Norbisabolane and eremophilane sesquiterpenoids from cultures of the Basidiomycete Polyporus ellisii.

Three new 11,12,15-norbisabolane sesquiterpenoids, polisins A-C (1-3), and four new eremophilane sesquiterpenoids, polylisins A-D (4-7), were isolated from cultures of the Basidiomycete Polyporus ellisii. These new structures were elucidated based on extensive spectroscopic studies and the structures of polisin A (1) and polylisin A (4) were confirmed by single-crystal X-ray crystallographic analysis. All compounds were evaluated for their inhibitory activities against two isozymes of 11β-hydroxysteroid dehydrogenases (11β-HSD1 and 11β-HSD2).