Marine algae are considered a diverse source of bioactive compounds. This study aimed to detect the presence of antiviral and anticancer potential in extracts of marine algae ,extraction, purification and identification of some marine algae in Egypt were conducted.Water and solvent extraction of Ulvalactuca, Sargassumdentifolium, and Cystoseiaramyrica was conducted. A sequence of extractions, including ethanol (EtOH), boiling water,hydrochloric acid and sodium hydroxide, were evaluated for their antitumour and antiviral activities using liver and brain tumour cell lines and measles, mumps and hepatitis B virus (HBV). The most promising extracts were purified by fractionation using precipitation by cetylpyridinium chloride (CPC), size exclusion chromatography and anion exchange chromatography. The structures of the active compounds were identified by a series of chemical analyses, including sugar analysis, configurational analysis, high-performance liquid chromatography (HPLC), infrared spectroscopy (IR), gas-liquid chromatography-mass spectroscopy (GLC-MS) and 1H,13C nuclear magnetic resonance (NMR) at ZV. The active compounds from water extraction were identified mainly as polysaccharides and sulphated polysaccharides. The antitumour and antiviral activities of the purified ethanolic extraction were attributable to compounds identified as Ethyl Palmitate. These compounds are safe with no cytotoxic effect. These could pave the way for further studies that may lead to its medical application.

Keywords: Extracts, marine algae, antiviral, antitumour