紫外光诱导下的固体胆红素自由基性质的ESR研究

ESR STUDIES ON POWDER BILIRUBIN FREE RADICALS INDUCED BY UV

利用电子自旋共振方法对固体胆红素及其自由基在紫外照射下的变化进行了研究,发现在紫外光下仅引起胆红素超氧自由基及半醌自由基浓度的增加,而没有新的自由基形式生成,指出Foote提出的光氧化机理假说的中间体自由基即是由上述两种自由基构成,并通过电子计算机对ESR谱的摸拟,提出了紫外辐照下的胆红素自由基形成机理,推测胆红素光化学反应的途径及产物与这两种自由基浓度及在不同环境下的反应活性有关.

The characters cf powder bilirubin free radicals under UV irradiation were studied by ESR method . It has been discovered that UV light only induced an increase in the concentration of bilirubin superoxide radical and semiquinone radical , but no new free radical forms are produced. It is suggested that the free radical medium [BR+ -O2-] of Foote's mechanism for photoxidation of bilirubin is really composed of both of the free radicals mentioned above with simulation of bilirubin ESR spectrum, a further mechanism about the formation of bilirubin free radical under UV irradiction was given . And the relationship between bilirubin photochemical characters and the both free radical concentrations as well as their activity in some conditions was also deduced.