Purification and radical scavenging effect of Laminaria japonica polysaccharide

A purified polysaccharide of WPS-1-1 was obtained from crude extracts of Laminaria japonica by S-300 gel chromatography.The average molecular weight of WPS-1-1 was 112ku. Monosaccharides analysis revealed that WPS-1-1 was composed of fucose, xylose, galactose and mannose with a molar ratio of 6.9∶3.3∶1.5∶1. The results of infrared spectrum indicated that WPS-1-1 contained β-pyranose and sulfate group. In vitro, radical scavenging tests revealed that WPS-1-1 showed significant function of scavenging superoxide and hydroxyl radicals with IC 50 value of 0.35 and 1.0mg /mL.It could be a potential functional free-radical scavenger.