Novel absorbance peak of gentisic acid following the oxidation reaction
Novel absorbance peak of gentisic acid following the oxidation reaction
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DOI：
10.1371/journal.pone.0232263
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发表时间：
2020-04-29
期刊：
影响因子：
3.7
通讯作者：
Tokuhara, Yasunori
中科院分区：
文献类型：
--
作者：
Hosokawa, Sho;Shukuya, Kenichi;Tokuhara, Yasunori
龙胆酸(GA)是乙酰水杨酸(ASA)的代谢物，与尿酸尿液中高水平排泄的同型龙胆酸(HGA)是结构非常相似的二价酚酸。含有HGA的尿液因其氧化而呈深棕色。我们最近报道了一种新的氧化HGA的方法，即氢氧化钠(NaOH)与强氧化剂五水合次氯酸钠(NaOCl中心点5H(2O)O)加成。在本研究中，我们尝试使用我们的方法来氧化结构类似于HGA的GA。在此，我们观察了GA溶液的颜色变化，并分析了以NaOCl5H(2)O为中心的NaOH加入GA后的吸收光谱，并用LC/TOF-MS研究了GA的氧化反应。结果表明，GA溶液具有独特的吸收光谱，其中心点为5H(2)O的NaOH通过氧化反应在约500 nm处产生一峰，该方法无需昂贵的分析仪器或复杂的方法即可测定样品溶液中的GA。
Gentisic acid (GA), a metabolite of acetylsalicylic acid (ASA), and homogentisic acid (HGA), which is excreted at high levels in alkaptonuria, are divalent phenolic acids with very similar structures. Urine containing HGA is dark brown in color due to its oxidation. We recently reported a new oxidation method of HGA involving the addition of sodium hydroxide (NaOH) with sodium hypochlorite pentahydrate (NaOCl center dot 5H(2)O), which is a strong oxidant. In the present study, we attempted to oxidize GA, which has a similar structure to HGA, using our method. We herein observed color changes in GA solution and analyzed the absorption spectra of GA after the addition of NaOH with NaOCl center dot 5H(2)O. We also examined the oxidation reaction of GA using a liquid chromatography time-of-flight mass spectrometer (LC/TOF-MS). The results obtained indicated that GA solution had a unique absorption spectrum with a peak at approximately 500 nm through an oxidation reaction following the addition of NaOH with NaOCl center dot 5H(2)O. This spectrophotometric method enables GA to be detected in sample solutions without expensive analytical instruments or a complex method.