title: Isolation and characterization of feruloylated arabinoxylan oligosaccharides from the perennial cereal grain intermediate wheat grass (Thinopyrum intermedium).
abstract: In comparison to the annual grain crops dominating current agricultural production, perennial grain species require fewer chemical and energy inputs and improve soil health and erosion control. The possibility for producing sustainable grain harvests from marginal land areas is motivating research initiatives to integrate perennial grains into commercial cropping and food processing systems. In this study, the feruloylated arabinoxylans from intermediate wheat grass (Thinopyrum intermedium, IWG), a promising perennial grain candidate in agronomic screening studies, were investigated. Insoluble fiber isolated from IWG whole grain flour was subjected to either mildly acidic (50 mM TFA, 100 °C, 2 h) or enzymatic (Driselase) hydrolysis. The liberated feruloylated arabinoxylan oligosaccharides were concentrated with Amberlite XAD-2, separated with gel chromatography (Sephadex LH-20, water), and purified with reversed-phase HPLC (C18, water-MeOH gradient). Thirteen feruloylated oligosaccharides were isolated (including eight structures described for the first time) and identified by LC-ESI-MS and NMR. Linkage-type analysis via methylation analysis, as well as the monosaccharide and phenolic acid profiles of the IWG insoluble fiber were also determined. IWG feruloylated arabinoxylans have a relatively simple structure with only short feruloylated side chains, a lower backbone substitution rate than annual rye and wheat varieties, and a moderate phenolic acid content.
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Adenauerring 20A, 76131 Karlsruhe, Germany. Electronic address: rachel.schendel@kit.edu.
authors.forename: Rachel R
authors.initials: RR
authors.lastname: Schendel
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Adenauerring 20A, 76131 Karlsruhe, Germany. Electronic address: andibecker@live.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Becker
authors.affiliation: University of Minnesota-Twin Cities, Department of Food Science and Nutrition, 1340 Eckles Avenue, St. Paul, MN 55108, USA. Electronic address: tylxx001@umn.edu.
authors.forename: Catrin E
authors.initials: CE
authors.lastname: Tyl
authors.affiliation: Karlsruhe Institute of Technology (KIT), Institute of Applied Biosciences, Department of Food Chemistry and Phytochemistry, Adenauerring 20A, 76131 Karlsruhe, Germany. Electronic address: mirko.bunzel@kit.edu.
authors.forename: Mirko
authors.initials: M
authors.lastname: Bunzel
mesh_terms: D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D003373:Coumaric Acids / Q000737:chemistry / Q000302:isolation & purification*; D062385:Hydroxybenzoates / Q000737:chemistry / Q000302:isolation & purification; D008745:Methylation; D000066889:Triticale / Q000737:chemistry*; D014990:Xylans / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D003373:Coumaric Acids; D062385:Hydroxybenzoates; D014990:Xylans; C085118:arabinoxylan; C004999:ferulic acid; C017616:phenolic acid
keywords: Arabinoxylans; Ferulic acid; Feruloylated oligosaccharides; Intermediate wheatgrass; Thinopyrum intermedium