Synthesis of guanidino sugar conjugates as GlcβArg analogs.

The β-glucosyl linkage to the guanidine group of arginine (Arg) is found in amylogenin, a glycoprotein from sweet corn. Such a linkage is formed by a rare N-glycosylation of proteins. Synthesis of analogs of the unusual N-glycosidic linkage (GlcβArg) with an acetamido or triazole spacer between the glycosyl residue and the guanidine moiety was accomplished by the reaction of fully acetylated sugar unit containing a free amino group with bis-Boc-thiourea. Synthesis of N-glucosylarginine with an amido linker was also achieved during the present study. This methodology was also extended to the synthesis of cationic glucolipid.