Pleuromutilin antibacterial agents: patent review 2001 – 2006

Derivatives of the naturally occurring pleuromutilin, of which certain analogs were successfully developed in veterinary medicine, have regained interest in the past few years as promising antibacterial agents with potential for human use. This review provides an overview of patents related to pleuromutilin derivatives during 2001 – 2006. Representative compounds along with their antibacterial activities are selected for this purpose, and a section focuses on pleuromutilins in clinical development and practice, in particular retapamulin. Most of the patents reveal the usefulness of different analogs as antibacterial agents effective against multi-drug-resistant organisms, whereas one patent disclosed the in vitro effectiveness of pleuromutilins against Helicobacter pylori. Few patents disclosed novel formulations, methods of preparation in order to improve efficacy, delivery, stability upon storage and synthesis of pleuromutilins.