Methylation analysis of carrageenans from the seaweed Iridaea undulosa

Two carrageenans from Iridaea undulosa, isolated by precipitation of the crude polysaccharide at O.70-1.05 M and 1.55-1.65 M KCl concentrations, were studied by methylation analysis. Acid hydrolysis of the methylated derivative of the less soluble carrageenan (molar ratio galactose: 3,6-anhydrogalac...

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Autores principales: Matulewicz, María Cristina, Cerezo, Alberto Saúl
Publicado: 1980
Materias:
Gigartinaceae
Iridaea undulosa
methylation analysis: carrageenans.
seaweed
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319422_v19_n12_p2639_Matulewicz
http://hdl.handle.net/20.500.12110/paper_00319422_v19_n12_p2639_Matulewicz
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00319422_v19_n12_p2639_Matulewicz
record_format dspace
spelling paper:paper_00319422_v19_n12_p2639_Matulewicz2023-06-08T14:59:11Z Methylation analysis of carrageenans from the seaweed Iridaea undulosa Matulewicz, María Cristina Cerezo, Alberto Saúl Gigartinaceae Iridaea undulosa methylation analysis: carrageenans. seaweed Two carrageenans from Iridaea undulosa, isolated by precipitation of the crude polysaccharide at O.70-1.05 M and 1.55-1.65 M KCl concentrations, were studied by methylation analysis. Acid hydrolysis of the methylated derivative of the less soluble carrageenan (molar ratio galactose: 3,6-anhydrogalactose: sulphate 1.00: 0.50: 1.20) yielded major amounts of 2,6-di-O-methylgalactose (51.3 mol %), 4,6-di-O-methylgalactose (25.6%) and 4-O-methylgalactose (51.3mol%), 4,6-di-O-methylgalactose (25.6%) and 4-O-methylgalactose (13.4%). Minor quantities of 3-O-methylgalactose (4.6%) and 6-O-methylgalactose (3.2%) were found together with traces of 2,3,6- and/or 2,4,6-tri-O-methylgalactose, 2-O-methylgalactose and galactose. Oxidative acid hydrolysis produced 3,6-anhydro-2-O-methylgalactonic acid and 3,6-anhydrogalactonic acid in a molar ratio 3.5-4.0:1.0. The methylated derivative of the more soluble carrageenan (molar ratio galactose:3,6-anhydrogalactose:sulphate 1.00:0.04:1.43) gave on acid hydrolysis, 2,3,4,6-tetra-O-methylgalactose (4.6%), 2,3,6-tri-O-methylgalactose (4.2%), 2,4,6-tri-O-methylgalactose (10.7%), 4,6-di-O-methylgalactose (24.1%), 3,6-di-0-methylgalactose (8.0%), 2,3-di-O- methylgalactose (3.4%), 2,4-di-O-methylgalactose (4.6%), 2,6-di-O-methylgalactose (4.2%), 3-O-methylgalactose (19.5%),4-O-methylgalactose (9.6%),6-O-methylgalactose(3.1%),galactose (3.4%)and traces of 2-O-methylgalactose. © 1980. Fil:Matulewicz, M.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Cerezo, A.S. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1980 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319422_v19_n12_p2639_Matulewicz http://hdl.handle.net/20.500.12110/paper_00319422_v19_n12_p2639_Matulewicz
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Gigartinaceae
Iridaea undulosa
methylation analysis: carrageenans.
seaweed
spellingShingle Gigartinaceae
Iridaea undulosa
methylation analysis: carrageenans.
seaweed
Matulewicz, María Cristina
Cerezo, Alberto Saúl
Methylation analysis of carrageenans from the seaweed Iridaea undulosa
topic_facet Gigartinaceae
Iridaea undulosa
methylation analysis: carrageenans.
seaweed
description Two carrageenans from Iridaea undulosa, isolated by precipitation of the crude polysaccharide at O.70-1.05 M and 1.55-1.65 M KCl concentrations, were studied by methylation analysis. Acid hydrolysis of the methylated derivative of the less soluble carrageenan (molar ratio galactose: 3,6-anhydrogalactose: sulphate 1.00: 0.50: 1.20) yielded major amounts of 2,6-di-O-methylgalactose (51.3 mol %), 4,6-di-O-methylgalactose (25.6%) and 4-O-methylgalactose (51.3mol%), 4,6-di-O-methylgalactose (25.6%) and 4-O-methylgalactose (13.4%). Minor quantities of 3-O-methylgalactose (4.6%) and 6-O-methylgalactose (3.2%) were found together with traces of 2,3,6- and/or 2,4,6-tri-O-methylgalactose, 2-O-methylgalactose and galactose. Oxidative acid hydrolysis produced 3,6-anhydro-2-O-methylgalactonic acid and 3,6-anhydrogalactonic acid in a molar ratio 3.5-4.0:1.0. The methylated derivative of the more soluble carrageenan (molar ratio galactose:3,6-anhydrogalactose:sulphate 1.00:0.04:1.43) gave on acid hydrolysis, 2,3,4,6-tetra-O-methylgalactose (4.6%), 2,3,6-tri-O-methylgalactose (4.2%), 2,4,6-tri-O-methylgalactose (10.7%), 4,6-di-O-methylgalactose (24.1%), 3,6-di-0-methylgalactose (8.0%), 2,3-di-O- methylgalactose (3.4%), 2,4-di-O-methylgalactose (4.6%), 2,6-di-O-methylgalactose (4.2%), 3-O-methylgalactose (19.5%),4-O-methylgalactose (9.6%),6-O-methylgalactose(3.1%),galactose (3.4%)and traces of 2-O-methylgalactose. © 1980.
author Matulewicz, María Cristina
Cerezo, Alberto Saúl
author_facet Matulewicz, María Cristina
Cerezo, Alberto Saúl
author_sort Matulewicz, María Cristina
title Methylation analysis of carrageenans from the seaweed Iridaea undulosa
title_short Methylation analysis of carrageenans from the seaweed Iridaea undulosa
title_full Methylation analysis of carrageenans from the seaweed Iridaea undulosa
title_fullStr Methylation analysis of carrageenans from the seaweed Iridaea undulosa
title_full_unstemmed Methylation analysis of carrageenans from the seaweed Iridaea undulosa
title_sort methylation analysis of carrageenans from the seaweed iridaea undulosa
publishDate 1980
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00319422_v19_n12_p2639_Matulewicz
http://hdl.handle.net/20.500.12110/paper_00319422_v19_n12_p2639_Matulewicz
work_keys_str_mv AT matulewiczmariacristina methylationanalysisofcarrageenansfromtheseaweediridaeaundulosa
AT cerezoalbertosaul methylationanalysisofcarrageenansfromtheseaweediridaeaundulosa
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