Diazabicyclooctanes (DBOs): a potent new class of non-β-lactam β-lactamase inhibitors

The β-lactams have been among the most successful classes of antibacterial agents for the past half century. However, a disturbing increase in resistance to β-lactams has been noted among Gram-negative bacteria, which is attributable to β-lactamase enzymes not within the spectrum of currently marketed β-lactams or β-lactam/β-lactamase inhibitor combinations. Diazabicyclooctanes (DBOs) were first investigated as β-lactam mimics in the mid-1990s by chemists at Hoechst Marion Roussel (now part of Sanofi-Aventis) and proved to be a rich source of β-lactamase inhibitors (BLI). Two members of this novel series of highly potent, broad spectrum BLIs are now in clinical development and their properties are reviewed here.

► Diazabicyclooctanes (DBO) are a novel class with a β-lactam-like mode of action.
► The first DBOs to reach clinical development are β-lactamase inhibitors.
► DBO β-lactamase inhibitors inhibit class A and class C β-lactamases and are more potent than current commercial inhibitors.
► DBOs with an additional ring (DTOs?) have antibacterial activity.