Isolation, identification, and antioxidant activity of polysaccharides from the shell of abalone (Haliotis discus hannai Ino)

In this study, two antioxidative substances, a homogeneous polysaccharide [abalone shell polysaccharide (ASP-1), corresponding to the first peak by size exclusion chromatography] and a non-polysaccharide compound [abalone shell compound (ACS-2), corresponding to the second peak by size exclusion chromatography], were extracted from the abalone (Haliotis discus hannai Ino) shell. We primarily focused on the investigation of ASP-1. As a heteropolysaccharide, ASP-1 is comprised of 9.3% uronic acid and 86.4% saccharide, the latter including mannose, ribose, rhamnose, glucose, galactose, arabinose, and two unknown monosaccharides, NO1 and NO2, with a mass ratio of 9.5:10.1:2.2:18.2:21.8:5.5:16.5:16.2. The antioxidant activity assays indicated that 5.0 mg/mL ASP-1 has significant scavenging effects on superoxide radicals (86.2%) compared to the positive control of ascorbic acid (95.6%).