Antioxidant and DNA protecting activity of carboxymethylated polysaccharides from Cortex periplocae

In this study, polysaccharide from Cortex periplocae (CPP) was modified and three carboxymethylation modification polysaccharides (CPPCs) were obtained, and their physicochemical characteristics and in vitro biological activities were investigated. Based on the ultraviolet-visible (UV–Vis) scan, CPPs (CPP and CPPCs) did not contain nucleic acids or proteins. However, the Fourier transform infrared (FTIR) spectrum showed a new absorption peak around 1731 cm−1. In addition, three absorption peaks near 1606, 1421, and 1326 cm−1 were enhanced after carboxymethylation modification. Based on UV–Vis scan, the maximum absorption wavelength of Congo Red + CPPs exhibited a red-shift compared to Congo Red meant CPPs had a triple helix conformation. Scanning electron microscopy (SEM) indicated that CPPCs exhibited more fragments and non-uniform-sized filiform than CPP. Thermal analysis showed that CPPCs degraded between the temperature 240 °C–350 °C and CPP in the 270 °C–350 °C. In addition, the antioxidant and DNA protecting activities of CPPCs were significantly enhanced compared to CPP. Overall, this study demonstrated the potential applications of CPPs in food and pharmaceutical industries.