Abstract
Polymerization reactions of the lignans matairesinol and pinoresinol
with the stable radical 2,2-diphenyl-1-picrylhydrazyl (DPPH) were
studied. The reactions were rapid and almost quantitative. The molecular
weight distribution (MWD) of the formed lignan dimers and polymers was
determined by high-performance size-exclusion chromatography (HPSEC)
combined with evaporative light-scattering detection (ELSD), and the
compounds were characterized by HPLC-MS, pyrolysis-GC/MS, NMR,
MALDI-ToF-MS, and GC-MS of the monomeric and dimeric units formed by
KMnO4 oxidation. The yield of high-MW polymers is higher for
pinoresinol (69%) than for matairesinol (43%). According to the
HPSEC-ELSD analyses, the MWD is also broader for the pinoresinol
polymers. The latter seem to consist mainly of hepta-hexacontalignans
(MW 2.5–21.4 kDa), whereas the matairesinol polymers are mainly
penta-pentadecalignans (MW 1.8–5.3 kDa). The polymers seem to contain
mainly unmodified lignan units linked by 5-5′ bonds.
| Original language | English |
|---|---|
| Pages (from-to) | 283-294 |
| Journal | Holzforschung |
| Volume | 66 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2012 |
| MoE publication type | A1 Journal article-refereed |
Funding
This study is part of the LigniVal project in the Tekes BioRefine program. Funding from Tekes, Metso Power Oy, Oy Metsä-Botnia Ab, Stora Enso Oyj and Roal Oy is acknowledged. The work is also part of the activities at the Åbo Akademi University Process Chemistry Center within the Finnish Center of Excellence Program by the Academy of Finland.
Keywords
- 2,2-diphenyl-1-picrylhydrazyl (DPPH)
- evaporative light-scattering detection (ELSD)
- high-performance size exclusion chromatography (HPSEC)
- KMnO4 oxidation
- lignan polymers
- lignans
- MALDI-ToF-MS
- matairesinol
- pinoresinol
- pyrolysis-GC/MS (Py-GC/MS