Structural characterization of natural ideal 6-0-sulfated agarose from red alga Gloiopeltis furcata

A charge and size uniform polysaccharide GW2M was extracted with cold water from red alga Gloiopeltis furcata and purified by strong anion ion-exchange and gel permeation chromatography. Its chemical structure was identified by methylation, H-1-H-1 COSY, H-1-C-13 HMQC and H-1-C-13 HMBC techniques. The experimental data showed that GW2M was composed of galactose (40.3%), 3,6-anhydro-galactose (34.1%) and sulfate (24.8%) with an average molecular mass of 20.6 kDa. The results proved GW2M was a linear repeating sequence of alternating (1 - 3)-linked 6-0-sulfated-beta-o-galactose (G65) and (1 - 4)-linked 3,6-anhydro-alpha-L-galactose (A) which made it to be an ideal 6-0-sulfated-agarose. The sequences of serial oligosaccharides prepared by mild acid and reductive acid hydrolysis from GW2M were confirmed using electrospray collision induced dissociation tandem mass spectrometry (ES-CID-MS/MS) technique. CD 2012 Elsevier Ltd. All rights reserved.