Association of κ‐carrageenan subjected to deep alkaline hydrolysis

Abstract

κ‐carrageenan is a linear sulfated anionic gelling polysaccharide obtained from red seaweed algae by an alkaline hydrolysis. We applied static and dynamic light scattering (DLS), capillary viscometry, FT‐IR, and electrophoretic DLS to gain insight into the effect of deep alkaline hydrolysis (95 °C, pH = 10 during Th = 60, 75, and 90 min) on κ‐carrageenan macromolecules in a coil conformation. As DLS of coil‐like κ‐carrageenans is usually complicated by spurious permanent aggregates, the alkaline hydrolysis of κ‐carrageenans has not been studied by DLS. By applying a double‐dialysis procedure (first against water, then against 0.1 M NaCl), we succeeded in obtaining dilute solutions of coil‐like κ‐carrageenans with unimodal DLS distributions. Association that started with increasing concentration was attributed to attractive dipole‐dipole interactions between ion‐pairs formed by condensed counter‐ions in the vicinity of carboxyl groups of the reducing ends. The second type of stickers resulted from the compositional heterogeneity of κ‐carrageenan, namely, from the traces of ι‐carrageenan blocks which amount increased with hydrolysis. With increasing Th we observed both the progressive decrease of molecular mass and the growth of association. Lowering the temperature and increasing concentration during lyophilization strengthened the intermolecular junctions, leading to the formation of permanent aggregates.

Synthesis and comparative assessment of antiradical activity, toxicity, and biodistribution of κ‐carrageenan‐capped selenium nanoparticles of different size: in vivo and in vitro study

“…Previously, it was shown in [37, 38] that in the presence of potassium ions the κ‐CG macromolecules transform from a state of a ball to a spiral structure. These spirals are grouped together through interaction with the potassium ion to afford a number of macromolecular aggregates, which are also involved in the synthesis of nanocomposites.…”

PCR Instrument-assisted Acidolysis for Monosaccharide Composition Analysis of Serum Glycans

“…Releasing monosaccharides from glycans is the bottleneck of monosaccharide composition analysis [21,22]. It is usually conducted in a sealed glass ampoule at 105-120 •C for 1-6 h [23] or in a PicoTag station [10].…”

Microwave Instrument-assisted Acid Hydrolysis plus HPAEC-PAD for Quantitative Glycan Monosaccharide Composition Analysis of Serum/Plasma Samples

“…Releasing monosaccharides from serum/plasma glycans is the bottleneck of monosaccharide composition analysis [19,20]. It is usually conducted in a sealed glass ampoule at 105-120 °C for 1-6 h [21] or in a PicoTag station [10].…”