Structure and cytotoxicity of a new lanostane-type triterpene glycoside from the sea cucumber Holothuria hilla.

A new triterpene glycoside, hillaside C (1), was isolated from the sea cucumber Holothuria hilla Lesson, which is found in the South China Sea, and its structure has been elucidated by spectral analysis (ESI-MS and NMR) and chemical transformations. Four known compounds, holothuria A, thymine, uracil, and cholesterol, were also obtained. Compound 1 exhibited significant cytotoxicity against eight human tumor cell lines (A-549, MCF-7, IA9, CAKI-1, PC-3, KB, KB-VIN, and HCT-8) with IC50 values in the range of 0.15-3.20 microg/ml.