Institute for Medical Research and Occupational Health, Zagreb, Croatia.
Arh Hig Rada Toksikol. 2019 Jun 1;70(2):134-139. doi: 10.2478/aiht-2019-70-3290.
I have shown that by averaging antioxidant activity (AA) values measured by different methods it is possible to obtain an excellent correlation (R2=0.960) between the first electrochemical oxidation potential, Ep1, and AA. Separate correlations using the AA values obtained with each of the four methods [R2 were 0.561 for diphenyl-1-picrylhydrazyl (DPPH), 0.849 for Folin Ciocalteu reagent (FCR), 0.848 for the ferric-reducing ability of plasma (FRAP), and 0.668 for the Trolox equivalent antioxidant capacity (TEAC)] were all worse, and in some cases not useful at all, such as the one for DPPH. Also, the sum of atomic orbital spin populations on the carbon atoms in the skeleton of radicals ( s(C) Σ AOSPRad), calculated with the semi-empirical parameterisation method 6 (PM6) in water, was used to correlate both Ep1 and AA, yielding R2=0.926 and 0.950, respectively. This showed to be a much better variable for the estimation of Ep1 and AA than the bond dissociation energy (BDE), R2=0.854 and 0.901 for Ep1 and AA, respectively, and especially the ionisation potential (IP), R2=0.445 and 0.435 for Ep1 and AA, respectively.
我已经证明，通过平均不同方法测量的抗氧化活性（AA）值，可以在第一电化学氧化电位 Ep1 和 AA 之间获得极好的相关性（R2=0.960）。使用四种方法中的每一种方法获得的 AA 值进行单独的相关性分析[R2 分别为二苯基-1-苦基肼基（DPPH）的 0.561、Folin Ciocalteu 试剂（FCR）的 0.849、血浆铁还原能力（FRAP）的 0.848 和 Trolox 等效抗氧化能力（TEAC）的 0.668]，相关性都较差，在某些情况下甚至完全没有用，例如 DPPH。此外，还使用在水中使用半经验参数化方法 6（PM6）计算的自由基骨架碳原子上的原子轨道自旋密度总和（s(C)ΣAOSPRad）来关联 Ep1 和 AA，分别得到 R2=0.926 和 0.950。与键离解能（BDE）相比，这一变量对于 Ep1 和 AA 的估计要好得多，R2 分别为 0.854 和 0.901，尤其是电离势（IP），R2 分别为 0.445 和 0.435。
