title: The detection of radical scavenging compounds in crude extract of borage (Borago officinalis L.) by using an on-line HPLC-DPPH method.
abstract: The rapid evaluation of antioxidant activity of crude borage (Borago officinalis L.) extract was determined by using DPPH free radical method. This borage extract resulted in a rapid decrease of the absorbance and showed very high hydrogen-donating capacity towards the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical. A new HPLC-DPPH on-line method was applied for a screening of several radical scavenging components in this borage extract as well as for quantitative analysis. This on-line HPLC-DPPH method was developed using a methanolic solution of DPPH-stable radical. The HPLC-separated analytes reacted post-column with the DPPH solution in methanol. The induced bleaching was detected as a negative peak photometrically at 515 nm. The separation of antioxidative components was carried out by gradient HPLC with mobile-phase composition ranging from 2% to 80% acetonitrile with 2% acetic acid in water, UV detection was carried out at 280 nm. The HPLC analysis of borage extract revealed the presence of several radical scavenging components in the borage extract. The results obtained from the chromatograms suggest that some compounds present in the extract possess high radical quenching ability. The dominant antioxidative compound in the crude extract of borage leaves was identified as rosmarinic acid.
authors.affiliation: Department of Food Technology, Kaunas University of Technology, Radvilenu pl. 19, LT 3028 Kaunas, Lithuania.
authors.forename: Donata
authors.initials: D
authors.lastname: Bandoniene
authors.forename: Michael
authors.initials: M
authors.lastname: Murkovic
mesh_terms: D000975:Antioxidants / Q000032:analysis*; D001713:Biphenyl Compounds; D029683:Borago / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D002934:Cinnamates / Q000032:analysis; D053630:Depsides; D016166:Free Radical Scavengers / Q000032:analysis*; D005609:Free Radicals; D006834:Hydrazines; D010851:Picrates; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry / Q000378:metabolism; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D000097123:Rosmarinic Acid
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D002934:Cinnamates; D053630:Depsides; D016166:Free Radical Scavengers; D005609:Free Radicals; D006834:Hydrazines; D010851:Picrates; D010936:Plant Extracts; D000097123:Rosmarinic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl