## 3 Results and Discussion
### \({}^{1}\)H NMR Analysis of ALCM, ALSM, and FUCCM Fractions  
The adjinates and fucoidan were analyzed using \({}^{1}\)H NMR, and the findings are presented in Figure 3, Tables 4 and 5. FUCCM is mainly composed of \(\alpha\)-I-fucose presenting intense signals at 1.26-1.47 ppm, which are the characteristic regions of tucopyrannose assigned to the CH\({}_{3}\) methyl group of H-6 [56] and at 5.13 ppm confirming the \(\alpha\)-linked fucose monomers [57]. Peaks at 1.94-2.15 ppm correspond to the CH\({}_{3}\) proton of O-acetyl groups [58]. H-1 and C-H protons of O-substituted carbons of \(\alpha\)-L-isomers extend from 5.09 to 5.45 ppm, whereas ring proton H-2-H-5 spread out from 3.56 to 4.86 ppm [48]. By comparing with proton chemical shifts of each \(\mathcal{O}\)-sulfated l-fucose isomer [59], the resonance of H-6 in the region of 1.38 ppm indicates that sulfates could be bonded to C-4 of FUCCM [58] (Table 5). In order to determine more precisely the sulfate group positions, it is required to investigate as well the desulfated fucoidan residues. Other peaks appearing slightly at 4.73 and 4.77 ppm could be attributed to the mannuronic acid anomeric protons due to the presence of alginate traces in the FUCCM extracts. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**Alginates** & **Source** & \multicolumn{8}{c}{**Frequencies of Structural Blocks**} & \% M & \% G & \(\eta\) \\ \hline  & & **FG** & **FM** & **FGG** & **FMM** & **FMG** & **FGM** & **M/G** & \\ \hline ALSM \({}^{1}\) & _S. muticum_ & 0.54 & 0.46 & 0.47 & 0.40 & 0.063 & 0.063 & 0.87 & 46 & 54 & 0.25 \\ ALCM \({}^{2}\) & C. _myriophylloides_ & 0.47 & 0.53 & 0.43 & 0.49 & 0.038 & 0.038 & 1.12 & 53 & 47 & 0.15 \\ \hline \hline \end{tabular}  
\({}^{1}\) ALSM: alginate extracted from SM; \({}^{2}\) ALCM: alginate extracted from CM.  
\end{table} 
Table 4: Structural characterization of ALCM and ALSM extracted from _C. myriophylloides_ and _S. muticum_. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Monosaccharides** & **AGB \({}^{1}\)** & **AGP \({}^{2}\)** & **FUCCM \({}^{3}\)** & **ALCM \({}^{4}\)** & **ALSM \({}^{5}\)** \\ \hline Galactose (Gal) & 46.07 \(\pm\) 1.46 & 51.55 \(\pm\) 2.67 & Nd & Nd & Nd \\ Glucose (Glc) & 38.78 \(\pm\) 0.24 & 24.56 \(\pm\) 1.05 & 0.91 \(\pm\) 0.10 & 0.55 \(\pm\) 0.09 & 1.13 \(\pm\) 0.57 \\ Arabinose (Ara) & 12.08 \(\pm\) 1 & 17.32 \(\pm\) 1.33 & Nd & Nd & Nd \\ Xylose (Xyl) & 1.70 \(\pm\) 0.23 & 3.93 \(\pm\) 0.61 & Nd & Nd & Nd \\ Rhamnose (Rha) & 1.37 \(\pm\) 0.13 & 2.63 \(\pm\) 0.15 & Nd & Nd & Nd \\ Fucose (Fuc) & Nd \({}^{6}\) & Nd & 53.39 \(\pm\) 4.57 & 24.84 \(\pm\) 4.74 & 11.28 \(\pm\) 1.23 \\ Mannuronic acid (ManA) & Nd & Nd & 45.70 \(\pm\) 4.52 & 74.61 \(\pm\) 4.81 & 87.59 \(\pm\) 0.85 \\ \hline \hline \end{tabular}  
\({}^{1}\) AGB: sulfated glycoprotein (crude extract) extracted from CD; \({}^{2}\) AGP: sulfated glycoprotein (purified extract) extracted from CD; \({}^{3}\) FUCCM: fucoidan extracted from CM; \({}^{4}\) ALCM: alginate extracted from CM; \({}^{5}\) ALSM: alginate extracted from SM; \({}^{6}\) Nd: Not determined.  
\end{table} 
Table 3: GC/MS-EI analysis of different saccharide extracts. Figure 3: _Cont_. The \({}^{1}\)H NMR spectra of alignates ALCM and ALSM (Figure 3) were used to determine the structural block distribution and the rate of mannuronic and guluronic acid of each fraction through the M/G ratio (Table 4). According to [PERSON] et al. [35], signals at 5.07 and 4.46 ppm (signal I and signal III) were attributed to H-1 and H-5 of guluronic acid (G) residues, respectively. Theomeric proton of mannuronic acid (H-1) and the C-5 of alternating blocks (GM-5) (signal II) imbricated at 4.76-4.68 ppm. Minor signals at 1.21-1.27 ppm for ALSM and 1.20-1.42 ppm for ALCM correspond to fucopyranose residues, which confirm the results obtained by GC-MS-EI analysis, indicating the presence of slight impurities of fucoidan. Each alginate fraction showed a different M/G ratio, which was 0.87 and 1.12 for ALSM and ALCM, respectively.