1392435-02-7Relevant articles and documents
Synthesis of the O-linked hexasaccharide containing β-d-Galf- (1→2)-β-d-Galf in Trypanosoma cruzi mucins
Kashiwagi, Gustavo A.,Mendoza, Verónica M.,De Lederkremer, Rosa M.,Gallo-Rodriguez, Carola
experimental part, p. 6322 - 6332 (2012/09/05)
The hexasaccharide β-d-Galp-(1→2)-[β-d-Galp-(1→3)]- β-d-Galp-(1→6)-[β-d-Galf(1→2)-β-d-Galf(1→4)] -d-GlcNAc (1) is the largest carbohydrate structure released as alditol by reductive β-elimination from mucins of some strains of T. cruzi. The terminal β-d-Galp units are sites of sialylation by trans-sialidase which transfers sialic acid from the host to the parasite. Hexasaccharide 1 was synthesized by a [3 + 3]-convergent strategy based on a nitrile assisted glycosylation, using the trichloroacetimidate method. The β-d-Galf- (1→2)-β-d-Galf-d-GlcNAc synthon was sequentially constructed from the reducing end to the non-reducing end employing benzyl α-d- galactofuranoside as starting material for the internal Galf unit. The choice of this novel precursor, obtained in one-reaction step from galactose, allowed the introduction of an orthogonal and participating levulinoyl group at O-2. Thus, the diastereoselective construction of the Galf-β(1→4)-GlcNAc linkage by the trichloroacetimidate method of glycosylation was achieved. The 1H NMR spectrum of alditol 2 was identical to the product released by β-elimination from the parasite mucin. The Royal Society of Chemistry 2012.
