Figure 7
HSQC spectra of water-soluble lignins (WSL 130(1.0) and WSL 170(1.0) ). HSQC, heteronuclear single quantum coherence; WSL, water-soluble lignin; A, β-aryl-ether units (β-O-4); C, phenylcoumaran substructures (β-5); PCA, free p-coumaric acid; FA, ferulate; H, p-hydroxyphenyl units; G, guaiacyl units; S, syringyl units; S’, oxidized syringyl units bearing a carbonyl at C α .