Unprecedented anti-inflammatory biscembranoids with 3-hydroperoxy-3-methylcyclohex-1-ene moiety isolated from aquaculture Sarcophyton trocheliophorum

Abstract

Recent advancements in the discovery of natural products have made significant progress in rapidly identifying known compounds from complex extracts using advanced spectroscopic technologies. Among these methods, one powerful approach called MS/MS molecular networking (MN) organizes chemical similarity based on MS/MS fragmentation data, serving as a valuable complement to traditional dereplication strategies. In our ongoing research focused on lead discovery from a sustainable medicinal source, an aquaculture soft coral Sarcophyton trocheliophorum, the MN profiling approach revealed the chemical diversity of biscembranoid analogs. By analyzing the MN pattern, biscembranoid derivatives with unique MS/MS fragments were prioritized for further investigation. Two novel biscembranoids, sarcotroxide A (1) and B (2), were successfully obtained through targeted isolation. These novel biscembranes contained an unprecedented 3-hydroperoxy-3-methylcyclohex-1-ene moiety compared with all biscembranoid analogs. The chemical structures of the two new biscembranoids were confirmed through spectroscopic analyses and in silico calculations. Their anti-inflammatory properties were assessed against the generation of superoxide anion (O2•−) and elastase release in activated human neutrophils. Sarcotroxides A (1) and B (2) exhibited anti-inflammatory activity by inhibiting O2•− accumulation (with 43.67% and 61.62% inhibition) and elastase release (with 38.21% and 61.62% inhibition) at 10 µM. These findings validated the potential of these biscembranoids from the cultured S. trocheliophorum as promising candidates for the future development of anti-inflammatory agents specifically designed to target neutrophils.