Biotechnology for Biofuels and Bioproducts

Table 1 Chemical shifts (δ_13C/δ_1H) (ppm) of lignin components assigned in this study (DMSO-d ₆ and pyridine-d ₅ = 4:1)

From: Precipitate obtained following membrane separation of hydrothermally pretreated rice straw liquid revealed by 2D NMR to have high lignin content

		α(7)	β(8)	γ(9)	2	3	5	6
Aromatic region	Syringyl				104.5/7.03, 104.5/6.94, 104.5/6.84			104.5/7.03, 104.5/6.94, 104.5/6.84
	Guaiacyl				111.7/7.21		116.0/7.17, 116.1/7.08, 115.1/7.02, 114.9/6.88, 115.0/6.79	116.0/7.17, 116.1/7.08, 115.1/7.02, 114.9/6.88, 115.0/6.79
							119.5/7.06, 119.5/6.97, 119.1/6.88	119.5/7.06, 119.5/6.97, 119.1/6.88
	p-Hydroxyphenyl				128.3/7.30, 129.8/7.33			128.3/7.30, 129.8/7.33
	Ferulate		111.6/7.42, 115.7/6.45					123.6/7.22
	p-Coumarate	145.4/7.73			130.5/7.66, 130.3/7.60, 130.3/7.54, 130.3/7.48	116.2/6.95, 114.5/6.64, 114.1/6.51, 114.0/6.41	116.2/6.95, 114.5/6.64, 114.1/6.51, 114.0/6.41	130.5/7.66, 130.3/7.60, 130.3/7.54, 130.3/7.48
Aliphatic side chain	Cinnamyl alcohol			61.9/4.26
	β-O-4	73.0/5.16, 72.2/5.10, 72.3/5.04
	β-O-4-H/G (erythro)	71.2/4.97	84.9/4.44	60.8/3.44
	β-O-4-H/G (threo)		84.1/4.52	60.7/3.82
	β-O-4-S		86.7/4.25
	β-5	87.4/5.64	52.2/3.73
	5-5/4-O-β	83.2/5.11	87.7/3.62

Methoxyl groups were assigned at 56.1/3.92 and 56.0/3.77 ppm

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