Table 3 Assignments of ¹³C–¹H correlation signals in the 2D-HSQC NMR spectra from lignin

B_β

52.19/3.54

Phenylcoumaran (B)

C_β

55.98/3.37

C_β–H_β in resinol (C)

MeO

56.23/3.72

C–H in methoxyls

I_γ

63.65–65.41/3.88–3.97

C_γ–H_γ in cinnamyl alcohol end-groups (I)

A_γ

62.48/3.45

C_γ–H_γ in phenylglycerol (A)

A_β

75.89/3.50

C_β–H_β in phenylglycerol (A)

A_α

77.70/4.39

C_α–H_α in phenylglycerol (A)

C_γ

71.34/3.79

C_γ–H_γ in resinol (C)

S_2,6

106.64/7.23

C_2,6–H_2,6 in syringyl units (S)

G₂

115.58/6.82

C₂–H₂ in guaiacyl units (G)

G₅

115.48/6.81

C₅–H₅ in guaiacyl units (G)

G₆

115.49/6.80

C₆–H₆ in guaiacyl units (G)

FA₂

111.14/7.19

C₂–H₂ in ferulate (FA)

pCA

115.39/6.67

C–H in p-coumarates (pCA)

FA₆

127.36/7.38

C₆–H₆ in ferulate (FA)

H_2,6

129.17/7.87

C_2,6–H_2,6 in p-hydroxyphenyl units (H)