title: Structure of a peptide surrogate, tert-butoxycarbonylalanyl-psi(CH2S)-phenylalanine [Boc-Ala-psi(CH2S)-Phe-OH].
abstract: C17H25NO4S, Mr = 339.5, monoclonic, C2 a = 24.927 (8), b = 5.252 (4), c = 16.867 (7) A, beta = 122.70 (1) degree, V = 1858.2 (9) A3, Z = 4, D chi = 1.21 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 1.83 cm-1, F(000) = 728, T = 295 K. The final R value for 1466 independent observed reflections is 0.075. The thiomethylene dipeptide analogue possesses a C alpha i...C alpha i+1 distance somewhat smaller than in the extended amide counterpart due to a partially folded structure, especially in the C-terminal region. Pairs of molecules are held together by O-H...O = C (carboxylic acid) hydrogen bonds.
authors.affiliation: Department of Organic Chemistry, University of Padova, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Zanotti
authors.forename: C
authors.initials: C
authors.lastname: Toniolo
authors.forename: T J
authors.initials: TJ
authors.lastname: Owen
authors.forename: A F
authors.initials: AF
authors.lastname: Spatola
mesh_terms: D004151:Dipeptides; D015394:Molecular Structure; D009842:Oligopeptides; D014961:X-Ray Diffraction
chemical_list: D004151:Dipeptides; D009842:Oligopeptides; C062560:tert-butoxycarbonylalanyl-psi-thiomethylene-phenylalanine