Lupane Triterpenoids from the Stems of Euonymus carnosus

Fifteen new lupane-type triterpenoids (1–15) and 10 known triterpenoids (16–25) were isolated from the stems of Euonymus carnosus. The structures of the new compounds were elucidated on the basis of spectroscopic analyses, and the absolute configuration of compound 1 was confirmed by X-ray crystallographic analysis using anomalous scattering of Cu Kα radiation. In addition, the compounds were tested for their cytotoxic activity against five human cancer cell lines and their ability to inhibit LPS-induced nitric oxide production in the murine microglia BV2 cell line. Compound 11 exhibited moderate cytotoxicity against several human cancer cell lines, and compounds 1, 2, 4, 5, 20, and 25 showed neuritis inhibitory activity against microglial inflammation factor, with IC₅₀ values of 7.39, 7.48, 7.80, 3.48, 2.54, and 6.09 μM, respectively.