Preliminary Characterization and Bioactivities of Some Impatiens L. Water-Soluble Polysaccharides.

Preliminary characterization and bioactivity of water-soluble polysaccharides from four species- Royle, DC., L., and I. L.-were investigated. The yields of polysaccharides range widely from 1.97% for roots to 18.63% for aerial parts. SEC (Size exclusion chromatography) chromatograms show that all samples contained a low molecular weight part that consisted of components of similar molecular weight. The aerial parts and roots of , and aerial parts had considerable amounts of high molecular weight components up to 2.3 MDa. The sugar composition analysis revealed that polysaccharides consisted primarily of galactose, arabinose, rhamnose, mannose, xylose, and glucose. All polysaccharide fractions, except for roots, also contain galacturonic acid. Moreover, in vitro bioactivity of obtained polysaccharides were evaluated. The antioxidant activity was evaluated on the basis of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethyl-benzthia-6-sulfonic acid) (ABTS) radical scavenging assays. The highest antioxidant activity was obtained for aerial parts and roots. Among the tested fractions, only the polysaccharides from aerial parts were able to significantly decrease the production of IL-8 by 32.7 ± 10.5%. The results suggest that species can be considered as a new source of antioxidants.