Characterization of polysaccharides and their antioxidant properties from Plumula nelumbinis

Two novel polysaccharides, Plumula nelumbinis (P. nelumbinis) polysaccharide I (LNP I) and P. nelumbinis polysaccharide II (LNP II), were extracted and purified from P. nelumbinis, and a sulfated polysaccharide, P. nelumbinis polysaccharide III (LNP III), with a substitution degree of 0.62 was prepared from LNPI. The structures of the LNPs were preliminarily characterized using high performance size exclusion chromatography (HPSEC), gas chromatography-mass spectrometry (GC-MS), Fourier transformed infrared spectrometry (FT-IR), and nuclear magnetic resonance (NMR) spectrometry. In addition, evaluation of the antioxidant activity of the LNPs showed that they could significantly increase the proliferation of RAW264.7 macrophages (P < 0.05) and improve the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) based on cell model of H2O2-induced oxidative damage. This suggested that these LNPs may be used as potential antioxidants.