Two novel tetranortriterpenoids, turrapubesins A (1) and B (2), representing the first examples of halogenated and maleimide-bearing limonoids,
were isolated from the twigs and leaves of Turraea pubescens. The structures of 1 and 2 were elucidated by extensive spectroscopic analysis.
Their absolute configurations were determined by X-ray crystallography of 1 and by CD analysis of a dihydrogenated derivative of 2. Turrapubesin
A (1) exhibited weak cytotoxicity against the P-388 tumor cell line.