New insights into the structure of hybrid κ-/μ-carrageenan and its alkaline conversion

Hybridity of carrageenans water- and alkali-extracted from Chondracanthus chamissoi, Mazzaella laminarioides, Sarcothalia crispata, and Sarcothalia radula

“…It was found that the μ-carrabiose adopted three distributions: -μ-, -μ-μ-and -μ-μ-μ-, thereby explaining the asymmetrical 1 H NMR signals of the D6S-H1 (Jouanneau et al 2010a). The D6S-H1 signal recorded in the water-extracted samples showed similar asymmetry suggesting the cooccurrence of the three possible μ-carrabiose distributions.…”

“…The oligosaccharide mixtures obtained after degradation of the water-and alkali-extracted carrageenans by κ-carrageenase contained standard oligo-κ-carrageenans as well as hybrid oligosaccharides including oligo-κ-/ι-and oligo-κ-/μ-carrageenans. The chromatogram signals were ascribed to oligosaccharide structure based on previous investigations (Guibet et al 2008;Jouanneau et al 2010a). The oligosaccharide mixtures were composed of oligosaccharides with similar structure but their relative content depended on the extraction procedure as well as the algal source of the carrageenan.…”

“…Study of carrageenan hybridity has been facilitated by the use of carrageenases because the resulting degradation products reflect the structure of undigested carrageenan. The hybrid oligosaccharides obtained after degradation of κ-/ι-carrageenan (Guibet et al 2008) and κ-/μ-carrageenan (Jouanneau et al 2010a) by Pseudomonas carrageenovora κ-carrageenase were purified and their structure has been resolved by NMR. Similarly, enzymatic digestion of hybrid ι-/ν-carrageenan by Alteromonas fortis ι-carrageenase has been investigated (Jouanneau et al 2010b).…”

Structural analysis and cytokine-induced activity of gelling sulfated polysaccharide from the cystocarpic plants of Ahnfeltiopsis flabelliformis

“…The signal at 5.30 ppm was broad and asymmetric. It is probably the result of overlapping of H-1 signals of the 1,4-linked 3,6-anhydro-␣-d-galactose 2-sulfate (DA2S) of iota-carrageenan (predominant) and the 1,4-linked ␣-galactose 6-sulfate of mucarrageenan (minor amount), which is the biosynthetic precursor of kappa-carrageenan (Jouanneau, Boulenguer, Mazoyer, & Helbert, 2010;Jouanneau, Guibet et al, 2010). The signal at 4.61 ppm was characteristic of the H-1 of the 1,3-linked ␤-d-galactose of ␤-carrageenan (G).…”

Optimization of Carrageenan Extraction Process From Seaweed

“…Chemically, carrageenans are a family of hydrophilic linear sulfated galactans found exclusively in the cell walls of red marine algae. [4] It comprises a chemical structure of a backbone buildup of alternating disaccharide-repeating unit of 1,3-linked β-D galactose and 1,4-linked 3,6-anhydro-α-D-galactose forming a linear chain. [5] The difference in number and position of sulfate ester substituents and occurrence of the 3,6-anhydrogalactose residues give rise to three major types of carrageenans sorted with assigned Greek letters; lamda (λ), kappa (κ) and iota (ι).…”