Abstract
The Red Sea soft coral Sarcophyton glaucum was investigated for its sesquiterpene content. A novel 1,2-dioxolane sesquiterpene alcohol, dioxosarcoguaiacol (1) along with the known (+)-alloaromadendrene are reported. The structure of the new sesquiterpene was determined on the basis of extensive spectral analyses. (+)-Alloaromadendrene showed potent inhibition of the proliferation of the highly malignant + SA mammary epithelial cells at a dose of 20μM.