Institute of Chemistry, Jan Kochanowski University of Humanities and Sciences, Swietokrzyska St. 15G, PL-25406 Kielce, Poland.
Bioelectrochemistry. 2011 Oct;82(2):103-11. doi: 10.1016/j.bioelechem.2011.06.003. Epub 2011 Jun 23.
The anodic oxidation of oxidized forms of coenzyme Q(10) (ubiquinone, CoQ(10)) and Q(0) (CoQ(0)) on a glassy carbon macroelectrode (GC) and on a carbon fiber microelectrode (CF) was investigated in acetic acid using voltammetric techniques. Voltammograms recorded on these electrodes show well-defined peaks or waves in the potential range of above 1.5 V (vs. Ag/AgCl). The existence of these signals cannot be connected with the well-known redox couple CoQ/CoQH(2) but may be attributed to the irreversible and diffusion-controlled two-electron oxidation of methoxy groups in molecules of coenzymes. The overall number of electrons involved in the anodic oxidation of CoQ(10) is higher than for CoQ(0). This indicates that oxidation also proceeds in an unsaturated isoprene side chain. Smaller oxidation potentials for CoQ(10) in comparison to such unsaturated fatty acids as oleic, linoleic and linolenic ones indicate that this compound can show direct antioxidative properties. The antioxidative power of CoQ(10) is much smaller than that of reduced CoQ(10) (ubiquinol) and α-tocopherol. The results presented can be useful in the determination of this compound in real samples and in the assessment of biochemical properties of CoQ(10) in living cells.
辅酶 Q（10）（泛醌，CoQ（10））和 Q（0）（CoQ（0））的氧化形式在玻碳大电极（GC）和碳纤维微电极（CF）上的阳极氧化在醋酸中使用伏安技术进行了研究。在这些电极上记录的伏安图在 1.5V（相对于 Ag/AgCl）以上的电位范围内显示出定义良好的峰或波。这些信号的存在不能与众所周知的 CoQ/CoQH（2）氧化还原对相关联，而可能归因于辅酶分子中甲氧基基团的不可逆和扩散控制的二电子氧化。CoQ（10）阳极氧化中涉及的电子总数高于 CoQ（0）。这表明氧化也在不饱和异戊二烯侧链中进行。与油酸、亚油酸和亚麻酸等不饱和脂肪酸相比，CoQ（10）的氧化电位较小，表明该化合物具有直接抗氧化特性。CoQ（10）的抗氧化能力远小于还原型 CoQ（10）（泛醇）和α-生育酚。所提出的结果可用于在实际样品中测定该化合物，并评估 CoQ（10）在活细胞中的生化特性。
