Cheiloclines A–I. First examples of octacyclic sesquiterpene-triterpene hetero-Diels–Alder adducts

Cheiloclines A–I () have been isolated from the root bark of Cheiloclinium hippocratioides (Celastraceae). They represent the first examples of hetero-Diels–Alder adducts between a nor-triterpenequinone and a sesquiterpene. Their structures were elucidated on the basis of spectral analysis, including homonuclear and heteronuclear correlation NMR experiments (COSY, ROESY, HSQC and HMBC). These compounds were tested for antitumoral, antibacterial and aldose reductase inhibitory activities.