THE STRUCTURAL DETERMINATION OF THE AGAROID POLYSACCHARIDES FROM 4 NEW-ZEALAND ALGAE IN THE ORDER CERAMIALES BY MEANS OF C-13 NMR-SPECTROSCOPY

The structures of agaroid polysaccharides from four New Zealand seawee ds were determined primarily by means of C-13 NMR spectroscopy. The fo llowing substitutions occurred at the primary hydroxyls of the 3-linke d residues: Euptilota formosissima, total substitution by methyl ether ; Streblocladia glomerulata, total substitution by sulfate ester; Poly siphonia strictissima, mainly substitution by sulfate ester; Polysipho nia abscissoides, 70% substitution by sulfate ester, approximately 11% by methyl ether. The natural polymers of Euptilota formosissima, Stre blocladia glomerulata, and Polysiphonia abscissoides also contained L- galactosyl-6-sulfate residues at between 10-20% levels that were conve rted to 3,6-ahydrogalactosyl residues by alkali treatment, while that from Polysiphonia strictissima appeared to contain 4-linked-L-galactos yl residues, and also xylosyl residues at levels detectable by NMR spe ctroscopy.