A ¹³C N.M.R. study of some agar-related polysaccharides from New Zealand seaweeds

Abstract

The use of ¹³C nuclear magnetic resonance spectroscopy has yielded well resolved spectra of agaroses from marine algae of the Pterocladia species and Gracilaria secundata, and from the porphyran and alkali-modified porphyran of Porphyra columbina. A complete assignment of all signals in the spectra of these four undegraded polysaccharides has been made on the basis of ¹³C n.m.r. spectra which have been reported for various galactose derivatives and agaro-oligosaccharides. General shifts rules for carbohydrates have been used. Conformational aspects of the work are briefly discussed.