Fucoidan Extracted From Sporophyll of Undaria pinnatifida Grown in Weihai, China – Chemical Composition and Comparison of Antioxidant Activity of Different Molecular Weight Fractions

Abstract

Fucoidan is a multifunctional marine carbohydrate polymer that differs in its chemical composition and bioactivity both between seaweed species and within species from different locations across the globe. In this study, fucoidan was extracted from the sporophyll of Undaria pinnatifida grown in Weihai, Shandong Province, China. Fucoidan fractions with molecular weight cutoffs (MWCO) of >300 kDa and <10 kDa were obtained via dialysis. The fucoidan standard from Sigma (Fstd, ≥95, CAS: 9072-19-9), fucoidan crude extract (WH), >300 kDa fraction (300k) and <10 kDa fraction (10k) were compared in terms of chemical composition and antioxidant capacity. Based on Fourier transform infrared spectroscopy (FT-IR) analysis, Fstd, WH, and 300k all showed strong bands around 830 cm−1, corresponding to the sulfate substituent in the molecule. The results showed that compared with WH and 300 k, the degree of sulfation at 10k was the lowest. From Nuclear magnetic resonance spectroscopy (NMR) result, the four fucoidan samples all contain α-L-fucose. The primary antioxidant ability of the 10k is significantly higher than that of the 300k, WH, and Fstd, but the secondary antioxidant capabilities of the 10k and 300k were similar, and both were higher than that of the butylated hydroxyanisole (BHA). The ferric reducing antioxidant ability was higher in the 300k and WH fractions. This demonstrates that fucoidan extracted from U. pinnatifida grown in Weihai, China should be a useful nutraceutical resource.

Antioxidant Activity of Fucoidan Modified with Gallic Acid Using the Redox Method

“…The values obtained with FucA-GA and FucA (1.0 and 2.0 mg/mL) are close to that described (75.2%) for the non-commercial U. pinnatifida fucoidan [ 5 ], indicating that the fucoidan from this seaweed is a good hydroxyl ion-scavenging agent. However, Yu et al [ 60 ] reported commercial U. pinnatifida fucoidan with 30% hydroxyl radical scavenging activity; this seems to indicate that the product batch can also influence the observed antioxidant activity. In addition, these variations in fucoidans batch are common and are also related to factors such as seasonality, collection location, seaweed age, and fucoidan extraction/purification method [ 8 , 9 , 10 , 11 , 12 ].…”

Fucoidan from Marine Macroalgae: Biological Actions and Applications in Regenerative Medicine, Drug Delivery Systems and Food Industry

“…The amount of L-fucose in fucoidan outweighs other monosaccharides and accounts for more than 90% of its total sugar composition [ 4 ]. The other monosaccharides in fucoidan comprise varying proportions of uronic acid, galactose, glucose, xylose, mannose, rhamnose, arabinose and acetyl groups [ 17 , 31 , 32 , 33 ]. The composition and complexity of fucoidan polysaccharides vary among different species of brown macroalgae ( Table 1 ) and are largely influenced by geographical location and seasonal variations [ 33 , 34 ].…”

“…The other monosaccharides in fucoidan comprise varying proportions of uronic acid, galactose, glucose, xylose, mannose, rhamnose, arabinose and acetyl groups [ 17 , 31 , 32 , 33 ]. The composition and complexity of fucoidan polysaccharides vary among different species of brown macroalgae ( Table 1 ) and are largely influenced by geographical location and seasonal variations [ 33 , 34 ]. The diverse chemical compositions are reminiscent of their differences in biosynthesis.…”

“…The diverse chemical compositions are reminiscent of their differences in biosynthesis. Although fucoidans do not have a universal chemical structure [ 4 , 5 ], the scientific literature available to date suggests principally two structural types of fucoidans: Type I fucoidan has repeating units of α-(1→3)-linked α-L-fucopyranose and Type II fucoidan has alternately repeating units of α-(1→3)- and α-(1→4)-linked α-L-fucopyranose ( Figure 1 ) [ 20 , 31 , 33 , 35 ]. Several representatives of the orders Chordariales and Laminariales contain Type I fucoidan, whereas those from the order Fucales contain Type II fucoidan [ 14 , 19 , 22 , 23 , 36 ].…”

“…Membrane filtration using different molecular weight cut-off membranes is used for the fractional separation of fucoidans from other polysaccharides and also to separate their different molecular variants [ 49 ]. Size exclusion chromatography, also known as gel permeation chromatography, is also used for the fractional separation of fucoidan according to their molecular sizes [ 21 , 33 ].…”