Oligosaccharide synthesis by dextransucrase:: new unconventional acceptors

The acceptor reactions of dextransucrase offer the potential for a targeted synthesis of a wide range of di-, tri- and higher oligosaccharides by the transfer of a glucosyl group from sucrose to the acceptor. We here report on results which show that the synthetic potential of this enzyme is not restricted to 'normal' saccharides. Additionally functionalized saccharides, such as alditols, aldosuloses, sugar acids, alkyl saccharides, and glycals, and rather unconventional saccharides, such as fructose dianhydride, may also act as acceptors. Some of these acceptors even turned out to be relatively efficient: OC-D-glucopyranosyl-(1 --> 5)-D-arabinonic acid, alpha-D-glucopyranosyl-(1, 4)-D-glucpyranosol, alpha-D-glucopyranosyl-(1 --> 6)-D-glucitol, alpha-D-glucopyranosyl-(1 --> 6)-D-mannitol, alpha-D-fructofuranosyl-beta-D-fructofuranosyl-(1,2':2,3')-dianhydride, 1, 5-anhydro-2-deoxy-D-arabino-hex-1-enitol ('D-glucal'), and may therefore be of interest for future applications of the dextransucrase acceptor reaction. (C) 2002 Elsevier Science Ltd. All rights reserved.