Synthesis and characterization of copper(II) complexes of pyridine-2-carboxamidrazones as potent antimalarial agents

Synthesis, crystal structure and biological activities of a novel amidrazone derivative and its copper(II) complex — A potential antitumor drug

“…In addition, the shift of the amide ν(C_O) to lower frequencies (by 4 cm − 1 ) and the azomethine ν(C_N) to higher frequencies (by 9 cm − 1 ) confirms the involvement of these groups in the copper complexation. The shift of azomethine C_N stretching vibrations on metal complexation towards higher frequencies has been previously observed for the other amidrazone derivatives [25,30]. What is more, the very intense band observed at 1525 cm − 1 in the IR spectrum of the free ligand and attributed to the ν(C_N) vibrations of 2-pyridyl rings in the spectrum of 3 transforms into a broad absorption peak with the maximum at 1531 cm − 1 .…”

“…These properties made them useful in design and synthesis of novel functional materials [23,24]. Furthermore, amidrazone derivatives are of interest as ligands in medicinal chemistry following the reports on antitumor properties of their Cu(II), Au(III) and Pt(II) complexes [25][26][27] or antibacterial [28,29], antimalarial [30] and insulinmimetic activities [22] of many other 3d transition metal complexes.…”

Crystal structures ofN′-aminopyridine-2-carboximidamide andN′-{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide

“…Semi-empirical structural calculations demonstrate that the N-N bond in these azines is rotationally soft, thereby allowing significant twisting at little energy cost (Kesslen et al, 1999). Copper azine and imine complexes possess a significant antimalarial and antitumor action (Gokhale et al, 2001a(Gokhale et al, ,b, 2003. Coordination complexes of 2-acetylpyridine-pyridine-2-carboxamidrazone have been obtained with cadmium(II), copper(II), nickel(II) and manganese(II) ions.…”

“…For literature on N 0 -aminopyridine-2-carboximidamide and related molecules, see Case et al (1965). For the synthesis of N 0 -{[1-(pyridin-2-yl)ethylidene]amino}pyridine-2-carboximidamide and analogues, see Gokhale et al (2001aGokhale et al ( ,b, 2003 and Xu et al (1997Xu et al ( , 2000. For the coordination chemistry of N 0 -aminopyridine-2-carboximidamide, see Xu et al 2000, Gokhale et al (2001a) and Yue et al (2004,2006).…”

Review on supermolecules as chemical drugs

“…Some Cu(Ⅱ) complexes also exhibited notable antimalarial activity. The complexation of pyridine-2-carboxamidrazones with copper(Ⅱ) salts could enhance antimalarial activity significantly [139] , these results attracted many researchers' great interests in organic Cu(Ⅱ) complexes as antimalarial agents. Copper(Ⅱ) complex of buparvaquone [Cu(buparvaquone) 2 -(C 2 H 5 OH) 2 ] was found to give stronger antimalarial activity against Plasmodium falciparum strain than its Ni(Ⅱ), Co(Ⅱ), Fe(Ⅱ) and Mn(Ⅱ) complexes [140] , and exhibited better antimalarial activity both in vitro and in vivo than the parent drug buparvaquone.…”