Structure determination of polysaccharides in Aloe saponaria (Hill.) Haw. (Liliaceae)

Neutral polysaccharides that inhibit carrageenin-induced edema in rats were isolated from the nondialysate of the pulp of Aloe saponaria by gel filtration. These were shown to be a linear polymer of a 1,4-linked beta-D-mannopyranose (mol. wt. 15,000) containing 18% acetyl groups (As mannan 1), and a 1,4-linked alpha-D-mannopyranose polymer containing a single branch on the principal chain consisting of D-glucose residues linked at C-2 and C-4 (mol. wt. 66,000), with 10% acetyl groups (As mannan 2). As mannan 1 inhibited carrageenin-induced hind paw edema at 50 mg/kg ip in rats; As mannan 2 was not tested for pharmacological activity. A crude preparation of both As mannans was effective when given intraperitoneally, but was ineffective when given orally.