title: LC-MS-MS and GC-MS analyses of biologically active extracts and fractions from Tunisian Juniperus phoenice leaves.
abstract: BACKGROUND
  Despite some studies related to Juniperus phoenicea L. (Cupressaceae), phytochemical and biological investigations of this plant remain unexplored.
  
  
  OBJECTIVE
  This work is the first report dealing with the identification and characterization of volatile components and flavonoids in hexane and methanol extracts from J. phoenicea leaves Materials and methods: Antioxidant activity of hexane, and methanol extracts from J. phoenicea leaves were determined by DPPH-radical scavenging assay. α-Amylase inhibitory activity was evaluated by enzyme inhibition using in vitro assay (each extract was dissolved in DMSO to give concentrations of 50, 100 and 200 mg/mL). The chemical composition of fractions (Fr1-Fr3) from methanol extract was determined by high-performance liquid chromatography coupled with mass spectroscopy (HPLC-MS) analysis.
  
  
  CONCLUSIONS
  The hexane extract was analyzed by GC-MS technique which allowed the identification of 32 compounds. The main constituents were α-humulene (16.9%), pentadecane (10.2%) and α-cubebene (9.7%). Fraction Fr 2 exhibited a strong DPPH radical-scavenging activity (IC50=20.1 μg/mL) compared to that of BHT as well as the highest α-amylase inhibitory activity (IC50=28.4 μg/mL). Three flavonoids were identified in these fractions using HPLC-MS analysis: Quercetin 3-O-glucoside, isoscutellarein 7-O-pentoside and quercetin 3-O-pentoside. In addition, the more active fraction (Fr 2) was purified with semi-preparative HPLC affording one pure compound (amentoflavone) using1H NMR analysis. This compound exhibited powerful DPPH radical-scavenging (IC50=14.1 μg/mL) and α-amylase inhibition (IC50=20.4 μg/mL) effects.
  
  
  CONCLUSIONS
  This study provides scientific support to some medicinal uses of J. phoenicea found in North Africa.
authors.affiliation: a Laboratory of Chemistry of Natural Substances, Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Henda
authors.initials: H
authors.lastname: Keskes
authors.affiliation: b Laboratory of Animal Ecophysiology, Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Sahla
authors.initials: S
authors.lastname: Belhadj
authors.affiliation: c Laboratory of Environmental Bioprocesses , Center of Biotechnology of Sfax , Sfax , Tunisia.
authors.forename: Lobna
authors.initials: L
authors.lastname: Jlail
authors.affiliation: b Laboratory of Animal Ecophysiology, Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Abdelfattah
authors.initials: A
authors.lastname: El Feki
authors.affiliation: a Laboratory of Chemistry of Natural Substances, Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Damak
authors.affiliation: c Laboratory of Environmental Bioprocesses , Center of Biotechnology of Sfax , Sfax , Tunisia.
authors.forename: Sami
authors.initials: S
authors.lastname: Sayadi
authors.affiliation: a Laboratory of Chemistry of Natural Substances, Faculty of Sciences of Sfax , University of Sfax , Sfax , Tunisia.
authors.forename: Noureddine
authors.initials: N
authors.lastname: Allouche
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology; D001713:Biphenyl Compounds / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000302:isolation & purification* / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006586:Hexanes / Q000737:chemistry; D018653:Juniperus / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D008517:Phytotherapy; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification* / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry*; D010946:Plants, Medicinal; D012997:Solvents / Q000737:chemistry; D053719:Tandem Mass Spectrometry; D014416:Tunisia; D055549:Volatile Organic Compounds / Q000302:isolation & purification* / Q000494:pharmacology; D000516:alpha-Amylases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D004791:Enzyme Inhibitors; D005419:Flavonoids; D006586:Hexanes; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D055549:Volatile Organic Compounds; C004931:1,1-diphenyl-2-picrylhydrazyl; D000516:alpha-Amylases; D000432:Methanol
keywords: HPLC-DAD–ESI/MS; biological activities; semi-prep HPLC