<smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="country-region"><smarttagtype namespaceuri="urn:schemas-microsoft-com:office:smarttags" name="place"> Sulphated galactans of marine red alga <i style="">Laurencia</i> spp. (Rhodomelaceae, Rhodophyta) from the west coast of India</smarttagtype></smarttagtype>

Abstract

Sulphated galactans were isolated from four different species of <i style="">Laurencia</i> (<i style="">L. papillosa</i>, <i style="">L. cruciata</i>, <i style="">L. pedicularioides</i>, <i style="">L. majuscula</i>) from Indian waters. The crude sulphated polysaccharide (SPS) extracts contained ash (16-18%), moisture (14-18%), sugar (44-53%), sulphate (12-18%), protein (2-6%), 3,6-anhydrogalactose (14-27%) and uronic acid (4-9%). Crude extracts were chromatoghaphed on DEAE cellulose column and major fractions (0.5 <i>M</i> NaCl fraction) were characterized by GC-MS and ¹³C-NMR studies. Agarose-2-sulphate unit was identified in all the four polysaccharides samples. <i style="">Laurencia papillosa</i>, <i style="">L. cruciata</i> and <i style="">L. pedicularioides</i> SPS were found to be of similar type having 2-<i style="">O</i>-methy-3,6-anhydro-L-galactose and agaran 6¢-sulphate (porphyran) units. Agarobiose and agarose-6-sulphate were detected in <i style="">L. majuscula</i>. Identification and chemical nature of these sulphated polysaccharides in the <i>Laurencia</i> spp. of Indian waters are of chemotaxonomic significance in view of their potential applications as agaroid.