Abstract: In this study, a selenized polysaccharide from dandelion roots (Se-DRP) was prepared by HNO3-Na2SeO3 method. The physicochemical properties, structural characteristics, probiotics proliferation-promoting activity of Se-DRP and its inhibitory effect on α-amylase were investigated. The results showed that Se-DRP was a heteropolysaccharide with a molecular mass of 8 102 Da, and it was composed of galacturonic acid, rhamnose, arabinose, mannose, glucose and galactose with a molar ratio of 0.64:0.73:19.36:0.84:1.00:27.41. Nuclear magnetic resonance (NMR) analysis showed that the major sugar residues in Se-DRP were →6)-β-D-glucose-(1→, →5)-α-L-arabinose-(1→, →3)-β-D-galactose-(1→ and →4)-α-D-galacturonic acid-(1→. Se-DRP possessed probiotics proliferation-promoting activity and could be utilized by Lactobacillus plantarum 10665 and Lactobacillus acidophilus as a carbon source. In addition, Se-DRP exhibited α-amylase inhibitory activity with an inhibitory rate of (52.34 ± 1.45)% at a concentration of 4.0 mg/mL. These results provide a theoretical basis for further studies of Se-DRP and the utilization of dandelion resources.

Key words: selenized dandelion polysaccharide; structural characterization; physicochemical properties; prebiotic proliferation; α-amylase inhibitory activity