A hexacyclic ent-trachylobane diterpenoid possessing an oxetane ring from Mitrephora glabra
[chemical reaction: see text]. Three new ent-trachylobane diterpenoids (1-3) were isolated and structures elucidated from Mitrephora glabra Scheff. (Annonaceae). Mitrephorone A (1) possesses a hexacyclic ring system with adjacent ketone moieties and an oxetane ring, both of which are unprecedented among trachylobanes. All compounds were evaluated for cytotoxicity against a panel of cancer cells, where 1 displayed the most potent and broadest activity, and against a battery of antimicrobial assays, where all compounds were approximately equipotent
Li, C., Lee, D., Graf, T., Phifer, S., Nakanishi, Y., Burgess, J., ... Oberlies, N. (2005). A hexacyclic ent-trachylobane diterpenoid possessing an oxetane ring from Mitrephora glabra. Organic Letters, 7(25), 5709-5712.