Table 4.

2D HSQC signal assignment of sugarcane bagasse lignin extracted with [EMIM]oAc

No of signals	Signal (δC/δH)	Assignment
1	56.52/3.7	C–H in methoxyl group
2	60.12/3.5	Cγ–Hγ in β-O-4′ substructure
3	63/4.35	Cγ–Hγ in γ-acetylated β-O-4′ substructure
4	72/4.84	Cα–Hα in β-O-4′ substructure linked to syringyl unit
5	71/3.6	Cγ–Hγ in β–β′substructure
6	85.4/4.5	Cα–Hα in β–β′substructure
7	85.8/4.22	Cβ–Hβ in β-O-4′ substructure linked to syringyl unit (erythro form)
8	86/4.1	Cβ–Hβ in β-O-4′ substructure linked to syringyl unit (threo form)
9	103/6.7	C2,6–H2,6 in etherified syringyl unit
10	106.7/7.28	C2,6–H2,6 in Cα oxidized syringyl unit
11	111/6.9	C2–H2 in guaiacyl unit
12	115/6.7	C5–H5 in guaiacyl unit
13	117/6.2	C2′–H2′in spirodienone substructure
14	130/7.5	C2,6–H2,6 in p-hydroxycinnamyl alcohol or p-hydroxybenzoate
15	146/7.5	Cα–Hα in p-hydroxycinnamyl alcohol or p-hydroxybenzoate