title: Chemometrics-based Approach in Analysis of Arnicae flos.
abstract: BACKGROUND
  Arnica montana flowers have a long history as herbal medicines for external use on injuries and rheumatic complaints.
  
  
  OBJECTIVE
  To investigate Arnicae flos of cultivated accessions from Bulgaria, Poland, Germany, Finland, and Pharmacy store for phenolic derivatives and sesquiterpene lactones (STLs).
  
  
  METHODS
  Samples of Arnica from nine origins were prepared by ultrasound-assisted extraction with 80% methanol for phenolic compounds analysis. Subsequent reverse-phase high-performance liquid chromatography (HPLC) separation of the analytes was performed using gradient elution and ultraviolet detection at 280 and 310 nm (phenolic acids), and 360 nm (flavonoids). Total STLs were determined in chloroform extracts by solid-phase extraction-HPLC at 225 nm. The HPLC generated chromatographic data were analyzed using principal component analysis (PCA) and hierarchical clustering (HC).
  
  
  RESULTS
  The highest total amount of phenolic acids was found in the sample from Botanical Garden at Joensuu University, Finland (2.36 mg/g dw). Astragalin, isoquercitrin, and isorhamnetin 3-glucoside were the main flavonol glycosides being present up to 3.37 mg/g (astragalin). Three well-defined clusters were distinguished by PCA and HC. Cluster C1 comprised of the German and Finnish accessions characterized by the highest content of flavonols. Cluster C2 included the Bulgarian and Polish samples presenting a low content of flavonoids. Cluster C3 consisted only of one sample from a pharmacy store.
  
  
  CONCLUSIONS
  A validated HPLC method for simultaneous determination of phenolic acids, flavonoid glycosides, and aglycones in A. montana flowers was developed. The PCA loading plot showed that quercetin, kaempferol, and isorhamnetin can be used to distinguish different Arnica accessions.
  
  
  CONCLUSIONS
  A principal component analysis (PCA) on 13 phenolic compounds and total amount of sesquiterpene lactones in Arnicae flos collection tended to cluster the studied 9 accessions into three main groups. The profiles obtained demonstrated that the samples from Germany and Finland are characterized by greater amounts of phenolic derivatives than the Bulgarian and Polish ones. The PCA loading plot showed that quercetin, kaemferol and isorhamnetin can be used to distinguish different arnica accessions.
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Medical University, Sofia, 1000 Sofia, Bulgaria.
authors.forename: Dimitrina Zh
authors.initials: DZh
authors.lastname: Zheleva-Dimitrova
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Medical University, Sofia, 1000 Sofia, Bulgaria.
authors.forename: Vessela
authors.initials: V
authors.lastname: Balabanova
authors.affiliation: Department of Pharmacognosy, Faculty of Pharmacy, Medical University, Sofia, 1000 Sofia, Bulgaria.
authors.forename: Reneta
authors.initials: R
authors.lastname: Gevrenova
authors.affiliation: Department of Chemistry, Faculty of Pharmacy, Medical University, Sofia, 1000 Sofia, Bulgaria.
authors.forename: Irini
authors.initials: I
authors.lastname: Doichinova
authors.affiliation: Department of Plant and Fungal Diversity and Resources, Institute of Biodiversity and Ecosystem Research Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria.
authors.forename: Antonina
authors.initials: A
authors.lastname: Vitkova
keywords: Arnica montana; Asteraceae; chemometrics; flavonoids; high-performance liquid chromatography; phenolic acids