Isotope-Filtered 4D NMR Spectroscopy for Structure Determination of Humic Substances.
Isotope-Filtered 4D NMR Spectroscopy for Structure Determination of Humic Substances.
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DOI：
10.1002/anie.201503321
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发表时间：
2015-07-13
期刊：
影响因子：
--
通讯作者：
Uhrín D
中科院分区：
文献类型：
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作者：
Bell NG;Michalchuk AA;Blackburn JW;Graham MC;Uhrín D
腐殖物质是土壤有机质的主要组成部分，可以成为解决土壤肥力问题的绿色和可持续解决方案的一个组成部分。然而，从科学和监管的角度来看，它们的全球规模的应用受到阻碍，因为缺乏对这些含有数千个分子的色谱上不可分离的混合物的分子组成的理解。在这里，我们展示了同位素标记分子的多维核磁共振光谱如何实现腐殖化合物的结构表征。我们说明了这种方法，通过确定泥炭土富里酸，腐殖物质的操作部分的酚类芳香族部分的主要取代模式。我们的方法代表了一个范式的转变，在复杂的混合物中的小分子的结构测定中使用的NMR活性标签。与以前的标记方法，专注于标签的信号，我们利用标签直接探测它们所连接的分子的身份。
Humic substances, the main component of soil organic matter, could form an integral part of green and sustainable solutions to the soil fertility problem. However, their global-scale application is hindered from both scientific and regulatory perspectives by the lack of understanding of the molecular make-up of these chromatographically inseparable mixtures containing thousands of molecules. Here we show how multidimensional NMR spectroscopy of isotopically tagged molecules enables structure characterization of humic compounds. We illustrate this approach by identifying major substitution patterns of phenolic aromatic moieties of a peat soil fulvic acid, an operational fraction of humic substances. Our methodology represents a paradigm shift in the use of NMR active tags in structure determination of small molecules in complex mixtures. Unlike previous tagging methodologies that focused on the signals of the tags, we utilize tags to directly probe the identity of the molecules they are attached to.