Structural characterization of three acidic polysaccharides from Opuntia dillenii Haw. fruits and their protective effect against hydrogen peroxide-induced oxidative stress in Huh-7 cells

Three novel acidic polysaccharide fractions (OFPP-1, OFPP-2, OFPP-3) with different molecular weights (803.7,555.1 and 414.5 kDa) were isolated from the peeled Opuntia dillenii Haw.fruits by alkali-extraction, graded alcohol precipitation and column chromatography.Structural analysis indicated that OFPPs were pectic polysaccharides consisting of rhamnose, arabinose and galactose residues.The backbone of OFPP-1 consisted of a repeating unit →6as the side chains.The backbone of OFPP-2 consisted of a disaccharide repeating unit →2)-α-L-Rhap-(1→4)-β-D-GalpA-(1→ with T-β-L-Araf-(1→ as the branches substituted