title: NMR Spectroscopic Profiling of Arabinan and Galactan Structural Elements.
abstract: Pectic arabinans and galactans presumably affect the physiological and technological properties of plant cell walls and dietary fiber. Their complex structures are usually analyzed by time-consuming methods, which are based on chemical cleavage to monomers. To gain more detailed insights into the arabinan and galactan structures, a time-efficient approach based on enzymatic cleavage and two-dimensional NMR spectroscopy was developed. Heteronuclear single quantum coherence spectroscopy (HSQC) marker signals were evaluated for various structural elements, and relative response factors were determined, allowing a semiquantitative estimation of the structural composition. The method was applied to analyze different insoluble plant materials and soluble polysaccharides. It was demonstrated that the developed approach yielded comparable information about various structural elements that can also be detected by using the conventional methylation analysis. However, by using the NMR method, additional structural information, such as the anomeric configuration of the monomers, is obtained, demonstrating the value of this novel approach.
authors.affiliation: Department of Food Chemistry and Phytochemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Wefers
authors.affiliation: Department of Food Chemistry and Phytochemistry, Institute of Applied Biosciences, Karlsruhe Institute of Technology (KIT) , Adenauerring 20a, 76131 Karlsruhe, Germany.
authors.forename: Mirko
authors.identifier: http://orcid.org/0000-0003-0462-8076
authors.initials: M
authors.lastname: Bunzel
mesh_terms: D004043:Dietary Fiber / Q000032:analysis*; D005685:Galactans / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D009682:Magnetic Resonance Spectroscopy; D008745:Methylation; D010368:Pectins / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*
chemical_list: D004043:Dietary Fiber; D005685:Galactans; D011134:Polysaccharides; C030080:araban; D010368:Pectins
keywords: NMR spectroscopy; dietary fiber; pectins; polysaccharides; screening