Enrichment, purification and in vitro antioxidant activities of polysaccharides from Umbilicaria esculenta macrolichen

•A new method to enrich and separate UEP with macroporous resin is developed.•The Langmuir model indicates that a monolayer coverage of UEP is onto AB-8 resin.•UEP-1 is composed of mannose, rhamnose, glucose and galactose with 124.7kD.•UEP-2 comprises mannose and glucose with molecular weight of 249.4kD.•UEP possesses strong antioxidant activities, and may be a potential antioxidant.