Agar Extraction By-Products from <i>Gelidium sesquipedale</i> as a Source of Glycerol-Galactosides
oleh: Salim Lebbar, Mathieu Fanuel, Sophie Le Gall, Xavier Falourd, David Ropartz, Philippe Bressollier, Vincent Gloaguen, Céline Faugeron-Girard
| Format: | Article |
|---|---|
| Diterbitkan: | MDPI AG 2018-12-01 |
Deskripsi
Alkaline treatment is a common step largely used in the industrial extraction of agar, a phycocolloid obtained from red algae such as <i>Gelidium sesquipedale</i>. The subsequent residue constitutes a poorly valorized by-product. The present study aimed to identify low-molecular-weight compounds in this alkaline waste. A fractionation process was designed in order to obtain the oligosaccharidic fraction from which several glycerol-galactosides were isolated. A combination of electrospray ion (ESI)-mass spectrometry, <sup>1</sup>H-NMR spectroscopy, and glycosidic linkage analyses by GC-MS allowed the identification of floridoside, corresponding to Gal-glycerol, along with oligogalactosides, i.e., (Gal)<sub>2⁻4</sub>-glycerol, among which α-<span style="font-variant: small-caps;">d</span>-galactopyranosyl-(1→3)-β-<span style="font-variant: small-caps;">d</span>-galactopyranosylα1-2⁻glycerol and α-<span style="font-variant: small-caps;">d</span>-galactopyranosyl-(1→4)-β-<span style="font-variant: small-caps;">d</span>-galactopyranosylα1-2⁻glycerol were described for the first time in red algae.