Synthesis of Lewis A trisaccharide analogues in which D-glucose and L-rhamnose replace D-galactose and L-fucose, respectively.
In our effort to design a safe anti-cancer vaccine based on the tumor associated carbohydrate antigen Le(a)Le(x), we are studying the cross-reactivity between the Le(a) natural trisaccharide antigen and analogues in which the L-fucose, D-galactose, and/or D-glucosamine residues are replaced by L-rhamnose or D-glucose, respectively. We describe here the chemical synthesis of two such Le(a) trisaccharide analogues. In one trisaccharide, D-glucose replaces D-galactose and in the second analogue L-rhamnose and D-glucose replace L-fucose and D-galactose, respectively. Introduction of the rhamnose and fucose moiety onto the poorly reactive 4-OH group of the N-acetylglucosamine residue in a disaccharide acceptor was successful after bis-N-acetylation of the amine group. These analogues will be used in competitive binding experiments with anti-Le(a) antibodies and their solution conformations will be studied.
Liao
Liang
L
Department of Chemistry, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Auzanneau
France-Isabelle
FI
D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D005643:Fucose / Q000737:chemistry*; D005690:Galactose / Q000737:chemistry*; D005947:Glucose / Q000737:chemistry*; D007983:Lewis Blood Group Antigens / Q000737:chemistry*; D012210:Rhamnose / Q000737:chemistry*; D013237:Stereoisomerism; D014312:Trisaccharides / Q000138:chemical synthesis* / Q000737:chemistry
D007983:Lewis Blood Group Antigens; D014312:Trisaccharides; D005643:Fucose; D005947:Glucose; D012210:Rhamnose; D005690:Galactose