Uncommon Polycyclic Merosesquiterpenoids and Asteriscanoids from the Hainan Soft Coral Sinularia humesi†.

Main observation and conclusion: A rare highly fused racemic merosesquiterpenoid, 9‐epi‐verrubenzospirolactone (1), six new asteriscane‐type sesquiterpenoids, sinuhumesins A—F (4—9), and two related known ones (10 and 11) were isolated from Hainan soft coral Sinularia humesi. Compound 1 was further separated by chiral HPLC resolution to one pair of enantiomers [(+)‐1 and (–)‐1], respectively. The full structures of the new compounds were unambiguously determined by extensive spectroscopic analysis, chemical computation approaches, modified Mosher's method and/or X‐ray diffraction analysis, as well as comparison with previously reported data of related model compounds. [ABSTRACT FROM AUTHOR]