Kansuinone, a novel euphane-type triterpene from Euphorbia kansui

Kansuinone (1), a rearranged euphane triterpenoid containing a spiro [5,6] ring system, was isolated from the roots of Euphorbia kansui. Its structure and stereochemistry were elucidated on the basis of spectroscopic, CD, and computational methods. Kansuinone (1) exhibited inhibitory activity against human and mouse 11β-HSD1 (11β-hydroxysteroid dehydrogenase type 1), with IC50 values of 1.12 and 1.08 μM, respectively.