Sulfated polysaccharides from Bryopsis plumose. Comparison with those of other Bryopsidales (Chlorophyta)

PAULA VIRGINIA FERNÁNDEZ; ALBERTO S. CEREZO; JOSÉ M. ESTEVEZ; MARINA CIANCIA

Ensenada

Simposio; XX International Seaweed Symposium; 2010

XX International Seaweed Symposium

SULFATED POLYSACCHARIDES FROM BRYOPSIS PLUMOSA. COMPARISON WITH THOSE OF OTHER BRYOPSIDALES (CHLOROPHYTA). 1Paula V. Fernández, 2Alberto S. Cerezo, 3José M. Estevez, 1,2Marina Ciancia 1Cátedra de Química de Biomoléculas, Dpto. de Biología Aplicada y Alimentos, Facultad de Agronomía, UBA, Buenos Aires, Argentina. 2CIHIDECAR-CONICET, Dpto. de Química Orgánica, FCEN-UBA, Buenos Aires, Argentina. 3Dpto. de Fisiología, Biología Molecular y Celular, FCEN-UBA, Buenos Aires, Argentina Polysaccharides from Bryopsis plumosa were characterized and their structure was studied by methylation analysis and NMR spectroscopy. The major sulfated polysaccharide is a highly ramified (1®3)-b-D-galactan (molar ratio Gal:sulfate 1:0.9), sulfated mainly on C-4, partially substituted on C-6; terminal pyruvilated galactose units are present in important quantities. This structure is similar to that found for galactans from Codium sps. and was obtained by extraction with water at room temperature together with a non-sulfated arabinan. In the latter polysaccharide, the monosaccharide units are in the furanose form, a similar structure was found in small amounts in C. fragile after fractionation by ion exchange chromatography. Nevertheless, this structure is completely different to the main highly sulfated piranosic arabinan present in the same species, as well as in C. vermilara. Besides, by hot water extraction a sulfated rhamnan was detected in significant amounts. Based in our studies, cell walls in the green seaweeds of Bryopsidales group biosynthesize a great diversity of polysaccharides structures; not only the fibrillar polysaccharides are different, but there are also important differences in the acidic ones. A survey of these seldom studied structures will be presented.