title: β N-O turns and helices induced by β2-aminoxy peptides: synthesis and conformational studies.
abstract: Herein, we report an efficient route for the asymmetric synthesis of β(2)-aminoxy acids as well as experimental and theoretical studies of conformations of peptides composed of β(2)-aminoxy acids. The nine-membered-ring intramolecular hydrogen bonds, namely, β N-O turns, are generated between adjacent residues in those peptides, in accordance with our computational results. The presence of two consecutive homochiral β N-O turns leads to the formation of β N-O helical structures in solution, although both helical (composed of two β N-O turns of the same handedness) and reverse-turn (composed of two β N-O turns with opposite handedness) structures are of similar stability, as suggested by theoretical studies. Nevertheless, two slightly different conformations, with the same handedness, of β(2)-aminoxy monomers have been observed in the solid state and in solution according to our X-ray and 2D NOESY studies.
authors.affiliation: Department of Chemistry, Fudan University, Shanghai 200433, PR China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Jiao
authors.forename: Xiao-Wei
authors.initials: XW
authors.lastname: Chang
authors.forename: Wei
authors.initials: W
authors.lastname: Ding
authors.forename: Guo-Jun
authors.initials: GJ
authors.lastname: Liu
authors.forename: Ke-Sheng
authors.initials: KS
authors.lastname: Song
authors.forename: Nian-Yong
authors.initials: NY
authors.lastname: Zhu
authors.forename: Dan-Wei
authors.initials: DW
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Yang
mesh_terms: D006860:Hydrogen Bonding; D008962:Models, Theoretical; D009584:Nitrogen / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010455:Peptides / Q000138:chemical synthesis* / Q000737:chemistry; D017433:Protein Structure, Secondary
chemical_list: D010455:Peptides; D009584:Nitrogen; D010100:Oxygen