POLYSACCHARIDES OF ALGAE .48. POLYSACCHARIDE COMPOSITION OF SEVERAL CALCAREOUS RED ALGAE - ISOLATION OF ALGINATE FROM CORALLINA-PILULIFERA P-ET-R (RHODOPHYTA, CORALLINACEAE)

The polysaccharide composition of several calcareous red algae of the family Corallinaceae, namely, Alatocladia modesta (Yendo) Johansen, Bossiella compressa Kloczcova, B. cvetacea (Postels et Ruprecht) Johansen, Corallina frondescens Postels et Ruprecht, C. piluilifera Postels et Ruprecht, Corallina sp., Haliptylon splendens Kloczcova, Clathromorphum nei nereostratum Lebednik and Lithothamnion phymatodeum lz (Foslie) Foslie from different regions of Northwestern Pacific has been investigated. Glucose, galactose, xylose, and uronic acids were shown to be the main monosaccharide components of biomass of all the samples, whereas 3,6-anhydrogalactose was not detected. It was suggested that these monosaccharides are the constituents of floridean starch, sulfated xylogalactan, and a polyuronide. The corresponding polysaccharides were isolated from C. piluilifera a Postels er Ruprecht. Floridean starch was characterized as an amylopectin-like branched a-D-glucan by amylolysis, C-13-NMR spectrum, and iodine complex formation. Xylogalactan was found to contain galactose, xylose, and sulfate in a molar ratio of about 2.3:1:1 and practically devoid of 3,6-anhydrogalactose both before and after treatment with alkali. The polyuronide was proved to be alginic acid according to its monosaccharide composition and C-13-NMR spectrum; 1-->4-linked beta-D-mannuronic acid (M) and alpha-1-guluronic acid (G) residues (M/G 0.7) were shown to be arranged in blocks as in alginates of brown seaweeds. Hence, the corralinean algae differ considerably from other red seaweeds in their polysaccharide composition. The most interesting feature is the presence of alginates, which were regarded previously as specific components of brown seaweeds and several bacteria.