Mannose-functionalized dendritic oligothiophenes: synthesis, characterizations and studies on their interaction with Concanavalin A.

We have synthesized and characterized a series of dendritic oligothiophenes comprising peripheral mannose functionalities by copper-mediated 1,3-dipolar cycloaddition reaction. The hybrids were accessible either by attachment of acetyl-protected mannosides at the dendritic oligothiophene or by the direct synthesis of the deprotected mannose-oligothiophene conjugates by applying heterogeneous reaction conditions. The specific interaction of the functional dendritic hybrids with lectin protein Concanavalin A was investigated by absorption and fluorescence spectroscopic measurements. An enhancement of turbidity was observed due to the specific interaction of the mannosidic dendrimer with Con A. The specific interaction was further confirmed by fluorescence quenching upon addition of the mannosidic hybrid to Con A.