Aromatic moieties | σ C/σ H(ppm) and assignments | Control CEL | Two weeks CEL | Four weeks CEL | Six weeks CEL | Eight weeks CEL |
---|---|---|---|---|---|---|
Lignin aromatic units | Â | Â | Â | Â | Â | Â |
Syringyl (S) | 103.9/6.7 (S2/6), | 27.3 | 20.5 | 19.4 | 21.3 | 24.5 |
106.4/7.4 (S'2/6 with α oxidization) | ||||||
Guaiacyl (G) | 110.8/6.97 (G2) | 39.3 | 40.8 | 37.2 | 40.9 | 39.8 |
115.0/6.94 (G5),118.9/6.81 (G6) | ||||||
p-hydroxyphenyl (H) | 127.7/7.21 (H2/6) | 1.4 | 2.2 | 2.4 | 2.3 | 1.8 |
S/G ratio | Â | 0.69 | 0.50 | 0.52 | 0.52 | 0.61 |
Hydroxycinnamates | Â | Â | Â | Â | Â | Â |
p-benzonate (PB) | 132.4/7.63 (PB2/6) | 1.2 | ND | ND | ND | 0.2 |
p-coumarate (pCA) | 130.0/7.47 (pCA2/6),115.5/6.79 (pCA3/5) | 5.5 | 2.5 | 2.7 | 3.3 | 3.1 |
Ferulate (FA) | 110.9/7.32 (FA2), 122.5/7.15 (FA6) | 6.4 | 3.9 | 4.6 | 5.4 | 4.5 |
p-coumarate/ferulate | Â | 0.86 | 0.65 | 0.58 | 0.60 | 0.68 |
Cinnamates/lignin and tricin | Â | 0.18 | 0.09 | 0.10 | 0.12 | 0.11 |
Lignan | Â | Â | Â | Â | Â | Â |
Tricin (T) | 104.04/7.30 (T 2′/6'), 104.65/7.03 (T3) | 5.6 | 10 | 12 | 9.0 | 6.6 |
94.1/6.56 (T8), 98.8/6.22 (T6) | ||||||
Inter-unit bondages | Â | Â | Â | Â | Â | Â |
α-OH/β-O-4 | 71.1/4.74 (Aα-G), 71.8/4.8 (Aα-S) | 33.8 | 33.9 | 28.1 | 33.9 | 36.5 |
α-keto/β-O-4 | 82.7/5.1 (Aα-keto) | 2.4 | 0.8 | 0.6 | 0.8 | 1.1 |
Total β-O-4 |  | 36.5 | 34.7 | 28.7 | 34.7 | 37.6 |
Phenylcoumaran (β-5) | 85.9/5.5 (Bα), 53.0/3.4 (Bβ) | 5.7 | 4.2 | 3.3 | 5.2 | 4.2 |
Pino/resinol (β-β') | 84.8/4.7 (Cα), 53.5/3.1 (Cβ), | 0.9 | 1.2 | 1.6 | 1.5 | 1.2 |
Dibenzodioxocin (D) | 83.4/4.9 (Dα), 85.5/3.8 (Dβ) | 2.0 | 3.8 | 2.7 | 4.0 | 2.5 |
Spirodienone (SD) | 81.4/5.0 (SDα), 59.5/2.8 (SDβ) | ND | ND | ND | ND | ND |
α,β-diaryl ether (F) | 79.6/5.5 (Fα) | 2.1 | ND | ND | ND | 1.3 |
γ-ending groups |  |  |  |  |  |  |
γ-OH in X1 structure | 62-58/3.8-3.0 | 1.5 | 0.9 | 0.8 | 1.0 | 0.9 |
Acylation on γ position | 60.8-58.8/3.8-3.35 | 15.6 | 11.1 | 13.1 | 11.8 | 10.1 |