Tirucallane triterpenes from the leaf extract of Entandrophragma angolense.

From the leaves of Entandrophragma angolense, three triterpenoidal compounds were isolated and structurally elucidated by mass and NMR spectroscopy. They belong to the tirucallane group but two of them possess the rare seco-ring-A feature. The phytochemical data are discussed from a chemotaxonomic and biogenetic points of view.