Neuroprotective oleanane triterpenes from the roots of Bupleurum chinense

The discovery of new natural compounds with pharmacological properties is an increasingly important field, and a continuous phytochemical investigation of the roots of Bupleurum chinense D.C. has led to the isolation of 17 triterpenoids, including three new oleanane triterpenes (1–3) together with 14 known ones. Their structures were determined on the basis of 1D and 2D NMR spectra as well as HR-ESI-MS data. The cytotoxicities of all compounds against five selected human cancer cell lines were assayed. Only compounds 9 and 14 exhibited moderate activities. Recently, a number of investigations have focused on the neuroprotective properties of triterpenoids in B. chinense. In order to expand our knowledge about this herb, the neuroprotective effects of compounds 1–17 against hydrogen peroxide (H2O2)-induced neuronal cell damage in human neuroblastoma SH-SY5Y cells were evaluated. Compounds 1–3, 6–7 showed significant neuroprotective effects against H2O2-induced SH-SY5Y cell death. Preliminary structure–activity relationships (SARs) between neuroprotective effects and the isolates were also discussed.

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