RESUMEN
Backgrounds: Seaweeds are an important source of marine organisms that produce a lot of bioactive compounds. Materials and Methods: In this research, the seaweed Sargassum angustifolium was collected from Bushehr province of Persian Gulf of Iran. The seaweed was extracted by methanol:ethyl acetate (1:1) using maceration method. The compounds were isolated with different column chromatography and HPLC(High Performance Liquid Chromatography) by silica gel and hexane:ethyl acetate as mobile phase. Results: The isolated compounds were elucidated structurally by various 1 and 2 D-NMR and MS spectra. Besides the cytotoxicity test was done against HeLa using standard MTT assay and normal cells. Conclusion: It afforded four known sulfoquinovosyl diacylglycerides and fucosterol. Compounds 1-5 showed cytotoxic effects against HeLa and HUVEC cell lines, with IC50 values of 12.2 ± 2.3, 25.8 ± 3.7, 14.9 ± 2.6, 9.8 ± 1.2 µM, and 5.6 ± 1.2, respectively.