Triterpene acids from Euscaphis japonica and assessment of their cytotoxic and anti-NO activities.

Six new triterpenoids, euscaphic acids G-L (1-6), along with nine known triterpene acids, and two known lignans were isolated from the ethanolic extract of the twigs of Euscaphis japonica. This is the first report concerning 1α,3β-dihydroxy-12-oleanen-28-oic acid isolated from a natural source. The structures of the new compounds were established by spectroscopic analysis. The cytotoxic and anti-NO production activities for the isolates are also evaluated and discussed; compound 1, hederagenin (11), and arjunic acid (12) showed significant cytotoxicity against NCI-H460 cells, HT-29 cells, and CEM cells (IC₅₀ = 1.64 ± 0.87, 2.11 ± 1.54, 1.73 ± 0.64 µM, respectively). Some of the isolated triterpenoids showed marginal inhibitions on NO production induced by LPS.