Semi-synthesis of a 3-O-sulfated red seaweed galactan-derived disaccharide alditol.
Beta-D-Galp3-SO3-(1-->4)-3,6-anhydro-L-GalOH (agarobiitol 3(2)-sulfate, 4) was semi-synthetically prepared as follows: production of agarobiitol (1) from agarose by partial reductive hydrolysis, protection of the primary hydroxyl groups of 1 with trityl groups to produce the 1(1),6(2)-di-O-tritylated derivative (2), regioselective dibutylstannylene-mediated sulfation of 2 to give the 3(2)-O-sulfated-1(1),6(2)-di-O-tritylated compound (3), and detritylation of compound 3 to give the final product (4). This semi-synthetic route allowed the preparation of a red seaweed galactan-derived disaccharide alditol with sulfate group located at C-3 of the galactopyranosidic ring. Because red seaweed galactans are glycosidically linked at C-3 of the beta-D-Galp unit, a sulfated derivative with this structure could not be obtained by partial reductive hydrolysis of sulfated red seaweed galactans.
Gonçalves
Alan G
AG
Department of Chemistry, Dalhousie University, Halifax, NS, Canada B3H 4J3.
Noseda
Miguel D
MD
Duarte
M Eugênia R
ME
Grindley
T Bruce
TB
D002240:Carbohydrate Sequence; D004187:Disaccharides / Q000138:chemical synthesis*; D005685:Galactans / Q000737:chemistry*; D008969:Molecular Sequence Data; D000461:Rhodophyta / Q000737:chemistry
C512764:3-sulfogalactopyranosyl-(1-4)-3,6-anhydrogalactitol; D004187:Disaccharides; D005685:Galactans