Carbohydrates are one of the most important chemical classes of living organisms. They also have applications in various fields, such as biofuels or the food, pharmaceutical or cosmetic industries. However, minor chemical variations can have a major impact on their properties. While there is currently no satisfactory approach to finely characterize polysaccharides, particulary in complex extracts, mass spectrometry (MS) has emerged as a powerful tool for the structural analysis of other types of biopolymers, notably proteins.

However, the methods are not directly transposable to carbohydrates, which contain many structural elements that do not affect their mass (a phenomenon known as isomerism). As a result, these isomers are invisible to MS, which detects only mass. Today, technological advances are making it possible to start lifting this analytical barrier. More specifically, molecules can be separated according to their 3D conformations by combining ion mobility spectroscopy with MS (IM-MS).

We tested this approach on several dozen oligosaccharides, representative of the carbohydrates found in plants. The constructed network proved to be superior in grouping oligosaccharides according to informative structural characteristics, chieffly related to their backbone.