Structure Determination of Polysaccharides in Aloe arborescens var. natalensis

Abstract

Neutral polysaccharides and a glycoprotein were isolated by gel filtration from a nondialyzable fraction of Aloe arborescens var. natalensis Berger. These were shown to contain the following: a linear polymer of a (1, 6)-O-linked α-D-glucopyranose (mol. wt. 15,000); a branched polymer of an arabinogalactan (mol. wt. 30,000, molar ratio of galactose to arabinose 1:1.5) with two principle linear chains of (1-2)-O-L-arabinopyranose and (1-2)-O-D-galactopyranose at O-2 and O-6 of the D-galactopyranose residue; a linear polymer of a (1, 4)-O-linked β-D-mannopyranose (mol. wt. 40,000) with 10% acetyl group; a glycoprotein (mol. wt. 40,000; protein, 57%; hexosamine, 4%; and carbohydrate, 34%) consisting of glucose, mannose, galactose, glucosamine, galactosamine, N-acetylglucosamine (2:2:1:1:4:1) and amino acids (Asp, Thr, Ser, Glu, Gly, Ala, Val, Ile, Phe, Orn, Lys, Arg, and Pro). The linear chain of (1, 4)-O-linked β-D-mannopyranose with 10% acetyl groups and the glycoprotein enhanced phagocytosis in adult bronchial asthmatic.