Solid-phase synthesis of an A-B loop mimetic of the Cε3 domain of human IgE: Macrocyclization by Sonogashira coupling

Abstract

The solid-phase synthesis of a cyclic peptide containing the 21-residue epitope found in the A-B loop of the Cε3 domain of human immunoglobulin E has been carried out. The key macrocyclization step to form the 65-membered ring is achieved in ∼15% yield via an "on-resin" Sonogashira coupling reaction which concomitantly installs a diphenylacetylene amino acid conformational constraint within the loop.