title: Galactans from cystocarpic plants of the red seaweed Callophyllis variegata (Kallymeniaceae, Gigartinales).
abstract: The polysaccharide extracted from cystocarpic Callophyllis variegata was fractionated with potassium chloride yielding three small fractions that precipitated in the ranges of 0-0.05 M KCl, 1.20-1.25 M KCl, and 1.80-2.00 M KCl, and a main product soluble in 2.00 M KCl. These fractions were analyzed, and as the first one contained very high amounts of protein, it was not studied further. Structural analysis of the rest of the fractions (F1-F3) was carried out by methylation, desulfation-methylation, IR, and 13C NMR spectroscopy. The results are consistent for F1 with a carrageenan-type backbone mainly constituted by beta-D-galactose 2-sulfate linked to alpha-D-galactose 2,3,6-trisulfate and beta-D-galactose 2,4-disulfate linked to 3,6-anhydro-D-galactose 2-sulfate as dominant diads. In F2 these diads are present together with low amounts of beta-D-galactose 2-sulfate linked to 3,6-anhydro-D-galactose 2-sulfate, whose contribution becomes higher in F3. In addition, minor but significant amounts of L-galactose were detected. F1-F3 showed potent antiviral activity against herpes simplex types 1 and 2 and dengue type 2.
authors.affiliation: Departamento de Biodiversidad y Biología Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Rodríguez
authors.forename: Emilia R
authors.initials: ER
authors.lastname: Merino
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Pujol
authors.forename: Elsa B
authors.initials: EB
authors.lastname: Damonte
authors.forename: Alberto S
authors.initials: AS
authors.lastname: Cerezo
authors.forename: María C
authors.initials: MC
authors.lastname: Matulewicz
mesh_terms: D000998:Antiviral Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002247:Carbon Isotopes; D005685:Galactans / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D010936:Plant Extracts / Q000737:chemistry; D012624:Seaweed / Q000737:chemistry*; D012972:Sodium Hydroxide / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D000998:Antiviral Agents; D002247:Carbon Isotopes; D005685:Galactans; D010936:Plant Extracts; D012972:Sodium Hydroxide