【摘要】 光敏剂RB在光照射下与O2反应产生1O2,1O2与组氨酸或咪唑反应的中间产物使RNO发生氧化,导致RNO在440nm处吸光度减小,此即为RNO脱色反应.RNO脱色反应随着光照时间的增加而增大,表明RB受光照射后使1O2增加;随着组氨酸或咪唑浓度的增加,RNO脱色反应增大;咪唑在RNO脱色反应中的作用更明显.1O2淬灭剂NaN3或DABCO存在时,RNO脱色反应降低.利用RNO脱色反应检测到莴苣类囊体在强光照射下产生的1O2,随着光强和照射时间增加,类囊体中1O2的产生增加.更多还原

【Abstract】 Photosensitizer rose bengal (RB) reacts with O 2 to generate singlet oxygen ( 1O 2) under illumination . 1O 2 reacts with histidine or imidazole to form intermediate products which oxidize RNO. The reaction causes optical absorption of RNO at 440 nm to decrease. It is named the bleaching of RNO. Bleaching of RNO is increased with the increasing of RB illuminated time, which shows that the production of 1O 2 has grown in the reaction. Bleaching of RNO is promoted by the rising of the concentration of histidine or imidazole. Imidazole plays more evident role in the reaction than histidine does. Bleaching of RNO is decreased by the presence of 1O 2 quencher NaN 3 or DABCO. 1O 2 in lettuce thylakoids has been detected by the reaction in strong light. The production of 1O 2 grows with the increasing of light intensity and illuminated time in lettuce thylakoids.更多还原