Free fatty acids (FFAs) are vitally important components of lipids that modulate biological metabolism in various ways. Although the molecular structures are simple, the analysis of FFAs is still challenging due to their unique properties and wide concentration range. In the present study, a high-coverage liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the quantification of FFAs in serum samples using two structural analogues 5-(dimethylamino)naphthalene-1-sulfonyl piperazine (Dns-PP) and (diethylamino)naphthalene-1-sulfonyl piperazine (Dens-PP) as twin derivatization reagents. The Dns labeling of FFAs could significantly enhance their MS response via the introduction of the easily ionizable moiety of a tertiary amine-containing part and aid fragmentation in the multiple reaction monitoring (MRM) mode. Our results demonstrated that the detection sensitivities of FFAs were increased by 50–1500 fold compared with the nonderivatization method. At the same time, Dens-labeled standards were used as one-to-one internal standards to ensure accurate quantifications. Thirty-eight FFAs, covering short-, medium-, and long-chain, could be quantified in wide dynamic range with the lower limit of quantification (LLOQ) varied from 2 to 20 nM. Using this method, we analyzed serum FFAs in rat models of cisplatin-induced nephrotoxicity and irinotecan-induced gastrointestinal toxicity, respectively. The findings were further compared with those revealed by previous untargeted metabolomics. The results indicate that twin derivatization-based LC-MS provides a more accurate view of global FFA alternation and has great application potential in the fields of targeted metabolomics.
游离
脂肪酸(FFAs)是脂质的重要组成部分,它们以多种方式调节
生物代谢。尽管其分子结构简单,但由于其独特性质和浓度范围广泛,FFA的分析仍具有挑战性。在本研究中,我们建立了一种高覆盖率的
液相色谱-串联质谱(LC-MS/MS)方法,用于定量分析血清样本中的FFAs,使用两种结构类似物5-(
二甲氨基)
萘-1-磺酰
哌嗪(Dns-PP)和(二乙
氨基)
萘-1-磺酰
哌嗪(Dens-PP)作为双
衍生化试剂。Dns标记的FFAs通过引入易于离子化的含有叔胺的部分,显著增强了其MS响应,并有助于在多反应监测(MRM)模式下的碎裂。我们的结果表明,与非衍生化方法相比,FFAs的检测灵敏度提高了50-1500倍。同时,使用Dens标记的标准品作为一对一的内部标准,确保了准确的定量。可以定量分析38种FFAs,涵盖短链、中链和长链,具有广泛的动态范围,定量下限(LLOQ)从2到20 nM不等。利用这种方法,我们分别分析了
顺铂诱导的肾毒性和
伊立替康诱导的胃肠毒性的 rat 模型血清中的 FFAs。这些发现进一步与先前未靶向代谢组学揭示的结果进行了比较。结果表明,基于双衍生化的LC-MS提供了更准确的全球FFA变化视图,并在靶向代谢组学领域具有巨大的应用潜力。