Official Journal of the Japan Wood Research Society
Table 1 Assignment of lignin and polysaccharide 1H–13C correlation signals in the HSQC spectra shown in Fig. 4
Labels | δC/δH (ppm) | Assignment |
|---|---|---|
S2,6 | 103.9/6.69 | C2–H2 and C6–H6 in syringyl units |
S′2,6 | 106.4/7.18 | C2–H2 and C6–H6 in Cα-oxidized syringyl units |
Gc | 106.2/6.47 | Condensed-lignin aromatics related to 4-O-5 structures |
G′c | 107.4/6.26 | Condensed-lignin aromatics related to 4-O-5 structures |
G2 | 111.3/6.95 | C2–H2 in guaiacyl units |
G′2 | 111.7/7.39 | C2–H2 in Cα-oxidized guaiacyl units |
G6 | 118.9/6.75 | C6–H6 in guaiacyl units |
G′6 | 123.0/7.53 | C6–H6 in Cα-oxidized guaiacyl units |
G′′c | 108.5/6.90 | Condensed-lignin aromatics related to 4-O-5 structures |
Aβ(G) | 83.5/4.30 | Cβ–Hβ in β-O-4′ substructures linked to a guaiacyl unit |
Aβ(S) | 86.3/4.04 | Cβ–Hβ in β-O-4′ substructures linked to a syringyl unit |
Cα | 86.9/5.44 | Cα–Hα in β-5′ (phenylcoumaran) substructures |
Bα | 84.8/4.68 | Cα–Hα in β-β′ (resinol) substructures |
Dα | 81.3/5.08 | Cα–Hα in β-1′ (spirodienone) substructures |
–OMe | 55.5/3.74 | Methoxyl |
Gl1 | 103.1/4.30 | C1–H1 in (1–4) β-d-glucopyranoside |
X1/X′1 | 101.5/4.33 | C1–H1 in β-d-xylopyranoside/3-O-acetyl-β-d-xylopyranoside |
M1 | 100.5/4.56 | C1–H1 in (1–4) β-d-mannopyranoside |
X′2 | 73.1/4.46 | C2–H2 in 2-O-acetyl-β-d-xylopyranoside |
X′3 | 74.8/4.80 | C3–H3 in β-d-xylopyranoside |