The glycosyl-aldonolactone approach for the synthesis of beta-D-Galf-(1-->3)-D-Manp and 3-deoxy-beta-D-xylo-hexofuranosyl-(1-->3)-D-Manp

Carbohydr Res. 1998 Oct;311(4):183-9. doi: 10.1016/s0008-6215(98)00214-6.

Abstract

A convenient synthesis of free beta-D-Galf-(1-->3)-D-Manp (8a) is reported. The disaccharide is present as external unit in the lipopeptidophosphoglycan (LPPG) of Trypanosoma cruzi and internally in the lipophosphoglycan (LPG) of Leishmania. Condensation of 2,5,6-tri-O-benzoyl-D-mannono-1,4-lactone (1) with 1,2,3,5,6-penta-O-benzoyl-D-galactofuranose, promoted by SnCl4, led to the beta-glycosyl-lactone, a key intermediate for disaccharide 8a, readily obtained by successive reduction of the lactone with diisoamylborane and debenzoylation. As in the LPG of Leishmania the HO-3 group of the galactofuranose is glycosylated by alpha-D-Galp, we also synthesized 3-deoxy-beta-D-xylo-hexofuranosyl-(1-->3)-D-Manp (8b) and p-nitrophenyl 3-deoxy-beta-D-xylo-hexofuranoside for studying the influence of HO-3 in the interaction with specific glycosidases. The disaccharide 8a, and its corresponding alditol, were good substrates for the beta-D-galactofuranosidase from Penicillium fellutanum, whereas the 3-deoxyglycosides were not hydrolyzed by the enzyme.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbohydrate Sequence
  • Disaccharides / chemical synthesis*
  • Glycoside Hydrolases*
  • Glycosphingolipids / metabolism
  • Magnetic Resonance Spectroscopy
  • Models, Chemical
  • Molecular Sequence Data
  • Penicillium / enzymology
  • Substrate Specificity
  • beta-Galactosidase / metabolism*

Substances

  • 3-deoxy-xylo-hexofuranosyl-(1-3)-Manp
  • Disaccharides
  • Glycosphingolipids
  • lipophosphonoglycan
  • Glycoside Hydrolases
  • exo-beta-D-galactofuranosidase
  • beta-Galactosidase