Novel Cu(II)-quinoline carboxamide complexes: structural characterization, cytotoxicity and reactivity towards 5'-GMP

Three new ligands, N-(8-quinolyl)pyridine-2-carboxamide (HL1), N-(8-quinolyl)glycine-N'-Boc-carboxamide (HL2), N-(8-quinolyl)-L-alanine-N'-Boc-carboxamide (HL3), and their Cu(II) complexes have been synthesized. Crystallographic data reveal that complex I, [Cu(L1)(Ac)(H2O)], is penta-coordinated with a square-pyramidal geometry while complexes V [Cu(L2')(H2O)] and VI [Cu(L3')(H2O)] are tetra-coordinated to give square planar geometry. In vitro tests showed that the Cu(II) complexes with L1 (I-IV) exhibited cytotoxicity at a concentration of 10(-8) M against murine leukemia P-388 and human leukemia HL-60 cell lines, which is more potent than cisplatin. However, ligands HL2 and HL3 and their corresponding copper complexes demonstrated very weak in vitro activities towards the cell lines examined. ESMS data shows that complex I binds rapidly with 5'-GMP to form 1:1 and 2:2 adduct.