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Title: | Erythro/threo ratio of β-O-4-5 structures as an important structural characteristic of lignin. Part 4: Variation in the erythro/threo ratio in softwood and hardwood lignins and its relation to syringyl/guaiacyl ratio |
Authors: | Nawawi, Deded Sarip |
Issue Date: | 2005 |
Publisher: | IPB (Bogor Agricultural University) |
Abstract: | The proportion of erythro- and threo-forms of β-O-4-structures in lignin was elucidated by ozonation analysis of 21 wood species, and the relationship to the syringyl and guaiacyl composition was investigated. For all hardwood species, the erythro-form of β-O-4-structures predominated, although the extent varied widely, depending on wood species. In contrast, the proportion and amount of erythro- and threo-forms were very similar in all softwood species. The proportion of the erythro-form was greater in species with a higher methoxyl content in the lignin (correlation coefficient, R2=0.83). The S/V ratio (molar ratio of syringaldehyde and syringic acid to that of vanillin and vanillic acid) obtained by nitrobenzene oxidation was also strongly correlated with the proportion of the erythro-form (R2=0.99). Accordingly, the syringyl/guaiacyl ratio is closely related to the erythro/threo ratio. This stereochemical characteristic of β-O-4-structures is discussed in relation to the process of lignin formation. Keywords β-O-4 structure, erythro/threo ratio, hardwood, Klason lignin, lignin, methoxyl, nitrobenzene oxidation, ozonation, softwood, stereochemistry, syringyl/guaiacyl ratio |
URI: | http://repository.ipb.ac.id/handle/123456789/27983 |
Appears in Collections: | Faculty of Forestry |
Files in This Item:
File | Description | Size | Format | |
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b76.doc | Publikasi_Word | 17.71 kB | Microsoft Word | View/Open |
b76.pdf | Publikasi_pdf | 126.75 kB | Adobe PDF | View/Open |
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