Ribosomal synthesis of dehydrobutyrine- and methyllanthionine-containing peptides.

We report here the ribosomal synthesis of methyllanthionine-containing cyclic peptides involving a site-specific incorporation of vinylglycine under the reprogrammed genetic code, followed by the isomerization of the vinylglycine to dehydrobutyrine, and the subsequent intramolecular Michael addition of a cysteine residue placed at a downstream position of the vinylglycine.