Pharmaceutical and Medicinal Chemistry Department, The Pharmacetical and Drug Industries Research Division, National Research Centre, Dokki, Cairo 12311, Egypt.
Luminescence. 2011 May-Jun;26(3):202-7. doi: 10.1002/bio.1209. Epub 2010 May 29.
The purpose of this study was to identify the antioxidant activity of 16 compounds isolated from Piper cubeba (CNCs) through the extent of their capacities to scavenge free radicals, hydroxyl radical (HO(•)), superoxide anion radical O•(2)(-) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH(•)), in different systems. Electron paramagnetic resonance (EPR) and 5,5-dimethyl-1-pyrroline-N-oxide, DMPO, as the spin trap, and chemiluminescence techniques were applied. Using the Fenton-like reaction [Fe(II) + H(2)O(2)], CNCs were found to inhibit DMPO-OH radical formation ranging from 5 to 57% at 1.25 mmol L(-1) concentration. The examined CNCs also showed a high DPPH antiradical activity (ranging from 15 to 99% at 5 mmol L(-1) concentration). Furthermore, the results indicated that seven of the 16 tested compounds may catalyse the conversion of superoxide radicals generated in the potassium superoxide/18-crown-6 ether system, thus showing superoxide dismutase-like activity. The data obtained suggest that radical scavenging properties of CNCs might have potential application in many plant medicines.
本研究旨在通过测定 16 种从 Piper cubeba（CNCs）中分离得到的化合物清除自由基、羟自由基（HO(•)）、超氧阴离子自由基 O•(2)(-)和 2,2-二苯基-1-苦肼基自由基（DPPH(•))的能力，来确定它们的抗氧化活性。该研究采用了电子顺磁共振（EPR）和 5,5-二甲基-1-吡咯啉-N-氧化物（DMPO）作为自旋捕获剂，以及化学发光技术。结果表明，在 1.25mmol/L 浓度下，使用 Fenton 样反应[Fe(II) + H(2)O(2)]，CNCs 可抑制 DMPO-OH 自由基的形成，抑制率为 5%至 57%。研究还发现，所检测的 CNCs 对 DPPH 自由基也具有较高的清除活性（在 5mmol/L 浓度下，清除率为 15%至 99%）。此外，结果表明，在所测试的 16 种化合物中，有 7 种可能会催化钾超氧化物/18-冠-6 醚体系中生成的超氧自由基的转化，从而表现出超氧化物歧化酶样活性。这些数据表明，CNCs 的自由基清除特性可能在许多植物药中具有潜在的应用价值。
