Stereoselective Synthesis of the Gal‐α‐(1→3)‐Gal‐β‐(1→3)‐GlcNAc Trisaccharide: a new Ligand for DCAR and Mincle C‐Type Lectin Receptors

In this work, we have discovered that the Gal-alpha-(1 -> 3)-Gal-beta-(1 -> 3)-GlcNAc trisaccharide, a fragment of the B antigen Type-1, is a new ligand of two C-type lectin receptors (CLRs) i. e. DCAR and Mincle which are key players in different types of autoimmune diseases. Accordingly, we report here on a straightforward methodology to access pure Gal-alpha-(1 -> 3)-Gal-beta-(1 -> 3)-GlcNAc trisaccharide. A spacer with a terminal primary amine group was included at the reducing end of the GlcNAc residue thus ensuring the further functionalization of the trisaccharide Gal-alpha-(1 -> 3)-Gal-beta-(1 -> 3)-GlcNAc.The identification and synthesis of a new ligand for two C-type lectin receptors, i. e. dendritic cell activating receptor (DCAR) and macrophage-inducible C-type lectin (Mincle), are described.+ image