Table 3 Structural characteristics (lignin interunit linkages, PB, aromatic units, and S/G ratio) from integration of 1H–13C correlation peaks in the HSQC spectra of the WCW and three dissolved lignins from poplar wood.

Numbers for Lignin Interunit linkages are percent of the sum of the integrals for structures Aa and Ca is accounted for by the integral for each individual structure. Numbers for PB2/6 are percentage of total lignin content (G + S + S′ ) in each sample spectrum.

Lignin interunit linkages
  β-O-4 aryl ethers (A)938787
  Resinols (C)71313
p-Hydroxybenzoates (PB2/6)142220
Lignin aromatic units
  G (%)363034
  S (%)647066
  S/G ratio1.82.31.9