title: Synthesis of modified tuftsins containing monosaccharides or monosaccharide derivatives.
abstract: Synthesis of some modified tuftsins is described in which a monosaccharide or a monosaccharide derivative was incorporated in the molecule. Acylation of H-Thr-Lys(Z)-Pro-Arg(NO2)-OBzl with D(+)-gluco-1,5-lactone followed by catalytic hydrogenation gave N alpha-gluconyl-tuftsin. Glycosylation of the carboxyl function of the C-terminal arginine has been achieved by reacting, through the mixed anhydride procedure, Boc-Thr-Lys(Z)-Pro-OH with 2-deoxy-2-(NG-nitroargininamido)-D-glucopyranose followed by catalytic hydrogenation and trifluoroacetic acid treatment. O-Glucosyl-tuftsin has been prepared by reacting o-nitrophenyl N-benzyloxycarbonyl-O-[(alpha + beta) 2,3,4,6-tetra-O-benzyl-D-glucopyranosyl]-threoninate with H-Lys(Z)-Pro-Arg(NO2)-OBzl in the presence of 1-hydroxybenzotriazole. Flash chromatography on silica gel allowed a partial separation of the diastereoisomers, one of which has been isolated in a reasonable yield. The single diastereoisomer and the alpha + beta anomeric mixture were separately deblocked by catalytic hydrogenation and purified by RP-HPLC.
mesh_terms: D002241:Carbohydrates; D002855:Chromatography, Thin Layer; D006020:Glycopeptides / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D009904:Optical Rotation; D013329:Structure-Activity Relationship; D014405:Tuftsin / Q000031:analogs & derivatives* / Q000138:chemical synthesis*
chemical_list: D002241:Carbohydrates; D006020:Glycopeptides; D007202:Indicators and Reagents; D014405:Tuftsin