title: Transition metal complexes of buparvaquone as potent new antimalarial agents. 1. Synthesis, X-ray crystal-structures, electrochemistry and antimalarial activity against Plasmodium falciparum.
abstract: New Cu(II), Ni(II), Co(II), Fe(II), and Mn(II) metal complexes of buparvaquone [3-trans(4-tert.-butylcyclohexyl)methyl-2-hydroxy-1,4-naphthoquione] (L1H) have been synthesized and characterized using IR, electron paramagnetic resonance (EPR) spectroscopy, microanalytical methods and single crystal X-ray diffraction methods. The single crystal structures were determined for ligand L1H [space group P-1 with a=6.2072(14) A, b=10.379 (2) A, c=13.840 (3) A, V=878.7(3) A(3), Z=2, D(calcd.)=1.234 mg/m(3)] and copper complex [Cu(L1)(2)(C(2)H(5)OH)(2)] C1 [space group I2/a with a=17.149(14) A, b=9.4492(8) A, c=26.946(3) A, V=4335.3(7)A(3), Z=4, D(calcd.)=1.233 mg/m(3)]. All the metal complexes along with the parent ligand have been studied for their electrochemical properties using cyclic voltammetric techniques. The compounds were tested for their in vitro antimalarial activity against Plasmodium falciparum strains. A correlation between the antimalarial activity and the redox property of these complexes is presented. The copper complex C1 exhibits significantly higher growth inhibitory activity both in vitro and in vivo than the parent ligand.
authors.affiliation: Department of Chemistry, University of Pune, Ganeshkind Road, Pune 411007, India.
authors.forename: Nikhil H
authors.initials: NH
authors.lastname: Gokhale
authors.forename: Subhash B
authors.initials: SB
authors.lastname: Padhye
authors.forename: Simon L
authors.initials: SL
authors.lastname: Croft
authors.forename: Howard D
authors.initials: HD
authors.lastname: Kendrick
authors.forename: Wendy
authors.initials: W
authors.lastname: Davies
authors.forename: Christopher E
authors.initials: CE
authors.lastname: Anson
authors.forename: Annie K
authors.initials: AK
authors.lastname: Powell
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D018360:Crystallography, X-Ray; D004563:Electrochemistry; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D009285:Naphthoquinones / Q000737:chemistry* / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010963:Plasmodium falciparum / Q000187:drug effects*; D013055:Spectrophotometry, Infrared
chemical_list: D000962:Antimalarials; D008670:Metals; D009285:Naphthoquinones; C046326:buparvaquone