Structural characterization of an acetylated glucomannan with antiinflammatory activity and gastroprotective property from Cyrtopodium andersonii

A polysaccharide with an estimated weight-average molar mass of 5.35 × 105 was obtained from an aqueous extract of pseudobulbs of Cyrtopodium andersonii R. Br. It was composed of d-glucose and d-mannose in 1:3 molar ratio. Chemical and spectroscopic analyses revealed a linear structure of the polymer with a backbone composed of (1 → 4)-linked β-d-glucopyranosyl and mannopyranosyl units slightly branched at C-2, C-3, and C-6 by side chains, as terminal non reducing residues of d-mannopyranose and d-glucopyranose. It was found to contain 14.6% of acetyl groups substituted at C-2 of (1 → 4)-linked β-d-mannopyranosyl units. The acetylated glucomannan demonstrated antiinflammatory and antiulcerogenic activities.