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

Seven novel diterpenoids pachyclavulariolides G-L (1-6), secopachyclavulari aenone, A (7) along with two known compounds, pachyclavulariolide (8) and p achyclavulariolide E (9) have been isolated from the soft coral Pachyclavul aria violacea. The structures of 1-6 were established by spectroscopic and chemical methods along with extensive single crystal X-ray analyses. The st ructure of 8 was further confirmed and the relative configuration of 9 was fully established also by X-ray structure analyses. Cytotoxicity of these c ompounds toward various cancer cell lines also is described. (C) 2001 Elsev ier Science Ltd. All rights reserved.