Conformational analysis of 6-deoxy-6-iodo-D-glucose in aqueous solution

Abstract

Complete 1H and 13C assignments for 6‐deoxy‐6‐iodo‐D‐glucose, an analogue of glucose which is transported across the cell membrane, are given. These allowed rotameric populations around the C(5)—C(6) bond to be determined. Comparison with those observed for glucose suggests that the 6‐OH group does not play a major role in glucose transport. Copyright © 2000 John Wiley & Sons, Ltd.

Conformation, dynamics, solvation and relative stabilities of selected β-hexopyranoses in water: a molecular dynamics study with the gromos 45A4 force field

“…If this interpretation is correct, the present force field 265 appears to provide an accurate description for Glc (both in vacuum and in water; besides a possible marginal overstabilization of g + over t compared to the most recent experimental determinations for Glc 95,96,98,103,104 ), but tends to significantly overstabilize the g + conformer (at the expense of the t conformer) for Gal (both in vacuum and in water). A reoptimization of the torsional parameters used in GROMOS GROMOS 45A4 for the x dihedral angle (at least in hexopyranoses with an axial 4-OH group) seems therefore to be required (work in progress).…”

“…61 Conformation of the exocyclic hydroxymethyl group: The conformational properties of the exocyclic hydroxymethyl dihedral angle x (C 4 -C 5 -C 6 -O 6 ) in aldohexopyranoses may be investigated based on NMR coupling constants together with appropriate Karplus-type equations. [90][91][92][93][94][95][96][97][98] The reported conformer populations around x (to our knowledge only available for glucose, 93,95,96,[98][99][100][101][102][103][104] mannose 105 and galactose, 93,95,96,100,102,104 either free or O 1 -methylated) show significant variations between different literature sources. However, all studies evidence a clear predominance of the g + and t rotamers (with comparable populations, g À being nearly absent) for glucose and mannose.…”

A reoptimized GROMOS force field for hexopyranose‐based carbohydrates accounting for the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers

“…The calculated populations are compared with corresponding experimental estimates from the literature in Table 8. The reported conformer populations around ω (to our knowledge only available for Glc,132–134, 238, 316–321 Man,322 and Gal,132, 133, 238, 317, 319, 321 either free or O 1 ‐methylated) show significant variations between different literature sources. For Glc and Man, all studies evidence a clear predominance of the gg and gt rotamers, tg being nearly absent.…”

Conformational properties of glucose-based disaccharides investigated using molecular dynamics simulations with local elevation umbrella sampling

“…These are the conformations usually referred to as gt and gg, respectively (the first letter corresponding tox and the second to x; Section 2.3). The (near) absence of the tg conformer, also evidenced by NMR, 91,96,[182][183][184][185][186][187][188][189][190][191][192][193]194 and X-ray crystallography 195,196 experiments, is a wellknown feature of D-hexopyranoses and D-hexopyranosides presenting the gluco configuration (or C 2 or/and C 3 epimer thereof). As discussed in details elsewhere, 48 however, the exact origin of this conformational preference is still a matter of discussion, different authors invoking distinct effects as a main cause (e.g., the gauche effect, [197][198][199]185,200,201 intramolecular H-bonding, 185,188,202 1,3-syn-diaxial repulsion with the C 4 hydroxyl group, 197,199,185 or specific solvation effects 188,[203][204][205][206][207][208][209]201 ).…”