Syntheses of two trimannose analogs each containing C-mannosyl or 5-thio- C-mannosyl residue: their affinities to concanavalin A

Abstract

C-Mannosyl residue-containing trimannose Man Cα(1,6){Man α(1,3)Man} ( 2) and 5-thio- C-mannosyl residue-containing trimannose 5SMan Cα(1,6){Man α(1,3)Man} ( 3) were synthesized via a glycosyl radical addition to enone derivative of mannose ( 6). Dissociation constants for the binding of these trisaccharides to concanavalin A (ConA) were determined by a fluorescence anisotropy inhibition assay: K d = 198 and 31 μM, respectively. The unexpectedly large K d value for the compound 2 compared with the compound 3 and the natural trimannose 1 demonstrates a characteristic of C-glycoside.