title: Free Radical Scavenging Fingerprints of Selected Aromatic and Medicinal Tunisian Plants Assessed by Means of TLC-DPPH(•) Test and Image Processing.
abstract: Aqueous-methanol extracts prepared from 10 Tunisian plant species were analyzed for the presence of potent direct antioxidants. The analyzed species included: Anacyclus clavatus Desf., Erica multiflora L., Cistus salvifolius L., Centaurium erythraea Rafn., Marrubium vulgare L., Lavandula stoechas L., Artemisia campestris L., Origanum majorana L., Salvia officinalis L., and Pistacia lentiscus L. All the extracts were chromatographed on the RP18 W plates with methanol-water-acetic acid (48 + 47 + 5, v/v/v) mobile phase. Upon completion of the chromatographic development and the drying step, the plates were stained with a chloroform solution of 2, 2-diphenyl-1-picrylhydrazyl radical (DPPH(•)). An image processing protocol, with use of Sorbfil TLC Videodensitometer, was applied to quantitatively measure the activity of polyphenols and to screen complex samples for the presence of free radical scavengers. The activity of the individual compounds was compared with that of rutin, used as a standard. The TLC-DPPH(•) test showed that C. salvifolius had the most potent antioxidant activity, as it possessed the highest activity coefficient (calculated as the sum of the areas under the peaks of all active compounds/area under peak of rutin). The proposed procedure may be used to differentiate potent chain-breaking antioxidants and compounds propagating radical chain reactions.
authors.affiliation: High School of Food Industries in Tunis, 58 Alain Savary St, 1003 Tunis, Tunisia; and Laboratory of Structural Organic Chemistry, Faculty of Sciences of Tunis, 2092 El Manar, Tunisia.
authors.forename: Salma Kammoun
authors.initials: SK
authors.lastname: El Euch
authors.forename: Łukasz
authors.initials: Ł
authors.lastname: Cieśla
authors.forename: Nabiha
authors.initials: N
authors.lastname: Bouzouita
mesh_terms: D001713:Biphenyl Compounds / Q000378:metabolism*; D002855:Chromatography, Thin Layer / Q000379:methods*; D016166:Free Radical Scavengers / Q000302:isolation & purification*; D007091:Image Processing, Computer-Assisted; D010851:Picrates / Q000378:metabolism*; D010936:Plant Extracts / Q000032:analysis*; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl