Isosarcophytoxide Derivatives with a 2,5-Dihydrofuran Moiety from the Soft Coral .

The present chemical investigation on the organic extract of the soft coral has contributed to the isolation of four new cembranoids: 16- and 16-hydroperoxyisosarcophytoxides ( and ), 16- and 16-methoxyisosarcophytoxides ( and ), and a known cembranoid, lobocrasol (). The structures of all isolates were elucidated by detailed spectroscopic analysis. Their structures were characterized by a 2,5-dihydrofuran moiety, of which the relative configuration was determined by DU8-based calculation for long-range coupling constants (). The cytotoxicity and immunosuppressive activities of all isolates were evaluated in this study.