Cytotoxic 19-oxygenated steroids from the South China Sea gorgonian, Pacifigorgia senta

Bioassay guided chemical investigation of the gorgonian Pacifigorgia senta led to the discovery of a new 19-oxygenated steroid, cholesta-5,24-diene-3β,7β,19-triol (1), as well as three known steroids (2–4). The structure of 1 was determined by extensive spectroscopic analysis, including NMR and MS spectra. All of the compounds exhibited cytotoxicities against HepG2, Hep3B, MCF-7/ADR, PC-3 and HCT-116 cell lines, with the IC₅₀ values ranging from 7.0 to 29.7 μM. It is the first report on the chemical constituents of the coral species P. senta.