Synthesis and Application of Unprotected Cyclic Peptides as Building Blocks for Peptide Dendrimers

摘要

We describe an efficient regiospecific method for cyclization of unprotected peptide segments based on intramolecular transthioesterification of unprotected cysteinyl peptide thioesters under the control of ring-chain tautomeric equilibrium in aqueous buffered solutions at pH ranging from 5 to 7.5. The initial cyclization to form an intramolecular thioester under the ring-chain tautomeric equilibrium is reversible and could be performed in relatively high concentrations without observable oligomerization.