title: Contribution of major lipophilic antioxidants to the antioxidant activity of basil extracts: an EPR study.
abstract: BACKGROUND
  The present research analyses the contribution of some lipid antioxidants to the antioxidant activity of lipophilic extracts from basil by an electron paramagnetic resonance (EPR) study using the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH). DPPH assay is considered an easy and accurate method with regard to measuring the antioxidant activity of plant extracts and EPR has already been employed to determine antioxidant activities of lipophilic plant extracts.
  
  
  RESULTS
  Lipid extracts were obtained from basil grown hydroponically for 20 or 35 days from sowing and in soil for 35 days from sowing. Fast and slow rate constants were distinguishable in the decay kinetics of DPPH mixture added with lipid extract. Antioxidants with kinetics characterized by a fast decay rate were tocopherols and chlorophylls, whereas those characterized by a slow decay rate were carotenoids, among which were β-carotene, lutein, β-apo-8'-carotenal and zeaxanthin. The 20-day hydroponically grown sample, which showed higher contents of tocopherol, chlorophyll and carotenoid molecules, was the sample endowed with the higher content of fast lipophilic antioxidants (FLA) and slow lipophilic antioxidants (SLA).
  
  
  CONCLUSIONS
  The three samples showed different compositions of FLA and SLA, giving rise to different decay kinetics. Despite the differences, in all samples tocopherol contributed about 0.3% to the bulk of FLA, whereas the figure for chlorophyll was about 40%, evidencing the relevant but little-studied role of chlorophyll as an antioxidant.
authors.affiliation: Dipartimento di Biologia delle Piante Agrarie, Università di Pisa, 56124 Pisa, Italy. csgherri@agr.unipi.it
authors.forename: Cristina
authors.initials: C
authors.lastname: Sgherri
authors.forename: Calogero
authors.initials: C
authors.lastname: Pinzino
authors.forename: Flavia
authors.initials: F
authors.lastname: Navari-Izzo
authors.forename: Riccardo
authors.initials: R
authors.lastname: Izzo
mesh_terms: D000975:Antioxidants / Q000032:analysis* / Q000737:chemistry; D001713:Biphenyl Compounds / Q000737:chemistry; D002338:Carotenoids / Q000032:analysis / Q000737:chemistry; D002734:Chlorophyll / Q000032:analysis / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers / Q000032:analysis / Q000737:chemistry; D005609:Free Radicals / Q000737:chemistry; D018527:Hydroponics; D007700:Kinetics; D008055:Lipids / Q000032:analysis* / Q000737:chemistry; D018649:Ocimum basilicum / Q000737:chemistry* / Q000254:growth & development; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D024505:Tocopherols / Q000032:analysis / Q000737:chemistry
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D005609:Free Radicals; D008055:Lipids; D010851:Picrates; D010936:Plant Extracts; D002734:Chlorophyll; D002338:Carotenoids; C004931:1,1-diphenyl-2-picrylhydrazyl; D024505:Tocopherols