Helical structures of homo-chiral isotope-labeled α-aminoisobutyric acid peptides
The chiral deuterium- and 13C-isotope-labeled α-aminoisobutyric acids CD3-Aib and 13CH3-Aib were enantioselectively synthesized from L-Ala aldimine using simplified Maruoka chiral phase-transfer catalysts. Homo-chiral (S)-CD3-Aib homopeptides, up to decamers, were prepared. A (R)-CD3-Aib polymer and...
Gespeichert in:
Veröffentlicht in: | Tetrahedron 2016-09, Vol.72 (39), p.5864-5871 |
---|---|
Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | The chiral deuterium- and 13C-isotope-labeled α-aminoisobutyric acids CD3-Aib and 13CH3-Aib were enantioselectively synthesized from L-Ala aldimine using simplified Maruoka chiral phase-transfer catalysts. Homo-chiral (S)-CD3-Aib homopeptides, up to decamers, were prepared. A (R)-CD3-Aib polymer and (S)-13CH3-Aib polymer were also prepared. Conformational studies on homopeptides using CD spectra and an X-ray crystallographic analysis revealed that the preferred conformations were 310-helical structures comprising equal amounts of right-handed (P) and left-handed (M) helical-screw structures. The α-carbon chiral centers induced by the D- or 13C-isotope substitution of Aib were incapable of controlling the helical-screw directions of their oligopeptides and short polymers.
[Display omitted] |
---|---|
ISSN: | 0040-4020 1464-5416 |
DOI: | 10.1016/j.tet.2016.08.011 |