Compositional Analysis and Antioxidant Activity Assessment of Polysaccharide Extracted from Snow Lotus (Saussurea) Species

Abstract

Plant polysaccharides have been paid more attentions due to their effects on normal health and chronic diseases. A selective and sensitive method based on pre-column derivatization using 1-(2-naphthyl)-3-methyl-pyrazolone as the labeling reagent followed by high performance liquid chromatography with ultraviolet detection and online mass spectrometry identification (HPLC/DAD-ESI/MS) has been developed. Each monosaccharide was derivatized by 1-(2-naphthyl)-3-methyl-pyrazolone and separated on an Akasil-C18 column. Nine monosaccharides investigated presented excellent linear responses (r² > 0.9993). Limits of detection and quantification varied from 0.33 to 2.06 pmol and 1.10 to 6.82 pmol, respectively. Compositional analysis of polysaccharides from Saussurea involucrata, S. laniceps and S. medusa was made by this method. Galacturonic acid, rhamnose, glucose + galactose and arabinose were found to be the major components. Additionally, antioxidant activities of polysaccharides from these three species were comparatively assessed. Polysaccharides from S. involucrate and S. laniceps showed similar antioxidant activities, which relatively higher than that of S. medusa.