title: Benzophenones from Hypericum elegans with antioxidant and acetylcholinesterase inhibitory potential.
abstract: BACKGROUND
  Hypericum elegans is used in Bulgarian folk medicine for treatment of wounds, depression, gastrointestinal and bacterial diseases.
  
  
  OBJECTIVE
  RECENTLY, NEW NATURAL BENZOPHENONES: Elegaphenone and O-glycosides: Hypericophenonoside, Neoannulatophenonoside and Elegaphenonoside as well as already known 7-Epiclusianone were isolated from the titled species. The aim of the present study was to evaluate the antioxidant and acetyl cholinesterase inhibitory potential of the isolated compounds.
  
  
  METHODS
  1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) di-ammonium salt (ABTS) free radicals, ferric reducing antioxidant power (FRAP) assay as well as inhibition of lipid peroxidation in linoleic acid system were used for determination of antioxidant activity. Modified Ellman's colorimetric method was carried out to assess the acetyl cholinesterase inhibition potential. Hyperoside and Galantamine hydrobromide were used as positive controls.
  
  
  RESULTS
  Hypericophenonoside was found to possess the strongest DPPH radical scavenging activity (IC50 = 181.85 ± 6.82 μM), while Neoannulatophenonoside showed the highest ABTS (IC50 = 0.25 ± 0.005 μM) and lipid peroxidation inhibitor activity. FRAP activity was demonstrated only by prenylated aglycones - Elegaphenone [942.16 ± 4.03 μM Trolox Equivalent (TE)] and 7-Epiclusianone (642.95 ± 3.95 μM TE) and was stronger compared to the control Hyperoside (421.75 ± 9.29 μM TE). Elegaphenone and 7-Epiclusianone were found to possess moderate acetyl cholinesterase inhibitory potential with IC50 values of 192.19 ± 3.54 μM and 142.97 ± 4.62 μM, respectively.
  
  
  CONCLUSIONS
  The results obtained revealed that H. elegans is a potential natural source of bioactive compounds and benzophenones could be useful in therapy of free radical pathologies and neurodegenerative disorders.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Medical University of Sofia, Dunav str. 2, 1000 Sofia, Bulgaria.
authors.forename: Dimitrina
authors.initials: D
authors.lastname: Zheleva-Dimitrova
authors.forename: Paraskev
authors.initials: P
authors.lastname: Nedialkov
authors.forename: Georgi
authors.initials: G
authors.lastname: Momekov
keywords: Acetylcholinesterase inhibition; Hypericum elegans; antioxidant activity; benzophenones