Norditerpenes and norsesterterpenes from Salvia yosgadensis

The aerial parts of Salvia yosgadensis afforded five new terpenes with unusual skeletons, together with two known norditerpenes, ambreinolide and norambreinolide. The new compounds were elucidated as 6 alpha-hydroxyambreinolide, 6 alpha-hydroxynorambreinolide, 6 alpha-hydroxy-8 alpha-acetoxy-13,14,15,16-tetranorlabdan-12-oic acid, and two 19,20-dinorsesterterpenes, named as yosgadensonol and 13-epi-yosgadensonol. Their structures were determined by spectroscopic means, particularly by extensive 1D and 2D NMR studies.