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 Ph3SbCl2 or Ph3BiCl2 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)(Ph3Sb)OH, and the bismuth(V) complex is a dinuclear compound bridged by an oxygen atom, (Lp)2(Ph3Bi)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.

Antiparasitic activities of novel ruthenium/lapachol complexes

“…In fact, there are some findings showing that lapachol-metal complexes are biologically more active than the free molecule [15][16][17][18]. Ruthenium complexes are considered to be one of the most promising types of metal compounds for cancer treating, due its interesting chemical properties, such as: versatility in ligand exchange, octahedral geometry and variability of oxidation states [19,20].…”

Importance of metal complexes for development of potential leishmanicidal agents

“…[Ru II (h 6 -p-cymene 5 )Cl 2 (KTZ)], 27 was the most active complex against L. major promastigotes with LD 50 , Relative Activity (LD 50 and >150, respectively. This complex was synthesized from addition KTZ to a suspension of [Ru II (h 6 -p-cymene 5 )Cl 2 ] 2 in acetone and stirred at room temperature.…”

“…Most notably complex, Organometallic "piano-stool" arene-Ru II -CTZ compound [Ru II (h 6 -p-cymene) 5 Cl 2 (CTZ)], 26 was prepared from the addition of a solution of [Ru II (h 6 -p-cymene 5 )Cl 2 ] 2 in acetone to CTZ and stirred at room temperature. This complex increased the activity of CTZ by Relative Activity [(LD 50 of CTZ)/(LD 50 of Ru II -CTZ complex)] ¼ 110 against promastigotes of L. major, without appreciable toxicity to normal human osteoblasts (IC 50 Mammalian cells ¼ 7.5 mM) resulting in nanomolar 50% lethal dose (LD 50¼ 15 nM) and therapeutic index [TI¼ (IC 50 in mammalian cells)/(LD 50 in parasites)] >500. In a high-content imaging assay (HCIA) on L. major infected intraperitoneal mouse macrophages (70% inhibitory concentration), complex 26 showed significant inhibition on the proliferation of intracellular amastigotes of L. major (IC 70 ¼ 29 nM).…”

Recent advances on antimony(III/V) compounds with potential activity against tumor cells

“…17) has been synthesized and characterized by IR, and NMR spectroscopy and X-ray crystallography [32]. The compound contains sixcoordinated antimony.…”