Cytotoxic Isoprenoids from the Red Sea Soft Corals Sarcophyton glaucum and Xenia umbellate

. Three cytotoxic cembranoids , sarcophytolol (1), sarcophytolide B (2) and sarcophytolide C (3) were identified from the Et2O-soluble fraction derived from the crude extract of the soft coral Sarcophyton glaucum, along with three known aromadendrane-type sesquiterpenoids, aromadendrene (4), palustrol (5) and viridiflorol (6) were isolated from Xenia umbellata collected from the Red Sea water, Jeddah. Chemical structures were determined by analyzing their NMR and MS data. Compounds 1-6 were evaluated for potential cytotoxic activities, employing five cancer panels; HepG2, MCF-7, A549, PC-3 and VERO. Interestingly, compounds 1 and 3 exhibited selective cytotoxic effects on HepG2 and showed no toxicity to the other cell lines. However, 2 showed selective cytotoxic effect on MCF-7 with no toxicity on other cell lines. Meanwhile compounds 4-6 showed cytotoxic activity against both MCF-7 and HepG2 with no toxicity on normal VERO cells.