Structural analysis and antiviral activity of a sulfated galactan from the red seaweed Schizymenia binderi (Gigartinales, Rhodophyta)

BETTY MATSUHIRO; ANA F. CONTE; ELSA B. DAMONTE; ADRIANA A, KOLENDER; MARÍA C. MATULEWICZ; ENRIQUE G. MEJÍAS; CARLOS A. PUJOL; ELISA A. ZÚÑIGA

CARBOHYDRATE RESEARCH

Elsevier Ltd.

Lugar: Oxford, Gran Bretaña; Año: 2005 vol. 340 p. 2392 - 2402

0008-6215

Aqueous extraction of gametophytic Schizymenia binderi afforded a polysaccharide composed of galactose and sulfate groups in the ratio 1.0:0.89 together with uronic acids (6.8 wt %) and minor amounts of other neutral sugars. Alkaline-treatment of the polysaccharide afforded a polysaccharide devoid of 3,6-anhydrogalactose. 13C NMR spectroscopy of the desulfated alkali-treated polysaccharide showed a backbone structure of alternating 3-linked b-D-galactopyranosyl and 4-linked a-galactopyranosyl units that are predominantly of the D-configuration and partly of the L-configuration. Methylation, ethylation and NMR spectroscopic studies of the alkali-treated polysaccharide indicated that the sulfate groups are located mainly at positions O-2 of 3-linked b-D-galactopyranosyl residue and at position O-3 of 4-linked-a-D-galactoyranosyl residues, the latter is partially glycosylated at position O-2.  The sulfated galactan from S. binderi exhibited highly selective antiviral activity against Herpes simplex virus types 1 and 2, with selectivity indices (ratio cytotoxicity/antiviral activity) >1000 for all assayed virus strains. This compound was shown to interfere with the initial adsorption of viruses to the cell.