title: Radical scavenging ability of some compounds isolated from Piper cubeba towards free radicals.
abstract: 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.
authors.affiliation: Pharmaceutical and Medicinal Chemistry Department, The Pharmacetical and Drug Industries Research Division, National Research Centre, Dokki, Cairo 12311, Egypt. enein@gawab.com
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Aboul-Enein
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Kładna
authors.forename: Irena
authors.initials: I
authors.lastname: Kruk
mesh_terms: D016166:Free Radical Scavengers / Q000737:chemistry* / Q000302:isolation & purification; D005609:Free Radicals / Q000737:chemistry*; D015394:Molecular Structure; D031701:Piper / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D016166:Free Radical Scavengers; D005609:Free Radicals; D010936:Plant Extracts