Isolation from sugar beet cell walls of arabinan oligosaccharides esterified by two ferulic acid monomers.
Side chains of sugar beet (Beta vulgaris) pectins, which are mainly composed of arabinose (Ara) and galactose (Gal) residues, are esterified by ferulic acid units. Enzymatic hydrolysis of beet cell walls yielded several feruloylated oligosaccharides, which were separated by hydrophobic interaction chromatography. Two new oligomers were isolated in the fraction eluted by 25:75 (v/v) ethanol:water. An arabinotriose and an arabinotetraose esterified by two ferulic acid residues were obtained, and their structure was elucidated by mass spectrometry. It is shown that feruloyl groups are linked to O-5 of Ara residues, in addition to the known O-2 position. This work establishes for the first time, to our knowledge, that two neighboring Ara units may be esterified by two ferulic acid units. This close proximity may have important biochemical implications.
Unité de Recherche sur les Polysaccharides, leurs Organisations et Interactions, Institut National de la Recherche Agronomique, boîte postale 71627, 44316, Nantes cedex 03, France.
Sébastien V
SV
Levigne
Marie-Christine J
MC
Ralet
Bernard C
BC
Quéméner
Brigitte N-L
BN
Pollet
Catherine
C
Lapierre
Jean-François J
JF
Thibault
D027461:Beta vulgaris / Q000378:metabolism*; D002473:Cell Wall / Q000378:metabolism; D003373:Coumaric Acids / Q000378:metabolism*; D004951:Esterification; D015394:Molecular Structure; D009844:Oligosaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D011134:Polysaccharides / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization
D003373:Coumaric Acids; D009844:Oligosaccharides; D011134:Polysaccharides; C030080:araban; C004999:ferulic acid