Limonoids and Triterpenoids as 11β-HSD1 Inhibitors from Walsura robusta

Nine new cedrelone-type limonoid derivatives, walsunoids A–I (1–9), and 11 known compounds were isolated from the leaves of Walsura robusta. Walsunoid A (1) is a new degradation product of cedrelone-type limonoids, and walsunoid I (9) is a rare cedrelone-type limonoid amide. Their structures and absolute configurations were determined by spectroscopic data, single-crystal X-ray diffraction, and ECD data analyses. Five compounds showed moderate inhibitory activities against human and/or mouse 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) with IC₅₀ values ranging from 0.69 to 9.9 μM.