Structure of highly substituted agarans from the red seaweeds Laurencia obtusa and Laurencia filiformis.
Carbohydr Polym
; 101: 705-13, 2014 Jan 30.
Article
em En
| MEDLINE
| ID: mdl-24299829
ABSTRACT
The water extracts from red seaweeds Laurencia obtusa and Laurencia filiformis comprise complex sulfated agarans. Those from L. obtusa have 3-linked ß-d-galactose units in part sulfated on 2-position or methylated on 6-position, while the 4-linked units are mostly 3,6-anhydro-α-l-galactose and α-l-galactose 6-sulfate, some of the latter units are substituted with ß-d-xylose on 3-position, precluding alkaline cyclization. The 3-linked ß-d-galactose units of the agarans from L. filiformis are mostly sulfated on 2-position, but approximately half of these residues also carry the 4,6-O-(1-carboxyethylidene) group. The 4-linked 3,6-anhydro-α-l-galactose units are methylated or substituted in part with single stubs of ß-d-xylose on 2-position. This is the first time that substitution with xylose of 3,6-anhydro-α-l-galactose is reported. Besides, α-l-galactose 2-sulfate carrying single stubs of ß-d-xylose on 3-position was also detected. These galactans have some common structural characteristics with those of other species of this genus, but also others that are specific for these species.
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MEDLINE
Assunto principal:
Laurencia
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Galactanos
Idioma:
En
Ano de publicação:
2014
Tipo de documento:
Article