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用固态NMR检测和定量C丰富的硬木中的酸注射末组¹³

Zhaoxi Zheng¹, Klaus Schmidt-Rohr¹

¹Department of Chemistry, Brandeis University, Waltham, MA, 02453, United States.

Solid state nuclear magnetic resonance

|July 27, 2024

概括

对于硬木木质素结构至关重要的酸注射末组,首次使用先进的固态13CNMR量化. 这些末端群体占树和树中全部注射基单元的很小但很大一部分 (2-5%).

科学领域:

生物化学生物化学
聚合物科学聚合物科学
分析化学分析化学

背景情况:

氨基单元在硬木木质素中很丰富,但它们的末组度仍未定量.
准确的硬木木质素分子模型需要精确地了解终端组度.

研究的目的:

量化测量 () 末组的度在硬木木质素的注射剂单位.
为了确定正规和终端组syringyl单元的准确13C化学转移.
为了帮助开发更现实的硬木木质素结构分子模型.

主要方法:

使用均13C丰富的年轻木和木硬木.
采用先进的固态13C核磁共振技术,包括光谱编辑的2D 13C-13C核磁共振和2D 13C-13C交换光谱与对角抑制.
使用水解的13C-树木验证了峰值分配,并分析了与凝结胺醇的潜在重叠.

主要成果:

成功地解决和识别了与OH终结的syringyl单位相对应的小信号.
确定了对常规和终端组syringyl单元的精确13C化学转移,从guaiacyl单元或凝结宁中进行最小的重叠.
量化的基注射末组在木中为2 ± 1%,在木中为5 ± 2%.

结论:

酸注射基末组构成了硬木中总注射基单位的低但可测量的百分比.
这些发现需要将这种低终端组度纳入未来硬木木质素分子模型.
这些定量数据有助于我们更好地了解硬木木质素的复杂结构及其在各种应用中的含义.

关键词:

硬木的二维NMR对硬木进行了二维NMR检测.硬木的木质素结构是坚硬的.整个木材中的素.含有酸的酸含量醇注射剂单位是醇注射剂的单位.定量固态 (13)C 核磁共振反应频谱编辑频谱编辑色素 (tannin) 是一种色素.

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