Antioxidant Properties of Different Molecular Weight Polysaccharides from Seaweed Sargassum Fusiform

Abstract

This study comparatively analyzed the antioxidant activities of original and three degraded sargassum fusiform polysaccharide fractions, named SFP0, SFP1, SFP2, and SFP3, with molecular weight of 16.2, 8.21, 3.83, and 2.23 kDa, respectively. Results revealed that the
scavenging activity of various SFP fractions for hydroxyl, DPPH, and ABTS radicals and the
reducing power increased with decreasing molecular weight of SFP within 16.2-2.23 kDa.
SFP3, with the lowest molecular weight of about 2.23 kDa, exhibited the strongest radical
scavenging capacity. Moreover, the Fe2+ chelating ability also increased with decreasing
molecular weight of various SFP fractions. The active groups (such as -OSO3H) of
low-molecular-weight polysaccharides was easily exposed and possessed high degree of
freedom and low space steric hindrance; hence, their chelating ability increased. These SFP
fractions, especially SFP3, may be potential anti-stone drugs.