Crystal structure of N-{N-[N-(tert-butoxycarbonyl)-l-α-aspartyl]-l-α-aspartyl}-l-α-aspartic acid 14,24,34-trimethyl ester 31-2-oxo-2-phenylethyl ester {Boc-[Asp(OMe)]3-OPac}

Abstract

In the title homotripeptide {Boc-[Asp(OMe)]3-OPac}, C28H37N3O13, all peptide bonds adopt an s-trans conformation with respect to the N—H and C=O groups. In the crystal, N—H...O hydrogen bonds result in an infinite parallel β-sheet structure running along the b-axis direction. The Boc protecting group at the N-terminus of the peptide is disordered over two sites with occupancy factors of 0.504 (5) and 0.496 (5).

Keywords

• crystal structure
• peptide
• hydrogen bonding
• homopeptide