Studies of mannan and related compounds. V. Detailed examination of the branched structure of konjac glucomannan.

Abstract

Konjac glucomannan, a reserve polysaccharide from Amorphophallus koniac 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.