Quantification of Metabolites from Two-Dimensional Nuclear Magnetic Resonance Spectroscopy: Application to Human Urine Samples
Quantification of Metabolites from Two-Dimensional Nuclear Magnetic Resonance Spectroscopy: Application to Human Urine Samples
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DOI：
10.1021/ac902405z
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发表时间：
2009-12-15
影响因子：
7.4
通讯作者：
Sinha, Neeraj
中科院分区：
文献类型：
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作者：
Rai, Ratan Kumar;Tripathi, Pratima;Sinha, Neeraj
我们提出了一个从二维(2D)H-1-C-13异核单量子关联(HSQC)核磁共振(核磁共振)实验中定量测定自然丰度体液的代谢物的一般方案。从二维HSQC谱定量的方案包括测量质子共振的弛豫参数，如代谢物的T-1和T-2，以及用于精确定量的H-1-C-13异核J耦合。从2D HSQC核磁共振谱测量的交叉峰体积乘以计算的校正因子(取决于二维核磁共振实验参数和松弛参数)，以测量准确的代谢物定量。修正因子从理论上由Bloch方程的解和乘积算符形式推导而来。在含有已知浓度的氨基酸混合物的溶液上测试了该方案的准确性。对于人体尿样，通过加标实验检验了该方法测量各种代谢物浓度的准确性。该方案在性质上是通用的，可应用于任何其他用于代谢组学研究的体液样本。我们还利用散点图对人体尿样的二维H-1-C-13HSQC核磁共振谱中各种代谢物的交叉峰体积进行了测试，以进行聚类分析，从而使该方案完整地用于代谢谱分析。
We present a general scheme for metabolite quantification from a two-dimensional (2D) H-1-C-13 heteronuclear single quantum correlation (HSQC) nuclear magnetic resonance (NMR) experiment of body fluids observed in natural abundance. The scheme of quantification from 2D HSQC spectra consists of measurement of relaxation parameters of proton resonances, such as T-1 and T-2 of the metabolites and H-1-C-13 heteronuclear J-coupling for accurate quantification. The measured cross-peak volume from 2D HSQC NMR spectra is multiplied by a calculated correction factor (which depends upon two-dimensional NMR experimental parameters and relaxation parameters) to measure accurate quantification of the metabolite. The correction factor is theoretically derived from the solution of the Bloch equation and product operator formalism. The accuracy of the scheme is tested on a solution containing a mixture of amino acids of known concentration. For human urine samples, the accuracy of the method for measuring the concentration of various metabolites was tested with spike-in experiments. The scheme is general in nature and can be applied to any other body fluid samples for metabonomic studies. We also test the measured cross-peak volume of various metabolites from 2D H-1-C-13 HSQC NMR spectra of human urine samples for clustering analysis with scatter plots, making the scheme complete for metabolic profiling.