Laboratory of Science Fundamental University Amar Telidji, BP37G Laghouat, Algeria and Department of Analytical Chemistry, Applied Chemometricsand Molecular Modelling, Vrije Universiteit Brussel (VUB), Laarbeeklaan 103, B-1090 Brussels, Belgium.
Laboratory of Science Fundamental University Amar Telidji, BP37G Laghouat, Algeria.
Analyst. 2020 Jan 21;145(2):557-571. doi: 10.1039/c9an01643k. Epub 2019 Nov 26.
Antioxidant activity can be measured by a variety of methods, that include hydrogen atom transfer (HAT) and single electron transfer (ET) methods. Most of these techniques are spectrophotometric, and thus incapable of quantifying or indicting individual antioxidant compounds. Nowadays, the integration of chromatographic and chemometric approaches allows a high-throughput identification and activity prediction of herbal products. The ethyl acetate fraction from the aqueous-acetone extract of Pistacia atlantica leaves is frequently used for the isolation of antioxidants. In this study it is investigated for its antioxidant properties in order to define a potential methodology for the determination of the antioxidant capacity of herbal extracts (which need to be confirmed by future studies). The seven free radical assays evaluated can be divided into two groups depending on the oxidizing reagent. Three methods use stable, non-biological radicals, i.e. the diphenyl-1-picrylhydrazyl (DPPH) assay, the azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assay, and the N,N-dimethyl-p-phenylenediamine (DMPD) assay, which have no direct physiological importance. Four methods work with biological radical producers, including superoxide anion (O˙), hydroxyl (˙OH), nitric oxide (NO˙) and peroxyl (ROO˙) are produced metabolically in living organisms, and thus direct information on an extract's protective action is obtained. Furthermore, the reducing power method by potassium ferricyanide (RPC), and the iron (ferrous) ion chelating activity also have been investigated. The antioxidant activities of the samples were measured according to the different methods and modelled as a function of the HPLC fingerprints using the partial least squares (PLS) technique. The regression coefficients of the models were studied to indicate the peaks potentially responsible for the antioxidant activity. From the combined results of the different PLS models, we recommend using the DPPH, RPC and ROO˙ assays, to evaluate the overall antioxidant capacity; in the case study of P. atlantica leaves.
抗氧化活性可以通过多种方法来测量，包括氢原子转移 (HAT) 和单电子转移 (ET) 方法。这些技术大多是分光光度法，因此无法定量或指示单个抗氧化化合物。如今，色谱和化学计量学方法的结合允许高通量鉴定和预测草药产品的抗氧化活性。从阿月浑子叶的水-丙酮提取物的乙酸乙酯部分经常用于分离抗氧化剂。在这项研究中，它被研究其抗氧化特性，以便为确定草药提取物的抗氧化能力定义一种潜在的方法（这需要通过未来的研究来证实）。评估的七种自由基测定方法可以根据氧化剂分为两组。三种方法使用稳定的、非生物自由基，即二苯基-1-苦基肼（DPPH）测定法、氮蓝四唑（ABTS）测定法和 N,N-二甲基-对苯二胺（DMPD）测定法，它们没有直接的生理重要性。四种方法与生物自由基产生剂一起工作，包括超氧阴离子 (O˙)、羟基 (˙OH)、一氧化氮 (NO˙) 和过氧自由基 (ROO˙)，它们在生物体内代谢产生，因此可以直接获得提取物的保护作用信息。此外，还研究了用铁氰化钾（RPC）的还原能力法和铁（亚铁）离子螯合活性。根据不同的方法测量样品的抗氧化活性，并使用偏最小二乘法 (PLS) 技术将其建模为 HPLC 指纹图谱的函数。研究了模型的回归系数，以指示潜在负责抗氧化活性的峰。根据不同 PLS 模型的综合结果，我们建议使用 DPPH、RPC 和 ROO˙测定法来评估整体抗氧化能力；在阿月浑子叶的情况下。
