Senegalensions A–C, Three Limonoids from Khaya senegalensis

Hidden treasures : Senegalensions A ( 1 ) and B ( 2 ) with a unique C2–C4 linkage and senegalension C ( 3 ), possessing a rare spiro ring system with an unusual tricyclo[3.3.1.0 1, 10 ]nonane moiety, were isolated from the leaves and twigs of Khaya senegalensis . Their structures were elucidated by extensive spectroscopic analysis. The absolute configuration of 1 was determined by computational methods. A plausible biosynthetic pathway was proposed.