Structural analysis of novel kestose isomers isolated from sugar beet molasses

摘要

Eight kestose isomers were isolated from sugar beet molasses by carbon-Celite column chromatography and HPLC. GC-FID and GC-MS analyses of methyl derivatives, MALD-TOF-MS measurements and NMR spectra were used to confirm the structural characteristics of the isomers. The H-1 and C-13 NMR signals of each isomer saccharide were assigned using COSY, E-HSQC, HSQC-TOCSY, HMBC and H2BC techniques. These kestose isomers were identified as alpha-D-fructofuranosyl-(2- >2)-alpha-D-glucopyranosyl-(1 < - > 2)-beta-D-fructofuranoside, alpha-D-fructofuranosyl-(2- > 3)-beta-D-fructofuranosyl-(2 < ->1)-alpha-D-glucopyranoside, alpha-D-fructofuranosyl-(2- >4)-beta-D-fructofuranosyl-(2 < ->1)-alpha-D-glucopyranoside, beta-D-fructofuranosyl-( 2- >4)-beta-D-fructofuranosyl-(2< ->1)-alpha-D-glucopyranoside, beta-D-fructofuranosyl-(2- > 3)-alpha-D-glucopyranosyl-(1 < -> 2)-beta-D-fructofuranoside, alpha-D-fructofuranosyl-(2-> 1)-beta-D-fructofuranosyl-(2 < ->1)-alpha-D-glucopyranoside, alpha-D-fructofuranosyl-(2- >6)-alpha-D-glucopyranosyl-(1 < ->2)-beta-D-fructofuranoside, and alpha-D-fructofuranosyl-(2- >6)-beta-D-fructofuranosyl-(2 < ->1)-alpha-D-glucopyranoside. The former five compounds are novel saccharides. c 2016 Elsevier Ltd. All rights reserved.