Department of Biophysics, Institute of Physics, Maria Curie-Sklodowska University, 20-031 Lublin, Poland.
Institute of Agrophysics, Polish Academy of Sciences, 20-290 Lublin, Poland.
J Phys Chem Lett. 2023 Aug 24;14(33):7440-7444. doi: 10.1021/acs.jpclett.3c01374. Epub 2023 Aug 14.
Here, we address the problem of the antioxidant activity of carotenoids in biomembranes. The activity of lutein and zeaxanthin in the quenching of singlet oxygen generated by photosensitization was monitored in lipid vesicles using a singlet oxygen-sensitive fluorescent probe and with the application of fluorescence lifetime imaging microscopy. The antioxidant activity of xanthophylls was interpreted on the basis of electron paramagnetic resonance oximetry results showing that xanthophylls constitute a barrier to the penetration of molecular oxygen into lipid membranes: to a greater extent in the 13- configuration than in all-. These results are discussed in relation to the - photoisomerization of xanthophylls observed in the human retina. It can be concluded that photoisomerization of xanthophylls is a regulatory mechanism that is important for both the modulation of light filtration through the macula and photoprotection by quenching singlet oxygen and creating a barrier to oxygen permeation to membranes.
在这里，我们解决了类胡萝卜素在生物膜中抗氧化活性的问题。使用单线态氧敏感荧光探针和荧光寿命成像显微镜，在脂质体中监测叶黄素和玉米黄质在光敏化产生的单线态氧猝灭中的活性。根据电子顺磁共振血氧测定结果，解释了叶黄素的抗氧化活性，结果表明叶黄素构成了阻止分子氧进入脂质膜的屏障：在 13-构型中比在全-构型中更为显著。这些结果与在人视网膜中观察到的叶黄素的光异构化有关。可以得出结论，叶黄素的光异构化是一种调节机制，对黄斑的光过滤调节和通过猝灭单线态氧和在膜上形成氧渗透屏障来进行光保护都很重要。
