Antimicrobial Activity of Highly Fluorinated Thiocarbamates and Dithiocarbamates

Background: The widespread occurrence of resistance to current antibiotics has triggered increasing research efforts to design and develop innovative antibacterial and antifungal agents that could overcome such antimicrobial resistance. Objective: The aim of this work was the in vitro evaluation of twelve highly fluorinated Nmonosubstituted thiocarbamates and dithiocarbamates and six non-fluorinated analogs against nine bacterial strains and three fungal species. Methods: The in vitro antimicrobial activity against the tested microrganisms was evaluated using the microdilution broth method. Results: Escherichia coli ATCC 8739, Salmonella sp., Staphylococcus aureus 6539 and all the three fungi (Aspergillus niger, Aspergillus flavus and Penicillium expansum) exhibited the highest rate of susceptibility, whilst Enterococcus faecuim ATCC 19436 and particularly Escherichia coli DH5α were less susceptible. Thiocarbamate (1i) and dithiocarbamate (2i) showed both the lowest MIC values (3.9 μg/mL) and the widest spectrum of antibacterial activity. Furthermore, the N-ethyl derivatives inhibited more efficiently the growth of bacteria than N-aryl analogs. Conclusion: The fluorinated compounds showed, in general, a relatively more potent antibacterial activity than non-fluorinated counterparts. The results indicate that these thiocarbamates and dithiocarbamates could be promising candidates as potential antimicrobial agents.