Extraction, structural analysis and antioxidant activity of aloe polysaccharide

Using fresh aloe as a raw material, aloe polysaccharide was prepared by the water extraction. After pro-tein removal by sevage method, the aloe polysaccharide was refined by dialysis. The aloe polysaccha-ride was separated by diethylaminoethyl-52 (DEAE-52) cellulose column and Sephadex G-10 0 to obtain a single component of aloe polysaccharide. The molecular weight and monosaccharide components were determined by size exclusion chromatography-multi-angle laser light scatterer-differential refractive in-dex detector (SEC-MALLS-RI) and high performance liquid chromatography (HPLC), respectively, and the structure was confirmed by nuclear magnetic resonance (NMR) spectrum. The molecular weight of aloe polysaccharide was 1.32 x 10 6 Da. The monosaccharide components were fucose (Fuc), arabinose (Ara), rhamnose (Rha), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), galacturonic acid (Gal-UA) and glucuronic acid (Gul-UA), and the proportions of each component were 0.37%, 7.52%, 3.46%, 10.23%, 26.99%, 1.61%, 35.02%, 14.25% and 0.55%, respectively. In order to obtain the structure-activity relationship (SAR) of aloe polysaccharide, the derivatives, including acetylated aloe polysaccharides (AAP), phospho-rylated aloe polysaccharides (PAP) and carboxylated aloe polysaccharides (CAP) were synthesized. Results of antioxidant test in vitro showed that aloe polysaccharide and its derivatives had a good activity.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

Fresh aloe was used to prepare aloe polysaccharide through water extraction. Protein removal and dialysis were conducted for refinement. Aloe polysaccharide was separated and characterized, and its derivatives were synthesized for antioxidant testing. Aloe polysaccharide and its derivatives exhibited good antioxidant activity.