Bioactivity-guided fractionation of an alcohol extract of the soft coral Sarcophyton glaucum collected from the intertidal areas and the fringing coral reefs near Hurghada, Red Sea, Egypt resulted in the isolation of a new
lactone cembrane diterpene,
sarcophytolide. The structure of this compound was deduced from its spectroscopic data and by comparison of the spectral data with those of known closely related
cembrane-type compounds. In antimicrobial assays, the isolated compound exhibited a good activity towards Staphylococcus aureus, Pseudomonas aeruginosa, and Saccharomyces cerevisiae.
Sarcophytolide was found to display a strong cytoprotective effect against
glutamate-induced neurotoxicity in primary cortical cells from rat embryos. Preincubation of the neurons with 1 or 10 microg/ml of
sarcophytolide resulted in 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%, respectively. Administration of
sarcophytolide during the post-incubation period following
glutamate treatment did not prevent neuronal cell death. Pretreatment 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 against
glutamate may be partially due to an increased expression of the proto-oncogene bcl-2. The coral secondary metabolite,
sarcophytolide, might be of interest as a potential
drug for treatment of
neurodegenerative disorders.