Effect of Fe (III), Zn (II), and Cr (III) complexation on the physicochemical properties and bioactivities of corn silk polysaccharide

In this paper, Fe (III), Zn (II), and Cr (III) were used to complex with corn silk polysaccharide (CSP) by classical methods and CSP-Fe, CSP-Zn, and CSP-Cr were successfully synthesized, respectively. The physicochemical properties and structural features were characterized by chemical composition analysis, inductive coupled plasma-mass spectrometry (ICP-MS), ultraviolet-visible (UV-Vis) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, fourier transform infrared (FT-IR) spectroscopy, circular dichroism (CD) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC), respectively. The antioxidant activities and inhibitory effects on α-glucosidase of CSP, CSP-Fe, CSP-Zn, and CSP-Cr were compared. The results showed that the Fe (III), Zn (II), and Cr (III) chelation could change the morphology, conformation, thermostability, and biological activities of CSP. CSP-Zn exhibited higher antioxidant activities and inhibition effects on α-glucosidase than CSP, which suggested that it could be considered as a potential candidate for developing an ingredient of functional foods for antidiabetics.