A polysaccharide from a tea (infusion) of Maytenus ilicifolia leaves with anti-ulcer protective effects

Maytenus ilicifolia is a medicinal plant used as a tea ( infusion) for treatment of stomach ulcers. This tea furnished a polysaccharide after several purification steps, consisting of a freezing-thawing process, Fehling precipitation, ultrafiltration, and dialysis. It consisted of arabinose, galactose, galacturonic acid, 4-O-methylglucuronic acid, rhamnose, and glucose in a 42: 41: 6: 5: 4: 2 molar ratio. Methylation analysis, controlled Smith degradation, and NMR spectroscopy indicated that it was a type II arabinogalactan containing a (1-->3)- linked, beta-D-Galp main chain, substituted at O-6 by (1-->6)- linked,beta-D-Galp chains, which were mainly substituted at O-3 by (1-->5)- and (1-->3)- linked alpha-L-Araf chains, and nonreducing end-units of alpha-L-Araf and 4-O-Me-GlcpA. This polysaccharide significantly inhibited ethanol-induced gastric lesions in rats with an ED50 of 9.3 mg/kg, suggesting that the arabinogalactan liberated from the infusion has a protective anti-ulcer effect.