Chemical Characterization of Ancient Buried Wood

A combined pyrolysis mass spectrometric and light microscopic study of peatified Calluna wood isolated from raised bog peat deposits

“…6. A decrease in the S/G ratio in peatified wood was also observed by Hedges et aL (1985), Saiz-Jimenez et al (1987), Iiyama et al (1988), Stout et al (1988), Bates et al (1991) and Hatcher et al (1989b). The latter author observed a relationship between S/G decrease and an increase in catechol and phenolic compounds.…”

Structural Modification of Lignin in Peat during Peat Formation at Tropical Swamp

“…Iiyama and co-workers 21 reported that total yield of neutral monosaccharide of buried hardwoods for 6,000-10,000 years was 15-20% of those from sound wood, probably due to anaerobic atmosphere immediate after buried. Cell wall polysaccharides of plants litter are quickly decomposed, while lignin and polysaccharides covalently associated with lignin resist significantly to biological degradation 21,23,26 . The neutral monosaccharide detected from AL insol fraction would be released from the cell wall polysaccharides associated chemically with lignin.…”

“…6). It is well documented that wood samples decayed by microorganisms give lower values of total yield of alkaline nitrobenzene oxidation products than those of fresh plant cell walls 21,23 , because of significant condensation by radical coupling reaction due to the activities of lignin peroxidase 17,23,25,43 . In general, the molar ratio of hydroxybenzoic acids (sum of p-hydroxybenzoic, vanillic and syringic acids) to hydroxybenzaldehydes (sum of p-hydroxybenzalde, vanillin and syringaldehyde) (Acid/Ald ratio) of alkaline nitrobenzene oxidation products increases significantly with the progress of biological modification of lignin 23,48 .…”

“…The aromatic units would derive from biologically modified lignin 44 . Lignin would be dominant in peat, because lignin is one of major component of vascular plant tissues as the origin of peat organics and significantly low degradation rate by microorganisms 21,48 . Therefore making clear structural modification of plant cell wall components, especially lignin, during peat formation, would be essential to develop sustainable management systems for these relatively fragile ecosystems.…”

Short Note

“…However, the degradation rate of cellulose in the interior wood recorded only 4%, while that of hemicellulose 17%, indicating that the hemicellulose is much more attacked than the cellulose at the initial stage of deterioration of wood in the sea water. Preferential degradation of cellulose in the archaeological wood samples would be due to microbial attack, while the degradation of hemicellulose due to the chemical attack (liyama et al 1988;Kohara and Okamoto 1956). However, it is also well documented that the lysis of hemicellulose is more severe than that of cellulose in the archaeological wood samples (Fujii et al 1988;Hoffmann et al 1986;Taniguchief Λ/.…”