Synthesis, structural characterization and anti-proliferative activity of thiosemicarbazones

Thiosemicarbazones are a class of compounds which have been extensively studied for their anti-proliferative biological properties. The biological properties include antitumor, antibacterial, antiviral and antimalarial, with many diseases studied and reported in the literature. Their mechanism of action is speculated to be through DNA intercalation, Ribonucleotide reductase inhibition, Topoisomerase II inhibition etc. A series of substituted acenaphthenequinone thiosemicarbazones were synthesized and characterized using 1H NMR and mass spectrometry. These were expected to potentially show an inhibition mechanism through DNA intercalation. In this study, a series of &agr;-(N) heterocyclic thiosemicarbazone based on 8-hydroxy-2-quinoline carboxaldehyde and 2-acetylquinoline were synthesized and characterized using 1H NMR. A series of 2-acetylthiazole thiosemicarbazones were characterized using 1H NMR and mass spectrometry. This series of compounds showed two equilibrium solution forms when dissolved in deuterated dimethyl sulfoxide. Their equilibrium constants were calculated based on the integration values obtained from 1H NMR peaks. Palladium complexes of ATZ-dMTSC and ATZ-PTSC were synthesized and characterized using 1H NMR. Some of these synthesized compounds were studied for anti-proliferative activity against Bacteria: Bacillus subtilis G+, Staphylococcus aureus G+, Escherichia coli G-, and Pseudomonas aeruginosa G-. Yeast: Candida albicans, and Saccharomyces cerevisiae, and the mold studied was Aspergillus niger..