Synthesis, characterization of novel thiosemicarbazone derivatives and preparation of thiosemicarbazone added antibacterial textiles

Bacterial infectious diseases have been significantly controlled with the discovery of antibiotics. However, over time, antibiotic resistance developed by bacteria through various mechanisms has revealed the need for the development of new antimicrobial agents. Textile products offer a suitable environment for the growth of bacteria. For this reason, the use of antibacterial textiles, especially in places with high human circulation such as hospitals, public transport and hotels, contributes to the prevention of bacterial infections and their spread. In this study, seven phenylurea acetophenone derivatives with different substituents and seven thiosemicarbazone derivatives synthesised by their reaction with thiosemicarbazide were synthesised. The antimicrobial activity of the thiosemicarbazones was evaluated by microdilution method against bacterial strains Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 700603 and clinically isolated Candida albicans fungal strain. The antibacterial activity of the compounds against bacterial strains was determined with minimum inhibition concentration (MIC) values of 7.81-250 µg/mL. They also exhibited antifungal activity against C. albicans fungal strains with MIC values of 62.5-125 µg/mL. Among the thiosemicarbazones, compound E6 with -4Cl-3CF3 substituent showed very strong antibacterial activity against S. aureus and E. faecalis bacterial strains with MIC values of 7.81 and 15 µg/mL, respectively. We aimed to add antibacterial properties to textile materials with the strong activity of meta-substituted phenylurea thiosemicarbazone derivative E6 compound, E7 compound and para-substituted E4 compound having the same closed formula as E6. The antibacterial activities of the fabrics were evaluated qualitatively by the agar diffusion method and quantitatively against S. aureus and E. coli bacterial strains under conditions similar to the ASTM E2149 standard. In cotton fabrics, nearly 100% bacteriocidal activity was detected against S. aureus in high concentration applications and nearly 100% bacteriostatic activity was detected in lower concentrations. In polyester fabrics, E4 and E6 compounds were found to exhibit 54.21-71.78% and 56.94-99.31% bacteriostatic activity against both bacterial strains, respectively.