Biomimetic formation of gramicidin S by dimerization-cyclization of pentapeptide precursor on solid support

Abstract The biomimetic formation of gramicidin S, cyclo(- d -Phe-Pro-Val-Orn-Leu-) 2 , by the dimerization and cyclization of pentapeptide precursor without the protection of δ-amino group of the Orn residue was examined on a solid support. The cyclization of H- d -Phe-Pro-Val-Orn-Leu-oxime on a resin with an oxime group of 0.62 mmol/g in 1,4-dioxane directly gave gramicidin S in a 50% yield. The dimerization–cyclization mode on the solid support was similar to that of the biosynthesis of gramicidin S on an enzyme.