Identification of all classes of spin-trapped carbon-centered radicals in soybean lipoxygenase-dependent lipid peroxidations of ω-6 polyunsaturated fatty acids via LC/ESR, LC/MS, and tandem MS
Identification of all classes of spin-trapped carbon-centered radicals in soybean lipoxygenase-dependent lipid peroxidations of ω-6 polyunsaturated fatty acids via LC/ESR, LC/MS, and tandem MS
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DOI：
10.1016/s0891-5849(03)00031-5
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发表时间：
2003-04-15
影响因子：
7.4
通讯作者：
Mason, RP
中科院分区：
文献类型：
--
作者：
Qian, SY;Yue, GH;Mason, RP
利用在线高效液相色谱/电子自旋共振（LC/ESR）和质谱（MS）相结合的技术，我们先前鉴定了在亚油酸过氧化过程中形成的所有预期的碳中心脂源自由基（L-.(d)）的自旋捕获加合物。在本研究中，采用LC/ESR和LC/MS相结合的方法，鉴定了两种omega-6多不饱和脂肪酸（亚油酸和花生四烯酸）在α -[4-吡啶基- 1-氧化物]- n-叔丁基硝基（POBN）存在下与大豆脂氧合酶反应形成的自旋捕获脂源碳中心自由基。采用LC/ESR和LC/MS相结合的方法对亚油酸和花生四烯酸脂氧合酶依赖性过氧化反应中脂源性碳中心自由基进行了检测和鉴定，并采用串联质谱法（MS/MS）进行了确证。L-的五类。(d)由两种omega-6 PUFAs形成，包括脂质烷基自由基（L-）、环氧基自由基（OL.）、二羟基基自由基（L-）。（OH）(2))和各种R-。和(RCOOH) - r -。脂质烷氧基自由基的β -断裂，给出了不同的保留时间：POBN/L-。（OH）(2)近似于4-6 min， POBN/R-。和POBN / (RCOOH) - r -。类似于8-22分钟，POBN/L-。和PBON / OL。类似于25-36分钟。-6 PUFAs过氧化反应的主要裂解产物是戊基自由基。然而，p -裂解产物的比例因pH、[PUFA]和[O-2]的不同而有显著差异。(C) 2003 Elsevier Inc.
Using the combined techniques of on-line high performance liquid chromatography/electron spin resonance (LC/ESR) and mass spectrometry (MS), we previously identified spin-trapped adducts of all expected carbon-centered lipid-derived radicals (L-.(d)) formed in linoleic acid peroxidation. In the present study, spin trapped lipid-derived carbon-centered radicals formed from the reactions of two omega-6 polyunsaturated fatty acids (PUFAs: linoleic and arachidonic acids) with soybean lipoxygenase in the presence of alpha-[4-pyridyl 1-oxide]-N-tert-butyl nitrone (POBN) were identified using a combination of LC/ESR and LC/MS. All expected lipid-derived carbon-centered radicals in lipoxygenase-dependent peroxidations of linoleic acid and arachidonic acid were detected and identified by the combination of LC/ESR and LC/MS with confirmation by tandem mass spectrometry (MS/MS). The five classes of L-.(d) formed from both omega-6 PUFAs including lipid alkyl radicals (L-.), epoxyallyic radicals (OL.), dihydroxyallyic radicals (L-.(OH)(2)), and a variety of R-. and (RCOOH)-R-. from beta-scission of lipid alkoxyl radicals, gave distinct retention times: POBN/L-.(OH)(2) similar to4-6 min, POBN/R-. and POBN/(RCOOH)-R-. similar to8-22 min, POBN/L-. and PBON/OL. similar to25-36 min. The major beta-scission products in peroxidations of omega-6 PUFAs were the pentyl radicals. The ratio of P-scission products, however, varied significantly depending on pH, [PUFA], as well as [O-2]. (C) 2003 Elsevier Inc.