Fig. 1. β-Lactam antibiotics and β-lactamase inhibitors. Chemical structure of the β-lactam ring, alongside generic structures of the major β-lactam antibiotic subclasses and representatives from these subclasses. The β-lactam ring in these structures is shown in red. Numbering typically begins from the atom in the top position of the ring fused to the β-lactam (e.g., sulfur in penicillins). The structures of common β-lactam-based and non-β-lactam-based β-lactamase inhibitors (BLIs) are also shown.