¹³C‐nmr spectroscopy of red algal galactans

Abstract

Abstract 13 C‐nmr spectra of red seaweed galactans, belonging to the agar and carrageenan groups or having the “intermediate” type of structure, were interpreted on the basis of 13 C‐nmr spectra of model compounds. Signal assignments have been made for most of the known extreme structures of such galactans. 13 C‐nmr spectroscopy was shown to be a rapid and convenient method of structural analysis, which permits one to determine the type of galactan structure, the absolute configurations of its constituents (galactose and 3,6‐anhydrogalactose), and the positions of the sulfate and O ‐methyl groups in a polysaccharide molecule.