Evidence for demethylation of syringyl moieties in archaeological wood using pyrolysis-gas chromatography/mass spectrometry.
Archaeological oak (Quercus sp.) wood samples, ranging from 16(th) C. AD to 6000 BP, were studied using flash pyrolysis-gas chromatography/mass spectrometry to obtain insight into angiosperm lignin degradation. The pyrolysates revealed evidence of a number of 3-methoxy-1,2-benzenediol derivatives, methoxycatechols, directly related to 2,6-dimethoxyphenol, syringyl, moieties which are characteristic building blocks of angiosperm lignin. Mass spectra and mass chromatograms of these compounds are reported. The finding of these characteristic pyrolysis products in well-preserved archaeological wood provides unequivocal evidence that demethylation of syringyl units occurs very early in wood degradation. It is highly likely that the absence of abundant 3-methoxy-1, 2-benzenediols in degrading plant materials containing angiosperm lignin relates to the lability of these newly formed moieties.
van Bergen
P F
PF
Organic Geochemistry Group, Faculty of Earth Sciences, Utrecht University, PO Box 80021, 3508 TA Utrecht, The Netherlands.
Poole
I
I
Ogilvie
T M
TM
Caple
C
C
Evershed
R P
RP
D001106:Archaeology; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006358:Hot Temperature; D008031:Lignin / Q000737:chemistry*; D019684:Magnoliopsida / Q000737:chemistry*; D008745:Methylation; D014934:Wood
D008031:Lignin