COMPOSITION, STRUCTURAL CHARACTERISTICS, AND ANTITUMOR PROPERTIES OF POLYSACCHARIDES FROM THE BROWN ALGAE Dictyopteris polypodioides AND Sargassum sp.

The polysaccharide compositions of the brown algae Dictyopteris polypodioides and Sargassum sp. from the Mediterranean Sea were determined. The principal polysaccharide of the studied algae (about 12% of the dry alga weight) was alginic acid. The content of water-soluble polysaccharides was low. The amount of fucoidan was less than 1% of the dry alga weight; of neutral polysaccharides, less than 0.25%. The monosaccharide compositions of fucoidans and neutral polysaccharides were investigated. Experiments on soft agar-agar models showed that fucoidans from D. polypodioides and Sargassum sp. exhibited antitumor activity against RPMI-7951 human melanoma cells.