Fucoidan from New Zealand Undaria pinnatifida: monthly variations and determination of antioxidant activities.

The content and composition of fucoidans extracted from Undaria pinnatifida from mussel farms at the Marlborough Sounds, New Zealand were investigated using CaCl2 extraction. Crude fucoidan (F0) was subsequently extracted on a monthly basis from U. pinnatifida harvested from July to October 2011 from mussel farms in the Marlborough Sounds, New Zealand. Fucoidan yield varied between the frond and sporophyll parts of the algae, with the sporophyll consistently the highest content. The yield from the sporophyll increased significantly from July (25.4-26.3%) to September (57.3-69.9%). Sulphate content in the extracted fucoidan increased more than twice within the same period, while fucose content remained constant. F0 was further purified by ion-exchange chromatography to yield three fractions, F1, F2 and F3. All three fucoidan fractions contained fucose as the primary sugar component followed by galactose, with xylose, glucose and mannose as minor constituents. All fractions exhibited strong antioxidant activities using the DPPH scavenging and CUPRAC assays. This study showed that sporophyll maturation of U. pinnatifida in New Zealand influenced fucoidan content and composition. Sporophyll fucoidan could potentially be a good resource for natural antioxidants.