Amylose hydroxymethyl group conformation

Fig. 17.—Newman-Type Projections showing the two States A and B Corresponding to the gauche-gauche and gauche-trans Conformations of the Hydroxymethyl Group of Amylose. [Reproduced with permission from Fig. 1 of P. Dais and R. H. Marchessault, Macromolecules, 24 (1991) 4611-4614. 1991 American Chemical Society.]...

Figure 4.52 Cartoon of hydrogen bonding in V-amylose. The hydroxymethyl groups adopt the gg conformation. The locations of the hydrogens forming hydrogen bonds are speculative.

The structures of V - and V -amylose are similar. In both cases the amylose chains form left-handed helices pack in an antiparallel manner in the space group V -amylose i " was originally believed to have a sixfold helical conformation but further refinement has shown only twofold symmetry due to different rotational positions of glucose hydroxymethyl groups. The structure contains significant amounts of water. This refinement locates these guest molecules in interstitial sites between neighbouring helices of amylose... 

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