Synthesis of carbazole-linked cyclic and acyclic peptoids with antibacterial activity

This paper describes the synthesis of several novel cyclic and acyclic peptoids, the former structurally comprising a tripeptide moiety linked through a carbazole scaffold. In a key step, a ring-closing metathesis reaction was used giving efficient access to this new class of cyclic peptoids. The target compounds were tested against Staphylococcus aureus (ATCC 6538P) and their minimum inhibitory concentration (MIC) values were determined. These compounds showed moderate to poor activities with MIC values ranging from 15–250 μg/mL.