A New Sulfated Cholestane From the Sea Urchin Mesocentrotus nudus With Cytotoxic Activity

A new sulfated cholestane derivative, 5α,8α-epidioxy-cholesta-6-en-3β-O-sulfate (1), together with three known sterols, cholest-7-ene-3,5,6-triol (2) and a mixture of 24(S)-hydroxy-24-vinylcholesterol (3) and 24(R)-hydroxy-24-vinylcholesterol (4), was isolated from the viscera of the sea urchin Mesocentrotus nudus. The structures were elucidated by comprehensive spectroscopic analyses (1D and 2D NMR and HRESIMS) and by comparison with reported data. Compound 1 exhibited moderate cytotoxicity against K562 human leukemia and SW480 human colon cancer cells, with IC₅₀ values of 16.72 ± 0.28 µM and 17.79 ± 0.32 µM, respectively. This work represents the first report of a 5α,8α-epidioxy sterol from the genus Mesocentrotus and adds to the chemical diversity of sea urchin sulfated sterols, providing a basis for further biological evaluation.