Oligosaccharides related to tumor‐associate antigens. Part 3. Synthesis of the propyl glycosides of the trisaccharide β‐D‐Galp‐(1→3)‐β‐D‐GalpNAc‐(1→3)‐α‐D‐Galp and of the Tetrasaccharide α‐L‐Fucp‐(1→2)‐β‐D‐Galp‐(1→3)‐β‐D‐GalpNAc‐(1→3)‐α‐D‐Galp, components of a tumor antigen recognized by the antibody MBr1

摘要: The synthesis of the trisaccharide β-D-Galp-(1→3)-β-D-GalpNAc-(1→3)-α-D-Galp-1-OPr (2) and tetrasaccharide α-L-Fucp-(1→2)-β-D-GalpNAc-(1→3)-β-D-Galp-1-OPr (3), starting from disaccharidic dihydrooxazole donor 5, is described. Glycosylation 5 with 6 in presence Me3SiOTf gave 7 which was deprotected standard methods to give, via8, compound 2 (Scheme 1). Alternatively, protection 8 as 4′,6′-O-benzylidene derivative 9 followed by glycosylation 10 deprotection afforded 3 2). Biological testing showed that unable inhibit binding monoclonal antibody MBr1 target tumor cells MCF7, while inhibits ca. 7-fold extent respect previously tested α-L-Fucp-(1→2)-β-D-Galp-(1→3)-β-D-GalpNAc-1-OPr. These results indicate galactose corresponding unit D 1 plays an important role defining MBr1-recognized epitope confirm essential fucose for MAb recognition.