Polysaccharides from the green seaweed Codium decorticatum. Structure and cell wall distribution

Diversity of Sulfated Polysaccharides From Cell Walls of Coenocytic Green Algae and Their Structural Relationships in View of Green Algal Evolution

“…A third sulfated polysaccharide type was also found in water soluble extracts from Codium species and corresponded to 4-linked β- d -mannans, similar to those found as fibrillar components in these seaweeds, as well as plant mannans and galactomannans, but sulfated on C-2 and, in a lesser extent, on C-6 ( Ciancia et al, 2007 ; Fernández et al, 2012 ; Fernández et al, 2015 ) ( Figure 4E ) . A paper reporting immunomodulatory activity of a mannan from C. fragile postulated a structure corresponding to a 3-linked mannan comprising α- and β-units, sulfated on C-4 of the latter units ( Tabarsa et al, 2013 ).…”

“…In this paper, the structure of a sulfated, pyruvylated (1→3)(1→6)-β- d -galactan obtained from C. yezoense was exquisitely studied by chemical and spectroscopic methods. Acidic galactans of this kind were found in many other Codium species, including C. fragile ( Ciancia et al, 2007 ; Estevez et al, 2009 ; Ohta et al, 2009 ; Li et al, 2016 ), C. vermilara ( Ciancia et al, 2007 ; Fernández et al, 2013 ), C. isthmocladum ( Farias et al, 2008 ; Araujo Sabry et al, 2019 ), C. decorticatum ( Fernández et al, 2015 ), and C. divaricatum ( Li et al, 2015 ). They showed highly ramified structures, which contained linear backbone segments of 3-linked β- d -galactopyranose residues connected by (1→6)-linkages, some of 3-linked residues were substituted at C-6, by short oligosaccharide chains also containing (1→3)- and (1→3,6)-linkages or by single β- d -galactopyranose residues.…”

“… Possible structure for a fragment containing all the major structural features of sulfated polysaccharides (A) A galactan from Codium species, (B) An homogeneous fraction from Bryopsis plumosa , (C) Galactans from species in the Halimedaceae, (D) Pyranosic arabinan from Codium species, (E) Mannan from Codium species. Structures were proposed by the authors of this review based on the major components detected by Bilan et al, 2007 ; Estevez et al, 2009 ; Ciancia et al, 2012 ; Fernández et al, 2012 ; Fernández et al, 2013 ; Arata et al, 2015 ; Fernández et al, 2015 . …”

“…The occurrence of the latter unit was proved by negative-ion electrospray tandem mass spectrometry of oligosaccharides obtained from the galactan from C. divaricatum in mild acid conditions ( Li et al, 2016 ), and it was also detected recently in C. isthmocladum ( Araujo Sabry et al, 2019 ). In the galactan from C. decorticatum , almost half of the pyruvate was forming a 6-membered ring with O -4 and O -6 of 3-linked β- d -galactose units ( Fernández et al, 2015 ).…”

“…This arabinan had a high anticoagulant activity by complex mechanisms, comprising direct and indirect inhibition of thrombin ( Fernández et al, 2013 ). Arabinans from C. decorticatum were less sulfated and showed a high degree of branching at C-2, at least in part with single stubs of arabinose ( Fernández et al, 2015 ). In the case of C. fragile , not only pyranosic 3-linked sulfated β- l -arabinans, but also furanosic non sulfated α- l- arabinan structures were detected, and they were associated to the presence of hydroxyproline rich glycoproteins (HRGP) ( Estevez et al, 2009 ).…”