Construction of supramolecular helices and breaking the helicity by forming supramolecular β-sheet structures using suitable self-assembling pseudopeptide building blocks

Guha, S., Drew, M. G.B. and Banerjee, A. (2010) Construction of supramolecular helices and breaking the helicity by forming supramolecular β-sheet structures using suitable self-assembling pseudopeptide building blocks. Crystal Growth & Design, 10 (11). pp. 4716-4721. ISSN 1528-7483 doi: 10.1021/cg901581r

Abstract/Summary

Bis-valine derivatives or malonamide (Guha,S.; Drew, M.G.B. Small 2008, 4, 1993-2005) and a bis-valine derivative of 1,1-cyclopropone dicarboxamide were used as building blocks for the construction of supramolecular helical structures. The six-membered intramolecular hydrogen-bonded scaffold is formed, and this acts as a unique supramolecular synthon for the construction of a pseudopeptide-based supramolecular helical structure. However, in absence of this intramolecular hydrogen bond. intermolecular hydrogen bonds are formed among the peptide strands. This leads to a supramolecular beta-sheet structure. Proper selection of the supramolecular synthon (six-membered intramolecular hydrogenbonded scaffold) promotes supramolecular helix formation, and a deviation from this molecular structure dictates the disruption of supramolecular helicity. In this study, six crystal structures have been used to demonstrate that a change in the central angle and/or the central core structure of dicarboxamides can be used to design either a supramolecular helix or a beta-sheet.