title: Partial and total C-6 oxidation of gelling carrageenans. Modulation of the antiviral activity with the anionic character.
abstract: The optimal conditions for the full C-6 oxidation of κ- and ι-carrageenans using (2,2,6,6-tetramethylpiperidinyl)oxy (TEMPO) in the presence of sodium hypochlorite and sodium bromide were assessed. The fully oxidized products were characterized by NMR spectroscopy. Partially oxidized products were also obtained and analyzed by chemical and spectroscopical methods. The antiviral activity of carrageenans against herpes simplex virus HSV-1 and HSV-2 determined by plaque reduction assay, was not largely affected by full oxidation of the polysaccharides, but an increase in activity was detected by partial oxidation. A specific overoxidation on C-2 of the 3,6-anhydrogalactose moiety of κ-carrageenan was identified, solved experimentally and rationalized through the application of molecular modeling.
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: Vanina A
authors.initials: VA
authors.lastname: Cosenza
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: Diego A
authors.initials: DA
authors.lastname: Navarro
authors.affiliation: Laboratorio de Virología, Departamento de Química Biológica - IQUIBICEN, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Pujol
authors.affiliation: Laboratorio de Virología, Departamento de Química Biológica - IQUIBICEN, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina.
authors.forename: Elsa B
authors.initials: EB
authors.lastname: Damonte
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, 1428 Buenos Aires, Argentina. Electronic address: stortz@qo.fcen.uba.ar.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Stortz
keywords: Antiviral activity; Carrageenans; Oxidation; TEMPO; Uronic acids