Synthesis and Biological Evaluation of 4/5‐Aroyl‐2‐aminoimidazoles as Microbial Biofilm Inhibitors

Abstract

We had earlier used Oroidin, a 2‐aminoimidazole‐pyrrole natural microbial biofilm inhibitor, as a structural prototype to develop its 4/5‐acyl modified form as an anti‐biofilm lead for further optimization. Herein, as a part of our efforts towards that direction, we report the design, synthesis, as well as anti‐bacterial, anti‐biofilm, and fungal adhesion inhibition activities of various 4/5‐aroyl‐2‐aminoimidazoles. These simplified Oroidin analogues are moderately active against bacterial biofilms and attest to the need for an aliphatic acyl linker that was part of the original 4/5‐acyl modified Oroidin lead. From our studies, protonation propensity of the 2‐aminoimidazole group of the series emerges as an important pre‐requisite for potent antibiofilm activity. Also, the fungal biofilm screening studies identified analogue 8 b as an active molecule.