| Abstract:The morphologiy of fibers, chemical components, lignin structure and the lignin distribution in cell wall of Pennisetumsinese were analyzed. Fiber Quality Analyzer (FQA) analysis showed that average fiber length was 0.96mm and the width was 23.1 μm, fiber length-width ratio reached to 41.1. Alkaline nitrobenzene oxidation quantitative analysis revealed that Pennisetumsinese lignin was typical GSH-type. It was found that the highest content of hydroxyl groups was aliphatic OH (3.96 mmol/g), and non-condensed phenolic hydroxyl accounted for a large proportion content of the total phenolic hydroxyl (96.3%). In addition, 2D-HSQC NMR analysis indicated that the alkyl aryl ether linkages was predominant (β-O-4′, 84.4% of total linkages), followed by resinols (β-β′, 9.9%) and phenylcomumarans (β-5′5.7%). Moreover, aromatic regions showed large quantity of S-type and G-type lignin, and the S/G ratio was 1.25. Confocal Raman microscopy (CRM) indicated that the concentrations of lignin and hydroxycinnamic acid (HCA) in the cell walls followed the decreasing order, as CC＞CML＞SW, but the concentration of HCA waslowerthan that of lignin. |
