Poly(β-phosphorylated nitrones): preparation and characterisation of a new class of spin trap
作者:Valérie Roubaud、Hélène Dozol、Cécile Rizzi、Robert Lauricella、Jean-Claude Bouteiller、Béatrice Tuccio
DOI:10.1039/b111691f
日期:2002.4.29
Four new poly(β-phosphorylated nitrones), the 1,3,5-tris[N-(1-diethylphosphono-1-methylethyl)-N-oxidoiminiomethyl]benzene (TN) 1, the 1,3-bis[N-(1-diethylphosphono-1-methylethyl)-N-oxidoiminiomethyl]benzene (MDN) 2, the 1,4-bis[N-(1-diethylphosphono-1-methylethyl)-N-oxidoiminiomethyl]benzene (PDN) 3, and the 1,2-bis[N-(1-diethylphosphono)-1-methylethyl)-N-oxidoiminiomethyl]benzene (ODN) 4, derived from the mono-nitrone N-benzylidene-1-diethoxyphosphoryl-1-methylethylamine N-oxide (PPN) 5, were synthesised. The capacity of 1â4 to act as spin-trapping agents was investigated in phosphate buffers at pH 5.8 and 7.2.
Complex EPR spectra were obtained for the spin adducts with ortho-dinitrone 4. The three other compounds efficiently trapped superoxide and several carbon-centred radicals, giving mono-spin adducts, although only weak signals were obtained with the hydroxyl radical. When the spin trap concentration was kept below 1 mmol dmâ3, the formation of di-radicals also occurred. The half-lives of the superoxide spin adducts of 1â3 were in the range of 5â12 min and did not change significantly between pH 5.8 and 7.2. A competitive kinetic study showed that the trinitrone 1 trapped the methyl radical 1.9 times more rapidly than either α-(1-oxidopyridin-1-ium-4âyl)-N-tert-butylnitrone (POBN) or 5-diethoxyphosphoryl-5-methyl-4,5-dihydro-3H-pyrrole N-oxide (DEPMPO) at pH 7.2.
四种新的聚(δ-磷酸化硝基),即 1,3,5-三[N-(1-二乙基膦酰基-1-甲基乙基)-N-氧代亚氨基甲基]苯 (TN) 1、1,3-双[N-(1-二乙基膦酰基-1-甲基乙基)-N-氧代亚氨基甲基]苯 (MDN) 2、1、4-双[N-(1-二乙基膦酰基-1-甲基乙基)-N-氧代亚氨基甲基]苯 (PDN) 3 和 1,2-双[N-(1-二乙基膦酰基)-1-甲基乙基)-N-氧代亚氨基甲基]苯 (ODN) 4、合成了由 N-亚苄基-1-二乙氧基磷酰-1-甲基乙胺 N-氧化物(PPN)5 衍生的单硝酮 1â4。研究人员在 pH 值为 5.8 和 7.2 的磷酸盐缓冲液中考察了 1â4 作为自旋捕获剂的能力。其他三种化合物有效地捕获了超氧化物和几种以碳为中心的自由基,得到了单自旋加合物,但羟自由基只得到了微弱的信号。当自旋阱浓度保持在 1 mmol dmâ3 以下时,也会形成二自由基。1â3 的超氧化物自旋加合物的半衰期为 5-12 分钟,在 pH 值为 5.8 和 7.2 之间变化不大。竞争动力学研究表明,在 pH 值为 7.2 时,三硝基酮 1 捕获甲基自由基的速度是δ-(1-氧代吡啶-1-鎓-4âyl)-N-叔丁基硝酮(POBN)或 5-二乙氧基磷酰-5-甲基-4,5-二氢-3H-吡咯 N-氧化物(DEPMPO)的 1.9 倍。