N-substituted 2-aminoimidazole Inhibitors of MRSA Biofilm Formation Accessed Through Direct 1,3-bis(tert-butoxycarbonyl)guanidine Cyclization

Antibiotic resistance is a significant problem and is compounded by the ability of many pathogenic bacteria to form biofilms. A library of N-substituted derivatives of a previously reported 2-aminoimidazole/triazole (2-AIT) biofilm modulator was constructed via α-bromoketone cyclization with 1,3-bis(tert-butoxycarbonyl)guanidine, followed by selective substitution. Several compounds exhibited the ability to inhibit biofilm formation by three strong biofilm forming strains of methicillin resistant Staphylococcus aureus (MRSA). Additionally, a number of members of this library exhibited synergistic activity with oxacillin against planktonic MRSA. Compounds with this type of dual activity have the potential to be used as adjuvants with conventional antibiotics.