THE POLYSACCHARIDES OF FURCELLARIA FASTIGIATA: I. ISOLATION AND PARTIAL MERCAPTOLYSIS OF A GEL-FRACTION

Abstract

Addition of potassium chloride to an aqueous extract of the red alga Furcellariafastigiata precipitated a polysaccharide containing residues of D-galactose and 3,6-anhydro-D-galactose in the approximate ratio 1.3:1. Approximately two monomer units in five bore sulphate half-ester groups. The fraction gave a single, sharp peak in the analytical ultracentrifuge. Partial mercaptolysis afforded the crystalline diethyl mercaptals of D-galactose, 3,6-anhydro-D-galactose, and 4-O-β-D-galactopyranosyl-3,6-anhydro-D-galactose (A); the respective yields were 27%, 20%, and 42% w/w of the recovered mercaptolysate. The polysaccharide resembles κ-carregeenin.