Further new bis-cembranoids from the Hainan soft coral Sarcophyton tortuosum.

Two new bis-cembranoids, ximaolides F (1) and G (2), were isolated from the Hainan soft coral Sarcophyton tortuosum. The structures and relative configurations of the two new compounds were elucidated by the combination of spectroscopic methods, chemical conversion of ximaolide F (1) into ximaolide G (2), and comparison with related model compounds.