Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR.

摘要: A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of before and after dilute acid pretreatment, characterize general changes in the lignin polysaccharide components. Intensities most (15 16) peaks related aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, cinnamyl alcohol, methoxyl, increased or remained unchanged pretreatment. In contrast, intensities (11 13) aliphatic linkages ferulate decreased. Decreased heterogeneity three cellulose components acid-insoluble residues resulted similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived showed positive correlations (r = 0.71 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), formate concentrations liquid hydrolysates, negative –0.95 –0.97) xylose concentration residue yield. These results fate by suggesting that regions were retained insoluble starch-derived transformed into 5-HMF, hydrolysate.