Bissubvilides A and B, Cembrane–Capnosane Heterodimers from the Soft CoralSarcophyton subviride

Two new biscembranoid-like compounds, bissubvilides A (1) and B (2), were isolated together with sarsolilide B (3), the proposed biogenetic precursor to 1, from the soft coral Sarcophyton subviride. The structures and absolute configurations were solved by spectroscopic analysis and TDDFT/ECD and DFT/NMR calculations. The bissubvilides represent a novel biscembranoid-like skeleton presumed to derive from a cembrane-type diene and a capnosane-type dienophile via a Diels-Alder reaction. These two molecules exerted no cytotoxicity against MG-63 or A549 tumor cells or HuH7 tumor stem cells.