Regiospecific transglycolytic synthesis and structural characterization of6-O-alpha-glucopyranosyl-glucopyranose (isomaltose)

The enzymatic synthesis of 6-O-alpha-glucopyranosyl-glucopyranose (isomalto se) was achieved. The regio-specific transglycosylation reaction was cataly zed by a crude preparation of alpha-D-glucosidase from Aspergillus niger, u sing p-nitrophenyl alpha-D-glucopyranose as the donor and glucopyranose as the acceptor. The yield of the reaction was 59% on a molar basis with respe ct to the donor. The structural identity of the product was fully determine d by HPLC, HPAEC-PAD, ionspray mass spectrometry and C-13 NMR. (C) 2000 Aca demic Press.