Sarcophytolide: a new neuroprotective compound from the soft coral Sarcophyton glaucum

Bioactivity-guided fractionation of an alcohol extract of the soft coral Sa rcophyton glaucum collected from the intertidal areas and the fringing cora l reefs near Hurghada, Red Sea, Egypt resulted in the isolation of a new la ctone cembrane diterpene, sarcophytolide. The structure of this compound wa s deduced from its spectroscopic data and by comparison of the spectral dat a with those of known closely related cembrane-type compounds. In antimicro bial assays, the isolated compound exhibited a good activity towards Staphy lococcus aureus, Pseudomonas aeruginosa, and Saccharomyces cerevisiae. Sarc ophytolide was found to display a strong cytoprotective effect against glut amate-induced neurotoxicity in primary cortical cells from rat embryos. Pre incubation of the neurons with 1 or 10 mu g/ml of sarcophytolide resulted i n a significant increase of the percentage of viable cells from 33 +/- 4% ( treatment of the cells with glutamate only) to 44 +/- 4 and 92 +/- 6%, resp ectively. Administration of sarcophytolide during the post-incubation perio d following glutamate treatment did not prevent neuronal cell death. Pretre atment of the cells with sarcophytolide for 30 min significantly suppressed the glutamate-caused increase in the intracellular Ca2+ level ([Ca2+](i)). Evidence is presented that the neuroprotective effect of sarcophytolide ag ainst glutamate may be partially due to an increased expression of the prot o-oncogene bcl-2. The coral secondary metabolite, sarcophytolide, might be of interest as a potential drug for treatment of neurodegenerative disorder s. (C) 1998 Elsevier Science ireland Ltd. All rights reserved.