Synthesis, crystal structures, in vitro biological evaluation of zinc(II) and bismuth(III) complexes of 2-acetylpyrazine N(4)-phenylthiosemicarbazone

Two metal complexes formulated as [Zn(L)2]2·H2O (1) and [Bi(L)(NO3)2(CH3OH)] (2), where HL = 2-acetylpyrazine N(4)-phenylthiosemicarbazone, have been synthesized and characterized by elemental analysis, IR, MS, NMR and single-crystal X-ray diffraction studies. Biological studies, carried out in vitro against selected bacteria and the K562 leukemia cell lines, respectively, have shown that the free ligand and its two complexes may be endowed with important biological properties, especially HL with MIC = 3.90 μg/mL against Pseudomonas aeruginosa, the zinc(II) complex 1 with IC50 = 1.0 μM against K562 leukemia cell lines, respectively. The compounds HL and 1 may exert their cytotoxicity activity via induced loss of mitochondria membrane potential (MMP).

Graphical abstract2-Acetylpyrazine N(4)-phenylthiosemicarbazone (HL) and its metal complexes formulated as [Zn(L)2]2·H2O (1) and [Bi(L)(NO3)2(CH3OH)] (2) have been synthesized and structurally characterized. Biological studies, carried out in vitro against selected bacteria and the K562 leukemia cell lines, respectively, have shown that the free ligand and its complexes may be endowed with important biological properties. Compounds HL and 1 may exert their cytotoxicity via induced loss of MMP.Figure optionsDownload full-size imageDownload as PowerPoint slide