Table 2 Select solid-state ¹³C NMR chemical shift assignments [21, 22]

156.2

H

C4

152.0

G

C3, C4 etherified

148.0

G

C3, C4 nonetherified

143.0

G

C₄OH (free phenolic)

133.4

S. G

C1 (S or G) and/or C5 (G), 5–5

131

G

C1, 5–5 C4 nonetherified

128.9

H

C1, C2/C6, C3/C5 (R = aliphatic)

116.6

H

C3/C5, C4 etherified

116.0

G

C5

111.8

G

C2

110.6

H

C3/C5, C4 nonetherified

87.0

G

C_α, β-5

86.4

H

C_α, β-5

81.0

H

C_β, β-O-4

73.9

H

C_α, β-O-4

63.8

H

C_γ, β-O-4

63.5

G

C_γ, β-5

60.0

–

C_γ, β-O-4

54.8

G

C_β, β-5, β–β

54.5

H

C_β, β-5, β–β

54.0

–

C_β, β-5, β–β, also methoxyl