Abstract

The second-derivative mode of the Fourier transform I.R. spectra of dried algal material has been applied to distinguish the carrageenans-producing Stenogramme interrupta from the isomorphous species Rhodymenia howeana. Spectra of the tetrasporophyte S. interrupta showed bands assigned to a ?-carrageenan type polysaccharide, while the gametophytic and cystocarpic plants showed the characteristic absorptions of ?-and ?-carrageenans. Results were confirmed by hot water extraction of samples of the three nuclear phases of S. interrupta and characterization of the extracts by chemical analysis.