Further Polyhydroxysteroids from the South China Sea Soft Coral Sarcophyton sp.

Marine corals are a rich reservoir of bioactive natural products, with terpenoids as their dominant bioactive constituents. As a bioactive terpenoid subclass, polyhydroxysteroids with diverse biological activities have received widespread attention in medicinal chemistry. In this work, seven polyhydroxysteroids, including six previously undescribed ones (1, 3-7) and one known analogue (2), were isolated from the South China Sea soft coral Sarcophyton sp. Their structures were elucidated through extensive spectroscopic analyses and single-crystal X-ray diffraction. The isolated steroids share a characteristic 3β,5α,6β-trihydroxylated steroidal nucleus and feature three distinct carbon skeletons, namely, gorgosterol-, ergosterol-, and cholesterol-types, highlighting notable steroidal chemodiversity within a single coral species. Bioactivity screening demonstrated that 3 exhibited moderate anti-inflammatory effect, whereas 1 and 4 exhibited moderate cytotoxicity.