Synthesis, characterization, and in vitro anti-neoplastic activity of novel vic-dioximes bearing thiosemicarbazone side groups and their mononuclear complexes

Two novel vicinal dioxime ligands containing thiosemicarbazone units, (2E)-2-[4-(diethylamino)benzylidene]-N-[(1Z, 2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydrazine carbothioamide ((LH2)-H-1) and (2E)-2-[4-(dimethylamino)benzylidene]-N-[(1Z,2E)-N-hydroxy-2-(hydroxyimino)ethanimidoyl]hydra-zinecarbothioamide ((LH2)-H-2), were synthesized. Using the HL-60 human leukemia cell line, the in vitro anti-neoplastic activity of these thiosemicarbazone-oxime derivatives was evaluated. Mononuclear nickel(II), copper(II), and cobalt(II) complexes with a metal: ligand ratio of 1:2 for both the (LH2)-H-1 and (LH2)-H-2 ligands were also synthesized. To characterize these compounds, Fourier transform-infrared spectroscopy (FT-IR), mass spectrometry (MS), magnetic susceptibility measurements, H-1 and C-13 nuclear magnetic resonance (NMR), ultraviolet-visible (UV-Vis) absorption spectroscopy, heteronuclear multiple-bond correlation (HMQC), and elemental analysis were performed. For (LH2)-H-1, (LH2)-H-2, and each of their derivatives, antiproliferative effects against HL-60 cells were exhibited and the associated IpC50 values ranged from 5 mu M to 20 mu M. Furthermore, (LH2)-H-1 and its derivatives inhibited the proliferation of HL-60 cells more effectively than (LH2)-H-2, and 5 mu M [Cu((LH)-H-1)(2)] exhibited the strongest antiproliferative activity. (C) 2014 Elsevier Inc. All rights reserved.