Extraction optimization, preliminary characterization and antioxidant activity of glycoproteins from the muscle of sepia pharaonis

Abstract

The extraction, purification, preliminary characterization and antioxidant activity of glycoproteins from Sepia pharaonis muscle (SPMG) were investigated. The optimal extraction conditions were obtained using a Box-Behnken design. The crude SPMG was purified by DEAE-Cellulose 52 ion-exchange and Sephadex G-100 gel chromatography and two fractions (SPMG-I and SPMG-II) were obtained. SPMG-I and SPMG-II were rich in Glu, Asp, Leu, Arg and Lys with the molecular weight of 42.5 and 36.3 kDa, respectively. The glucose was the predominant monosaccharide composition of SPMG-I and SPMG-II. The existence of O-glycosidic linkage in SPMG-I and SPMG-II was demonstrated by a β-elimination reaction. SPMG-I and SPMG-II were characterized by FT-IR. SPMG, SPMG-I and SPMG-II showed excellent antioxidant activities and SPMG-I exhibited the highest antioxidant ability. These may provide theoretical basis for further system research and rational development and utilization of SPMG resource.