Yin Huiyong, Porter Ned A
Department of Chemistry, Division of Clinical Pharmacology, Center in Molecular Toxicology, Vanderbilt Institute of Chemical Biology, Vanderbilt University, Nashville, Tennessee, USA.
Methods Enzymol. 2007;433:193-211. doi: 10.1016/S0076-6879(07)33011-5.
Free radical-induced autoxidation of lipids containing polyunsaturated fatty acids (PUFA) has been implicated in numerous human diseases including atherosclerosis, neurodegenerative diseases, and cancer. Autoxidation of PUFAs generates hydroperoxides as primary oxidation products and further oxidation leads to cyclic peroxides as secondary oxidation products. It is challenging to identify these peroxides by conventional electro-spray ionization (ESI) mass spectrometry (MS) method because of their thermal and chemical instability under most analytical conditions. Ag(+) coordination ion-spray CIS-MS has proven to be a powerful tool to analyze these intact lipid peroxides. Ag(+) preferentially complexes with the double bonds and induces characteristic fragmentation in the gas phase. Monocyclic peroxides, bicyclic endoperoxides, serial cyclic peroxides, and dioxolane-isoprostane peroxides have been identified from the oxidation of cholesteryl arachidonate and phospholipids containing arachidonate. This technique has been widely used for structural identification but it is difficult to make it a quantitative tool because of the formation of multiple silver adducts.
含有多不饱和脂肪酸（PUFA）的脂质的自由基诱导自氧化与包括动脉粥样硬化、神经退行性疾病和癌症在内的多种人类疾病有关。PUFA的自氧化产生氢过氧化物作为主要氧化产物，进一步氧化导致环状过氧化物作为次要氧化产物。由于这些过氧化物在大多数分析条件下的热稳定性和化学稳定性，通过传统的电喷雾电离（ESI）质谱（MS）方法鉴定它们具有挑战性。Ag(+)配位离子喷雾CIS-MS已被证明是分析这些完整脂质过氧化物的有力工具。Ag(+)优先与双键络合并在气相中诱导特征性裂解。从胆固醇花生四烯酸酯和含有花生四烯酸的磷脂的氧化中已鉴定出单环过氧化物、双环内过氧化物、串联环状过氧化物和二氧戊环-异前列腺素过氧化物。该技术已广泛用于结构鉴定，但由于形成多个银加合物，很难使其成为定量工具。
