Structural Characteristics and Antitumor Activity of Fucoidans from the Brown Alga Sargassum muticum

Water-soluble polysaccharides from two specimens of brown alga Sargassum muticum (April 2014 and June 2015), which synthesized heterogeneous sulfated fucoidans, were isolated and studied. Both specimens produced insignificant amounts of laminarans. Two of three fucoidan fractions from alga collected in April contained mannogalactofucans; one, galactofucan (Fuc–Gal, 2:1). The alga specimen collected in June afforded two galactofucans of different structures (Fuc–Gal, 1:1 and 3:1). Studies of the antitumor activity of the obtained fucoidans and their modified derivatives showed a lack of cytotoxicity and the manifestation of activity against DLD-1 human colon carcinoma cells.