Multi-step degradation method for β-O-4 linkages in lignins: γ-TTSA method. Part 3. Degradation of milled wood lignin (MWL) from Eucalyptus globulus

Abstract

Abstract Milled wood lignin (MWL) of Eucalyptus globulus has been treated by a selective degradation method for β-O-4 linkages, which lets the lignin carbohydrate complexes (LCC) intact. The method consists of four reaction steps: (1) γ-tosylation, (2) thioetherification, (3) sulfonylation and (4) mild alkali treatment (γ-TTSA method). Each step was followed by spectroscopies for chemical structural analysis; especially, the HSQC-NMR analysis was in focus. It was demonstrated that β-O-4 linkages were selectively and quantitatively cleaved by the γ-TTSA method while the β-β linkages in the MWL remained intact. The method leads to an enrichment of LCCs.