Two novel Diels-Alder adducts from Hippocratea celastroides roots and their insecticidal activity

Two novel compounds, celastroidine A (1) and B (2), were isolated from the roots of Hippocratea celastroides K. Their structures were elucidated by spectroscopical and X-ray diffraction studies. Celastroidine A (1) (C 50 H 74 O 5 ) was identified as a Diels-Alder adduct of a triterpene plus a diterpene and celastroidine B (2) as a beyerane, a type of dimer of two diterpene (C 40 H 60 O 4 ). Both compounds could be formed in vivo by a Diels-Alder...