各種溶媒中におけるカードランの超音波処理が高分子・立体構造・レオロジー特性に与える影響
Curdlan, a microbial polysaccharide with β-(1→3)-glycosidic linkages, has limited water solubility at room temperature owing to crystalline regions stabilized by hydrogen bonding. This study investigated how ultrasonication (60 min) alters the macromolecular, structural, and rheological properties of curdlan in three solvent systems: 0.1 M NaOH, DMSO, and 0.1 M alkali-neutralization (AN). Water solubility reached 16.26%, 13.62%, and 15.37% in DMSO, NaOH, and AN conditions, respectively, with corresponding molecular weights of 10.53, 19.27, and 17.25 kDa. Curdlan in DMSO showed preferential susceptibility to ultrasonic degradation, accompanied by a conformational shift from flexible chains to irregular helices due to disruption of both inter- and intramolecular hydrogen bonds. In contrast, the triple-helix conformation in the other two solvents remained largely unchanged, suggesting that flexible-chain conformations are more prone to ultrasonic degradation than rigid-rod forms. Rheological properties declined across all conditions following ultrasonication. These findings provide a mechanistic basis for solvent-dependent ultrasonic modification of curdlan relevant to food science and biomedical applications.
In DMSO, ultrasonication disrupts both inter- and intramolecular hydrogen bonds in curdlan, converting flexible-chain conformations to irregular helices, reducing molecular weight, and enhancing water solubility. Rigid triple-helix conformations in NaOH and AN solvents resist this degradation.
This is basic research at the cellular or molecular level. For human application, inhalation is the most promising delivery route, but inhalation carries explosion risk and concentration matters (empirical LFL of 10%; high-concentration devices are not recommended).
See also:
https://h2-papers.org/en/papers/40020276