) 2(Ph 3Bi) 2O. Both compounds inhibited the growth of a chronic myelogenous leukemia cell line and the complex of Bi(V) was about five times more active than free lapachol. This work provides a rare example of an organo-Bi(V) complex showing significant cytotoxic activity. © 2011 by the authors; licensee MDPI, Basel, Switzerland.