Studies on Mannan in Wood Pulp

Part IV. Isolation and Purification of Glucomannan

Abstract

Glucomannan was isolated from holocellulose pulp of pine (Pines densiflora Sieb. et Zucc.) using dimethylsulfoxide and aqueous alkali. It was found that there were present also, in the pulp, separate two glucomannans as the possible contaminants. Purification of the glucomannan by extraction with dimethylsulfoxide, the following acetylation and fractionation resulted essentially homogeneous glucomannan triacetate [α]D -30.7° contained mannose and glucose only in the ratio 36:10. Measurements of intrinsic viscosity in the chloroform solution gave [η] 0.776 and 0.291 for high and low molecular parts of the acetate respectively. The glucomannan derived its acetate showed [α]D-36.5° and 78.5% mannose content