Direct modifications of the cyclic peptide Polymyxin B leading to analogues with enhanced in vitro antibacterial activity.

Synthetic modifications have been made directly to the cyclic peptide core of polymyxin B, enabling the further understanding of structure activity relationships of this antimicrobial peptide. Such modified polymyxins are also substrates for enzymic hydrolysis, enabling the synthesis of a variety of semi-synthetic analogues, resulting in compounds with increased in vitro antibacterial activity.