Rapid Mass Spectrometric Analysis of a Novel Fucoidan, Extracted from the Brown AlgaCoccophora langsdorfii

Abstract

The novel highly sulfated (35%) fucoidan fraction Cf2 , which contained, along with fucose, galactose and traces of xylose and uronic acids was purified from the brown alga Coccophora langsdorfii. Its structural features were predominantly determined (in comparison with fragments of known structure) by a rapid mass spectrometric investigation of the low-molecular-weight fragments, obtained by “mild” (5 mg/mL) and “exhaustive” (maximal concentration) autohydrolysis. Tandem matrix-assisted laser desorption/ionization mass spectra (MALDI-TOF/TOFMS) of fucooligosaccharides with even degree of polymerization (DP), obtained by “mild” autohydrolysis, were the same as that observed for fucoidan from Fucus evanescens, which have a backbone of alternating (1 → 3)- and (1 → 4) linked sulfated at C-2 and sometimes at C-4 of 3-linked α-L-Fucp residues. Fragmentation patterns of oligosaccharides with odd DP indicated sulfation at C-2 and at C-4 of (1 → 3) linked α-L-Fucp residues on the reducing terminus. Minor sulfation at C-3 was also suggested. The “exhaustive” autohydrolysis allowed us to observe the “mixed” oligosaccharides, built up of fucose/xylose and fucose/galactose. Xylose residues were found to occupy both the reducing and nonreducing termini of FucXyl disaccharides. Nonreducing galactose residues as part of GalFuc disaccharides were found to be linked, possibly, by 2-type of linkage to fucose residues and were found to be sulfated, most likely, at position C-2.

Therapies from Fucoidan: An Update

“…Additional methods of examination of the tertiary structure of fucoidans include NMR spectroscopy and mass spectroscopy. As recently outlined by Anastyuk et al , mass spectroscopy has limitations because the fucoidans tend to desulfate rather than ionize during measurement [ 46 , 47 ]. They describe rational examination of different fucoidans using exhaustive hydrolysis followed by MALDI-TOF and ESI mass spectroscopy.…”

Relevance of the Extraction Stage on the Anti-Inflammatory Action of Fucoidans

“…In order to prevent the coextraction of low-molecular-weight compounds, colored substances, lipids, and lipophilic pigments, preliminary extraction stages can be performed. This pre-extraction stage has been frequently addressed with 70–96% ethanolic solutions at 25–80 °C [ 112 , 113 , 125 , 126 ], with acetone [ 10 , 127 , 128 ], or with solvent mixtures [ 118 , 123 , 129 , 130 , 131 , 132 , 133 ]. Alternatively, deoiling by sc-CO 2 extraction was proposed [ 134 , 135 ].…”

“…However, higher severity could favor the extraction of phlorotannins, found at higher concentrations compared to extracts from conventional hot water extraction [ 184 , 185 ]. Morimoto et al [ 186 ] confirmed that hydrothermal treatment at 140 °C allowed fucoidan depolymerization without causing desulfation, being more rapid than aqueous processing at room temperature for prolonged times (several days) [ 125 ], an alternative that can also cause desulfation [ 149 ]. Vaamonde-García et al [ 104 ] reported the attenuation of osteoarthritis associated anti-inflammation by fucoidans obtained from the crude extract by pressurized hot water extraction from Sargassum muticum and Undaria pinnatifida .…”

Fucoidan Characterization: Determination of Purity and Physicochemical and Chemical Properties

“…The polymer can be chemically depolymerized via partial acid hydrolysis using 0.2 N TFA at 60 °C or 0.75 mM H 2 SO 4 at 60 °C following the solvolytic desulfation step [ 179 ]. In contrast with autohydrolysis, enzymatic depolymerization by fucoidanses was reported, albeit not widely [ 181 ]. Nevertheless, the role of fucoidan-degrading enzymes or fucoidanses is discussed in Section 6 regarding their enzymatic modifications of fucoidans as a potential prerequisite for conducting spectrometric analysis.…”