Structure characteristics, hypoglycemic and immunomodulatory activities of pectic polysaccharides from Rosa setate x Rosa rugosa waste.

In this study, two polysaccharide components named WSRP-2a and WSRP-2b, were purified from Rosa setate x Rosa rugosa waste via anion exchange and gel filtration chromatography. Monosaccharide composition, Congo red assay, FT-IR and NMR spectra analysis confirmed that both of these fractions were mainly composed of galacturonic acid, arabinose, galactose and rhamnose, which were pectin-type polysaccharides with non-triple-helix structure. WSRP-2a and WSRP-2b, however, differed in molecular weight of 56.8 kD and 23.9 kD. The followed bioassay presented their impressive hypoglycemic and immunomodulatory activities. WSRP-2a promoted more proliferation, NO release, and the secretion of cytokines in RAW264.7 macrophages, while WSRP-2b presented higher α-amylase and α-glucosidase inhibitory activities. Collectively, these results suggested that the Rosa Setate x Rosa Rugosa waste biomass could be used as a promising source of bioactive pectic polysaccharides.