Secopieristoxins A and B, two unusual diterpenoids with a new 9,10-secograyanane skeleton from the fruits of Pieris formosa

► Secopieristoxins A and B were new highly acylated grayanane diterpenoids isolated from the fruits of Pieris formosa. Ring B of Secopieristoxins A and B has suffered an oxidative cleavage between C-9 and C-10. Structures of the new compounds were elucidated on the basis of extensive spectroscopic analysis.