Instituto de Recursos Naturales y Agrobiología de Sevilla (IRNAS), CSIC, P.O. Box 1052, E-41080 Seville, Spain.
J Agric Food Chem. 2011 Oct 26;59(20):11088-99. doi: 10.1021/jf201222r. Epub 2011 Sep 22.
The structural characteristics of the lignins from flax (Linum usitatissimum) fibers and shives were studied. Significant differences in the content and composition of the lignin from both parts were observed. The lignin contents were 3.8% in the fibers and 29.0% in the shives. Analysis by Py-GC/MS indicated a H:G:S molar ratio of 13:72:15 in the milled wood lignin (MWL) isolated from flax fibers and a molar ratio of 5:87:8 in the MWL isolated from flax shives. In addition, 2D-NMR showed a predominance of β-O-4' aryl ether linkages, followed by β-5' phenylcoumaran and β-β' resinol-type linkages in both MWLs, with a higher content of condensed linkages in flax shives. Thioacidolysis (followed by Raney nickel desulfurization) gave further information on the lignin units involved in the different linkages and confirmed the enrichment of G units. The thioacidolysis dimers released were similar from both lignins, with a predominance of the β-5' followed by β-1' and 5-5' structures.
研究了亚麻（Linum usitatissimum）纤维和木髓中木质素的结构特征。观察到这两个部位木质素的含量和组成有显著差异。纤维中的木质素含量为 3.8%，而木髓中的木质素含量为 29.0%。通过 Py-GC/MS 分析表明，从亚麻纤维中分离出的磨木木素（MWL）的 H:G:S 摩尔比为 13:72:15，而从亚麻木髓中分离出的 MWL 的摩尔比为 5:87:8。此外，2D-NMR 显示两种 MWL 中均以 β-O-4'芳基醚键合为主，其次是 β-5'苯基肉桂醇和 β-β'树脂醇型键合，且木髓中的缩合键含量更高。硫代酸解（随后用雷尼镍脱硫）提供了有关不同键合中涉及的木质素单元的更多信息，并证实了 G 单元的富集。从两种木质素中释放出的硫代酸解二聚体相似，以 β-5'为主，其次是 β-1'和 5-5'结构。
