Pachyclavulariolides G–L and secopachyclavulariaenone A, seven novel diterpenoids from the soft coral Pachyclavularia violacea

Seven novel diterpenoids pachyclavulariolides G–L (1–6), secopachyclavulariaenone A (7) along with two known compounds, pachyclavulariolide (8) and pachyclavulariolide E (9) have been isolated from the soft coral Pachyclavularia violacea. The structures of 1–6 were established by spectroscopic and chemical methods along with extensive single crystal X-ray analyses. The structure of 8 was further confirmed and the relative configuration of 9 was fully established also by X-ray structure analyses. Cytotoxicity of these compounds toward various cancer cell lines also is described.