Total Synthesis and Activity of the Metallo-β-lactamase Inhibitor Aspergillomarasmine A.

Resistance to β-lactam antibiotics is mediated primarily by enzymes that hydrolytically inactivate the drugs by one of two mechanisms: serine nucleophilic attack or metal-dependent activation of a water molecule. Serine β-lactamases are countered in the clinic by several codrugs that inhibit these enzymes, thereby rescuing antibiotic action. There are no equivalent inhibitors of metallo-β-lactamases in clinical use, but the fungal secondary metabolite aspergillomarasmine A has recently been identified as a potential candidate for such a codrug. Herein we report the synthesis of aspergillomarasmine A. The synthesis enabled confirmation of the stereochemical configuration of the compound and offers a route for the synthesis of derivatives in the future.