Synthesis, characterization and antiprotozoal studies of some metal complexes of antimalarial drugs

Metal complexes of the antimalarials trimethoprim (TMP), chloroquine (CQ), and pyrimethamine (pyrm) formulated as [Mn(TMP)Cl-2(CH3OH)], [Co(TMP)(2)Cl-2(CH3OH)], [Pt(CQ)(2)Cl-2] and [Cu(pyrm)(2)(CH3COO)(2)] have been synthesized and characterized by elemental analysis, magnetic susceptibility measurements, IR and UV-Vis spectroscopy. The IR and electronic spectra are consistent with the proposed geometry for the complexes. The Mn(II) and Pt(II) complexes are four coordinate while the Cu(II) and Co(II) have octahedral geometry. The complexes were tested for in vitro activity against cultures of Trypanosoma cruzi, L. donovani, T. b. rhodesiense and the resistant strains of Plasmodium falciparum to determine their antiprotozoal activities and for their cytotoxicity with L-6 cells. The Pt(II) complex of chloroquine showed enhanced activity against the resistant strain of Plasmodium falciparum.