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Diastereomeric Right- and Left-Handed Helical Structures with Fourteen (R)-Chiral Centers.
- Source :
- Chemistry - A European Journal; 12/22/2017, Vol. 23 Issue 72, p18120-18124, 5p, 1 Color Photograph, 4 Diagrams, 1 Graph
- Publication Year :
- 2017
-
Abstract
- The relationship between chiral centers and the helical-screw control of their peptides has already been reported, but it has yet to be elucidated in detail. A chiral four-membered ring α,α-disubstituted α-amino acid with a (R,R)-butane-2,3-diol acetal moiety at the γ-position, but no α-chiral carbon, was synthesized. X-ray crystallographic analysis unambiguously revealed that its homo-chiral heptapeptide formed right-handed (P) and left-handed (M) 3<subscript>10</subscript>-helical structures at a ratio of 1:1. They appeared to be enantiomeric at the peptide backbone, but diastereomeric with fourteen (R)-configuration chiral centers. Conformational analyses of homopeptides in solution also indicated that diastereomeric (P) and (M) helices existed at approximately equal amounts, with a slight preference toward right-handedness, and they quickly interchanged at room temperature. The circumstances of chiral centers are important for the control of their helical-screw direction. [ABSTRACT FROM AUTHOR]
- Subjects :
- HELICAL structure
PEPTIDES
AMINO acids
CHIRALITY
X-ray crystallography
Subjects
Details
- Language :
- English
- ISSN :
- 09476539
- Volume :
- 23
- Issue :
- 72
- Database :
- Complementary Index
- Journal :
- Chemistry - A European Journal
- Publication Type :
- Academic Journal
- Accession number :
- 126975943
- Full Text :
- https://doi.org/10.1002/chem.201705306