Halistanol Disulfate B, a Novel Sulfated Sterol from the Sponge Pachastrella sp.:  Inhibitor of Endothelin Converting Enzyme

As part of a search for novel inhibitors of endothelin converting enzyme (ECE), the MeOH extract of a South African sponge, Pachastrella sp., was shown to be active. Bioassay-guided fractionation of the extract yielded a novel sterol sulfate, halistanol disulfate B (1). The structure and stereochemistry of 1 was established mainly by interpretation of spectral data. Disulfate (1) was found to be active at a micromolar concentration in the ECE assay.