Antibacterial and cytotoxicity studies with epoxides obtained from eugenol and analogues

Eugenol (1) is well stablished bioactive compound. Many reports have shown its antibacterial, antifungal, antiviral and antiparasitic potential. While working in the synthesis of new and potential heterocyclic antifungal agents, we had to prepare some epoxide intermediates from eugenol and from its O-methylated and nitro analogues. We took advantage of the availability of these intermediates (2-5) and decided to evaluate their antibacterial and cytotoxic potential (CC50, Vero cells), following the findings of others that pointed out eugenol epoxide as an effective antibacterial compound. However, unlike what was reported in the literature, no evidence of antibacterial activity against S. aureus ATCC 6538, E. coli ATCC 25922 and S. mutans ATCC 25175 was observed with epoxides 2-5 in the disk diffusion assays (concentration range 500-31.25 µg.mL-1). On the other side, confirming what is related to the presence of epoxide groups, the cytotoxicpotential with them was clearly enhanced in relation to eugenol.