Structural characterization of arabinoxylans from two African plant species Eragrostis nindensis and Eragrostis tef using various mass spectrometric methods Barbara Plancot 1 , Gaëtan Vanier 1 , Florian Maire 2 , Muriel Bardor 1 , Patrice Lerouge 1 , Jill M. Farrant 3 , John Moore 4 , Azeddine Driouich 1 , Maïté Vicré-Gibouin 1 , Carlos Afonso 2 and Corinne Loutelier-Bourhis 2 * 1 Laboratoire Glyco-MEV EA 4358, GRR IRIB, GRR VASI, Plateforme de Recherche en Imagerie Cellulaire de Haute-Normandie, Faculté des Sciences, Université de Rouen, 76 821, Mont saint Aignan, Cedex, France 2 Normandie Université, COBRA, UMR6014 and FR3038, Université de Rouen, INSA de Rouen, CNRS, IRCOF, 1 rue Tesnière, 76821, Mont-Saint-Aignan, Cedex, France 3 Molecular and Cell Biology Department, University of Cape Town Private Bag, Rondebosch, 7701, South Africa 4 Institute for Wine Biotechnology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa RATIONALE: The arabinoxylans are one of the main components of plant cell walls and are known to play major roles in plant tissues properties depending in particular on their structural features. It has been recently shown that one of the strategies developed by resurrection plants to overcome dehydration is based on cell wall composition. For this purpose, the structural characterization of arabinoxylans from desiccation-tolerant grass Eragrostis nindensis (E. nindensis) was compared with its close relative, the desiccation-sensitive Eragrostis tef (E. tef) in order to further understand mechansism of desiccation tolerance in resurrection plants. METHODS: Ion mobility spectrometry coupled to mass spectrometry (IM-MS) in combination with the conventional mass spectrometric approaches, including matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), electrospray ionization multistage tandem mass spectrometry (ESI-MS n ) and gas chromatography/mass spectrometry (GC/MS), were used to characterize arabinoxylan fragments obtained after endo-xylanase digestion of leave extracts from E. nindensis and E. tef. RESULTS: Whole fingerprinting by MALDI-MS analysis showed the presence of various arabinoxylan fragments within leaves of E. nindensis and E. tef. The monosaccharide composition and some linkage information were determined by GC/MS experiments. Information regarding the branching and sequence details was obtained by ESI-MS n experiments after sample permethylation. The presence of structural isomeric ions with different collision cross sections was evidenced by IM-MS which could be differentiated using ESI-MS n . CONCLUSIONS: We have shown that an orthogonal approach, and especially IM-MS associated to ESI-MS n (n = 2 to 4) and GC/MS allowed characterization of arabinoxylan fragments of E. nindensis and E. tef and revealed the presence of isomeric structures. The same arabinoxylan structures were identified for both species but in different relative abundance. Moreover, this work illustrated that IM-MS can efficiently separate isomeric structures and advantageously complements the conventional mass spectrometric methodologies used for arabinoxylan structural characterization. Copyright © 2014 John Wiley & Sons, Ltd. Mass spectrometry (MS) has for some time proven to be useful for the structural characterization of carbohydrates, since MS can offer high sensitivity and the possibility to analyse mixtures. [1–3] In particular, matrix-assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI) techniques associated with tandem mass spectrometry (MS/MS) enable understanding of structural information yielding monosaccharide sequence as well as the determination of branching/linkages and anomericity. [3–5] Thus, heterogeneous polysaccharides such as arabinoxylans which constitute cell wall components of some plant or cereal tissues have been studied. [6–8] The methodology typically used for characterization of such arabinoxylans involved for example endo-xylanase digestion of the cell wall polysaccharides followed by MS analyses; MALDI-TOF-MS and ESI-MS for identification of arabinoxylan fragments and gas chromatography (GC)/MS for composition of constitutive monosaccharides obtained after hydrolysis and derivatization * Correspondence to: C. Loutelier-Bourhis, Normandie Université, COBRA, UMR6014 and FR3038, Université de Rouen, INSA de Rouen,CNRS, IRCOF, 1 rue Tesnière, 76821 Mont-Saint- Aignan Cedex, France. E-mail: corinne.loutelier@univ-rouen.fr Copyright © 2014 John Wiley & Sons, Ltd. Rapid Commun. Mass Spectrom. 2014, 28, 908–916 Research Article Received: 3 July 2013 Revised: 15 November 2013 Accepted: 26 January 2014 Published online in Wiley Online Library Rapid Commun. Mass Spectrom. 2014, 28, 908–916 (wileyonlinelibrary.com) DOI: 10.1002/rcm.6859 908