Synthesis of trisaccharides containing internal galactofuranose O-linked in Trypanosoma cruzi mucins

VERÓNICA M. MENDOZA; GUSTAVO A. KASHIWAGI; ROSA M. DE LEDERKREMER; CAROLA GALLO -RODRIGUEZ

CARBOHYDRATE RESEARCH

Elsevier

Lugar: New York; Año: 2010 vol. 345 p. 385 - 396

0008-6215

The trisaccharides b-D-Galf-(1→2)-b-D-Galf-(1→4)-D-GlcNAc (5) and b-D-Galp-(1→2)-b-D-Galf-(1→4)-D-GlcNAc (6) constitute novel structures isolated as alditols when released by reductive b-elimination frommucins of Trypanosoma cruzi (Tulahuen strain). Trisaccharides 5 and 6 were synthesized employing thevaldonolactone approach. Thus, a convenient D-galactono-1,4-lactone derivative was used for the introduction of the internal galactofuranose and the trichloroacetimidate method was employed for glycosylation reactions. Due to the lack of anchimeric assistance on O-2 of the galactofuranosyl precursor, glycosylation studies were performed under different conditions. The nature of the solvent strongly determined the stereochemical course of the glycosylation reactions when the galactofuranosyl donor was substituted either by 2-O-Galp or 2-O-Galf.