Proteoglycans (PGs) are glycoproteins with numerous relevant biological functions. Chondroitin sulfate (CS), which belong to PGs, are complex oligomers widespread in the organism. Synthesis of mimics of CS is an interesting strategy to study the interaction with biologically relevant proteins, such as lectins or growth factor, and is also a synthetic challenge. Thereby, the goal of this project is to obtain a range of multivalent CS grafted onto various platforms. To begin, we are focusing on non-sulfated disaccharides.
An hemisynthesis starting from commercially available CS polymer was previoulsy optimized in the team to obtain the disaccharide I, which is the key starting material for our synthesis.  Since the trichloroacetyl group is known to be difficult to reduce, especially in the presence of other protecting groups, we propose to synthesize the imidate building block II bearing a trifluoracetyl protecting group on the amine. Introduction of the aglycon moiety (compound III) functionalized by a terminal azido group will allow the synthesis of the multivalent disaccharide using click chemistry on various alkynyl platforms. [2,3]
- Lopin, C.; Jacquinet, J.-C. From Polymer to Size-Defined Oligomers: An Expeditious Route for the Preparation of Chondroitin Oligosaccharides. Angewandte Chemie International Edition 2006, 45 (16), 2574–2578. https://doi.org/10.1002/anie.200503551.
- Müller, C.; Despras, G.; Lindhorst, T. K. Organizing Multivalency in Carbohydrate Recognition. Chem. Soc. Rev. 2016, 45 (11), 3275–3302. https://doi.org/10.1039/C6CS00165C.
- Domínguez‐Rodríguez, P.; Reina, J. J.; Gil‐Caballero, S.; Nieto, P. M.; Paz, J. L. de; Rojo, J. Glycodendrimers as Chondroitin Sulfate Mimetics: Synthesis and Binding to Growth Factor Midkine. Chemistry – A European Journal 2017, 23 (47), 11338–11345. https://doi.org/10.1002/chem.201701890.