The Polysaccharide of “Junsai (Brasenia schreberi J. F. Gmel)” Mucilage; Fragmentation Analysis by Successive Smith Degradations and Partial Acid Hydrolysis

Abstract

Detailed structural features of the Junsai (Brasenia schreberi J. F. Gmel) polysaccharide was elucidated by characterization of its degradation products from Smith degradation and partial acid hydrolysis.
Four successive Smith degradations yielded a degraded polysaccharide (7.1%), which might represent the core moiety of the polysaccharide. Methylation analysis showed that it contained a backbone chain of β-(1→3)-linked D-mannose residues, many of which were at-tached at the C-2 positions with side chains consisting of β-(1→3)-linked D-galactose and L-fucose residues. In addition, there were (1→3)-linked rhamnose, -fucose, -galactose, and (1→4)-linked D-glucuronic acid residues which appeared to occur as peripheral side chains. Partial acid hydrolysis of Junsai polysaccharide with an acid afforded a new trisaccharide, O-α-L-rhanmopyranosyl-(1→3)-O-α-D-galactopyranosyl-(1→3)-L-fucopyranose, in addition to 3-O-β-D-galactopyranosyl-D-galactose, and 2-O-β-D-glucopyranosyluronic acid)-D-mannose.
These results suggest that Junsai polysaccharide must have an extremely complicated struc-ture, to which its unique physical properties are ascribed.