Characterization of O-acetil-(4-O-methylglucurono)xylans from Eucalyptus urograndis

Quimica nova

Piló-Veloso, Dorila¹  Magaton, Andréia da Silva¹  Colodette, Jorge Luiz² 

[1] Universidade Federal de Minas Gerais, Belo Horizonte, Brasil;Universidade Federal de Viçosa, Viçosa, Brasil

关键词: Eucalyptus urograndis;    xylans;    NMR.;   

DOI  :  10.1590/S0100-40422008000500027

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

The O-acetyl-4-O-methyl-(glucurono)xylanswere isolated from E. urograndis by extraction with dimethyl sulfoxide,analysed for monosaccharide composition and structurally characterized by NMRspectroscopy. These xylans contained one 4-O-methyl-glucuronic acid substituentand 5.5 acetyl groups for approximately 10 xylose residues. About 10% of 4-O-methyl-glucuronicacid (MeGlcA) units were branched at O-2. The O-acetyl-4-O-methyl-(glucurono)-xylanswere 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 polydispersityof this xylan were 34.9 kDa and 1.16, respectively, as measured by size-exclusionchromatography.

【 授权许可】

CC BY