School of Chemistry and Physics, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Centre for Materials Science, Queensland University of Technology, Brisbane, QLD, 4000, Australia.
Nat Commun. 2023 Jul 4;14(1):3940. doi: 10.1038/s41467-023-39617-9.
Fatty acid isomers are responsible for an under-reported lipidome diversity across all kingdoms of life. Isomers of unsaturated fatty acids are often masked in contemporary analysis by incomplete separation and the absence of sufficiently diagnostic methods for structure elucidation. Here, we introduce a comprehensive workflow, to discover unsaturated fatty acids through coupling liquid chromatography and mass spectrometry with gas-phase ozonolysis of double bonds. The workflow encompasses semi-automated data analysis and enables de novo identification in complex media including human plasma, cancer cell lines and vernix caseosa. The targeted analysis including ozonolysis enables structural assignment over a dynamic range of five orders of magnitude, even in instances of incomplete chromatographic separation. Thereby we expand the number of identified plasma fatty acids two-fold, including non-methylene-interrupted fatty acids. Detection, without prior knowledge, allows discovery of non-canonical double bond positions. Changes in relative isomer abundances reflect underlying perturbations in lipid metabolism.
脂肪酸异构体是所有生命领域脂质组多样性报道不足的原因。不饱和脂肪酸的异构体在当代分析中经常被不完全分离和缺乏足够的结构解析诊断方法所掩盖。在这里，我们介绍了一种全面的工作流程，通过将双键的液相色谱和质谱与气相臭氧氧化相结合来发现不饱和脂肪酸。该工作流程包括半自动数据分析，并能够在包括人血浆、癌细胞系和胎脂在内的复杂介质中进行从头鉴定。靶向分析包括臭氧氧化，即使在不完全色谱分离的情况下，也能够在五个数量级的动态范围内进行结构分配。由此，我们将鉴定出的血浆脂肪酸数量增加了一倍，包括非亚甲基中断脂肪酸。无需事先了解即可进行检测，从而可以发现非典型双键位置。相对异构体丰度的变化反映了脂质代谢的潜在扰动。
