Caracterização das O-acetil-(4-O-metilglicurono)xilanas isoladas da madeira de Eucalyptus urograndis

Química Nova

Andréia Da Silva Magaton²  Dorila Piló-veloso²  Jorge Luiz Colodette¹ 

[1] ,Universidade Federal de Minas Gerais Departamento de Química Belo Horizonte MG ,Brasil

关键词: Eucalyptus urograndis;    xylans;    NMR;   

DOI  :  10.1590/S0100-40422008000500027

来源: SciELO

【 摘 要 】

The O-acetyl-4-O-methyl-(glucurono)xylans were isolated from E. urograndis by extraction with dimethyl sulfoxide, analysed for monosaccharide composition and structurally characterized by NMR spectroscopy. These xylans contained one 4-O-methyl-glucuronic acid substituent and 5.5 acetyl groups for approximately 10 xylose residues. About 10% of 4-O-methyl-glucuronic acid (MeGlcA) units were branched at O-2. The O-acetyl-4-O-methyl-(glucurono)-xylans were composed of the following (1 → 4)-linked β-D-xylopyranosyl structural elements: unsubstituted (51 mol%), 2-O-acetylated (12 mol%), 3-O-acetylated (20 mol%), 2,3-di-O-acetylated (6 mol%) and [MeGlcA α-(1 → 2)] [3-O-acetylated] (11 mol%). The weight-average molar mass and polydispersity of this xylan were 34.9 kDa and 1.16, respectively, as measured by size-exclusion chromatography.

【 授权许可】

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