title: Synthesis and structural study of highly constrained hybrid cyclobutane-proline γ,γ-peptides.
abstract: Two diastereomeric series of hybrid γ,γ-peptides derived from conveniently protected derivatives of (1R,2S)- and (1S,2R)-3-amino-2,2-dimethylcyclobutane-1-carboxylic acid and cis-4-amino-L: -proline joined in alternation have efficiently been prepared through convergent synthesis. High-resolution NMR experiments show that these compounds present defined conformations in solution affording very compact structures as the result of intra and inter residue hydrogen-bonded ring formation. (R,S)-cyclobutane containing peptides adopt more twisted conformations than (S,R) diastereomers. In addition, all these γ-peptides have high tendency to aggregation providing vesicles of nanometric size, which were stable when allowed to stand for several days, as verified by transmission electron microscopy.
authors.affiliation: Departament de Química, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
authors.forename: Raquel
authors.initials: R
authors.lastname: Gutiérrez-Abad
authors.forename: Daniel
authors.initials: D
authors.lastname: Carbajo
authors.forename: Pau
authors.initials: P
authors.lastname: Nolis
authors.forename: Carles
authors.initials: C
authors.lastname: Acosta-Silva
authors.forename: Juan A
authors.initials: JA
authors.lastname: Cobos
authors.forename: Ona
authors.initials: O
authors.lastname: Illa
authors.forename: Miriam
authors.initials: M
authors.lastname: Royo
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Ortuño
mesh_terms: D003503:Cyclobutanes / Q000737:chemistry; D019281:Dimerization; D006860:Hydrogen Bonding; D009682:Magnetic Resonance Spectroscopy; D046529:Microscopy, Electron, Transmission; D008968:Molecular Conformation; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry*; D011392:Proline / Q000031:analogs & derivatives / Q000737:chemistry; D011487:Protein Conformation; D013237:Stereoisomerism
chemical_list: D003503:Cyclobutanes; D010455:Peptides; D011392:Proline