Synthesis, characterisation and antimicrobial activity of some new thiosemicarbazones

Four different thiosemicarbazones, viz., m-anisaldehyde, thiosemicarbazone (1a), acetophenone-thiosemicarbazone (2a), 2-hydroxy-5-methyl benzene-1,3dicarbal thiosemidicarbazone (3a) and 2,6-diacetyl-pyridine thiosemidicarbazone (4a) have been synthesized by the reaction of different carbonyl compounds with thiosemicarbazide (a) and were characterized by their TLC, elemental analysis and IR spectral data. All compounds have been screened for their biocidal activity in vitro by serial dilution method against gram +ve bacteria Staphylococcus aureus and gram -ve Escherichia coli and two common fungi Aspergillus niger and Aspergillus flavus. All the thiosemicarbazones have shown several-fold increase in antimicrobial activity as compared to their constituting thiosemicarbazide and carbonyl compounds.