title: Tyrosinase inhibitory properties of phenylpropanoid glycosides and flavonoids fromTeucrium poliumL. var.gnaphalodes.
abstract: OBJECTIVE
  In food industry, the inhibition of tyrosinase is very important, because this enzyme catalyzes the oxidation of phenolic compounds found in fruits and vegetables into quinones, which contribute in undesirable color and taste of fruits and vegetables.Teucrium poliumL. var.gnaphalodes(Lamiaceae), a wild-growing flowering plant that has many applications in food preparations and traditional medicine. In Persian language, this medicinal herb is called Kalpoureh.
  
  
  METHODS
  1D- and 2D-NMR experiments were used to determine the chemical structures of the isolated compounds. Antioxidant and tyrosinase inhibitory activities of the isolated compounds were evaluated using DPPH, FRAP and mushroom tyrosinase inhibition assays.
  
  
  RESULTS
  In this research, we isolated two phenylpropanoid glycosides including verbascoside and poliumoside and two flavonoids including jaranol and isorhoifolin using chromatographic techniques. We found promising antioxidant and anti-tyrosinase compounds fromTeucrium poliumL. var.gnaphalodes.
  
  
  CONCLUSIONS
  To date, different compounds have been isolated and characterized fromT. poliumincluding terpenoids and flavonoids. But no phytochemical study has been reported fromT. poliumvar.gnaphalodes. Poliumoside and jaranol showed promising antioxidant and tyrosinase inhibitory activities, respectively.
authors.affiliation: Department of Pharmcognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Boghrati
authors.affiliation: Department of Pharmcognosy, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Maryam
authors.initials: M
authors.lastname: Naseri
authors.affiliation: Department of Nutrition, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Rezaie
authors.affiliation: Eskitis Institute, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Ngoc
authors.initials: N
authors.lastname: Pham
authors.affiliation: Eskitis Institute, Griffith University, Brisbane, QLD 4111, Australia.
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Quinn
authors.affiliation: Department of Pharmacodynamics and Toxicology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Tayarani-Najaran
authors.affiliation: Biotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Mehrdad
authors.initials: M
authors.lastname: Iranshahi
keywords: DPPH; FRAP; Isorhoifolin; Jaranol; Lamiaceae; Mushroom tyrosinase -; Poliumoside; Teucrium polium var.- gnaphalodes; inhibition assay