Structural characterization of polysaccharide obtained from red seaweed Gracilaria caudata (J Agardh)

► Polysaccharide from marine alga Gracilaria caudata (PGC) was recovery with 32.8% of yield. ► Characterization was performed by microanalysis, FT-IR and NMR spectroscopy. ► The structure is constituted by β-d-galactopyranose and 6-α-l-anhydrogalactose. ► Methyl and pyruvic acid groups were also detected.