## 3 Results and Discussion
### Structural Characterization of JSP
#### 3.2.3 NMR Investigations  
Several assignments were deduced by comparing the NMR results of JSP and JDP with the \({}^{1}\)H\({}^{1/3}\)C NMR spectra of (i) a sulfated xylogalactan from _C. officinalis_ showing an alternating \(\rightarrow\)4)-\(\alpha\)-\(\iota\)-Gal\(p\)-(1,3)-\(\beta\)-d-Gal\(p\)-(1\(\rightarrow\) backbone devoid of 3,6-AnGal\(p\), in which the C-6 of the \(\beta\)-d-Gal\(p\) units is substituted almost completely, mainly by \(\beta\)-d-Xyl\(p\) and also by sulfate groups, while the C-2 of \(\alpha\)-\(\iota\)-Gal\(p\) moieties was partially substituted by sulfate and methoxy groups and the C-3 of the same unit also carries some sulfate groups [20]; (ii) a sulfated galactan extracted from _J. maximus_ having a repeating backbone of \(\rightarrow\)3)-\(\beta\)-d-Gal\(p\)-(1,4)-\(\alpha\)-\(\iota\)-Gal\(p\)-(1\(\rightarrow\), highly branched on the _O_-2 and _O_-3 of \(\alpha\)-(1,4)-l-Gal\(p\) by short side chains and on the O-6 of \(\beta\)-(1,3)-p-Gal\(p\) by terminal residues of \(\beta\)-d-Xyl\(p\)[4]; (iii) a sulfated xylogalactan produced from _J. rubens_ with a main backbone consisting of an agaran disaccharide repeating unit [\(\rightarrow\)4)-\(\alpha\)-\(\iota\)-Gal\(p\)-(1,3)-\(\beta\)-d-Gal\(p\)-(1\(\rightarrow\)] substituted mainly on the _O_-6 of the \(\beta\)-d-Gal\(p\) unit by \(\beta\)-d-Xyl\(p\) side stubs, and less with sulfate or methoxy groups, and also on _O_-2 and/or the _O_-3 of the \(\alpha\)-\(\iota\)-Gal\(p\) (or 3,6-\(\alpha\)-\(\iota\)-AnGal\(p\)) residues with methoxy and/or sulfate groups [3]; (iv) a sulfated xylogalactan isolated from _C. philulfera_ composed of alternating 3-linked \(\beta\)-d-Gal\(p\) and 4-linked \(\alpha\)-l-Gal\(p\) bearing single \(\beta\)-d-Xyl\(p\) substituents in the _O_-6 position of \(\beta\)-d-Gal\(p\) residues, whereas sulfate and methoxy groups occupy the _O_-2 and _O_-3 positions of \(\alpha\)-\(\iota\)-Gal\(p\) and _O_-6 of \(\beta\)-d-Gal\(p\) units [19]; (v) a xylogalactan extracted from _B. cetacea_ with a similar main chain consisting of \(\rightarrow\)4)-\(\alpha\)-\(\iota\)-Gal\(p\)-(1,3)-\(\beta\)-d-Gal\(p\)-(1\(\rightarrow\) partially sulfated on the _O_-6 of \(\beta\)-(1,3)-p-Gal\(p\), a feature unique to this species [47]; (vi) a complex xylogalactan produced from _L. heteroclatum_ composed of alternating 3-linked \(\beta\)-d-Gal\(p\) and 4-linked \(\alpha\)-\(\iota\)-Gal\(p\) highly substituted principally on the _O_-6 of the \(\beta\)-d-Gal\(p\) residues by \(\beta\)-d-xylosyl side stubs, and less with methoxy or sulfate groups, and also on the _O_-2 by sulfate or methoxy group of the \(\alpha\)-\(\iota\)-Gal\(p\) or 3,6-\(\alpha\)-\(\iota\)-AnGal\(p\) residues [2]; and finally (vii) a sulfated xylogalactan obtained from _Gracilaria caudata_ composed of alternating residues of 3-linked-\(\beta\)-d-Gal\(p\) and 4-linked-3,6-\(\alpha\)-\(\iota\)-AnGal\(p\) highly substituted by methoxy groups and pyruvate acid acetal. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{4}{c}{**Monosaccharides Composition (Molar \%)**} \\ \hline
**Gal** & **Xyl** & **Glc** & **Glc** \\ \hline
62.35 & 15.41 & 20.00 & 2.24 \\ \hline \hline \end{tabular}  
Analyses were run in triplicate and the relative standard deviations are less than 5%.  
\end{table} 
Table 2: Monosaccharides composition of JSP. The \({}^{1}\)H- and \({}^{13}\)C-NMR assignments of JSP and JDP spectra are given in Figures 2 and 3. The spectra showed a high degree of multiplicity, suggesting a great diversity in the \(\alpha\)-t-Gal\(p\) and \(\beta\)-d-Gal\(p\) backbone, which seems similar to those already published for other corallinans [2; 3; 4; 20; 47]. Signals related to theomeric regions are located in the range \(\delta\) 4.2-5.6 ppm for \({}^{1}\)H-NMR and \(\delta\) 100-110 ppm for \({}^{13}\)C-NMR [2; 3; 19].