title: Evaluation of anti-oxidant and acetylcholinesterase activity and identification of polyphenolics of the invasive weed Dittrichia viscosa.
abstract: BACKGROUND
  The bioactive metabolites derived from weeds have attracted the interest of the food and pharmaceutical industries due to their health benefits.
  
  
  OBJECTIVE
  To evaluate the anti-oxidant and acetylcholinesterase activity of Dittrichia viscosa extracts and characterise the polyphenolic metabolites using the LC coupled with diode-array detection (DAD) and positive mode electrospray ionisation (ESI) MS method with a view to evaluating the exploitation potential of this invasive weed.
  
  
  METHODS
  Roots and aerial parts of D. viscosa were extracted with solvents of increasing polarity and their major polyphenolic metabolites were identified by LC - DAD/ESI(+)/MS. The total phenolic content of the extracts was determined using the Folin-Ciocalteu method, while their anti-oxidant activity was evaluated on the basis of their ability to scavenge the stable free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydrogen peroxide. Thin-layer chromatography was used to screen for acetylcholinesterase inhibitors.
  
  
  RESULTS
  Stem extracts gave the highest phenolic content, whereas the roots showed the lowest content. Twenty-five polyphenolic constituents of the extracts were tentatively characterised according to their MS and UV spectroscopic data. Among the extracts studied, roots-ethyl acetate and flowers-diethyl ether revealed the highest activity according to the DPPH and chemiluminescence assays respectively.
  
  
  CONCLUSIONS
  The metabolic profile of D. viscosa was studied and the structures of the major polyphenolic metabolites were tentatively assigned based on their MS and UV-vis spectra. The extracts exhibited high levels of anti-oxidant and acetylcholinesterase inhibitory activity and the inhibitors are probably localised mainly in flowers and roots.
authors.affiliation: Department of Food Quality and Chemistry of Natural Products, Mediterranean Agronomic Institute of Chania/Centre International de Hautes Etudes Agronomiques Méditerranéennes, 73100, Chania, Crete, Greece.
authors.forename: Imen
authors.initials: I
authors.lastname: Trimech
authors.forename: Erika Krisztina
authors.initials: EK
authors.lastname: Weiss
authors.forename: Veronica Sanda
authors.initials: VS
authors.lastname: Chedea
authors.forename: Daniela
authors.initials: D
authors.lastname: Marin
authors.forename: Anastasia
authors.initials: A
authors.lastname: Detsi
authors.forename: Efstathia
authors.initials: E
authors.lastname: Ioannou
authors.forename: Vassilios
authors.initials: V
authors.lastname: Roussis
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Kefalas
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology*; D019659:Asteraceae / Q000737:chemistry*; D002800:Cholinesterase Inhibitors / Q000737:chemistry / Q000494:pharmacology*; D002853:Chromatography, Liquid; D013058:Mass Spectrometry; D015394:Molecular Structure; D057685:Plant Weeds / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D000975:Antioxidants; D002800:Cholinesterase Inhibitors; D059808:Polyphenols
keywords: Dittrichia viscosa; LC-MS; acetylcholinesterase inhibition activity; anti-oxidant activity; polyphenolic composition; weeds