STUDIES ON REACTIONS RELATING TO CARBOHYDRATES AND POLYSACCHARIDES: LIII. STRUCTURE OF THE DEXTRAN SYNTHESIZED BY THE ACTION OF LEUCONOSTOC MESENTERIOIDES ON SUCROSE

Abstract

The dextran synthesized from sucrose by the action of one strain of Leuconostoc mesenterioides has been subjected to chemical investigation. The polysaccharide has been hydrolyzed to glucose. The triacetate, tribenzoate, and trimethyl derivative (all calculated on a glucose anhydride unit) have been prepared. Hydrolysis of trimethyl dextran by the action of methanol-hydrochloric acid yielded dimethyl, trimethyl, and tetramethyl methyl glucosides in the ratio of 1: 3: 1. The products of hydrolysis have been identified as 2,3-dimethyl methyl glucoside, 2,3,4-trimethyl methyl glucoside, and 2,3,4,6-tetramethyl methyl glucoside.The results indicate that dextran is a polymer of a pentaglucopyranose anhydride. One of the glucopyranose units is attached as a side chain, the remaining four being most probably connected in linear chain union. Three of the linkages between building units are of the 1,6 type, while the remaining two are either 1,4 or 1,6.The antigenic properties shown by dextran are probably a result of the presence of the glucose side chains.