Ya que salio el tema de los Kahalalides y analogos varios ...
Bourel-Bonnet L, Rao KV, Hamann MT, Ganesan A.
School of Chemistry, University of Southampton, Southampton SO17 1BJ, United Kingdom.
The marine natural product kahalalide A, a cyclic depsipeptide, was prepared by total synthesis on solid-phase. A backbone cyclization strategy was followed, using the Kenner sulfonamide safety-catch linker. By NMR comparison of synthetic and naturally isolated material, the stereochemistry of the methylbutyrate side chain was established as (S). Several analogues were synthesized and tested for antimycobacterial activity. The results indicate that the alcohol functional group in the serine and threonine residues is important, while the methylbutyrate side chain can be replaced by an achiral hexanoate with an increase in activity.