Key Laboratory of Oilseeds Processing of Ministry of Agriculture, Key Laboratory of Biology and Genetic Improvement of Oil Crops of Ministry of Agriculture, Hubei Key Laboratory of Lipid Chemistry and Nutrition, Oil Crops Research Institute of Chinese Academy of Agricultural Sciences, Wuhan 430062, China.
Department of Nutrition and Food Hygiene, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, P. R. China.
Anal Chem. 2023 Oct 31;95(43):15933-15942. doi: 10.1021/acs.analchem.3c02789. Epub 2023 Oct 18.
Accurate oxylipin annotation is crucial for advancing our understanding of physiological processes in health and disease and identifying biomarkers. However, a full view of oxylipins for early diagnosis needs further attention due to the lack of proper analytical methods, which may be attributed to the wide dynamic range, poor sensitivity, extreme molecular complexity, and limited commercially available standards of oxylipins. Here, we devised a novel method by combining a chemical derivatization (CD)-based retention index (RI) algorithm and feature tandem mass spectrometric fragmentation annotation (CD-RI-LC-MS/MS) for identification and quantification of oxylipins. To this end, N,N-diethyl-1,3-diaminopropane (DEPA) was used for fast labeling of oxylipin (within 0.5 min at room temperature) to improve separation resolution and detection sensitivity. The RI algorithm was established to calibrate the retention time variances and assist the identification of oxylipins during liquid chromatography-tandem mass spectrometry (LC-MS) analysis. MS/MS analysis of in total 58 DEPA derivatives of authentic oxylipin standards was subsequently employed to obtain the tandem mass spectrometric feature fragmentation rules for further structure elucidation of the unknown regio-isomers. Finally, a method based upon CD-RI-LC-MS/MS was established for profiling oxylipins from Standard Reference Material (SRM) 1950 human plasma and nonalcoholic fatty liver disease (NAFLD) mouse liver tissue samples. A total of 87 and 96 potential oxylipins including 12 and 14 unreported oxylipins were detected and identified from human plasma and mouse liver tissues, respectively. The results showed that compared to the control group, in the liver samples of the NAFLD mouse, the content levels of prostaglandin (PG) E2, PGF2a, 8-hydroxy-eicosatrienoic acid (8-HETrE), and the newly discovered 2-hydroxy-octadecatrienoic acid (2-HOTrE) were remarkably increased, while the oxidation product of n-3 PUFA ( < 0.05) and all hydroperoxy oxylipins significantly decreased. On balance, this method contributes to future studies on oxylipin screening and application in other biological samples for facilitating the understanding of oxylipin roles in metabolic regulation of numerous diseases.
准确的氧化脂类注释对于深入了解健康和疾病中的生理过程以及识别生物标志物至关重要。然而，由于缺乏适当的分析方法，早期诊断所需的全面氧化脂类视图仍需要进一步关注，这可能归因于氧化脂类广泛的动态范围、较差的灵敏度、极端的分子复杂性以及有限的商业可得的氧化脂类标准。在这里，我们设计了一种新方法，将化学衍生化（CD）-基于保留指数（RI）算法和特征串联质谱碎裂注释（CD-RI-LC-MS/MS）相结合，用于鉴定和定量氧化脂类。为此，使用 N,N-二乙基-1,3-丙二胺（DEPA）对氧化脂类（在室温下在 0.5 分钟内）进行快速标记，以提高分离分辨率和检测灵敏度。建立 RI 算法以校准保留时间差异，以协助在液相色谱-串联质谱（LC-MS）分析过程中鉴定氧化脂类。随后对 58 种氧化脂类标准物的 DEPA 衍生物进行 MS/MS 分析，以获得串联质谱特征碎裂规则，以进一步阐明未知的区域异构体结构。最后，建立了一种基于 CD-RI-LC-MS/MS 的方法，用于从标准参考物质（SRM）1950 人血浆和非酒精性脂肪肝（NAFLD）小鼠肝组织样品中分析氧化脂类。从人血浆和小鼠肝组织中分别检测和鉴定了 87 种和 96 种潜在的氧化脂类，包括 12 种和 14 种未报道的氧化脂类。结果表明，与对照组相比，在 NAFLD 小鼠的肝组织样本中，前列腺素（PG）E2、PGF2a、8-羟基二十碳三烯酸（8-HETrE）和新发现的 2-羟基十八碳三烯酸（2-HOTrE）的含量明显增加，而 n-3 PUFA 的氧化产物（<0.05）和所有过氧氧化脂类显著减少。总的来说，该方法有助于未来的氧化脂类筛选研究，并应用于其他生物样品，以促进氧化脂类在多种疾病代谢调节中的作用的理解。
