8.3 Chemistry of Ulvans
171
Ulvan
Protein
Cellulose
Xyloglucan
Glucoronan
Fig. 8.1 Schematic representation of cell wall structure illustrating the location of ulvan in green
algae
8.3 Chemistry of Ulvans
Ulvans are heteropolysaccharides made up of several sugar units mainly: sulfated
rhamnose and xylose units, xylose, glucuronic acid and iduronic acid (Kim et al.
2011a). Figure 8.2 shows the structure of disaccharide units in ulvan. Ulvans are
polydisperse and molecular weight of different fractions could vary, for example,
Tabarsa et al. (2018) report weight average molecular weight (M w ) of fractions
extracted from U. intestinalis ranging between 87,100 and 194,100 g/mol following
extraction and fractionation of the crude ulvan into different molecular weights using
DEAE-Sepharose Fast Flow column.
The ulvan polymeric chain is arranged as repeating unit disaccharides of either
rhamnose and iduronic acid called the aldobiuronic acid (Lahaye and Robic 2007),
sulfated rhamnose and glucuronic acid or sulfated rhamnose and xylose (Michel and
Czjzek 2014). Arabinose and galactose are also said to be present in ulvans (Misurcova et al. 2012; Tabarsa et al. 2018). While the structure of the ulvan polymer could
vary depending on factors like source, species and harvest period, it is established
Fig. 8.2 Structures of a
disaccharide repeating unit
in ulvan comprising of a
glucuronic unit linked to a
sulfated rhamnose
171
Ulvan
Protein
Cellulose
Xyloglucan
Glucoronan
Fig. 8.1 Schematic representation of cell wall structure illustrating the location of ulvan in green
algae
8.3 Chemistry of Ulvans
Ulvans are heteropolysaccharides made up of several sugar units mainly: sulfated
rhamnose and xylose units, xylose, glucuronic acid and iduronic acid (Kim et al.
2011a). Figure 8.2 shows the structure of disaccharide units in ulvan. Ulvans are
polydisperse and molecular weight of different fractions could vary, for example,
Tabarsa et al. (2018) report weight average molecular weight (M w ) of fractions
extracted from U. intestinalis ranging between 87,100 and 194,100 g/mol following
extraction and fractionation of the crude ulvan into different molecular weights using
DEAE-Sepharose Fast Flow column.
The ulvan polymeric chain is arranged as repeating unit disaccharides of either
rhamnose and iduronic acid called the aldobiuronic acid (Lahaye and Robic 2007),
sulfated rhamnose and glucuronic acid or sulfated rhamnose and xylose (Michel and
Czjzek 2014). Arabinose and galactose are also said to be present in ulvans (Misurcova et al. 2012; Tabarsa et al. 2018). While the structure of the ulvan polymer could
vary depending on factors like source, species and harvest period, it is established
Fig. 8.2 Structures of a
disaccharide repeating unit
in ulvan comprising of a
glucuronic unit linked to a
sulfated rhamnose