These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Conformational features of C-glycosyl compounds: crystal structure and molecular modelling of "methyl C-gentiobioside".
    Author: Neuman A, Longchambon F, Abbes O, Gillier-Pandraud H, Pérez S, Rouzaud D, Sinaÿ P.
    Journal: Carbohydr Res; 1990 Jan 15; 195(2):187-97. PubMed ID: 2331701.
    Abstract:
    The crystal of "methyl C-gentiobioside" (methyl 8,12-anhydro-6,7-dideoxy-D-glycero-D-gulo-alpha-D-gluco-trideca pyranoside) (C14H26O10) is triclinic, space group P1, with a = 1.0181 (6) nm, b = 0.8093 (5) nm, c = 0.5066 (4) nm, alpha = 96.03 (5) degrees, beta = 99.94 (5) degrees, gamma = 90.85 (5) degrees. The two D-glucose residues have the 4C1 conformation. The orientation of the beta-(1----6) linkage is characterized by torsion angles phi = 55.9 degrees, psi = 175.1 degrees, and omega = -63.9 degrees. The orientation of the primary hydroxyl group at the non-reducing residue is gauche-trans (omega' = -53.6 degrees). There is no intramolecular hydrogen bond. Molecules are held together by a network of hydrogen bonds involving all of the hydroxyl groups. This crystal structure is the first experimental characterization of a "C-disaccharide". Unlike methyl gentiobioside, which has a high level of conformational flexibility, the "C-disaccharide" has a restricted flexibility. Each of the low-energy conformers in vacuo has a value of phi centered about 60 degrees, in agreement with the solid state conformation, and the exo-anomeric effect is no longer predominant.
    [Abstract] [Full Text] [Related] [New Search]