Synthesis of a 7-deazaguanine-functionalized β-amino acid:: Improved specificity of β-peptide helix organization

Nucleobase-functionalized beta-peptides are a suitable scaffold for the construction of well-defined tertiary structures organized by nucleobase pair recognition. Since guanine-rich oligomers are especially known to form higher aggregates, an enantiomerically pure 7-deazaguanine ((z)G)-functionalized nucleo-beta(3)-amino acid was synthesized from a beta-lactam derivative as a key intermediate. Incorporated into beta-peptide 14-helices it was possible to reduce aggregation phenomena and to increase recognition selectivity. Evidence for basepair-mediated helix recognition was obtained by temperature-dependent UV and CD spectroscopy. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)