New triterpenoids with diverse side-chains from the barks of Melia Toosendan

Nine new euphane- and apotirucallane-type triterpenoids (Toosendines A-I; 1-9), along with three known tirucallane-type compounds were isolated from the barks of Melia toosendan. Their structures were elucidated based on detailed spectroscopic analyses (HRESIMS, 1D/2D-NMR) and circular dichroism spectra. Results of bioactivities screening exhibited that compounds 1, 4 and 5 showed remarkable NO inhibitory activities in LPS-activated RAW 264.7 macrophages, meanwhile, compounds 1 and 4 showed moderate cytotoxicities against U2OS human cancer cell line.