34897-55-7Relevant academic research and scientific papers
CD spectra in methanol of β-oligopeptides consisting of β-amino acids with functionalized side chains, with alternating configuration, and with geminal backbone substituents - Fingerprints of new secondary structures?
Seebach, Dieter,Sifferlen, Thierry,Mathieu, Pascal A.,Haene, Andreas M.,Krell, Christoph M.,Bierbaum, Daniel J.,Abele, Stefan
, p. 2849 - 2864 (2007/10/03)
β-Hexa-, β-hepta-, and β-nonapeptides, 1-6, which carry functionalized side chains (CO2R. CO-2, (CH2)4NH+3, CH2-CH=CH2) consisting of β3-amino-acid residues of alternating configuration, or which carry geminal substituents in the 2- or 3-positions of all residues, have been synthesized (Schemes 1-3), and their CD spectra in MeOH are reported (Figs. 2-6). Strong Cotton effects (Θ> 105) are indicative of the presence of chiral secondary structures. It is suggested by simple modelling (Fig. 1) that the new β-peptides should not be able to fold to the familiar 314-helical structures. Still, three of them (3, 4, and 5) give rise to CD spectra matching those of β-peptides that are known to be present as (M)- or (P)-314-helices in MeOH solution. While possible folding motifs (Figs. 3,b. and 7) of the new β-peptides have been identified in crystal structures, an interpretation of the CD spectra has to be postponed until NMR solution structures become available. A list of all β-peptides giving rise to CD spectra with a minimum near 215 nm is included (Table).
