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Chemistry: Oxycarb Project Confirms Existence of New Chemical

So-called glycosylation reactions are required to convert sugars into high value-added molecules inside living organisms, and used in labs for technological purposes. Even though such reactions have been studied and used in chemistry for over a century, their inner workings remained shrouded in mystery. French and Spanish researchers working under the Oxycarb project have partly resolved the mystery by identifying ions called glycosyl cations. These reaction intermediates’ existence had been advanced at the theoretical level, but never observed first-hand.

Sugars play a central role in the chemistry and biology of living things. They also have strong potential from a technology standpoint, with applications in the medical and green chemistry fields. Understanding these molecules’ precise roles in said sciences is therefore a frontline knowledge issue. 

Solving the mystery of chemical reactions

So-called glycosylation reactions enable sugar activation and are therefore a necessary step in the creation of sugary chemical compounds with novel functions. This life-essential reaction has been studied and chemically exploited for over a century even without full understanding of the mechanism behind it. The Oxycarb project set out to learn more about glycosyl cations, considered key reaction intermediates, with the aid of researchers from the Institute of Chemistry of Poitiers (IC2MP UMR-CNRS 7285), and the Center for Cooperative Research in Biosciences (Bilbao - Spain).

A world first

What makes identifying glycosyl cations so tricky is their very short duration (estimated half-life of one picosecond in an organic environment). To overcome this obstacle, researchers used "super-acidic” conditions to generate, stabilise and study the reaction of glycosylation and its intermediates via low-temperature nuclear magnetic resonance (NMR). The use of super-acidic environments stronger than concentrated sulfuric acid has enabled researchers to create chemical reactions with no equivalents in traditional organic environments. This approach has made it possible for the first time ever to identify and characterise some of the cationic intermediates involved in glycosylation reactions. Research carried out by Oxycarb was even cited by an article in the respected chemical sciences journal Nature Chemistry.


The Oxycarb project - Using super-acidic conditions to identify new reaction intermediates in glycochemistry

Launched in 2012 under ANR’s Blanc Programme, the Oxycarb project brings together researchers from the Institute of Chemistry of Poitiers (IC2MP UMR-CNRS 7285) and Spanish researchers (CICbiogune). It benefited from an ANR grant in the amount of € 210k. The project also received funding from CNRS (PICS programme) and the Academy of Sciences (Foundation for the development of natural product chemistry) as well as technical support from the University of Poitiers and the Poitou-Charentes region.


Works cited
A. Martin, A. Arda, J. desired, A. Martin-Mingot, N. Probst, P. Sinaÿ, J. Jiménez-Barbero, S. Thibaudeau & Y. Blériot catching elusive glycosyl cations in a condensed phase with HF/SbF5 superacid Nat. Chem. 23 November 2015 doi: 10.1038/NCHEM.2399

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