title: Diurnal Variation of Essential of the Oil Components of Pycnocycla spinosa Decne. ex Boiss.
abstract: BACKGROUND
  Pycnocycla spinosa Decne. ex Boiss is an aromatic plant which showed relaxant effects on isolated ileum contractions and antidiarrheal activity. Thirty four components have been extracted from P. spinosa essential oil, of which several major constituents were found to show seasonal variation.
  
  
  OBJECTIVE
  The aim of this work is to evaluate the diurnal variation of its oil constituents during specific hours of the day.
  
  
  METHODS
  The Pycnocycla spinosa samples were collected at different times of the day. The hydro-distilled aerial parts oils of collected P. spinosa were analyzed by GC and GC/MS.
  
  
  RESULTS
  Fourteen monoterpenoid and nine sesquiterpenoid components were identified, of which the fluctuating constituents were p-cymene, trans-β-ocimene, β-citronellol, citronellyl pentanoate, geranyl isovalerate, α-humulene, caryophyllen oxide, α-cadinol, and α-eudesmol. The content of p-cymene in the essential oil in different daily times varied from 0.16 to 4.19%, and the geranyl isovalerate 7.75 -23.99%.
  
  
  CONCLUSIONS
  Essential oils with different qualities can be obtained according to the harvest time of the plant in a day.
authors.affiliation: Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, IR Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Asghari
authors.affiliation: Department of Medicinal Chemistry, Faculty of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, IR Iran.
authors.forename: Houshfar
authors.initials: H
authors.lastname: Gholamali
authors.affiliation: Isfahan Pharmaceutical Sciences Research Center, Isfahan University of Medical Sciences, Isfahan, IR Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Mahmoudi
authors.affiliation: Department of Agricultural Biotechnology, Tehran University, Tehran, IR Iran.
authors.forename: Matin
authors.initials: M
authors.lastname: Asghari
keywords: Gas Chromatography-Mass Spectrometry; Oils, Volatile; Plants