| The need to find new compounds that effectively target resistant-bacteria is becoming more and more urgent now that even drugs of last resort, such as vancomycin, are no longer immune to resistance. Mersacidin is a type B lantibiotic, active against gram-positive bacteria, including vancomycin-methicillin resistant S. aureus; which suggests that it may represent a new lead for antibacterial therapeutics. Present in this work are our recent efforts towards the total synthesis of the lantibiotic with the ultimate goal to develop derivatives that would enable the study of its mode of action, and thus, the design of novel drugs.;The CD-ring of mersacidin seems to play an important role in the bioactivity of the lantibiotic. In order to get access to this complex molecule, we have successfully synthesized the (Z)-AviMeCys subunit found in the ring by decarbonylation/decarboxylation of a carboxylic acid, and most importantly, we have synthesized a (Z)-AviMeCys D-ring containing cycle by application of these methods.;In order to get access to the CD-ring we have designed a synthesis that would allow for the late stage introduction of the double bond by these methods and we have successfully synthesized an advanced intermediate for the formation of this domain. Our approach for the introduction of (Z)-AviMeCys would eventually make the synthesis of the lantibiotic amenable by solid phase peptide synthesis. Finally, we also present the successful synthesis of the B-ring of mersacidin by application of solid phase peptide synthesis. We believe that our work represents an important contribution to the field of lantibiotics and to the ultimate synthesis of mersacidin. |
