Elucidation of LCC bonding sites via gamma-TTSA lignin degradation: crude milled wood lignin (MWL) from Eucalyptus globulus for enrichment of lignin xylan linkages and their HSQC-NMR characterization

作者：Ando Daisuke^*; Nakatsubo Fumiaki; Takano Toshiyuki; Yano Hiroyuki

来源：Holzforschung, 2016, 70(6): 489-494.

DOI：10.1515/hf-2015-0112

• gamma-TTSA method
• cleavage of beta-O-4 linkages
• crude milled wood lignin (MWL)
• HSQC-NMR
• lignin carbohydrate complex (LCC)
• lignin degradation

The selective lignin degradation in a LCC was proceeded with the gamma-TTSA method, which is a selective cleavage method for beta-O-4 linkages in lignins, in order to obtain more precise information concerning LCC bonding sites. To this purpose, crude MWL from Eucalyptus globulus, containing lignin and xylan, was treated by the gamma-TTSA method. This approach consists of four steps: (1) gamma-tosylation, (2) thioetherification, (3) sulfonylation, and (4) mild alkali treatment. The degradation products were extracted consecutively with Et2O, EtOAc, and THF for the lignin removal, and thus the residue was enriched in LCCs. The residue was characterized by HSQC-NMR. Results indicated that the residue contained xylan and beta-beta substructures, although lignin was degraded. It can be concluded that the beta-beta substructures play an important role in the bonding sites between lignin and xylan of Eucalyptus globulus.

• 出版日期2016-6