Synthesis and structure analysis of novel disaccharides containing D-psicose produced by endo-1,4-β-D-xylanase from Aspergillus sojae

Xylosylpsicoses (XPs) were synthesized by transglycosylation (TG) with arabinoxylan (AX) and D-psicose (D-psi) using endo-1,4-β-D-xylanase (EC 3.2.1.8) from Aspergillus sojae. The structures of XPs were analyzed by HPLC to determine sugar composition and molecular mass, by methylation analysis using GC-MS to determine linkage, and by 1H- and 13C-NMR spectrometries to obtain the anomeric configuration of glycosidic linkage. By chemical analysis, it was found that the structures of XPs are Xylpβ1-4Psip, Xylpβ1-5Psip, Xylpβ1-1Psif and Xylpβ1-6Psif.