TY - JOUR
T1 - Structural characterization of peptide oligomers containing (1R,2S)-2-aminocyclohexanecarboxylic acid (cis-ACHC)
AU - Choi, Soo Hyuk
AU - Ivancic, Monika
AU - Guzei, Ilia A.
AU - Gellman, Samuel H.
PY - 2013/6
Y1 - 2013/6
N2 - (1R,2S)-2-Aminocyclohexanecarboxylic acid (cis-ACHC) is a preorganized β-amino acid. cis-ACHC favors two conformations that feature gauche conformations about the Cα-Cβ bond with torsion angles of opposite signs. The diastereomeric β-amino acid trans-ACHC has been widely studied as a foldamer building block, but cis-ACHC has received less attention in this regard. We examined the conformational behaviour of three types of oligomer: (1) homooligomers of cis-ACHC, (2) β-peptides in which cis-ACHC and β3h-Ala alternate, and (3) 1:1 α/β- peptides in which cis-ACHC and Ala alternate. Two-dimensional NMR experiments suggest that all three types of oligomer adopt extended conformations rather than folded conformations in solution. Two crystal structures of oligomers that contain cis-ACHC residues, a cis-ACHC dimer and an α/β-peptide tetramer, show extended conformations in which the cis-ACHC residues contain six-membered-ring C=O⋯H-N hydrogen bonds.
AB - (1R,2S)-2-Aminocyclohexanecarboxylic acid (cis-ACHC) is a preorganized β-amino acid. cis-ACHC favors two conformations that feature gauche conformations about the Cα-Cβ bond with torsion angles of opposite signs. The diastereomeric β-amino acid trans-ACHC has been widely studied as a foldamer building block, but cis-ACHC has received less attention in this regard. We examined the conformational behaviour of three types of oligomer: (1) homooligomers of cis-ACHC, (2) β-peptides in which cis-ACHC and β3h-Ala alternate, and (3) 1:1 α/β- peptides in which cis-ACHC and Ala alternate. Two-dimensional NMR experiments suggest that all three types of oligomer adopt extended conformations rather than folded conformations in solution. Two crystal structures of oligomers that contain cis-ACHC residues, a cis-ACHC dimer and an α/β-peptide tetramer, show extended conformations in which the cis-ACHC residues contain six-membered-ring C=O⋯H-N hydrogen bonds.
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U2 - 10.1002/ejoc.201300118
DO - 10.1002/ejoc.201300118
M3 - Article
AN - SCOPUS:84878776403
SN - 0075-4617
SP - 3464
EP - 3469
JO - Justus Liebigs Annalen der Chemie
JF - Justus Liebigs Annalen der Chemie
IS - 17
ER -