Chemical Properties and Biological Activity of a Polysaccharide from Melocactus depressus

Abstract An arabinogalactan with mean M r of 6.85 × 10 4 , was isolated from the pulps of MELOCACTUS DEPRESSUS Hook by fractionation on Sephacryl S-300 HR. Chemical and spectroscopic studies indicated that it has a branched arabinogalactan type structure composed of β-(1→4) linked D-galactopyranose residues with β-(1→3) and β-(1→6) branching points. Its structural features include also α-(1→2), α-(1→3) and α-(1→5) linked L-arabinofuranose residues. The polysaccharide demonstrated a phagocytosis stimulating property.