Methyl angolensate: the antiulcer agent of the stem bark of Entandrophragma angolense.

Methyl angolensate (1), the major compound isolated from the methanol extract of the stem bark of Entandrophragma angolense produced a dose-related inhibition of gastric ulceration, 40 mg/kg body weight (B.W.) being more effective than 40 mg/kg B.W. of propranolol. The highest dose used (80 mg/kg B.W.) completely inhibited gastric ulceration and significantly reduced gastric acidity (P < 0.05). Furthermore, 1 (40 mg/kg B.W.) significantly reduced gastric acid secretion induced by histamine (1.0 mg/kg B.W.) and carbachol (1.0 mg/kg B.W.). These results suggest that 1 produces its antiulcer activity by inhibition of gastric acid secretion.