Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E8, Canada.
Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E8, Canada; Department of Computing Science, University of Alberta, Edmonton, AB, T6G 2E9, Canada; Department of Laboratory Medicine and Pathology, University of Alberta, Edmonton, AB, T6G 2B7, Canada; Faculty of Pharmacy and Pharmaceutical Sciences, University of Alberta, Edmonton, AB, T6G 2H7, Canada.
Anal Biochem. 2023 Nov 1;680:115303. doi: 10.1016/j.ab.2023.115303. Epub 2023 Sep 7.
Hippuric acid is an abundant metabolite in human urine. Urinary hippuric acid levels change with toxic exposure to aromatic compounds, consumption of fruits and vegetables, cancers, chronic kidney disease, schizophrenia and Crohn's disease. While urinary hippuric acid can be detected and quantified via mass spectrometry or nuclear magnetic resonance spectroscopy, a colorimetric assay would be preferable for a low-cost, point-of care clinical assay. Two colorimetric methods, that use p-dimethylaminobenzaldehyde (DMAB) or benzenesulfonyl chloride (PhSOCl), respectively, have been previously developed to detect hippuric acid but these assays have many limitations. We replaced PhSOCl with p-toluenesulfonyl chloride (p-TsCl), to create a simpler, faster and more accurate method that works with human urine. This modified colorimetric assay detects from 60 μM to 1000 μM hippuric acid in urine in 2 min. We also corrected for the effects of interfering compounds present in urine such that the assay works across many urine backgrounds. We validated this improved assay on multiple hippurate-spiked urine samples, observing an excellent correlation (R > 0.94) between observed and known hippurate concentrations. These data suggest that this colorimetric assay is accurate and should greatly facilitate the measurement of hippuric acid in urine to detect a variety of human conditions.
马尿酸是人体尿液中含量丰富的代谢物。尿液马尿酸水平会随着芳香族化合物的毒性暴露、水果和蔬菜的摄入、癌症、慢性肾病、精神分裂症和克罗恩病而变化。虽然可以通过质谱或核磁共振光谱法检测和定量尿液中的马尿酸，但比色法测定更适合低成本、即时护理的临床测定。先前已经开发了两种比色法，分别使用对二甲氨基苯甲醛（DMAB）或苯磺酰氯（PhSOCl）来检测马尿酸，但这些测定方法存在许多局限性。我们用对甲苯磺酰氯（p-TsCl）代替 PhSOCl，创建了一种更简单、更快、更准确的方法，适用于人尿液。该改良比色法可在 2 分钟内检测到尿液中 60 μM 至 1000 μM 的马尿酸。我们还校正了尿液中存在的干扰化合物的影响，使得该测定方法适用于多种尿液背景。我们在多个马尿酸加标尿液样本上验证了该改进后的测定方法，观察到观察到的和已知的马尿酸浓度之间具有极好的相关性（R>0.94）。这些数据表明，该比色法测定准确，应该极大地促进尿液中马尿酸的测量，以检测各种人体状况。
