Extraction, characterization and its antioxidant efficacy of polysaccharides from Sepia aculeata (Orbigny, 1848) cuttlebone

Ocean is the source of large group of structurally unique natural products that are mainly found in invertebrates such as sponges, tunicates, bryozoans and mollusks. In the present study, polysaccharide was extracted from the cuttlebone of Sepia aculeata and the structure was determined through Fourier transform infra red spectroscopy. Then, the antioxidant efficacy was evaluated through various antioxidant assays such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging assay, hydroxyl radical scavenging assay, superoxide radical scavenging assay and chelating ability on ferrous ions. The total sugar content of S. aculeata polysaccharides was 86.2%. The polysaccharide shows good antioxidant activity when compared with standard commercial antioxidants butylated hydroxyanisole (BHA) and ascorbic acid. The DPPH, superoxide and hydroxyl radical scavenging effect of polysaccharides was found to be 36.27% at 10 mg/ml, 59.57% at 0.5 mg/ml and 45.86% at 3.2 mg/ml, respectively. The chelating effect of polysaccharides was 48.61% at 10 mg/ml.   Key words: Polysaccharide, cuttlebone, Fourier transform infrared (FT-IR), antioxidant.