Polygalacturonic acid: Another anti-ulcer polysaccharide from the medicinal plant Maytenus ilicifolia

Maytenus ilicifolia is one of frequently used medicinal plants in Brazil. Its leaves are used in homemade and industrial medicines for effective treatment of stomach ulcers. A polygalacturonic acid (PGA) was obtained from its leaves by aqueous extraction, followed by fractionation via a freezing–thawing process and Fehling precipitation. Methylation analysis and 13C NMR spectroscopy showed PGA to consist of (1 → 4)-linked α-d-GalpA repeating units. It significantly inhibited ethanol-induced gastric lesions in rats, with an ED50 of 103 mg/kg, suggesting that it has a protective anti-ulcer effect. This polysaccharide may thus play an important role in the anti-ulcer effect of M. ilicifolia.