Carbohydrate Research 2009-12-14

NMR studies of the conformation of the natural sweetener rebaudioside A.

Wayne E Steinmetz, Alvin Lin

Index: Carbohydr. Res. 344(18) , 2533-8, (2009)

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Abstract

Rebaudioside A is a natural sweetener from Stevia rebaudiana in which four beta-D-glucopyranose units are attached to the aglycone steviol. Its (1)H and (13)C NMR spectra in pyridine-d(5) were assigned using 1D and 2D methods. Constrained molecular dynamics of solvated rebaudioside using NMR constraints derived from ROESY cross peaks yielded the orientation of the beta-D-glucopyranose units. Hydrogen bonding was examined using the temperature coefficients of the hydroxyl chemical shifts, ROESY and long-range COSY spectra, and proton-proton coupling constants.