Isolation and structural characterization of an immunostimulating polysaccharide from fuzi, Aconitum carmichaeli

A water-soluble polysaccharide named as FPS-1 was isolated from fuzi, the root of Aconitum carmichaeli Debx. by hot-water extraction, anion-exchange and gel-permeation chromatography and tested for its pharmacological activities. Its structural characteristics were investigated by FTIR, HPLC, NMR spectroscopy, methylation analysis and GLC-MS. Based on the data obtained, FPS-1 was determined to be an α-(1→6)-d-glucan, with a weight-average molecular weight of about 14,000 Da. The glucan is highly branched with a single glucose at the C-3 position every four residues, on average, along the main chain. In immunopharmacological studies, FPS-1 showed potent stimulating effects on murine lymphocyte proliferation induced by concanavalin A or lipopolysaccharide both in vitro and in vivo as well as on splenocyte antibody production.