抄録
It has been confirmed that there are two kinds of sulfate groups in red-algae mucilage which form thermal reversible gel, one of which is axial with respect to the pyranose ring and the other equatorial. The former forms 3, 6-anhydro-L-galactose by desulfation and, at the same time, intermolecular interaction increases markedly due to hydrogen bonding, while in the latter this does not occur and, consequently, an increase in gelling ability is not observed.