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

2-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.