The ethanol-extracted polysaccharide from Cynanchum paniculatum: Optimization, structure, antioxidant and antitumor effects

Cynanchum paniculatum has been applied for various diseases treatments, however, the polysaccharide components especially extracted using ethanol were rarely researched. In this study, ethanol solution with volume fraction of 75% was used for C. paniculatum polysaccharide preparation, and the extraction process optimization, structural characteristics, and bioactivities analysis were investigated. Results showed that extraction yield reached to 4.79 ± 0.24% under extraction temperature of 60 °C, extraction time of 4.5 h, liquid/solid ratio of 30 mL/g. Chemical constitutions and monosaccharide compositions, molecular weight determination results showed that the polysaccharide was mainly composed of glucose and xylose with a molar ratio of 1.00:0.63 (carbohydrate content of 94.91%, molecular weight of 5.1 kDa). Periodate oxidation, smith degradation, methylation, fourier transform infrared spectra and nuclear magnetic resonance analysis demonstrated that the glycosidic bonds configurations were mainly comprised of (1→2)-α-D-Glcp (39.86%), (1→2,4)-α-D-Glcp (10.32%) and (1→4)-β-D-Xylp (29.58%). The bioactivities determination experiments results suggested that the polysaccharide exhibited strong antioxidant activities and antitumor effects both in vitro and in vivo. These data indicated that the ethanol-extracted polysaccharide from C. paniculatum holds great application prospect as a novel bioactive adjuvant in the future due to the feasibility of industrial production.