32. Structural studies of dextrans. Part I. A dextran containing α-1,3-glucosidic linkages

A dextran (NRRL 1356-S) produced by a strain of Leuconostoc mesenteroides has been fragmented by acetolysis and separated into glucose (21%), isomaltose (2%), nigerose (20%), and 3-α-isomaltosylglucose (2%). The yield of nigerose was much greater than could be obtained by aqueous acid hydrolysis of the dextran. The structure of the trisaccharide proves that α-1,3- and α-1,6-bonds occur together in the same dextran molecule. The nature of the fragments obtained from the periodate-oxidized dextran indicated that few of the 1,3-linkages in the polysaccharide are contiguous.