Reszka K, Bilski P, Sik R H, Chignell C F
Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, National Institute of Health, Research Triangle Park, North Carolina 27709.
Free Radic Res Commun. 1993;19 Suppl 1:S33-44. doi: 10.3109/10715769309056s33.
The UV or visible irradiation of pigments such as curcumin, anthralin, benzanthrone, 1,8-dihydroxyanthraquinone, and rose bengal- or eosine-complexes with cationic surfactants in aerated aprotic solvents, such as benzene, toluene, acetone, n-heptane, cyclohexane, in the presence of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) generates EPR spectra with hyperfine splitting constants (hfsc's) aN = 12.75 G, a beta H = 10.50 G, a gamma H = 1.26 G in toluene, 12.83 G, 10.64 G, 1.24 G in benzene, 12.75 G, 10.19 G, 1.35 G in acetone and 12.54 G, 10.46 G, 1.38 G in n-heptane and cyclohexane. These spectra are similar to those observed when DMPO reacts with 18-crown-6 ether-solubilized KO2 in the respective solvents and suggests that the photoinduced EPR spectra can be safely assigned to the DMPO/superoxide radical adduct (1). A correlation between the hfsc's of 1 and solvent parameters, the solvent acceptor number AN and the Kosower Z value, has been evaluated in terms of its usefulness for the identification of the DMPO/superoxide adduct in organic media.
在通气的非质子溶剂（如苯、甲苯、丙酮、正庚烷、环己烷）中，用紫外线或可见光照射姜黄素、蒽林、苯并蒽酮、1,8 - 二羟基蒽醌以及玫瑰红或曙红与阳离子表面活性剂的络合物，在5,5 - 二甲基 - 1 - 吡咯啉 - N - 氧化物（DMPO）存在下，会产生电子顺磁共振（EPR）光谱，其超精细分裂常数（hfsc's）在甲苯中为aN = 12.75 G，aβH = 10.50 G，aγH = 1.26 G；在苯中为12.83 G，10.64 G，1.24 G；在丙酮中为12.75 G，10.19 G，1.35 G；在正庚烷和环己烷中为12.54 G，10.46 G，1.38 G。这些光谱与在相应溶剂中DMPO与18 - 冠 - 6醚增溶的KO₂反应时观察到的光谱相似，这表明光诱导的EPR光谱可以安全地归属于DMPO/超氧自由基加合物（1）。已经根据其在有机介质中鉴定DMPO/超氧加合物的有用性，评估了1的hfsc's与溶剂参数、溶剂受体数AN和科索尔Z值之间的相关性。
