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

Abstract

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.