• 13C NMR;
  • floridean starch;
  • galactans;
  • GC-MS;
  • Gracilaria millardetii;
  • Gracilaria textorii


Galactans containing methylated galactan moieties were extracted from Indian agarophytes, namely, Gracilaria millardetii and Gracilaria textorii growing naturally along the west coast of India. The galactans were treated with α-amylase to remove floridean starch. These were characterized by Fourier Transform-Infrared (FT IR), 13C-Nuclear Magnetic Resonance (C NMR), Gas Chromatography-Mass Spectrometry (GC MS), Inductively Coupled Plasma spectroscopy (ICP) and Gel Permeation Chromatography (GPC) and were found to be composed of d-galactose, 6-O-methyl-D-galactose and 3,6-anhydro-L-galactose. Methylation analyses revealed that both the polysaccharides consisted of 3-, 2,3-, 4,6-linked galactose as well as four-linked 3,6-anhydro galactose residues. Both the Gracilaria species produced low gelling (<100 g cm−2) and highly sulfated (2.1% to 4.8%) galactans containing very low heavy metal contents (ICP). These galactans may be of potential utility in food and biological applications.