A combination of high-resolution mass spectrometry based on an orbital ion trap and 2D NMR spectroscopy was first applied to the characterization of the structure of poorly studied lignins of herbaceous plants using dioxane lignin from sedge (Cárex) as an example. Macromolecules of the Cárex lignin are found to be constructed from guaiacyl, syringyl, and p-hydroxyphenyl structural units in a ratio of 57:22:21 bound mainly by ether β-O-4 bonds. The key role of p-hydroxycinnamic acids in the formation of the lignin structure and ester bonds with polysaccharides was shown. A possible structural formula of the macromolecule fragment of the Cárex lignin was proposed on the basis of an analysis of the 2D NMR spectra (HSQC).

中文翻译：

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通过高分辨率质谱和核磁共振光谱研究莎草 (Cárex) 木质素

以来自莎草 (Cárex) 的二恶烷木质素为例，首先将基于轨道离子阱的高分辨率质谱和 2D NMR 光谱相结合，用于表征研究不足的草本植物木质素的结构。发现 Cárex 木质素的大分子由愈创木酰基、丁香基和对羟基苯基结构单元以 57:22:21 的比例构成，主要由醚 β-O-4 键结合。显示了对羟基肉桂酸在形成木质素结构和与多糖的酯键中的关键作用。根据对 2D NMR 光谱 (HSQC) 的分析，提出了 Cárex 木质素大分子片段的可能结构式。