Isolation, characterization, and biological activities of halogenated sesquiterpenes and C15 acetogenins from the Okinawan sea hare, Aplysia argus

The sea hare, scientifically known as Aplysia argus, is the focus of considerable research interest owing to its unique halogenated metabolites that may have vast potential in the fields of medicine and pharmaceuticals. This paper reports the isolation of a new laurane-type sesquiterpene, 10-bromoisolaurinsiol (1), and a new halogenated C15 acetogenin (2), along with several known halogenated secondary metabolites from the sea hare Aplysia argus. Their structures and relative stereochemistries were established through comprehensive 1D and 2D NMR analyses. Fourteen compounds, some of which were novel, were evaluated for their cytotoxic effects against S1T cells (a cancer cell line derived from adult T-cell leukemia patients) and their potential as SARS-CoV-2 main protease inhibitors.