Synthesis, Characterization and Antioxidant Activities of Bioactive Polymer from Internal Bone of Sepia aculeata

To study the antioxidant potential of chitosan by different in vitro methods, including chelating ability on metal ions, DPPH and superoxide radical assays. Chitin was extracted from internal bone of Sepia aculeata (cuttlebone) and through deacetylation, chitosan was prepared. The extracted chitosan was characterized with FT-IR, FESEM, XRD and exhibits a crystalline, non-porous and smooth membranous structure. The antioxidant activity was performed to determine if the isolated bioactive compounds exhibit a potency against the free radicals. Furthermore, chitosan demonstrated antioxidant activity against DPPH at 14.08–51.17% at 0.1–10 mg/mL and superoxide radicals at 24.38–67.19% at 0.1–1.6 mg/mL. At the same time, compared to EDTA, ferrous ions showed a poor chelating activity of 28.20-74.60% at concentrations of 0.1–10 mg/mL. These results indicated that cuttlebone, due to its superior antioxidant activity and ferrous ion chelating ability, can serve as an effective organic antioxidant and food additive in the pharmaceutical industry.