Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions

Cryptonemia seminervis biosynthesizes a family of d,l-hybrid galactans based on the classical 3-linked β-d-galactopyranosyl→4-linked α-d- and α-l-galactopyranosyl alternating sequence (A-units→B-units) with major amounts of α-d- and α-l-galactose and 3,6-anhydro-d- and l-galactose and lesser percent...

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Autores principales:	Noseda, Miguel D., Cerezo, Alberto Saúl
Publicado:	2009
Materias:	Cryptonemia seminervis Halymeniales NMR spectroscopy Polysaccharides Red seaweed Sulfated galactans Biopolymers Kinetic theory Nuclear magnetic resonance Nuclear magnetic resonance spectroscopy Organic acids Rate constants Seaweed acetal alpha galactosidase carrageenan galactan galactose monosaccharide pyranoside pyruvic acid sulfate article biosynthesis carbohydrate analysis carbon nuclear magnetic resonance chemical reaction chemical structure cryptonemia seminervis cyclization depolymerization infrared spectroscopy kinetics methylation nonhuman priority journal proton nuclear magnetic resonance seaweed Algae, Red Galactans Nuclear Magnetic Resonance, Biomolecular Spectroscopy, Fourier Transform Infrared Cryptonemia
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v344_n17_p2364_Zibetti http://hdl.handle.net/20.500.12110/paper_00086215_v344_n17_p2364_Zibetti
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

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spelling	paper:paper_00086215_v344_n17_p2364_Zibetti2023-06-08T14:32:57Z Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions Noseda, Miguel D. Cerezo, Alberto Saúl Cryptonemia seminervis Halymeniales NMR spectroscopy Polysaccharides Red seaweed Sulfated galactans Cryptonemia seminervis Halymeniales NMR spectroscopy Red seaweed Sulfated galactans Biopolymers Kinetic theory Nuclear magnetic resonance Nuclear magnetic resonance spectroscopy Organic acids Rate constants Seaweed Polysaccharides acetal alpha galactosidase carrageenan galactan galactose monosaccharide pyranoside pyruvic acid sulfate article biosynthesis carbohydrate analysis carbon nuclear magnetic resonance chemical reaction chemical structure cryptonemia seminervis cyclization depolymerization infrared spectroscopy kinetics methylation nonhuman priority journal proton nuclear magnetic resonance seaweed Algae, Red Galactans Nuclear Magnetic Resonance, Biomolecular Spectroscopy, Fourier Transform Infrared Cryptonemia Cryptonemia seminervis Halymeniales Cryptonemia seminervis biosynthesizes a family of d,l-hybrid galactans based on the classical 3-linked β-d-galactopyranosyl→4-linked α-d- and α-l-galactopyranosyl alternating sequence (A-units→B-units) with major amounts of α-d- and α-l-galactose and 3,6-anhydro-d- and l-galactose and lesser percentages of 3,6-anhydro-2-O-methyl-l-galactose, 2-O-methyl-, 4-O-methyl- and 6-O-methylgalactoses. The dispersion of structures in this family is based on five structural factors, namely: (a) the amount and position of substituent groups as sulfate (major), pyruvic acid ketals, methoxyl and glycosyl side-chain (4-O-methyl galactopyranosyl and/or xylosyl); (b) the ratio galactose/3,6-anhydrogalactose in the B-units; (c) the ratio d,l-galactoses and d,l-3,6-anhydrogalactoses also in the B-units, (d) the formation of diads and (e) the sequence of the diads in the linear backbone. Considering these variables it is not unexpected to find in the fractions studied at least 18 structural units producing highly complex structures. Structural studies carried out in two major fractions (S2S-3 and S2S-4) showed that these galactans were formed mainly by β-d-galactopyranosyl 2-sulfate (20 and 11.9 mol %), β-d-galactopyranosyl 2-sulfate 4,6-O-(1′-carboxyethylidene) (8.9 and 6.0 mol %) and β-d-galactopyranosyl 2,6-sulfate (5.4 and 18.6 mol %), together with 3,6-anhydro-α-l-galactopyranosyl (11.4 and 7.3 mol %) and 3,6-anhydro-α-l-galactopyranosyl 2-sulfate (4.9 and 15.4 mol %) and minor quantities of 12-15 other structural units. Preparative alkaline treatment carried out on fraction (S2S-3) produced a quantitative formation of 3,6-anhydro α-l-galactopyranosyl units from precursor units (α-l-galactose 6-sulfate and α-l-galactose 2,6-sulfate). Kinetic studies on this 3,6-anhydro cyclization show a rate constant of 5.2 × 104 s-1 indicating diads of the type G→L6S/2,6S. Data from chemical, spectroscopic and kinetic studies suggest that, in S2S-3, the agaran block in the d,l-hybrid galactan is composed of the following diads: G(6R)→L6S/2,6S and G2S(P)(2,6S)→LA(2S)(2R)(2M) and the carrageenan block of G2S(P)→D(2S)(2,3S)(3S)(3,6S) in a molar ratio of agaran to carrageenan structures of ∼2:1. © 2009 Elsevier Ltd. All rights reserved. Fil:Noseda, M.D. 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. 2009 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v344_n17_p2364_Zibetti http://hdl.handle.net/20.500.12110/paper_00086215_v344_n17_p2364_Zibetti
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Cryptonemia seminervis Halymeniales NMR spectroscopy Polysaccharides Red seaweed Sulfated galactans Cryptonemia seminervis Halymeniales NMR spectroscopy Red seaweed Sulfated galactans Biopolymers Kinetic theory Nuclear magnetic resonance Nuclear magnetic resonance spectroscopy Organic acids Rate constants Seaweed Polysaccharides acetal alpha galactosidase carrageenan galactan galactose monosaccharide pyranoside pyruvic acid sulfate article biosynthesis carbohydrate analysis carbon nuclear magnetic resonance chemical reaction chemical structure cryptonemia seminervis cyclization depolymerization infrared spectroscopy kinetics methylation nonhuman priority journal proton nuclear magnetic resonance seaweed Algae, Red Galactans Nuclear Magnetic Resonance, Biomolecular Spectroscopy, Fourier Transform Infrared Cryptonemia Cryptonemia seminervis Halymeniales
spellingShingle	Cryptonemia seminervis Halymeniales NMR spectroscopy Polysaccharides Red seaweed Sulfated galactans Cryptonemia seminervis Halymeniales NMR spectroscopy Red seaweed Sulfated galactans Biopolymers Kinetic theory Nuclear magnetic resonance Nuclear magnetic resonance spectroscopy Organic acids Rate constants Seaweed Polysaccharides acetal alpha galactosidase carrageenan galactan galactose monosaccharide pyranoside pyruvic acid sulfate article biosynthesis carbohydrate analysis carbon nuclear magnetic resonance chemical reaction chemical structure cryptonemia seminervis cyclization depolymerization infrared spectroscopy kinetics methylation nonhuman priority journal proton nuclear magnetic resonance seaweed Algae, Red Galactans Nuclear Magnetic Resonance, Biomolecular Spectroscopy, Fourier Transform Infrared Cryptonemia Cryptonemia seminervis Halymeniales Noseda, Miguel D. Cerezo, Alberto Saúl Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
topic_facet	Cryptonemia seminervis Halymeniales NMR spectroscopy Polysaccharides Red seaweed Sulfated galactans Cryptonemia seminervis Halymeniales NMR spectroscopy Red seaweed Sulfated galactans Biopolymers Kinetic theory Nuclear magnetic resonance Nuclear magnetic resonance spectroscopy Organic acids Rate constants Seaweed Polysaccharides acetal alpha galactosidase carrageenan galactan galactose monosaccharide pyranoside pyruvic acid sulfate article biosynthesis carbohydrate analysis carbon nuclear magnetic resonance chemical reaction chemical structure cryptonemia seminervis cyclization depolymerization infrared spectroscopy kinetics methylation nonhuman priority journal proton nuclear magnetic resonance seaweed Algae, Red Galactans Nuclear Magnetic Resonance, Biomolecular Spectroscopy, Fourier Transform Infrared Cryptonemia Cryptonemia seminervis Halymeniales
description	Cryptonemia seminervis biosynthesizes a family of d,l-hybrid galactans based on the classical 3-linked β-d-galactopyranosyl→4-linked α-d- and α-l-galactopyranosyl alternating sequence (A-units→B-units) with major amounts of α-d- and α-l-galactose and 3,6-anhydro-d- and l-galactose and lesser percentages of 3,6-anhydro-2-O-methyl-l-galactose, 2-O-methyl-, 4-O-methyl- and 6-O-methylgalactoses. The dispersion of structures in this family is based on five structural factors, namely: (a) the amount and position of substituent groups as sulfate (major), pyruvic acid ketals, methoxyl and glycosyl side-chain (4-O-methyl galactopyranosyl and/or xylosyl); (b) the ratio galactose/3,6-anhydrogalactose in the B-units; (c) the ratio d,l-galactoses and d,l-3,6-anhydrogalactoses also in the B-units, (d) the formation of diads and (e) the sequence of the diads in the linear backbone. Considering these variables it is not unexpected to find in the fractions studied at least 18 structural units producing highly complex structures. Structural studies carried out in two major fractions (S2S-3 and S2S-4) showed that these galactans were formed mainly by β-d-galactopyranosyl 2-sulfate (20 and 11.9 mol %), β-d-galactopyranosyl 2-sulfate 4,6-O-(1′-carboxyethylidene) (8.9 and 6.0 mol %) and β-d-galactopyranosyl 2,6-sulfate (5.4 and 18.6 mol %), together with 3,6-anhydro-α-l-galactopyranosyl (11.4 and 7.3 mol %) and 3,6-anhydro-α-l-galactopyranosyl 2-sulfate (4.9 and 15.4 mol %) and minor quantities of 12-15 other structural units. Preparative alkaline treatment carried out on fraction (S2S-3) produced a quantitative formation of 3,6-anhydro α-l-galactopyranosyl units from precursor units (α-l-galactose 6-sulfate and α-l-galactose 2,6-sulfate). Kinetic studies on this 3,6-anhydro cyclization show a rate constant of 5.2 × 104 s-1 indicating diads of the type G→L6S/2,6S. Data from chemical, spectroscopic and kinetic studies suggest that, in S2S-3, the agaran block in the d,l-hybrid galactan is composed of the following diads: G(6R)→L6S/2,6S and G2S(P)(2,6S)→LA(2S)(2R)(2M) and the carrageenan block of G2S(P)→D(2S)(2,3S)(3S)(3,6S) in a molar ratio of agaran to carrageenan structures of ∼2:1. © 2009 Elsevier Ltd. All rights reserved.
author	Noseda, Miguel D. Cerezo, Alberto Saúl
author_facet	Noseda, Miguel D. Cerezo, Alberto Saúl
author_sort	Noseda, Miguel D.
title	Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
title_short	Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
title_full	Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
title_fullStr	Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
title_full_unstemmed	Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions
title_sort	galactans from cryptonemia species. part ii: studies on the system of galactans of cryptonemia seminervis (halymeniales) and on the structure of major fractions
publishDate	2009
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v344_n17_p2364_Zibetti http://hdl.handle.net/20.500.12110/paper_00086215_v344_n17_p2364_Zibetti
work_keys_str_mv	AT nosedamigueld galactansfromcryptonemiaspeciespartiistudiesonthesystemofgalactansofcryptonemiaseminervishalymenialesandonthestructureofmajorfractions AT cerezoalbertosaul galactansfromcryptonemiaspeciespartiistudiesonthesystemofgalactansofcryptonemiaseminervishalymenialesandonthestructureofmajorfractions
_version_	1768544940401360896

Galactans from Cryptonemia species. Part II: Studies on the system of galactans of Cryptonemia seminervis (Halymeniales) and on the structure of major fractions

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