Relationship between structure and some physico-chemical properties of funori from red seaweed Gloiopeltis

Abstract

The relationship between structural characteristics and some physico-chemical properties of ma-funori and fukuro-funori was elucidated. Ma-funori and fukuro-funori were extracted from red seaweeds which was harvested in Japan. The structure of ma-funori and fukuro-funori extracted from Gloiopeltis tenax and Gloiopeltis furcata , respectively, was characterized through FT-IR and NMR spectroscopy. The assignment of signals for ma-funori showed that structure of ma-funori was relatively regular with repeating unit (1,3)-β- D -galactopyranose 6-sulfated linking to (1,4)-3,6-anhydro-α- L -galactopyranose. In contrast, the structure of fukuro-funori was complex with substitute groups such as pyruvate acetal, sulfate ester and methyl ether groups interspersing in polysaccharide chain. The physico-chemical properties of two kinds of funori which are important to restoration and conservation of artistic heritage were characterized. The solubility of fukuro-funori in water was higher than that of ma-funori. The wettability of fukuro-funori solution was better than that of ma-funori solution, whereas ma-funori solution was higher in viscosity than fukuro-funori. The structural characteristic was the main factor to determine the difference in solubility, wettability, and viscosity of two kinds of funori.