Bioactive Quassinoids from the Seeds of Brucea javanica

Six new quassinoids (1–6) and eight known compounds of this type (7–14) were isolated from the seeds of Brucea javanica. Their structures were elucidated by analysis of their spectroscopic data and from chemical evidence. Compounds 1–5 were found to be unusual quassinoids with a 2,3-seco A ring. The configurations at C-4 in 4 and 5 were determined by a difference circular dichroism method. In in vitro bioassays, 8 and 10 showed inhibitory...