Chemical characters and antioxidative properties of sulfated polysaccharides from Laminaria japonica

A low molecular weight sulfated polysaccharide (L-A) was prepared by mild a cid hydrolysis of crude fucoidan (F-A) from Laminaria japonica. In comparis on with F-A, L-A had a lower proportion of fucose residues, but a similar p roportion of sulfate. The galactose content of both fractions was relativel y high, especially for L-A (57%). The antioxidant properties of the two pol ysaccharides were studied using two low-density lipoprotein oxidation syste ms. L-A had a stronger effect against low-density lipoprotein oxidation in both systems. F-A inhibited the AAPH-induced low-density lipoprotein oxidat ion, but had little effect on the Cu++-induced system due to its large mole cular mass. The active sulfated fraction L-A, containing galactose, mannose and fucose (about 9: 2: 2) is reported here for the first time.