Copeland E S, Grenan M M, Yang G C
J Invest Dermatol. 1975 May;64(5):349-56. doi: 10.1111/1523-1747.ep12512287.
Electron spin resonance spectroscopy has been used to demonstrate that the phototoxic antimalarial drug, 6,8-dichloro-2-phenyl-a-2-piperidnylquinolinemethanol (WR 7930), when irradiated with long-wave ultraviolet (UV) light (lambda greater than 320 nm) while held in a glassy matrix at 73 degrees K, enters a triplet state and releases hydrogen atoms in its environment. The steady-state concentration of triplet WR 7930 molecules and of hydrogen atoms is reduced 2 to 3 times when mercaptoethylamine (MEA) is also present in the UV-irradiated glass. Organosulfur radicals form on MEA while hydrogen atoms and triplet-state molecules are reduced in number. Hydrogen atoms and triplet WR 7930 molecules are considered as mediators of the phototoxicity of the antimalarial drug. Thus, hydrogen atom scavanging and chemical quenching of the triplet state are possible mechanisms by which protection against phototoxic effects could be gained. Protection is demonstrated in mice receiving 20 mg per kg WR 7930 intraperitoneally and exposed to long-wave UV for 20 hr when the radioprotective aminothiol-forming compound, 2-(3-aminopropylamino) ethyl dihydrogen phosphorothioate (WR 2721), is administered at 400 mg per kg immediately before irradiation. When no protective drug is administered concurrently, WR 7930 administration results in intense erythema, edema, and eventual necrosis of ear tissues.
电子自旋共振光谱已被用于证明，光毒性抗疟药物6,8-二氯-2-苯基-α-2-哌啶基喹啉甲醇（WR 7930），在73K的玻璃态基质中用长波紫外线（UV）（波长大于320nm）照射时，会进入三重态并在其周围环境中释放氢原子。当巯基乙胺（MEA）也存在于紫外线照射的玻璃中时，三重态WR 7930分子和氢原子的稳态浓度会降低2至3倍。MEA上会形成有机硫自由基，而氢原子和三重态分子的数量会减少。氢原子和三重态WR 7930分子被认为是抗疟药物光毒性的介质。因此，清除氢原子和三重态的化学猝灭可能是获得针对光毒性作用保护的机制。当在照射前立即以每千克400毫克的剂量给予辐射防护性氨基硫醇形成化合物2-(3-氨基丙基氨基)乙二氢硫代磷酸酯（WR 2721）时，对接受每千克20毫克WR 7930腹腔注射并暴露于长波紫外线20小时的小鼠显示出保护作用。当不同时给予保护性药物时，给予WR 7930会导致耳部组织出现强烈红斑、水肿并最终坏死。
