PINORESINOL STRUCTURES IN SOFTWOOD LIGNIN: SYNTHESIS AND CHARACTERIZATION OF NEW MODELS
Pinoresinol structures, being important components of softwood lignin, are readily detected by NMR. They escaped detection from β-ether cleaving degradation analysis presumably due to linkage at their 5-positions in 5-5- or 4-O-5linked units. In this study, new lignin model compounds related to such pinoresinol structures have been synthesized via a peroxidase-catalyzed H2O2 oxidative coupling reaction using 5-5- or 4-O-5-linked coniferyl alcohol (proposed intermediates) and coniferyl alcohol (CA). It was found that 5-5- or 4-O-5-linked coniferyl alcohol can cross-couple with CA producing pinoresinols in addition to other homo- and cross-coupled products. A total of seven new model compounds have been obtained and characterized by NMR. Based on NMR data of these model compounds, it was demonstrated that 5-5-linked pinoresinol and 4O-5-linked pinoresinol models could be differentiated in HMBC spectra. With appropriate modification (etherification) to the model compounds obtained in this study, it is likely t hat 5-5- or 4-O-5-linked pinoresinol structures in softwood lignin can be identified.
Fachuang Lu Fengxia Yue Runcang Sun John Ralph
State Kay Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, State Kay Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, Department of Biochemistry, and the DOE Great Lakes Bioenergy Research Center, University of Wiscons
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
363-367
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）