Gastroprotective effect and structure of a rhamnogalacturonan from Acmella oleracea.
Maneno muhimu
Kikemikali
The plant Acmella oleracea (L.) R.K.Jansen (Asteraceae), locally known as jambu, is widely used in Legal Amazon in local dishes and in folk medicine. A polysaccharide (SC) was isolated from this plant, following aqueous extraction, which contained uronic acid, galactose, arabinose, rhamnose, and glucose in a 15:2:1:1:0.5 molar ratio and had a M(w) 226,000 g/mol. Methylation analysis and NMR spectroscopy indicated that SC is a rhamnogalacturonan composed of a long chain of →4)-6-OMe-α-D-GalpA-(1→, interspersed with some α-L-Rhap residues, partly substituted by side-chains of type II arabinogalactans. SC significantly inhibited ethanol-induced gastric ulcers in rats with an ED₅₀ of 1.5 mg/kg, indicating that SC acts as gastroprotective agent.