Detailed Examination of the Branched Structure of Konjac Glucomannan

Konjac glucomannan, a reserve polysaccharide from Amorphophallus konjac tubers was isolated in a homogeneous state and is known to contain d-mannose and d-glucose in a molar ratio of 1.6: 1. Survival of some monosaccharides after the periodata oxidation and subsequent reduction of knojac glucomannan suggested that it was composed mainly of β-1,4 linkages, however, there was some branching in the polysaccharide. By analysis of the hydrolyzate of the permethylated sample by GC-MS, the branching structure through C3 of both d-mannose and d-glucose residues was confirmed. Yields of O-methyl mugars were also determined. The results indicate a branched structure for a native and non-denatured specimen of konjac glucomannan.