Synthesis of trisaccharides containing internal galactofuranose O-linked in Trypanosoma cruzi mucins.
The trisaccharides beta-D-Galf-(1-->2)-beta-D-Galf-(1-->4)-D-GlcNAc (5) and beta-D-Galp-(1-->2)-beta-D-Galf-(1-->4)-D-GlcNAc (6) constitute novel structures isolated as alditols when released by reductive beta-elimination from mucins of Trypanosoma cruzi (Tulahuen strain). Trisaccharides 5 and 6 were synthesized employing the aldonolactone 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.
Mendoza
Verónica M
VM
CIHIDECAR, Departamento de Química Orgánica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón II, 1428 Buenos Aires, Argentina.
Kashiwagi
Gustavo A
GA
de Lederkremer
Rosa M
RM
Gallo-Rodriguez
Carola
C
D002240:Carbohydrate Sequence; D009077:Mucins / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D013237:Stereoisomerism; D014312:Trisaccharides / Q000138:chemical synthesis*; D014349:Trypanosoma cruzi / Q000737:chemistry*
D009077:Mucins; D014312:Trisaccharides