POLYSACCHARIDES FROM TETRASPORIC PTEROCLADIA-CAPILLACEA EXTRACTED WITH WATER AT 50-DEGREES-C

Tetrasporic plants of Pterocladia capillacea were sequentially extract ed with water at different temperatures (room temperature, 50 degrees, 70 degrees and 90 degrees C). The polysaccharides obtained by extract ion at 50 degrees C were treated with Cetrimide and the complexed mate rial was subjected to fractional solubilization in solutions of increa sing sodium chloride concentration. The structures of the two major pr oducts obtained one soluble in cetrimide (SF50) and the other soluble in 0.5 M NaCl (F0.5) were investigated by methylation analysis and C-1 3 NMR spectroscopy. For SF50 an agarose-like structure was determined; in F0.5 an agarose backbone was also detected together with other str uctural features, mainly 4-linked alpha-L-galactose units substituted on the 3-position. These structures were compared with those of the an alogue fractions obtained from the product extracted with water at roo m temperature.