Bioactivity and sterols from Gracilariopsis Persica and Sargassum oligocystum

Abstract

Gracilariopsis Persica (Rhodophyta) and Sargassum oligocystum (Heterokontophyta) are two of the most abundant algae from Persian Gulf (1). In this study the cytotoxic effects of the mentioned algae on the Brine Shrimp Larvae (BSA) were evaluated (2) and the main sterols were identified. Separation and purification of the compounds was carried on silica gel column chromatography and HPLC to obtain 4 pure compounds 1–4. Structural elucidation of the constituents was based on the data obtained from H-NMR, 13C-NMR and Mass spectroscopy. The separated compounds from G. Persica were identified as cholesterol (1), 22-dehydrocholesterol (2) and the isolated constituents from S. oligocystum were identified as cholesterol (1), 22-dehydrocholesterol (2), fucosterol (3) and ostreasterol (4) based on the spectral data compared to those reported in literatures (3). The results of BSA indicated that the ethyl acetate extract of G. Persica showed a cytotoxic effect against A. salina nauplii (LC50=4µg/ml). The MeOH extract of G. Persica showed no activity but the aqueous methanol extract was less effective (LC50=40µg/ml) compared to berberine hydrochloride as a positive control (LC50=26µg/ml). The chloroform extract of S. oligocystum showed a cytotoxicty effect against A. salina nauplii (LC50=159µg/ml).