Terpenoids from the stems of Celastrus hindsii and their anti-RSV activities.

Two new oleanane-type triterpenoids (1-2), a new ursane-type triterpenoid (3), and a new podocarpane-type diterpenoid (4), together with 20 known compounds (5-24) were isolated from the stems of Celastrus hindsii Benth. Their structures were identified on the basis of the spectral data (HRESIMS, IR, UV, 1D, and 2D NMR) and the absolute configurations were determined by comparison of experimental and calculated ECD data. The structures of 1 and 4 were further confirmed by single crystal X-ray diffraction analysis. In addition, all compounds were evaluated for their in vitro antiviral activities against respiratory syncytium virus (RSV) using cytopathic effect (CPE) reduction assay. Compounds 7, 10, 11, 19 and 24 exhibited obvious anti-RSV activity with IC values from 1.55 to 6.25 μM.