Fig. 2
From: Xylan extraction from pretreated sugarcane bagasse using alkaline and enzymatic approaches
2D-NMR-HSQC spectra (δ C/δ H 52–135/2.4–7.8) of the GAX samples extracted from pretreated sugarcane bagasse. a GAX extracted by Hoije method; b GAX extracted by Lopez method; c GAX extracted by enzymatic treatment. The inset shows a 16-fold amplification of the aromatic region with the main lignin aromatic signals. The main carbohydrate and lignin structures identified are X, xylose units; Ar, arabinose units; U, glucuronic acid units; H, p-hydroxyphenyl units; G, guaiacyl units; S, syringyl units; PCA, p-coumaric acid. See Additional file 2: Table S1 for signal assignments