Synthesis of 4′-(2-ferrocenyl)-2,2′:6′2′′-terpyridine: Characterization and antiprotozoal activity of Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes

•A series of transition metal complexes of ferrocenyl terpyridine is described.•Four complexes were found active against Entamoeba histolytica.•Two complexes were found active against Plasmodium falciparum.•All the active compounds were non cytotoxic at the concentration of 10 μg/mL.

A terpyridine ligand Fctpy was reacted with divalent metals (Cu, Co, Mn, Ni and Zn), yielding five complexes of general formula [Metal(Fctpy)2][PF6]2. The structure of Fctpy was determined by single crystal X-ray diffraction studies. The complexes characterized using various spectroscopic techniques suggested an octahedral geometry around the central metal ion. These complexes were screened for their antiamoebic, trypanocidal and antimalarial activities. It was found that, complexes 2 and 3 showed better IC50 values than metronidazole against HM1:IMSS strain of Entamoeba histolytica. A substantial parasitic inhibition was not observed for the trypanocidal activity. However, for the erythrocytic stage of W2 strain of Plasmodium falciparum, the complexes inhibited β-hematin formation. At the concentration of 10 μg/mL, these complexes did not display toxicity.

Graphical abstractSynthesis of transition metal complexes of ferrocenyl terpyridine and their antiparasitic activity; five complexes were found to be more potent than the standard drug.Figure optionsDownload full-size imageDownload as PowerPoint slide