Peptoid residues and ?-turn formation

A set of terminally protected tripeptoids containing a residue of either N-methylglycine or N-isobutylglycine in position i + 1/ i + 2 were synthesized and tested for intramolecularly H-bonded beta-turn formation. By exploiting FT-IR absorption and H-1 NMR techniques, their folding tendencies were compared with those of a variety of reference peptides. The amount of beta-turn induction and the relative extent of the various types of intramolecularly H-bonded beta-turn conformers were determined in chloroform solution. Copyright (C) 2002 European Peptide Society and John Wiley Sons, Ltd.