Carboxyl-containing metabolites (CCMs) widely exist in living systems and are the essential components for life. Global characteristics of CCMs in biological samples are critical for the understanding of physiological processes and the discovery for the onset of relevant diseases. However, their determination represents a challenge due to enormous polarity differences, structural diversity, high structural similarity, and poor ionization efficiency in mass spectrometry. Herein, 5-(diisopropylamino)amylamine (DIAAA) derivatization coupled with liquid chromatography–mass spectrometry (LC-MS) was developed for mapping the CCMs. With this methodology, the sensitivity was significantly enhanced. More importantly, the hydrophobicity of polar CCMs, amino acids, TCA cycle intermediates, and short-chain fatty acids and the hydrophilicity of low-polar CCMs, long-chain fatty acids, and bile acids were significantly increased, resulting in a remarkable separation efficiency for which 68 CCMs can be simultaneously determined. Furthermore, the polarity-tuning effect was confirmed to be induced by the different impacts of aliphatic chains and nitrogen atom in DIAAA, the latter existing as a cation in the acidic mobile phase, using different derivatization reagents. Finally, this derivatization method was utilized to hunt for the potential biomarkers in colorectal cancer (CRC) patients and 52 CCMs, related with several key metabolic pathways, including amino acids metabolism, TCA cycle, fatty acid metabolism, pyruvate metabolism, and gut flora metabolism were identified. This innovative polarity-tuning derivatization-LC-MS approach was proved to be a valuable tool for probing global metabolome with high separation efficiency and sensitivity in various biological samples.

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极性调谐衍生化LC-MS方法在大肠癌中探测全球含羧基代谢物

含羧基的代谢物（CCM）广泛存在于生命系统中，是生命必不可少的成分。生物样品中CCM的全局特征对于理解生理过程和发现相关疾病的发作至关重要。然而，由于质谱中巨大的极性差异，结构多样性，高结构相似性和差的电离效率，它们的确定代表了挑战。本文中，开发了5-（二异丙基氨基）戊胺（DIAAA）衍生化与液相色谱-质谱联用（LC-MS）来绘制CCM的图。使用这种方法，灵敏度大大提高。更重要的是，极性CCM，氨基酸，TCA循环中间体和短链脂肪酸的疏水性以及低极性CCM的亲水性，长链脂肪酸和胆汁酸显着增加，导致了可同时测定68个CCM的显着分离效率。此外，通过使用不同的衍生化试剂，证实了脂肪族链和氮原子在DIAAA中的极性调节效应可诱导极性调整，DIAAA后者在酸性流动相中作为阳离子存在。最后，这种衍生化方法被用于寻找结直肠癌（CRC）患者和52个CCM中潜在的生物标志物，这些标志物与几种关键的代谢途径有关，包括氨基酸代谢，TCA循环，脂肪酸代谢，丙酮酸代谢和肠道菌群代谢。被确定。