Anti-inflammatory lupane triterpenoids from Menyanthes trifoliata.

A new lupane triterpenoid, 23-O-trans-feruloylcylicodiscic acid (1), as well as four known analogues (2‒5), was isolated from the EtOAc fraction of Menyanthes trefoliata. The structure of compound 1 was elucidated on the basis of extensive spectroscopic analysis, including 2D NMR data. The structures of the known compounds were established by comparison of their spectroscopic data with that in the literature. Compounds 1, 2, and 4 exhibited certain anti-NO production activities.