Metabolites of bird's nest fungi. Part 11. Diterpenoid metabolites of Cyathusearlei Lloyd

Abstract
The bird's nest fungus Cyathusearlei Lloyd produces new diterpenoid metabolites of the cyathin type. Cyathatriol is shown to have structure 1 and has been correlated with cyathin A3. 11,15-O,O-Diacetylcyathatriol (2), 15-O-acetylcyathatriol (3), and 11-O-acetylcyathatriol (4) have also been isolated. The first cyathins containing only two oxygens, cyathin B2 (19) and allocyathin B2 (12), are also described.