ENZYMIC HYDROLYSIS OF A GLUCOMANNAN FROM JACK PINE (PINUS BANKSIANA LAMB.)

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Abstract
A crude glucomannan was isolated from jack pine holocellulose in 17% yield. Repeated delignification and copper complexing of this product provided a purified glucomannan (5% of the holocellulose) containing glucose, mannose, galactose, and xylose in a molar ratio of 1025:1:1. This polysaccharide was hydrolyzed by a commercial hemicellulase preparation, the cleavage products being removed by continuous dialysis of the reaction mixture. The following oligosaccharides were isolated from the hydrolyzate and identified; yields are based on the glucomannan: 4-O-([beta]-D-mannopyranosyl)-D-mannopyranose, 18.5%; 4-O-([beta]-D-glucopyranosyl)-D-mannopyranose, 1.4%; 4-O-([beta]-D-mannopyranosyl)-D-glucopyranose, 0.7%; 6-O-([alpha]-D-xylopyranosyl)-D-glucopyranose, 0.5%; O-[beta]-D-mannopyranosyl (1[forward arrow] 4)-O-[beta]-D-mannopyranosyl (1[forward arrow]4)-D-mannopyranose, 6.5%; 0-[beta]-D-mannopyranosyl (1[forward arrow] 4)-O-[beta]-D-glucopyranosyl (1 [forward arrow] 4)-D-glucopyranose, 0.7%; O-a-D-xylopyranosyl (1[forward arrow] 6)-O-B-D-glucopyranosyl (l[forward arrow] 4)-D-glucopyranose, 0.1%; O-[beta]-D-mannopyranosyl (1 [forward arrow] 4)-O-B-D-mannopyranosyl (1[forward arrow] 4)-D-glucopyranose, 0.04%; 0-[beta]-D-glucopyranosyl (1[forward arrow] 4)-O-([beta]-D-mannopyranosyl (1[forward arrow]4)-D-mannopyranose, 0.03%; a trisaccharide containing arabinose, glucose, and mannose, 0.01%; a trisaccharide containing two units of arabinose and one of galactose, 0.01%.