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⁻¹. 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.