THE STRUCTURE OF A PYRUVYLATED CARRAGEENAN EXTRACTED FROM STENOGRAMMEINTERRUPTA AS DETERMINED BY C-13 NMR-SPECTROSCOPY

The polysaccharide extracted from Stenogramme interrupta was found to consist of 4-linked 3,6-anhydro-D-galactosyl-2-sulfate units alternati ng with either 3-linked D-galactosyl-4-sulfate eater or 3-linked D-gal actosyl-4,6-pyruvate acetal units. The structure was obtained solely t hrough the use of C-13 NMR spectroscopy, and a method to simplify the analysis of the complex spectra using set theory and matrices is shown . The trial structure obtained from the initial spectral set was used to predict spectra of desulfated and methylated polymers, and the resu ltant spectra fitted well with the predicted spectra. The logical outc omes of this result are that either Stenogramme interrupta is not in t he Phyllophoraceae, that the New Zealand alga termed Stenogramme inter rupta is not in the Phyllophoraceae and hence differs from the algae t ermed Stenogramme interrupta examined elsewhere, that pyruvylation is a characteristic feature of polysaccharides from the Phyllophoraceae b ut does not occur at any significant level in other members of this fa mily, or that these polysaccharide structures are not chemotaxonomical ly definitive.