Monocyclic β-lactams as antibacterial agents: facing antioxidant activity of N-methylthio-azetidinones.

A series of N-methylthio-β-lactams with antibacterial activity were thoroughly evaluated as antioxidants. We found that only the presence of a polyphenolic moiety anchored to the β-lactam ring ensured an adequate antioxidant potency. New compounds, efficiently combining in one structure antioxidant and antibacterial activity, may provide a promising basis for the development of new leads useful in adverse clinical conditions such as in cystic fibrosis patients, in whom colonization by MRSA and epithelial damage by chronic pulmonary oxidative stress take place.