New 4-O-substituted xylosyl units in the xyloglucan from leaves of Hymenaea courbaril.
A homogeneous fucogalactoxyloglucan, isolated from the leaves of Hymenaea courbaril, was analysed by methylation-GC-MS. These procedures involved derived partially O-methylated alditol acetates and acetylated aldononitriles, which demonstrated the presence of both 2-O- and 4-O-substituted Xylp units in the side-chains. The presence of the unusual, latter structure was confirmed by 2D NMR spectroscopy with a correlated HMQC C-4/H-4 signal at delta 77.8/3.73. A similar 4-O-substituted xylosyl structure was present in a decasaccharide Glc4Xyl3Gal2Fuc obtained via endo-glucanase treatment of the polysaccharide, which gave rise to a molecular ion with m/z 1555 (ESI-MS, Na+ form).
Busato
A P
AP
Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Paraná, CP 19046, 81531-990 Curitiba, Paraná, Brazil.
Vargas-Rechia
C G
CG
Gorin
P A J
PA
Petkowicz
C L
CL
Tischer
C A
CA
Bochicchio
R
R
Reicher
F
F
D002240:Carbohydrate Sequence; D002480:Cellulase / Q000378:metabolism; D007887:Fabaceae / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D005936:Glucans / Q000737:chemistry*; D008745:Methylation; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization; D014990:Xylans / Q000737:chemistry*
D005936:Glucans; D014990:Xylans; D002480:Cellulase