Human Topoisomerase IIα Inhibition by New Palladium (II) and Platinum (II) Complexes of a 2-Acetylpyrazine tert-butylthiosemicarbazone Ligand

Abstract

The new ligand, 2-acetylpyrazine- tert-butylthiosemicarbazone (APT-tBTSC) and its palladium
(II) and platinum (II) complexes have been synthesized. After the synthesis process, the ligand
and metal complexes were characterized and analyzed by 1 H Nuclear Magnetic Resonance
spectrometry (NMR), 13 C NMR, 1 H- 13 C HSQC, and 1 H- 15 N HSQC. We have determined that this
thiosemicarbazone compound ligates to Pd(II) and Pt(II) in a tridentate monoanionic fashion
forming a metal complex with the formula [Pd(APZ-tBTSC)Cl] and [Pt(APZ-tBTSC)Cl]. The
metal complexes were tested for anti-proliferative biological behavior with a panel of seven
microbes. The palladium and platinum complexes are found to be highly active against Gram
positive bacteria. Human topoisomerase IIα inhibition solution concentration found is between 2-
6 micro-molar.