Systhesis Of Oligosaccharides And Their Derivatives Associated With Xenotransplantation By One-Pot Strategy

Xenotransplantation is considered as a means of overcoming the shortage of donor organs for human transplantation. Hyperacute rejection (HAR) has been viewed as the most challenging barrier to the xenotransplantation of vascularized grafts between different species. It is triggered by specific binding of xenoreactive natural antibodies (anti- a Gal) in the circulation of human to the Gal a l-3Gal-R epitopes on the endothelial cells of the blood vessels within the graft of nonprimate mammals. One strategy to prevent anti-Gal binding to Gal a l-3Gal-R epitopes is the use of synthetic antigens. Trisaccharides Galal-3GalB1-4GlcB1-R and Galal-3GalB1?GlcNAcJ31 - R and pentasaccharide Galal-3GalB1-4GlcNAcB1-GalBl-4GlcB-R have been identified as the major a-Gal epitopes.In this thesis, we chosed a pentasaccharide, a disaccharide , two trisaccharides, two monosaccharides fragments as our target compounds based on the major a-Gal epitopes involved in the HAR . We accomplished the synthesis of the six fully protected target saccharide molecules by "one-pot sequential glycosylation" synthetic approach.This thesis dealt with the synthesis of 54 compounds via more than 40 steps, including 1 pentasaccharide, 2 trisaccharides, 13 disaccharides and 38 monosaccharides. To the best of our knowledge, 18 compounds among these were reported for the first time.