Abstract
The structures of water-soluble birch and beech xylans, extracted from holocellulose using dimethyl sulfoxide, were determined employing 1H and 13C NMR spectroscopy together with chemical analysis.
These polysaccharides were found to be O-acetyl-(4-O-methylglucurono)xylans containing one 4-O-methylglucuronic acid substituent for approximately every 15 d-xylose residues. The average degree of acetylation of the xylose residues in these polymers was 0.4.
The presence of the structural element →4)[4-O-Me-α-d-GlcpA-(1→2)][3-O-Ac]-β-d-Xylp-(1→ was demonstrated. Additional acetyl groups were present as substituents at C-2 and/or C-3 of the xylopyranosyl residues. Utilizing size-exclusion chromatography in combination with mass spectroscopy, the weight-average molar masses (and polydispersities) were shown to be 8000 (1.09) and 11,100 (1.08) for birch and beech xylan, respectively.
These polysaccharides were found to be O-acetyl-(4-O-methylglucurono)xylans containing one 4-O-methylglucuronic acid substituent for approximately every 15 d-xylose residues. The average degree of acetylation of the xylose residues in these polymers was 0.4.
The presence of the structural element →4)[4-O-Me-α-d-GlcpA-(1→2)][3-O-Ac]-β-d-Xylp-(1→ was demonstrated. Additional acetyl groups were present as substituents at C-2 and/or C-3 of the xylopyranosyl residues. Utilizing size-exclusion chromatography in combination with mass spectroscopy, the weight-average molar masses (and polydispersities) were shown to be 8000 (1.09) and 11,100 (1.08) for birch and beech xylan, respectively.
| Original language | English |
|---|---|
| Pages (from-to) | 373-377 |
| Journal | Carbohydrate Research |
| Volume | 337 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - 2002 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- hardwood
- hemicellulose
- extraction
- xylan
- structure
- O-acetylation
- 1H and 13C NMR spectroscopy
- MALDI-MS