Nitric oxide (NO) is a small molecule involved in the regulation of many physiological processes. It plays a crucial role in the regulation of nervous system, immune and inflammatory responses, and blood flow. NO is synthesized by nitric oxide synthase (NOS) during two-step oxidation of l-arginine to l-citrulline. Intermediates and derivatives of NO metabolism, such as l-arginine, l-citrulline, asymmetrical dimethylarginine (ADMA), symmetrical dimethylarginine (SDMA), and dimethylamine (DMA), are investigated as potential biomarkers. In this article, we present a novel analytical method that allowed for simultaneous analysis of l-arginine, ADMA, SDMA, l-citrulline, and DMA, in a single-step extraction and derivatization using benzoyl chloride. In brief, aliquots of serum were mixed with internal standard solution mixture (50 µM D6-DMA, 20 µM D7-ADMA, and 100 µM D7-arginine) and 0.025 M borate buffer, pH 9.2 (10:1:5). The derivatization process was performed at 25 °C for 5 min using 10% benzoyl chloride. A reverse phase column was used for chromatographic separation. Quantitation was performed using following ions (m/z): 279.1457, 286.1749, 307.1717, 314.2076, 280.1297, 150.0919, and 156.1113 for l-arginine, D7-arginine, ADMA, SDMA, D7-ADMA, l-citrulline, DMA, and D6-DMA, respectively. The method was validated, and its assay linearity, accuracy and precision, recovery, and limits of detection (1.7 µM l-arginine, 0.03 µM ADMA, 0.02 µM SDMA, 0.36 µM l-citrulline, 0.06 µM DMA) and quantification (3.2 µM l-arginine, 0.08 µM ADMA, 0.05 µM SDMA, 1.08 µM l-citrulline, 0.19 µM DMA) were determined. The method is sensitive, reliable, repeatable, and reproducible. It can be applied in the routine clinical/diagnostic laboratory.Graphical abstract

中文翻译：

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使用液相色谱-质谱法定量分析人血清中的 L-精氨酸、二甲基化精氨酸衍生物、L-瓜氨酸和二甲胺

一氧化氮（NO）是一种小分子，参与许多生理过程的调节。它在神经系统、免疫和炎症反应以及血流的调节中发挥着至关重要的作用。NO 由一氧化氮合酶 (NOS) 在 L-精氨酸两步氧化为 L-瓜氨酸过程中合成。NO 代谢的中间体和衍生物，如 L-精氨酸、L-瓜氨酸、不对称二甲基精氨酸 (ADMA)、对称二甲基精氨酸 (SDMA) 和二甲胺 (DMA)，被作为潜在的生物标志物进行研究。在本文中，我们提出了一种新颖的分析方法，该方法允许在使用苯甲酰氯的单步提取和衍生化中同时分析 L-精氨酸、ADMA、SDMA、L-瓜氨酸和 DMA。简而言之，将等份血清与内标溶液混合物（50 µM D6-DMA、20 µMD7-ADMA 和 100 µMD7-精氨酸）和 0.025 M 硼酸盐缓冲液（pH 9.2）混合（10:1:5）。使用 10% 苯甲酰氯在 25°C 下进行衍生化过程 5 分钟。使用反相柱进行色谱分离。Quantitation was performed using following ions (m/z): 279.1457, 286.1749, 307.1717, 314.2076, 280.1297, 150.0919, and 156.1113 for l-arginine, D7-arginine, ADMA, SDMA, D7-ADMA, l-citrulline, DMA, and分别为D6-DMA。该方法经过验证，其测定线性、准确度和精密度、回收率以及检测限（1.7 µM L-精氨酸、0.03 µM ADMA、0.02 µM SDMA、0.36 µM L-瓜氨酸、0.06 µM DMA）和定量（3.2 µM）测定了 L-精氨酸、0.08 µM ADMA、0.05 µM SDMA、1.08 µM L-瓜氨酸、0.19 µM DMA。该方法灵敏、可靠、重复性好、重现性好。可应用于常规临床/诊断实验室。图形摘要