Photoelectron Spectroscopic Study of Ascorbate and Deprotonated Ascorbate Anions Using an Electrospray Ion Source and a Cryogenically Cooled Ion Trap
Photoelectron Spectroscopic Study of Ascorbate and Deprotonated Ascorbate Anions Using an Electrospray Ion Source and a Cryogenically Cooled Ion Trap
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使用电喷雾离子源和低温冷却离子阱对抗坏血酸和去质子化抗坏血酸阴离子进行光电子能谱研究
DOI：
10.1021/acs.jpca.1c06540
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发表时间：
2021
期刊：
影响因子：
--
通讯作者：
Bowen, Kit H.
中科院分区：
文献类型：
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作者：
Marshall, Mary;Zhu, Zhaoguo;Harris, Rachel;Collins, Evan;Bowen, Kit H.
活性氧（ROS）在生物系统中是通过多种机制形成的。这些物种具有很强的反应性，与许多疾病有关，包括癌症和心血管疾病。清除体内活性氧的一种方法是使用自由基清除剂，自由基清除剂是一种能够放弃一个电子来中和活性氧的化合物，同时又能形成稳定的自由基。抗坏血酸是一种常见的自由基清除剂，也称为维生素c。在生理pH值下，抗坏血酸主要以抗坏血酸阴离子C6H7O6 -的形式存在。抗坏血酸阴离子，以及阴离子（C6H6O62 -），是一种有效的抗氧化剂，因为它能够从去质子化产生的孤对中提供一个电子。在脉冲阴离子光电子能谱仪中加入电喷雾电离源，用光电子能谱法研究抗坏血酸阴离子和去质子化的抗坏血酸阴离子。抗坏血酸阴离子和去质子化抗坏血酸阴离子的抗氧化性能根据实验垂直脱离能（VDE）得到，因此，阴离子的电离能分别为3.85和2.68 eV。
Reactive oxygen species (ROS) in biological systems are formed through a variety of mechanisms. These species are very reactive and have been associated with many diseases, including cancer and cardiovascular disease. One way of removing ROS from the body is through the use of radical scavengers, which are compounds capable of giving up an electron to neutralize the ROS yet form a stable radical species themselves. A common radical scavenger is ascorbic acid, also known as vitamin C. At physiological pH, ascorbic acid is predominately present as the ascorbate anion, C6H7O6–. The ascorbate anion, as well as the dianion (C6H6O62–), is an effective antioxidant due to its ability to donate an electron from a lone pair generated by deprotonation. An electrospray ionization source was added to our pulsed anion photoelectron spectrometer to study ascorbate anions and deprotonated ascorbate dianions via photoelectron spectroscopy. The antioxidant behavior of the ascorbate anion and the deprotonated ascorbate dianion was confirmed based on the experimental vertical detachment energy (VDE), and, therefore, the ionization energy of the anions, 3.85 and 2.68 eV, respectively.