Polisaccharides from Cystocarpic Plants of the Red Seaweed Callophyllis Variegata
Departamento de Química Orgánica, CIHIDECAR-CONICET, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Pabellón 2, Ciudad Universitaria, 1428 Buenos Aires, Argentina
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Molecules 2000, 5(3), 551-552; https://doi.org/10.3390/50300551
Published: 22 March 2000
Abstract
:The crude polysaccharide from cystocarpic Callophyllis variegata was fractionated with potassium chloride yielding three minor fractions which precipitated between 0.05-0.10 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 analysed and structural analysis of the major one was carried out by methylation, FT-IR and 13C NMR.
Introduction
Experimental
The crude polysaccharide and the fractions were analyzed using the methods mentioned in ref. [3]. The fraction soluble in 2.00 M KCl was converted into the corresponding triethylammonium salt and was methylated by the Hakomori procedure as described in ref. [3]. The samples were subjected to reductive hydrolysis and further acetylation, and were analyzed by GC [3]. The d:l-galactose ratio was determined by the method of ref. [4].
Results and discussion
Cystocarpic plants of Callophyllis variegata, collected in Puerto Deseado (Provincia de Santa Cruz), were extracted with water at room temperature and the crude product was analyzed (carbohy-drate content, sulphate, primary sulphate and protein; composition in monosaccharides, d:l-galactose ratio). These analyses showed a molar ratio Gal:3,6-AnGal:sulfate of 1.00:0.24:0.56 and the absence of l-galactose suggesting the presence of a carrageenan. The usual way to fractionate a system of car-rageenans is based on the solubility of the component polysaccharides in solutions of different potas-sium chloride concentration; the preparative fractionation yielded three fractions which precipitated between 0.05-0.10 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 as described for the crude polysaccharide. Chemical analysis of the soluble fraction gave a molar ratio Gal:3,6-AnGal:sulfate of 1.00:0.16:1.47 and a d-:l-galactose ratio of 5.5:1.0. The structural analysis (methylation, FT-IR and 13C NMR) of this fraction will be reported.
Acknowledgements
This work was supported by grants from CONICET (PIA N° 6714) and the University of Buenos Aires (TW83).
References and Nores
- Usov, A. I.; Ivanova, E. G.; Shashkov, A. S. Botanica Marina 1983, 26, 285.
- Falshaw, R.; Furneaux, R. H.; Stevenson, D. E. Abstracts of the XVIth International Seaweed Symposium. 1998; 43. [Google Scholar]
- Ciancia, M.; Matulewicz, M. C.; Cerezo, A. S. Phytochemistry 1997, 45, 1009.
- Cases, M. R.; Cerezo, A. S.; Stortz, C. A. Carbohydrate Research 1995, 269, 333–341.
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MDPI and ACS Style
Merino, E.R.; Cerezo, A.S.; Matulewicz, M.C. Polisaccharides from Cystocarpic Plants of the Red Seaweed Callophyllis Variegata. Molecules 2000, 5, 551-552. https://doi.org/10.3390/50300551
AMA Style
Merino ER, Cerezo AS, Matulewicz MC. Polisaccharides from Cystocarpic Plants of the Red Seaweed Callophyllis Variegata. Molecules. 2000; 5(3):551-552. https://doi.org/10.3390/50300551
Chicago/Turabian StyleMerino, E. R., A. S. Cerezo, and M. C. Matulewicz. 2000. "Polisaccharides from Cystocarpic Plants of the Red Seaweed Callophyllis Variegata" Molecules 5, no. 3: 551-552. https://doi.org/10.3390/50300551
