Cucurbitane-type triterpenoids from the branches and leaves of Elaeocarpus sylvestris

The chemical structures of nine cucurbitane-type triterpenoids from the branches and leaves of Elaeocarpus sylvestris (Elaeocarpaceae), including undescribed 29-hydroxymogroside I E2, epimogroside I E2, epimogroside I E1, 24-oxomogroside I E1, and 11-O-acetylmogroside I E1, were determined using mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. The absolute configuration of 29-hydroxymogroside I E2 was confirmed by performing an X-ray diffraction analysis. Cucurbitacin D and 11-O-acetylmogroside I E1 showed cytotoxicity toward human leukemia HL-60, human lung adenocarcinoma A549, human hepatoma SMMC-7721, human breast cancer MCF-7, and human colon cancer SW480 cell lines. The presence of a 11-O-acetyl group might increase the cytotoxicity of this type of triterpenoids.