Phytochemical investigation of the root tubers of Lindera aggregata resulted in the isolation of five new sesquiterpene lactones, linderagalactones A-E (1-5), along with eight known sesquiterpenoids, 3-eudesmene-1beta,11-diol, hydroxylindestenolide, strychnistenolide, hydroxyisogermafurenolide, atractylenolide III, linderane, neolinderalactone, and linderalactone. The structures and relative configurations of 1-5 were determined by spectroscopic methods, especially HRESIMS and 2D NMR techniques. The absolute configurations of 1-4 were defined by comparison of quantum chemical TDDFT calculated and experimental ECD spectra. Linderagalactone A (1) is a halogenated sesquiterpene lactone possessing a unique rearranged carbon skeleton. Linderagalactone E (5), linderane, hydroxylindestenolide, and linderalactone showed hepatoprotective activity against H2O2-induced oxidative damages on HepG2 cells with EC(50) values of 67.5, 167.0, 42.4, and 98.0 microM, respectively.

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Four new cycloartane triterpenoids, together with the known gardenolic acid B, were isolated from Kleinhovia hospita. The triterpenoids (1-3) contain a unique 21,23-diacetal side-chain, while compound 4 contains two alpha,beta-unsaturated ketone moieties. Their structures and relative configurations were determined by spectroscopic methods, including 2D NMR and IR. These compounds showed promising hepatoprotective effects on nitrofurantoin-induced cytotoxicity in human liver-derived Hep G2 cells.