RADICAL ADDUCTS OF NITROSOBENZENE AND 2-METHYL-2-NITROSOPROPANE WITH 12,13-EPOXYLINOLEIC ACID RADICAL, 12,13-EPOXYLINOLENIC ACID RADICAL AND 14,15-EPOXYARACHIDONIC ACID RADICAL - IDENTIFICATION BY HPLC EPR AND LIQUID-CHROMATOGRAPHY THERMOSPRAY MS
RADICAL ADDUCTS OF NITROSOBENZENE AND 2-METHYL-2-NITROSOPROPANE WITH 12,13-EPOXYLINOLEIC ACID RADICAL, 12,13-EPOXYLINOLENIC ACID RADICAL AND 14,15-EPOXYARACHIDONIC ACID RADICAL - IDENTIFICATION BY HPLC EPR AND LIQUID-CHROMATOGRAPHY THERMOSPRAY MS
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DOI：
10.1042/bj2760447
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发表时间：
1991-06-01
影响因子：
4.1
通讯作者：
TOMER, KB
中科院分区：
文献类型：
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作者：
IWAHASHI, H;PARKER, CE;TOMER, KB
亚油酸与大豆脂肪氧合酶反应生成亚油酸衍生自由基，用亚硝基苯捕获，用高效液相色谱法分析得到的自由基加合物。电脉冲还原法和液相色谱-热喷雾-质谱。检测到三个亚硝基苯自由基加合物（峰I、II和III）;这些得到以下母离子质量：峰I为402，峰II为402，峰III为386。峰I和峰II的质量对应于多一个氧原子的亚油酸基团[L（O）.]。自由基可能是碳中心的，因为O-17（2）的使用没有导致额外的超精细分裂。自由基加合物Ⅰ峰epr的计算机模拟光谱还表明，自由基是碳中心的。在13-氢过氧亚油酸与FeSO 4的反应中也检测到I自由基峰。由上述结果可知，峰I可能是12，13-环氧亚油酸自由基。一个高血压病人电脉冲还原法使用[9，10，12，13-H-2（4）]亚油酸的实验表明12，13-环氧亚油酸自由基是C-9中心自由基。峰II可能是峰I的异构体。在没有大豆脂氧合酶的反应混合物中观察到的峰III对应于亚油酸自由基（L.）。在亚油酸、亚麻酸和花生四烯酸与大豆脂肪氧合酶的反应中，分别检测到12，13-环氧亚油酸自由基、12，13-环氧亚麻酸自由基和14，15-环氧花生四烯酸自由基。
Linoleic acid-derived radicals, which are formed in the reaction of linoleic acid with soybean lipoxygenase, were trapped with nitrosobenzene and the resulting radical adducts were analysed by h.p.l.c.-e.p.r. and liquid chromatography-thermospray-m.s. Three nitrosobenzene radical adducts (peaks I, II and III) were detected; these gave the following parent ion masses: 402 for peak I, 402 for peak II, and 386 for peak III. The masses of peaks I and II correspond to the linoleic acid radicals with one more oxygen atom [L(O).]. The radicals are probably carbon-centered, because the use of O-17(2) did not result in an additional hyperfine splitting. Computer simulation of the peak I radical adduct e.p.r. spectrum also suggested that the radical is carbon-centred. The peak I radical was also detected in the reaction of 13-hydroperoxylinoleic acid with FeSO4. From the above results, peak I is probably the 12,13-epoxylinoleic acid radical. An h.p.l.c.-e.p.r. experiment using [9,10,12,13-H-2(4)]linoleic acid suggested that the 12,13-epoxylinoleic acid radical is a C-9-centred radical. Peak II is possibly an isomer of peak I. Peak III, which was observed in the reaction mixture without soybean lipoxygenase, corresponds to a linoleic acid radical (L.). The 12,13-epoxylinoleic acid radical, 12,13-epoxylinolenic acid radical and 14,15-epoxyarachidonic acid radical were also detected in the reactions of linoleic acid, linolenic acid and arachidonic acid respectively, with soybean lipoxygenase using nitrosobenzene and 2-methyl-2-nitrosopropane as spin-trapping agents.