Martínez A T, Almendros G, González-Vila F J, Fründ R
Centro de Investigaciones Biológicas, CSIC, Madrid, Spain.
Solid State Nucl Magn Reson. 1999 Oct;15(1):41-8. doi: 10.1016/s0926-2040(99)00045-4.
In order to gain information about lignin molecular characteristics with a direct bearing on the remarkable susceptibility of some Austral hardwoods to biological delignification, milled-wood lignins were isolated and analyzed by spectroscopic techniques in the solid state. Cross polarization and magic-angle spinning 13C nuclear magnetic resonance (13C CPMAS NMR) and Fourier-transform infrared (FTIR) spectra of the lignin preparations were obtained. The most diagnostic peaks were assigned and quantified as percentages of the total spectral area, and the differences observed discussed in terms of lignin composition. The spectral patterns obtained revealed that the woods from Gevuina avellana, Eucryphia cordifolia and Nothofagus dombeyii have lignin with high syringyl/guaiacyl ratio, as evidenced by relative areas of 13C NMR signals at 153 and 148 ppm, and FTIR bands at 1,335 and 1,275 cm-1. The presence of syringyl-rich lignins, characterized by lower redox potential and condensation degree than guaiacyl-rich lignins, could be a structural factor contributing to the ease of extensive delignification of these woods by white-rot fungi.
为了获取与某些澳大利亚阔叶树对生物脱木质素的显著敏感性直接相关的木质素分子特征信息，通过固态光谱技术分离并分析了磨木木素。获得了木质素制剂的交叉极化和魔角旋转13C核磁共振（13C CPMAS NMR）以及傅里叶变换红外（FTIR）光谱。对最具诊断性的峰进行了归属，并将其作为总光谱面积的百分比进行了量化，并根据木质素组成讨论了观察到的差异。所获得的光谱模式表明，盖维纳榛木、心叶尤克里木和多姆贝假山毛榉的木材具有高紫丁香基/愈创木基比率的木质素，这由153和148 ppm处13C NMR信号的相对面积以及1335和1275 cm-1处的FTIR谱带所证明。富含紫丁香基的木质素的存在，其特征在于氧化还原电位和缩合程度低于富含愈创木基的木质素，可能是导致这些木材易于被白腐真菌广泛脱木质素的一个结构因素。
