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N‐(diethylthiocarbamoyl)benzimidoyl chloride reacts with methyl esters of glycine, L‐alanine, L‐valine under formation of pro‐ligands 1 which undergo de‐esterification in reactions with Cu(CH3COO)2 and finally form complexes 2 with the compositions of [{Cu(L‐gly)}4] (2 a), [{Cu(L‐ala)}∞] (2 b) and [{Cu(L‐val)}∞] (2 c). In all complexes, Cu(II) ion is coordinated by a dianion {L2−} via its (O,N,S) donor set and a bridging carboxylate O atom, and thus, adopts a distorted square‐planar coordination sphere. Treatment of complexes 2 with equimolar amounts of o‐phenanthroline results in the formation of square pyramidal ternary complexes with the compositions of [Cu(L)phen] (L=L‐gly, L‐ala, L‐val) (3). Antiproliferative effects of the compounds on MCF‐7 and Hep‐G2 cancer cells were studied. Generally, the ternary complexes 3 are more active than the complexes 2 and the pro‐ligands 1. In each series of compounds, the derivatives of L‐valine show higher cytotoxicity than those of L‐alanine and glycine. [ABSTRACT FROM AUTHOR]

Two novel benzoylthioureas derived from gallic acid, (tri‐O‐acetyl)galloyl‐N,N‐diethylthiourea HL1, and cinnamic acid, cinnamoyl‐N,N‐diethylthiourea HL2 have been successfully prepared and characterized by means of elemental analysis, IR, NMR, high‐resolution MS, and X‐ray crystallography. The organic ligands react with Ni(AcO)2 and Cu(AcO)2 in MeOH under formation of bis‐complexes with the compositions of [M(L)2] (M=Ni2+, Cu2+; L=L1, L2). Similar reactions with Co(AcO)2, however, result in Co(III) tris‐complexes [Co(L)3] (L=L1, L2) with the metal ions oxidized presumably by atmospheric dioxygen. X‐ray crystallography and spectroscopic characterization reveal a cis square‐planar coordination in the bis‐complexes and facial octahedral geometry in the tris‐complexes. In all of metal complexes, the deprotonated organic compounds ({L1}− and {L2}−) serve as (S,O)‐bidentate ligands. The ligand HL1 and its Ni(II) and Cu(II) complexes exhibit weak antiproliferative effects on the human MCF7 breast and HepG2 liver cancer cells with IC50 values in the range of 60–115 μM. Surprisingly, the tris‐complex [Co(L1)3] exhibits high cytotoxicity with IC50 values of 22.23±1.58 μM for MCF7 and 28.30±3.09 μM for HepG2 cancer cells. The activity against MCF7 cells is even more than that of cisplatin under the same conditions. [ABSTRACT FROM AUTHOR]