Table 2.

Signal assignments of lignin samples in the ¹³C NMR spectrum [25, 26]

δ (ppm)	Assignments	δ (ppm)	Assignments
178-168	Aliphatic COOR	115.6	C5 in G unit
152.3	C3/C5 in S unit	110.6	C2 in G unit
140-123	Condensed aromatics	103	C2,6 in S unit
129.2	C6 in H unit	50–90	Interunit linkages
128	C2/C6 H unit		(β-β′, β-5 and β-O-4′)
119	C6/C5 in G unit	56.5	OCH3 in G and S unit

G: guaiacyl unit, S: syringyl unit, H: p-hydroxyphenyl unit