Preparation, Characteristics And Bioactivity Of Polysaccharide Iron Complex

Abstract

A new onion polysaccharide-iron (III) complex (OPS-iron) was preparated and characterized. The preparation conditions of OPS-iron (III) were optimized and the physicochemical properties were characterized by physicochemical methods, scanning electron microscopy (SEM), electron paramagnetic resonance (EPR) spectroscopy, Ultraviolet-visible spectroscopy (UV-Vis), and Fourier transform infrared (FTIR) spectroscopy, respectively. In vitro antioxidant activity of polysaccharides and OPS-Fe were evaluated by determining the radical (DPPH and hydroxyl radical) scavenging abilities. The highest iron content of OPS-iron (III) complex (20.18%) was obtained at the conditions: the ratio of OPS and FeCl36H2O was 3:5 (w/w), the pH value of alkali solution was 10, the reaction temperature was 30 ◦C and the reaction time was 6 h. The iron (III) was shown to be bound through the binding sites of the polysaccharide OPS and it could form spatially separated iron centers on the polysaccharide backbone. OPS-iron (III) complex was found to have good digestive availability and antioxidant activities in the in vitro assays, which suggested the OPS-iron (III) complex might be used as a new iron supplement candidate. In vitro free radical scavenging activity of OPS-Fe was significantly better than OPS. The IC50 of OPS-Fe against DPPH and hydroxyl radical were 3.785 mg/mL and 1.460 mg/mL, respectively