Structural characterization and anti-fatigue activity of polysaccharides from the roots of Morinda officinalis

Three polysaccharicles MP-1, MP-2, and MP-3 were isolated from hot water extract of Chinese medicine Morinda officinalis through 95% ethanol precipitation and gel-filtration chromatography (DEAE-Sepharose CL-6B column and Sephadex G-75 or G-100 column). MP-1 was identified as an inulin-type fructan with simple linear (2 -> 1)-linked structure. Both MP-2 and MP-3 were acidic polysaccharicles which consisted predominantly of galacturonic acid, arabinose and galactose. Partial structure characterization of MP-3 was carried out by partial acid hydrolysis and periodate oxidation. The total polysaccharicles of the herb were tested in mice weight-loaded swimming model and were found to have anti-fatigue activity. (C) 2008 Elsevier B.V. All rights reserved.