O-feruloylated, O-acetylated oligosaccharides as side-chains of grass xylans.
Partial acid hydrolysis of cell wall material from Festuca arundinacea cell cultures yielded a novel O-feruloylated trisaccharide (3). Treatment of 3 with Driselase, which contains beta- but not alpha-D-xylosidase, released xylose plus the known compound, beta-D-xylopyranosyl-(1-->2)-(5-O-feruloyl)-L-arabinose. Since 3 contained one NaIO4-resistant xylose residue, it was concluded to be beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1--> 2)-(5-O-feruloyl)-L-arabinose. Partial acid hydrolysis of Festuca cell walls also yielded several higher-M(r) feruloylated oligosaccharides, including a feruloylated pentasaccharide, 4 (sugar composition: Ara + Xyl2 + two non-pentose residues) and a feruloylated heptasaccharide, 5 (Ara + Xyl3 + three non-pentose residues). Compounds 4 and 5 were endogenously O-acetylated but 3 was not. Similar or identical compounds were found in hydrolysates of 20 additional species of the Gramineae. These products represent a series of complex side-chains which, in vivo, are attached via Araf residues to the parent xylan. Their possible biological roles are discussed.
Wende
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ICMB, DBS, University of Edinburgh, U.K.
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D000107:Acetylation; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002473:Cell Wall / Q000737:chemistry; D002478:Cells, Cultured; D002850:Chromatography, Gel; D003373:Coumaric Acids; D008969:Molecular Sequence Data; D009844:Oligosaccharides / Q000737:chemistry* / Q000302:isolation & purification; D006109:Poaceae / Q000737:chemistry* / Q000378:metabolism; D014990:Xylans / Q000096:biosynthesis / Q000737:chemistry* / Q000302:isolation & purification
D003373:Coumaric Acids; D009844:Oligosaccharides; D014990:Xylans; C004999:ferulic acid