title: Structure of the cyclohexapeptide cleromyrine II trihydrate.
abstract: C29H40N6O7.3H2O, Mr = 638.7, trigonal, P3(1)21, a = 14.190 (2), c = 29.833 (4) A, V = 5202 (1) A3, Z = 6, Dx = 1.22 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 7.8 cm-1, F(000) = 2052, T = 291 K, R = 0.069 for 1942 observed reflections. The new cyclohexapeptide cleromyrine II was isolated from Clerodendrum myricoides. Its structure was established by spectroscopic and X-ray diffraction methods as cyclo(-Gly-Tyr-Gly-Pro-Leu-Pro-). The conformation essentially consists of two beta-turns including the Pro residues and one central very short antiparallel beta-sheet stabilized by two intramolecular hydrogen bonds: N(Tyr2)...O(Leu5) = 2.94 (2) A and N(Leu5)...O(Tyr2) = 3.02 (2) A.
authors.affiliation: Laboratoire de Chimie Physique et de Cristallographie, Université Catholique de Louvain, Louvain-la-Neuve, Belgium.
authors.forename: J P
authors.initials: JP
authors.lastname: Declercq
authors.forename: B
authors.initials: B
authors.lastname: Tinant
authors.forename: S
authors.initials: S
authors.lastname: Bashwira
authors.forename: C
authors.initials: C
authors.lastname: Hootelé
mesh_terms: D000595:Amino Acid Sequence; D003460:Crystallization; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010456:Peptides, Cyclic / Q000302:isolation & purification; D010944:Plants / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D010456:Peptides, Cyclic; C066144:cleromyrine II