Simple And Efficient Preparation Of High-Purity Trehalulose From The Waste Syrup Of Isomaltulose Production Using Solid-Phase Extraction Followed By Hydrophilic Interaction Chromatography

A simple and efficient method was developed for the preparation of high-purity trehalulose from the waste syrup of isomaltulose production. The waste syrup was pre-treated with C18 solid-phase extraction, where 98% decolorization and 97% reducing sugar recovery were obtained, followed by hydrophilic interaction liquid chromatography separation on a cysteine-bonded zwitterionic column. Under optimized conditions, trehalulose was separated from isomaltulose isomer and prepared on a semi-preparative scale with >99% purity. The structure of the prepared trehalulose was subsequently confirmed by nuclear magnetic resonance, and three tautomers of trehalulose (alpha-D-glucosylpyranosyl-1,1-beta-D-fructopyranose, alpha-D-glucosylpyranosyl-1,1-beta-D-fructofuranose, and alpha-D-glucosylpyranosyl-1,1-alpha-D-fructofuranose) were detected and completely characterized by C-13 NMR spectroscopy for the first time in this study. The tautomerization of alpha-D and beta-D type transition was observed by hydrophilic interaction liquid chromatography on an AdvanceBio Glycan Mapping column, with smaller particle size (2.7 mu m). Furthermore, the prepared trehalulose was applied as a standard for trehalulose quantification during the sucrose conversion by Klebsiella sp. LX3. The combination of solid-phase extraction and hydrophilic interaction liquid chromatography offers a new avenue for the preparation of sugar isomers from complex natural or fermentation products.