SULFATED XYLOGALACTANS FROM NOTHOGENIA-FASTIGIATA

Fractionation of the Cetrimide salt of the sulphated polysaccharides of Nothogenia fastigiata led to the isolation of a complex product constituted by a xylogalactan sulphate and a xylomannan sulphate. Its structural study by methylation and desulphation-methylation analyses and C-13 NMR spectroscopy indicated for the xylogalactan sulphate a backbone formed by 4-linked alpha-L-galactopyranose and 3-linked beta-D-galactopyranose. The alpha-L-galactopyranosyl units are either 6-sulphated having single stubs of (1-->3)-linked xylose or galactose, 3-sulphated or nonsubstituted. The beta-D-galactopyranosyl residues are non-substituted or 4-sulphated. The xylomannan sulphate is similar to that previously isolated from this seaweed.