Sulphated polysaccharides from Indian samples of Enteromorpha compressa (Ulvales, Chlorophyta):: Isolation and structural features

Heteroglycan and xyloglucan rich fractions were extracted from Indian samples of Enteromorpha compressa in 25% yield by sequential extractions with water and alkali. This heteroglycan is sulfated and has an apparent molecular mass of 55 kDa. Chemical structural analysis of this polysaccharide revealed a branched structure having 1,4- and 1,2,4-linked rhamnose 3-sulphate, 1,4-linked glucose, 1,3- and 1,6- linked galactose, 1,4- and terminally linked glucuronic acid and 1,4-linked xylose partially sulfated on 0-2. Chemical and spectroscopic analysis showed that the 4-M KOH extracted hernicellulosic fraction contained an unusual beta-(1,4)-linked linear xyloglucan. Enzyme hydrolysis and analysis of the resulting fragments by matrix-assisted laser desorption ionization-time of flight-mass spectrometry (MALDI-TOF-MS) showed that this linear polymer contained partially sulfated Glc(3)Xyl(2) or Glc(4)Xyl(2) as oligomeric building subunits. (c) 2007 Elsevier Ltd. All rights reserved.