Extraction, structural analysis, derivatization and antioxidant activity of polysaccharide from Chinese yam
Shiyang Zhou1, Gangliang Huang2, Guangying Chen3
1Active Carbohydrate Research Institute, Chongqing Key Laboratory of Green Synthesis and Application, College of Chemistry, Chongqing Normal University, Chongqing 401331, China; Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571127, China.
Abstract:
The polysaccharide of yam was extracted by hot water method and purified by column chromatography. The physicochemical properties of Chinese yam polysaccharide were analyzed by UV, IR, GPC, 1D-NMR and 2D-NMR spectra. The results showed that Chinese yam polysaccharide had α-d-Gluc-(1 → 4) glycoside bond, and the C2 hydroxyl group was replaced by ethoxyl group. The average molecular weight was determined to be 7.28 × 104. It showed that The scavenging effect of yam polysaccharide on hydroxyl radicals was similar to VC. The sulfated polysaccharide (SP), phosphorylated polysaccharide (PP), carboxymethylated polysaccharide (CP) and acetylated polysaccharide (A-P) were identified by IR and NMR. The results showed that P and its derivatives showed good antioxidant activity. Especially, their scavenging ability to hydroxyl radicals reached the level of VC. This laid a theoretical foundation for the development of yam polysaccharide-related foods.
