Three novel oligosaccharides synthesized using Thermoanaerobacter brockii kojibiose phosphorylase

BACKGROUND Recently synthesized novel oligosaccharides have been produced primarily by hydrolases and glycosyltransferases, while phosphorylases have also been subject of few studies. Indeed, phosphorylases are expected to give good results via their reversible reaction. The purpose of this study was to synthesis other novel oligosaccharides using kojibiose phosphorylase. RESULTS Three novel oligosaccharides were synthesized by glucosyltransfer from beta-D-glucose 1-phosphate (beta-D-G1P) to xylosylfructoside [O-alpha-D-xylopyranosyl-(1-->2)-beta-D-fructofuranoside] using Thermoanaerobacter brockii kojibiose phosphorylase. These oligosaccharides were isolated using carbon-Celite column chromatography and preparative high performance liquid chromatography. Gas liquid chromatography analysis of methyl derivatives, MALDI-TOF MS and NMR measurements were used for structural characterisation. The 1H and 13C NMR signals of each saccharide were assigned using 2D-NMR including COSY (correlated spectroscopy), HSQC (herteronuclear single quantum coherence), CH2-selected E-HSQC (CH2-selected Editing-HSQC), HSQC-TOCSY (HSQC-total correlation spectroscopy) and HMBC (heteronuclear multiple bond correlation). CONCLUSION The structure of three synthesized saccharides were determined, and these oligosaccharides have been identified as O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-xylopyranosyl-(1-->2)-beta-D-fructofuranoside (saccharide 1), O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-glucopyranosyl-(1-->2)-O-alpha-D-xylopyranosyl-(1-->2)-beta-D-fructofuranoside (saccharide 2) and O-alpha-D-glucopyranosyl-(1-->[2-O-alpha-D-glucopyranosyl-1]2-->2)-O-alpha-D-xylopyranosyl-(1-->2)-beta-D-fructofuranoside (saccharide 3).