Three New Limonoids from Melia toosendan

In order to find new and biologically active compounds, the constituents of the root bark of Melia toosendan were investigated, and three new limonoids, 29-[(2-methylbutanoyl)oxy]-2 alpha-hydroxyamoorastatone (1), 1,3-epi-29-[(2-methylbutanoyl)oxy]-2 alpha-hydroxyamoorastatone (2), and 1,3-epi-29-[(2-methylpropanoyl)oxy]-2 alpha-hydroxyamoorastatone (3), were isolated from the root bark of Melia toosendan. Their structures were elucidated by means of extensive spectroscopic studies.