Seven new unusual polysulfated steroids-topsentiasterol sulfate G (1), topsentiasterol sulfate I (2), topsentiasterol sulfate H (3), bromotopsentiasterol sulfate D (4), dichlorotopsentiasterol sulfate D (8), bromochlorotopsentiasterol sulfate D (9), and 4β-hydroxyhalistanol sulfate C (10), as well as three previously described-topsentiasterol sulfate D (7), chlorotopsentiasterol sulfate D (5) and iodotopsentiasterol sulfate D (6) have been isolated from the marine sponge Halichondria vansoesti. Structures of these compounds were determined by detailed analysis of 1D- and 2D-NMR and HRESIMS data, as well as chemical transformations. The effects of the compounds on human prostate cancer cells PC-3 and 22Rv1 were investigated.
