Monocyclic β-lactams: new structures for new biological activities.

The azetidinone core-structure offers a unique approach to the design and synthesis of new derivatives with unique biological properties. During the last two decades researches convincingly demonstrated that the prospect of structural modifications of monocyclic β-lactams with specific substituents is an effective procedure for the detection and improvement of important pharmacological effects different from antibacterial activity. As a matter of fact, new β-lactam compounds demonstrated biological activity as inhibitors of a wide range of enzymes. This review reports the latest developments on monocyclic β-lactam compounds activity as anticancer, antitubercular, HFAAH inhibitors, HDAC inhibitors, anti-inflammatory drugs (tryptase inhibitors), Cathepsin K inhibitors, and vasopressin inhibitors. We attempted to highlight the intertwined relationships between structural features and biological activities, by analysing groups anchored on the three positions of the azetidinone ring as sources of molecular diversity.