Table 2.

Approximate percentages of linkages found in softwood and hardwood lignin [33].

Linkage Type	Approximate Percentage (%)
	Softwood	Hardwood
β-O-4	45–50	60
5–5	18–25	5
β-5	9–12	6
4-O-5	4–8	7
β-1	7–10	7
β-β	3	3