Kalihioxepanes A-G:Seven Kalihinene Diterpenoids from Marine Sponge Acanthella cavernosa Collected off the South China Sea

Comprehensive Summary Seven new kalihinene diterpenoids,kalihioxepanes A-G(1-7)bearing a rare oxepane ring,were isolated from sponge Acanthella cavernosa collected from the South China Sea.The structures and absolute configurations were elucidated by comprehensive spectroscopic analysis,single crystal X-ray diffraction,and quantum chemical calculation methods.Kalihioxepane A(1)displayed strong cytotoxicity against H69 and K562 tumor cells,while kalihioxepane B(2)showed moderate cytotoxicity against K562 cells.