Two New β-strand Mimics Original Research Article

In a previous report, Nowick and co-workers described β-strand mimic A, which duplicates the structure and hydrogen-bonding pattern of one edge of a tetrapeptide in a β-strand conformation (Nowick, J. S.; Pairish, M.; Lee, I. Q.; Holmes, D. L.; Ziller, J. W. J. Am. Chem. Soc. 1997, 119, 5413). β-Strand mimic A is composed of a 5-amino-2-methoxybenzoic acid unit linked to a 5-hydrazino-2-methoxybenzamide unit by means of an acylhydrazine group. This paper introduces two related β-strand mimics (B and C) and reports their comparison to β-strand mimic A. β-Strand mimic B is composed of a 5-amino-2-methoxybenzoic acid unit linked by a diacylhydrazine group to a fumaramide unit; β-strand mimic C is composed of a 5-amino-2-methoxybenzoic acid unit linked by a diacylhydrazine group to a peptide. β-Strand mimics A–C were connected to tripeptide (Phe-Ile-Leu) groups by means of 1,2-diaminoethane diurea turn units to form artificial β-sheets 1–3. 1H NMR studies, involving ROESY, chemical shift, coupling constant, and variable temperature experiments, reveal that 1–3 adopt hydrogen-bonded antiparallel β-sheet conformations and establish that all three templates are viable β-strand mimics.