Figure 1.

Major products formed following β-lactamase-catalysed carbapenem degradation. The structures of the different tautomeric and epimeric forms of the carbapenem-derived pyrroline ring are shown in red. The stereochemical assignments in brackets refer to the C-2 configuration, indicated with asterisks. The structure of the initial acyl-enzyme complex formed following the nucleophilic attack of serine (in serine β-lactamases or penicillin-binding proteins) with the carbapenem β-lactam ring is shown (shaded in grey).