title: Carrageenan and agaran structures from the red seaweed Gymnogongrus tenuis.
abstract: The galactan system biosynthesized by the red seaweed Gymnogongrus tenuis (Phyllophoraceae) is constituted by major amounts of κ/ι-carrageenans, with predominance of ι-structures, which were isolated by extraction with hot water in high yield (∼ 45%). A small amount of non-cyclized carrageenans mostly of the ν-type was also obtained. Besides, 12% of these galactans are agaran structures, which were present in major quantities in the room temperature water extracts, but they were also found in the hot water extract. They are constituted by 3-linked β-D-galactose units partially substituted on C-6 with sulfate or single stubs of β-D-xylose and 4-linked residues that comprise α-L-galactose units partially sulfated or methoxylated on C-3 or sulfated on C-3 and C-6 and 3,6-anhydro-α-L-galactose. Related structural patterns were previously found for agarans synthesized by other carrageenophytes. Results presented here show that these agarans are low molecular weight molecules independent of the carrageenan structures, with strong interactions between them.
authors.affiliation: Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, Buenos Aires 1417, Argentina.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Perez Recalde
authors.affiliation: Escuela de Bioanálisis, Facultad de Medicina, Universidad Central de Venezuela, Av. Carlos Raúl Villanueva, Ciudad Universitaria, Los Chaguaramos, Caracas 1051, Venezuela.
authors.forename: Dilsia J
authors.initials: DJ
authors.lastname: Canelón
authors.affiliation: Escuela de Química, Facultad de Ciencias, Universidad Central de Venezuela, Av. Paseo de los Ilustres, Ciudad Universitaria, Los Chaguaramos, Caracas 1450, Venezuela.
authors.forename: Reinaldo S
authors.initials: RS
authors.lastname: Compagnone
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires 1428, Argentina.
authors.forename: María C
authors.initials: MC
authors.lastname: Matulewicz
authors.affiliation: Departamento de Química Orgánica - CIHIDECAR (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires 1428, Argentina.
authors.forename: Alberto S
authors.initials: AS
authors.lastname: Cerezo
authors.affiliation: Cátedra de Química de Biomoléculas, Departamento de Biología Aplicada y Alimentos, Facultad de Agronomía, Universidad de Buenos Aires, Av. San Martín 4453, Buenos Aires 1417, Argentina; Departamento de Química Orgánica - CIHIDECAR (CONICET-UBA), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Buenos Aires 1428, Argentina. Electronic address: ciancia@agro.uba.ar.
authors.forename: Marina
authors.initials: M
authors.lastname: Ciancia
mesh_terms: D002351:Carrageenan / Q000737:chemistry* / Q000302:isolation & purification; D005685:Galactans / Q000737:chemistry* / Q000302:isolation & purification; D006358:Hot Temperature; D000461:Rhodophyta / Q000737:chemistry*; D012624:Seaweed / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D005685:Galactans; D014867:Water; D002351:Carrageenan
keywords: Agaran; Carrageenan; Polysaccharide structure; Red seaweed; Sulfated galactan