Latitudinal variation in chemical composition and biological activities of fucoidans from Macrocystis pyrifera (brown algae): first insights along the Chilean coast.

In this study the chemical composition of fucoidans from Macrocystis pyrifera seaweed collected along a latitudinal gradient on the Chilean coast was investigated. Three water-soluble fucoidans were extracted and characterized using different physico-chemical techniques. Their antioxidant, anticoagulant, and cytotoxic activities were also assessed. The results showed that three extracted fucoidans contained a high degree of sulfation and had a high molecular weight. The sugar analysis revealed the presence of fucose, mannose, galactose, glucuronic acid, and glucose monosaccharides at different molar ratios, depending on the collection site, with Fuc:Man ratio ranging from 7.7. to 17.3. 2D NMR analysis suggested that M. pyrifera contained a fucoidan with a highly regular α-1 → 3 glycosidic bond, which was completely sulfated at the O-4 position and partially sulfated at O-2. The anticoagulant activity test showed that the clotting time for the three fucoidans was longer at concentrations of 100 and 500 μg mL. Fucoidans exhibited moderate to low antioxidant activity. Finally, a high selectivity index (>3) for all fucoidans on P-388 leukemia cancer cells was obtained. These results suggest that fucoidans extracted from M. pyrifera have a high potential as natural anticoagulants, and antitumoral agents for industrial applications.