Structural characterization, physicochemical property, and antioxidant activity of polysaccharide components from Eucommia ulmoides leaves
Mengpei Liu, Yan Wang, Rong Wang, Qingxin Du, Lu Wang
Abstract
Abstract Background Eucommia ulmoides ( E. ulmoides ) leaves are identified as a new resource of medicine and food homology. In this study, the structural characterization, physicochemical properties, and antioxidant activity of E. ulmoides polysaccharides (EUP) were studied. Results Three components with different molecular weights of 1.51 × 10 5 Da (EUP 1 ), 3.05 × 10 4 Da (EUP 2 ) and 1.17 × 10 5 Da (EUP 3 ) were purified from E. ulmoides leaves. They were composed of l -rhamnose ( Rha ), d -arabinose ( Ara), d -mannose ( Man ), d - glucose ( Glu ) and d -galactose ( Gal ), while EUP 2 also contained small amounts of d -xylose ( Xyl ). Three components all had typical polysaccharides absorption peaks, which may be polysaccharides with β configuration of pyranose structure, and amorphous structure of acid polysaccharides with good thermal stability below 270 ℃. However, the molecular weight, monosaccharide composition and apparent morphology of the three components were different, resulting in a stronger scavenging ability of EUP 2 and EUP 3 against DPPH and OH free radicals. Conclusion The results will provide a theoretical reference for developing EUP-related foods and drugs. Graphical Abstract