Ultrasound-assisted extraction of polysaccharides from brown alga Fucus evanescens. Structure and biological activity of the new fucoidan fractions.

摘要

The application of an ultrasound-assisted extraction method, combined with ion-exchange chromatography, has allowed separation of the total fucoidan fraction (F1) from the brown alga Fucus evanescens into two fractions, F2 and F3, in the ratio 1:0.2. The traditionally extracted F1 differs from F3 only by the acetate groups at C3 being somewhat predominant. F2 is described as having acetate groups located chaotically, and contains galactose and xylose residues, in addition to fucose. F3 consists of fucose residues acetylated almost exclusively at C3. Therefore, with ultrasound-assisted extraction from the brown alga Fucus evanescens, a new regular 1 -& 3;1 -& 4-alpha-L-fucan was obtained. It is sulphated at C2 and acetylated at C3 of the fucose residue and showed anticancer activity in vitro towards human colon carcinoma cells comparable to the total fraction F1.