A water soluble glucomannan isolated from an immunomodulatory active polysaccharide of Salvia officinalis L.

A water soluble glucomannan has been isolated from the decoloured and defatted aerial parts of sage (Salvia officinalis L.) by water extraction, followed by ion-exchange chromatography, and precipitation with Fehling reagent. It was composed of d-glucose and d-mannose residues in the mole ratio of 1.0:1.3 and had Mw ∼ 8000. Chemical and spectroscopic analyses revealed a linear structure of the polymer with a backbone composed of β-1,4-linked glucopyranosyl and mannopyranosyl units slightly branched at C-6 by side chains, mainly as single α-glucosyl and mannosyl stubs.